diff --git a/toonz/sources/common/expressions/tgrammar.cpp b/toonz/sources/common/expressions/tgrammar.cpp
index 9a21c8a..7fa7720 100644
--- a/toonz/sources/common/expressions/tgrammar.cpp
+++ b/toonz/sources/common/expressions/tgrammar.cpp
@@ -538,7 +538,7 @@ public:
   bool matchToken(const std::vector<Token> &previousTokens,
                   const Token &token) const override {
     int i = (int)previousTokens.size();
-    return i == 1 && token.getText() == "?" || i == 3 && token.getText() == ":";
+    return ((i == 1 && token.getText() == "?") || (i == 3 && token.getText() == ":"));
   }
   bool isFinished(const std::vector<Token> &previousTokens,
                   const Token &token) const override {
@@ -571,8 +571,8 @@ public:
   }
   bool matchToken(const std::vector<Token> &previousTokens,
                   const Token &token) const override {
-    return previousTokens.empty() && token.getText() == "(" ||
-           previousTokens.size() == 2 && token.getText() == ")";
+    return ((previousTokens.empty() && token.getText() == "(") ||
+            (previousTokens.size() == 2 && token.getText() == ")"));
   }
   bool isFinished(const std::vector<Token> &previousTokens,
                   const Token &token) const override {
@@ -647,9 +647,9 @@ public:
   bool isFinished(const std::vector<Token> &previousTokens,
                   const Token &token) const override {
     if (previousTokens.empty()) return false;
-    return m_minArgCount == 0 && previousTokens.size() == 1 &&
-               token.getText() != "(" ||
-           previousTokens.back().getText() == ")";
+    return ((m_minArgCount == 0 && previousTokens.size() == 1 &&
+               token.getText() != "(") ||
+            (previousTokens.back().getText() == ")"));
   }
   TokenType getTokenType(const std::vector<Token> &previousTokens,
                          const Token &token) const override {
diff --git a/toonz/sources/common/expressions/ttokenizer.cpp b/toonz/sources/common/expressions/ttokenizer.cpp
index d6b2372..15485f4 100644
--- a/toonz/sources/common/expressions/ttokenizer.cpp
+++ b/toonz/sources/common/expressions/ttokenizer.cpp
@@ -65,7 +65,7 @@ void Tokenizer::setBuffer(std::string buffer) {
       while (s[i] != '"' && s[i] != '\0') token.append(1, s[i++]);
 
       m_tokens.push_back(Token(token, Token::Ident, j));
-    } else if (isascii(s[i]) && isalpha(s[i]) || s[i] == '_') {
+    } else if ((isascii(s[i]) && isalpha(s[i])) || s[i] == '_') {
       // ident
       token = std::string(1, s[i++]);
 
@@ -73,7 +73,7 @@ void Tokenizer::setBuffer(std::string buffer) {
         token.append(1, s[i++]);
 
       m_tokens.push_back(Token(token, Token::Ident, j));
-    } else if (isascii(s[i]) && isdigit(s[i]) || s[i] == '.') {
+    } else if ((isascii(s[i]) && isdigit(s[i])) || s[i] == '.') {
       // number
       while (isascii(s[i]) && isdigit(s[i])) token.append(1, s[i++]);
 
@@ -83,8 +83,8 @@ void Tokenizer::setBuffer(std::string buffer) {
         while (isascii(s[i]) && isdigit(s[i])) token.append(1, s[i++]);
 
         if ((s[i] == 'e' || s[i] == 'E') &&
-            (isascii(s[i + 1]) && isdigit(s[i + 1]) ||
-             (s[i + 1] == '-' || s[i + 1] == '+') && isascii(s[i + 2]) &&
+            (((isascii(s[i + 1]) && isdigit(s[i + 1])) ||
+             s[i + 1] == '-' || s[i + 1] == '+') && isascii(s[i + 2]) &&
                  isdigit(s[i + 2]))) {
           token.append(1, s[i++]);
 
diff --git a/toonz/sources/common/psdlib/psd.cpp b/toonz/sources/common/psdlib/psd.cpp
index aceb37b..a90ba79 100644
--- a/toonz/sources/common/psdlib/psd.cpp
+++ b/toonz/sources/common/psdlib/psd.cpp
@@ -296,7 +296,7 @@ bool TPSDReader::readLayerInfo(int i) {
 
     // layer name
     li->nameno = (char *)malloc(16);
-    sprintf(li->nameno, "layer%d", i + 1);
+    snprintf(li->nameno, 16, "layer%d", i + 1);
     namelen  = fgetc(m_file);
     li->name = (char *)mymalloc(NEXT4(namelen + 1));
     fread(li->name, 1, NEXT4(namelen + 1) - 1, m_file);
@@ -651,7 +651,7 @@ void TPSDReader::readImageData(TRasterP &rasP, TPSDLayerInfo *li,
   // L'indice è riferito al livello.
   // Nota che nel file photoshop le righe sono memorizzate dall'ultima alla
   // prima.
-  int rowOffset = abs(sby1) % m_shrinkY;
+  int rowOffset = std::abs(sby1) % m_shrinkY;
   int rowCount  = rowOffset;
   // if(m_shrinkY==3) rowCount--;
   for (j = 0; j < smallRas->getLy(); j++) {
diff --git a/toonz/sources/common/tapptools/tcolorutils.cpp b/toonz/sources/common/tapptools/tcolorutils.cpp
index e0a968c..daaddb8 100644
--- a/toonz/sources/common/tapptools/tcolorutils.cpp
+++ b/toonz/sources/common/tapptools/tcolorutils.cpp
@@ -1106,7 +1106,7 @@ void TColorUtils::buildColorChipPalette(QList<QPair<TPixel32, TPoint>> &palette,
       // remove the coner information from the corner point
       QMap<EdgePoint::QUADRANT, int>::const_iterator i = corners.constBegin();
       while (i != corners.constEnd()) {
-        edgePoints[i.value()].info & ~i.key();
+        edgePoints[i.value()].info &= ~i.key();
         ++i;
       }
       if (colorChips.count() >= maxColorCount) break;
diff --git a/toonz/sources/common/tapptools/tenv.cpp b/toonz/sources/common/tapptools/tenv.cpp
index fce9708..1777ec5 100644
--- a/toonz/sources/common/tapptools/tenv.cpp
+++ b/toonz/sources/common/tapptools/tenv.cpp
@@ -392,8 +392,8 @@ void VariableSet::load() {
     char *s = buffer;
     while (*s == ' ') s++;
     char *t = s;
-    while ('a' <= *s && *s <= 'z' || 'A' <= *s && *s <= 'Z' ||
-           '0' <= *s && *s <= '9' || *s == '_')
+    while (('a' <= *s && *s <= 'z') || ('A' <= *s && *s <= 'Z') ||
+           ('0' <= *s && *s <= '9') || *s == '_')
       s++;
     std::string name(t, s - t);
     if (name.size() == 0) continue;
diff --git a/toonz/sources/common/tcore/trandom.cpp b/toonz/sources/common/tcore/trandom.cpp
index d13e78c..8545d0f 100644
--- a/toonz/sources/common/tcore/trandom.cpp
+++ b/toonz/sources/common/tcore/trandom.cpp
@@ -103,10 +103,10 @@ float TRandom::getFloat()  // [0,1[
 
   switch (RandomFloatType) {
   case RANDOM_FLOAT_TYPE_1:
-    u = (u >> 5) & 0x007fffff | 0x3f800000;
+    u = ((u >> 5) & 0x007fffff) | 0x3f800000;
     break;
   case RANDOM_FLOAT_TYPE_2:
-    u = u & 0xffff7f00 | 0x0000803f;
+    u = (u & 0xffff7f00) | 0x0000803f;
     break;
   default:
     assert(0);
diff --git a/toonz/sources/common/tfx/tcacheresourcepool.cpp b/toonz/sources/common/tfx/tcacheresourcepool.cpp
index 7adf7f9..ec5809f 100644
--- a/toonz/sources/common/tfx/tcacheresourcepool.cpp
+++ b/toonz/sources/common/tfx/tcacheresourcepool.cpp
@@ -197,11 +197,13 @@ TCacheResource *TCacheResourcePool::getResource(const std::string &name,
   // Search for an already allocated resource
   if (m_searchIterator == m_memResources.end()) {
     m_searchIterator = m_memResources.lower_bound(name);
-    if (m_searchIterator != m_memResources.end())
-      if (!(name < m_searchIterator->first))
+    if (m_searchIterator != m_memResources.end()) {
+      if (!(name < m_searchIterator->first)) {
         m_foundIterator = true;
-      else if (m_searchIterator != m_memResources.begin())
+      } else if (m_searchIterator != m_memResources.begin()) {
         m_searchIterator--;
+      }
+    }
   }
 
   if (m_foundIterator) {
diff --git a/toonz/sources/common/tfx/tpredictivecachemanager.cpp b/toonz/sources/common/tfx/tpredictivecachemanager.cpp
index 5765494..a7223fe 100644
--- a/toonz/sources/common/tfx/tpredictivecachemanager.cpp
+++ b/toonz/sources/common/tfx/tpredictivecachemanager.cpp
@@ -156,7 +156,7 @@ void TPredictiveCacheManager::Imp::getResourceTestRun(
     it->second.m_usageCount++;
   else {
     // Already initializes usageCount at 1
-    m_resources.insert(std::make_pair(resource, PredictionData(resData))).first;
+    m_resources.insert(std::make_pair(resource, PredictionData(resData)));
   }
 }
 
diff --git a/toonz/sources/common/tgeometry/tgeometry.cpp b/toonz/sources/common/tgeometry/tgeometry.cpp
index e34ee3a..7e8ea1d 100644
--- a/toonz/sources/common/tgeometry/tgeometry.cpp
+++ b/toonz/sources/common/tgeometry/tgeometry.cpp
@@ -1,9 +1,7 @@
 
 
 #include "tgeometry.h"
-#ifdef LINUX
-#include <values.h>
-#endif
+
 
 using namespace std;
 
diff --git a/toonz/sources/common/tiio/bmp/filebmp.c b/toonz/sources/common/tiio/bmp/filebmp.c
index de23ae7..5f3e817 100644
--- a/toonz/sources/common/tiio/bmp/filebmp.c
+++ b/toonz/sources/common/tiio/bmp/filebmp.c
@@ -213,6 +213,8 @@ int read_bmp_line(FILE *fp, void *line_buffer, UINT w, UINT row, UCHAR **map,
     pad = (4 - ((w * 3) % 4)) & 0x03;
     rv  = load_lineBMP24(fp, pic, w, (UINT)pad);
     break;
+  default:
+    break;
   }
 
   return !rv; /* return 0 for unsuccess */
@@ -255,6 +257,8 @@ int write_bmp_line(FILE *fp, void *line_buffer, UINT w, UINT row, UCHAR *map,
     pad = (4 - ((w * 3) % 4)) & 0x03;
     rv  = line_writeBMP24(fp, p24, w, (UINT)pad);
     break;
+  default:
+    break;
   }
 
   return rv; /* 0 for unsuccess */
@@ -294,6 +298,8 @@ int skip_bmp_lines(FILE *fp, UINT w, UINT rows, int whence, BMP_SUBTYPE type)
     pad = (4 - ((w * 3) % 4)) & 0x03;
     rv  = skip_rowsBMP24(fp, w, (UINT)pad, rows, whence);
     break;
+  default:
+    break;
   }
 
   return !rv;
@@ -624,8 +630,9 @@ static int img_read_bmp_region(const MYSTRING fname, IMAGE **pimg, int x1,
   if ((hd->biBitCount != 1 && hd->biBitCount != 4 && hd->biBitCount != 8 &&
        hd->biBitCount != 24) ||
       hd->biPlanes != 1 || hd->biCompression > BMP_BI_RLE4) {
-    sprintf(buf, "Bogus BMP File! (bitCount=%d, Planes=%d, Compression=%d)",
-            hd->biBitCount, hd->biPlanes, hd->biCompression);
+    snprintf(buf, sizeof(buf),
+             "Bogus BMP File! (bitCount=%d, Planes=%d, Compression=%d)",
+             hd->biBitCount, hd->biPlanes, hd->biCompression);
 
     bmp_error = UNSUPPORTED_BMP_FORMAT;
     goto ERROR;
@@ -636,8 +643,9 @@ static int img_read_bmp_region(const MYSTRING fname, IMAGE **pimg, int x1,
        hd->biCompression != BMP_BI_RGB) ||
       (hd->biBitCount == 4 && hd->biCompression == BMP_BI_RLE8) ||
       (hd->biBitCount == 8 && hd->biCompression == BMP_BI_RLE4)) {
-    sprintf(buf, "Bogus BMP File!  (bitCount=%d, Compression=%d)",
-            hd->biBitCount, hd->biCompression);
+    snprintf(buf, sizeof(buf),
+             "Bogus BMP File!  (bitCount=%d, Compression=%d)",
+             hd->biBitCount, hd->biCompression);
     bmp_error = UNSUPPORTED_BMP_FORMAT;
     goto ERROR;
   }
diff --git a/toonz/sources/common/tiio/movsettings.cpp b/toonz/sources/common/tiio/movsettings.cpp
index 4b095fb..98952d4 100644
--- a/toonz/sources/common/tiio/movsettings.cpp
+++ b/toonz/sources/common/tiio/movsettings.cpp
@@ -112,7 +112,8 @@ void visitAtoms(const QTAtomContainer &atoms, const QTAtom &parent,
     int sonCount = QTCountChildrenOfType(atoms, curr, 0);
 
     char buffer[1024];
-    sprintf(buffer, "%d %d %d", (int)atomType, (int)id, sonCount);
+    snprintf(buffer, sizeof(buffer), "%d %d %d",
+      (int)atomType, (int)id, sonCount);
     string str(buffer);
 
     if (sonCount > 0) {
diff --git a/toonz/sources/common/tparam/tdoublekeyframe.cpp b/toonz/sources/common/tparam/tdoublekeyframe.cpp
index 9926afd..641840a 100644
--- a/toonz/sources/common/tparam/tdoublekeyframe.cpp
+++ b/toonz/sources/common/tparam/tdoublekeyframe.cpp
@@ -50,6 +50,8 @@ void TDoubleKeyframe::saveData(TOStream &os) const {
   case EaseInOutPercentage:
     os.child("prev") << m_value << m_speedIn.x;
     break;
+  default:
+    break;
   }
   std::string unitName = m_unitName != "" ? m_unitName : "default";
   // Dirty resolution. Because the degree sign is converted to unexpected
@@ -79,6 +81,8 @@ void TDoubleKeyframe::saveData(TOStream &os) const {
     os << m_frame << m_fileParams.m_path << m_fileParams.m_fieldIndex
        << unitName;
     break;
+  default:
+    break;
   }
   os.closeChild();
 }
@@ -149,6 +153,8 @@ void TDoubleKeyframe::loadData(TIStream &is) {
     is >> m_frame >> m_fileParams.m_path >> m_fileParams.m_fieldIndex >>
         m_unitName;
     break;
+  default:
+    break;
   }
   if (!is.matchEndTag()) throw TException(tagName + " : missing endtag");
   if (m_unitName == "default") m_unitName = "";
diff --git a/toonz/sources/common/tparam/tdoubleparam.cpp b/toonz/sources/common/tparam/tdoubleparam.cpp
index 37c9e9f..3c2a78d 100644
--- a/toonz/sources/common/tparam/tdoubleparam.cpp
+++ b/toonz/sources/common/tparam/tdoubleparam.cpp
@@ -379,6 +379,8 @@ double TDoubleParam::Imp::getValue(int segmentIndex, double frame) {
   case TDoubleKeyframe::SimilarShape:
     value = getSimilarShapeValue(k0, k1, frame, m_measure);
     break;
+  default:
+    break;
   }
   if (convertUnit) value = k0.convertFrom(m_measure, value);
   return value;
diff --git a/toonz/sources/common/tparam/tdoubleparamfile.cpp b/toonz/sources/common/tparam/tdoubleparamfile.cpp
index 05fce2f..7ad3723 100644
--- a/toonz/sources/common/tparam/tdoubleparamfile.cpp
+++ b/toonz/sources/common/tparam/tdoubleparamfile.cpp
@@ -9,7 +9,7 @@ namespace {
 //---------------------------------------------------------
 
 bool parseDouble(double &value, char *&s) {
-  if (!(*s == '-' || *s == '.' || '0' <= *s && *s <= '9')) return false;
+  if (!(*s == '-' || *s == '.' || ('0' <= *s && *s <= '9'))) return false;
   char *t = s;
   if (*s == '-') s++;
   while ('0' <= *s && *s <= '9') s++;
diff --git a/toonz/sources/common/trop/tblur.cpp b/toonz/sources/common/trop/tblur.cpp
index ff92e11..d6d5f57 100644
--- a/toonz/sources/common/trop/tblur.cpp
+++ b/toonz/sources/common/trop/tblur.cpp
@@ -10,7 +10,7 @@
 
 #ifdef USE_SSE2
 #include <emmintrin.h>
-#include <malloc.h>
+#include <stdlib.h>
 #endif
 
 
diff --git a/toonz/sources/common/trop/tconvolve.cpp b/toonz/sources/common/trop/tconvolve.cpp
index 7eb4a07..259801f 100644
--- a/toonz/sources/common/trop/tconvolve.cpp
+++ b/toonz/sources/common/trop/tconvolve.cpp
@@ -118,24 +118,24 @@ void doConvolve_cm32_row_9_i(PIXOUT *pixout, int n, TPixelCM32 *pixarr[],
     }
 
     pixout->r = (typename PIXOUT::Channel)(
-        (val[1].r * w1 + val[2].r * w2 + val[3].r * w3 + val[4].r * w4 +
-         val[5].r * w5 + val[6].r * w6 + val[7].r * w7 + val[8].r * w8 +
-         val[9].r * w9 + (1 << 15)) >>
+        (val[0].r * w1 + val[1].r * w2 + val[2].r * w3 + val[3].r * w4 +
+         val[4].r * w5 + val[5].r * w6 + val[6].r * w7 + val[7].r * w8 +
+         val[8].r * w9 + (1 << 15)) >>
         16);
     pixout->g = (typename PIXOUT::Channel)(
-        (val[1].g * w1 + val[2].g * w2 + val[3].g * w3 + val[4].g * w4 +
-         val[5].g * w5 + val[6].g * w6 + val[7].g * w7 + val[8].g * w8 +
-         val[9].g * w9 + (1 << 15)) >>
+        (val[0].g * w1 + val[1].g * w2 + val[2].g * w3 + val[3].g * w4 +
+         val[4].g * w5 + val[5].g * w6 + val[6].g * w7 + val[7].g * w8 +
+         val[8].g * w9 + (1 << 15)) >>
         16);
     pixout->b = (typename PIXOUT::Channel)(
-        (val[1].b * w1 + val[2].b * w2 + val[3].b * w3 + val[4].b * w4 +
-         val[5].b * w5 + val[6].b * w6 + val[7].b * w7 + val[8].b * w8 +
-         val[9].b * w9 + (1 << 15)) >>
+        (val[0].b * w1 + val[1].b * w2 + val[2].b * w3 + val[3].b * w4 +
+         val[4].b * w5 + val[5].b * w6 + val[6].b * w7 + val[7].b * w8 +
+         val[8].b * w9 + (1 << 15)) >>
         16);
     pixout->m = (typename PIXOUT::Channel)(
-        (val[1].m * w1 + val[2].m * w2 + val[3].m * w3 + val[4].m * w4 +
-         val[5].m * w5 + val[6].m * w6 + val[7].m * w7 + val[8].m * w8 +
-         val[9].m * w9 + (1 << 15)) >>
+        (val[0].m * w1 + val[1].m * w2 + val[2].m * w3 + val[3].m * w4 +
+         val[4].m * w5 + val[5].m * w6 + val[6].m * w7 + val[7].m * w8 +
+         val[8].m * w9 + (1 << 15)) >>
         16);
     p1++;
     p2++;
diff --git a/toonz/sources/common/trop/trop.cpp b/toonz/sources/common/trop/trop.cpp
index 8eb43ec..6d247b7 100644
--- a/toonz/sources/common/trop/trop.cpp
+++ b/toonz/sources/common/trop/trop.cpp
@@ -137,7 +137,7 @@ pix->r= pix->r*pix->m/T::maxChannelValue;
 pix->g= pix->g*pix->m/T::maxChannelValue;
 pix->b= pix->b*pix->m/T::maxChannelValue;
 }*/
-      *pix++;
+      pix++;
     }
   }
 }
@@ -163,7 +163,7 @@ pix->r= pix->r*pix->m/T::maxChannelValue;
 pix->g= pix->g*pix->m/T::maxChannelValue;
 pix->b= pix->b*pix->m/T::maxChannelValue;
 }*/
-      *pix++;
+      pix++;
     }
   }
 }
diff --git a/toonz/sources/common/tsystem/tfilepath.cpp b/toonz/sources/common/tsystem/tfilepath.cpp
index 862c5ac..a892a8a 100644
--- a/toonz/sources/common/tsystem/tfilepath.cpp
+++ b/toonz/sources/common/tsystem/tfilepath.cpp
@@ -244,10 +244,10 @@ void TFilePath::setPath(std::wstring path) {
     if (path.length() == 2 || !isSlash(path[pos])) m_path.append(1, wslash);
   }
   // se si tratta di un path in formato UNC e' del tipo "\\\\MachineName"
-  else if (path.length() >= 3 && path[0] == L'\\' && path[1] == L'\\' &&
-               iswalnum(path[2]) ||
-           path.length() >= 3 && path[0] == L'/' && path[1] == L'/' &&
-               iswalnum(path[2])) {
+  else if ((path.length() >= 3 && path[0] == L'\\' && path[1] == L'\\' &&
+               iswalnum(path[2])) ||
+           (path.length() >= 3 && path[0] == L'/' && path[1] == L'/' &&
+               iswalnum(path[2]))) {
     isUncName = true;
     m_path.append(2, L'\\');
     m_path.append(1, path[2]);
@@ -281,10 +281,10 @@ void TFilePath::setPath(std::wstring path) {
   // rimuovo l'eventuale '/' finale (a meno che m_path == "/" o m_path ==
   // "<letter>:\"
   // oppure sia UNC (Windows only) )
-  if (!(m_path.length() == 1 && m_path[0] == wslash ||
-        m_path.length() == 3 && iswalpha(m_path[0]) && m_path[1] == L':' &&
-            m_path[2] == wslash) &&
-      m_path.length() > 1 && m_path[m_path.length() - 1] == wslash)
+  if (!((m_path.length() == 1 && m_path[0] == wslash) ||
+        (m_path.length() == 3 && iswalpha(m_path[0]) && m_path[1] == L':' &&
+            m_path[2] == wslash)) &&
+      (m_path.length() > 1 && m_path[m_path.length() - 1] == wslash))
     m_path.erase(m_path.length() - 1, 1);
 
   if (isUncName &&
@@ -507,19 +507,19 @@ else
 //-----------------------------------------------------------------------------
 
 bool TFilePath::isAbsolute() const {
-  return m_path.length() >= 1 && m_path[0] == slash ||
-         m_path.length() >= 2 && iswalpha(m_path[0]) && m_path[1] == ':';
+  return ((m_path.length() >= 1 && m_path[0] == slash) ||
+          (m_path.length() >= 2 && iswalpha(m_path[0]) && m_path[1] == ':'));
 }
 
 //-----------------------------------------------------------------------------
 
 bool TFilePath::isRoot() const {
-  return m_path.length() == 1 && m_path[0] == slash ||
-         m_path.length() == 3 && iswalpha(m_path[0]) && m_path[1] == ':' &&
-             m_path[2] == slash ||
-         m_path.length() > 2 && m_path[0] == slash && m_path[1] == slash &&
+  return ((m_path.length() == 1 && m_path[0] == slash) ||
+          (m_path.length() == 3 && iswalpha(m_path[0]) && m_path[1] == ':' &&
+             m_path[2] == slash) ||
+          ((m_path.length() > 2 && m_path[0] == slash && m_path[1] == slash) &&
              (std::string::npos == m_path.find(slash, 2) ||
-              m_path.find(slash, 2) == m_path.size() - 1);
+              m_path.find(slash, 2) == (m_path.size() - 1))));
 }
 
 //-----------------------------------------------------------------------------
@@ -634,8 +634,8 @@ TFilePath TFilePath::getParentDir() const  // noSlash!
 {
   int i = getLastSlash(m_path);  // cerco l'ultimo slash
   if (i < 0) {
-    if (m_path.length() >= 2 && ('a' <= m_path[0] && m_path[0] <= 'z' ||
-                                 'A' <= m_path[0] && m_path[0] <= 'Z') &&
+    if (m_path.length() >= 2 && (('a' <= m_path[0] && m_path[0] <= 'z') ||
+                                 ('A' <= m_path[0] && m_path[0] <= 'Z')) &&
         m_path[1] == ':')
       return TFilePath(m_path.substr(0, 2));
     else
diff --git a/toonz/sources/common/tvectorimage/outlineApproximation.cpp b/toonz/sources/common/tvectorimage/outlineApproximation.cpp
index 2915c41..851169b 100644
--- a/toonz/sources/common/tvectorimage/outlineApproximation.cpp
+++ b/toonz/sources/common/tvectorimage/outlineApproximation.cpp
@@ -259,10 +259,10 @@ void makeOutline(/*std::ofstream& cout,*/
       areAlmostEqual( tq.getThickP0(), tq.getThickP2(), 1e-2 )*/;
 
   if (isAlmostAPoint ||
-      q_up && checkPointInOutline(q_up->getPoint(parameterTest), tq,
+      (q_up && checkPointInOutline(q_up->getPoint(parameterTest), tq,
                                   parameterTest, error) &&
           q_down && checkPointInOutline(q_down->getPoint(parameterTest), tq,
-                                        parameterTest, error)) {
+                                        parameterTest, error))) {
     /*	if (edge.first)
       cout << "left: "<< *(edge.first);
 else
diff --git a/toonz/sources/common/tvectorimage/tcomputeregions.cpp b/toonz/sources/common/tvectorimage/tcomputeregions.cpp
index 158370d..bf156bc 100644
--- a/toonz/sources/common/tvectorimage/tcomputeregions.cpp
+++ b/toonz/sources/common/tvectorimage/tcomputeregions.cpp
@@ -1402,10 +1402,10 @@ static bool addAutocloseIntersection(IntersectionData &intData,
     {
       const TThickQuadratic *q = s[i]->m_s->getChunk(0);
 
-      if (areAlmostEqual(q->getP0(), v[0], 1e-2) &&
-              areAlmostEqual(q->getP2(), v[1], 1e-2) ||
-          areAlmostEqual(q->getP0(), v[1], 1e-2) &&
-              areAlmostEqual(q->getP2(), v[0], 1e-2)) {
+      if ((areAlmostEqual(q->getP0(), v[0], 1e-2) &&
+              areAlmostEqual(q->getP2(), v[1], 1e-2)) ||
+          (areAlmostEqual(q->getP0(), v[1], 1e-2) &&
+              areAlmostEqual(q->getP2(), v[0], 1e-2))) {
         return true;
         addIntersection(intData, s, i, ii, DoublePair(0.0, w0), strokeSize,
                         isVectorized);
diff --git a/toonz/sources/common/tvectorimage/tregion.cpp b/toonz/sources/common/tvectorimage/tregion.cpp
index e287871..dda8122 100644
--- a/toonz/sources/common/tvectorimage/tregion.cpp
+++ b/toonz/sources/common/tvectorimage/tregion.cpp
@@ -820,13 +820,13 @@ int TRegion::Imp::leftScanlineIntersections(const TPointD &p,
         if (t0 <= s && s < t1) {
           double ys = getY(q, s);
 
-          solIdx[0] = (ys < m_y && m_y <= y0 || y0 <= m_y && m_y < ys) ? 0 : -1;
-          solIdx[1] = (ys < m_y && m_y < y1 || y1 < m_y && m_y < ys) ? 1 : -1;
+          solIdx[0] = ((ys < m_y && m_y <= y0) || (y0 <= m_y && m_y < ys)) ? 0 : -1;
+          solIdx[1] = ((ys < m_y && m_y < y1) || (y1 < m_y && m_y < ys)) ? 1 : -1;
         } else if (t1 < s && s <= t0) {
           double ys = getY(q, s);
 
-          solIdx[0] = (ys < m_y && m_y <= y0 || y0 <= m_y && m_y < ys) ? 1 : -1;
-          solIdx[1] = (ys < m_y && m_y < y1 || y1 < m_y && m_y < ys) ? 0 : -1;
+          solIdx[0] = ((ys < m_y && m_y <= y0) || (y0 <= m_y && m_y < ys)) ? 1 : -1;
+          solIdx[1] = ((ys < m_y && m_y < y1) || (y1 < m_y && m_y < ys)) ? 0 : -1;
         } else {
           solIdx[0] = isInYRange(y0, y1) ? (t0 < s) ? 0 : 1 : -1;
           solIdx[1] = -1;
diff --git a/toonz/sources/common/tvectorimage/tvectorimage.cpp b/toonz/sources/common/tvectorimage/tvectorimage.cpp
index ae249e8..757bcc7 100644
--- a/toonz/sources/common/tvectorimage/tvectorimage.cpp
+++ b/toonz/sources/common/tvectorimage/tvectorimage.cpp
@@ -1031,11 +1031,11 @@ bool TVectorImage::Imp::areWholeGroups(const std::vector<int> &indexes) const {
   UINT i, j;
   for (i = 0; i < indexes.size(); i++) {
     if (m_strokes[indexes[i]]->m_isNewForFill) return false;
-    if (!m_strokes[indexes[i]]->m_groupId.isGrouped() != 0) return false;
+    if (!m_strokes[indexes[i]]->m_groupId.isGrouped()) return false;
     for (j = 0; j < m_strokes.size(); j++) {
       int ret = areDifferentGroup(indexes[i], false, j, false);
       if (ret == -1 ||
-          ret >= 1 && find(indexes.begin(), indexes.end(), j) == indexes.end())
+          (ret >= 1 && find(indexes.begin(), indexes.end(), j) == indexes.end()))
         return false;
     }
   }
@@ -1268,20 +1268,23 @@ void TVectorImage::mergeImage(const TVectorImageP &img, const TAffine &affine,
       TGroupId())  // if is inside a group, new image is put in that group.
   {
     TGroupId groupId;
-    for (i = m_imp->m_strokes.size() - 1; i >= 0; i--)
+    for (i = m_imp->m_strokes.size() - 1; i >= 0; i--) {
       if (m_imp->m_insideGroup.isParentOf(m_imp->m_strokes[i]->m_groupId)) {
         insertAt = i + 1;
         groupId  = m_imp->m_strokes[i]->m_groupId;
         break;
       }
-    if (insertAt != 0)
-      for (i = 0; i < (int)img->m_imp->m_strokes.size(); i++)
-        if (!img->m_imp->m_strokes[i]->m_groupId.isGrouped())
+    }
+    if (insertAt != 0) {
+      for (i = 0; i < (int)img->m_imp->m_strokes.size(); i++) {
+        if (!img->m_imp->m_strokes[i]->m_groupId.isGrouped()) {
           img->m_imp->m_strokes[i]->m_groupId = groupId;
-        else
+        } else {
           img->m_imp->m_strokes[i]->m_groupId =
               TGroupId(groupId, img->m_imp->m_strokes[i]->m_groupId);
-
+	}
+      }
+    }
   }
 
   // si fondono l'ultimo gruppo ghost della vecchia a e il primo della nuova
@@ -2904,8 +2907,8 @@ void TVectorImage::Imp::regroupGhosts(std::vector<int> &changedStrokes) {
       while (i < m_strokes.size() &&
              ((currGroupId.isGrouped(false) != 0 &&
                m_strokes[i]->m_groupId == currGroupId) ||
-              currGroupId.isGrouped(true) != 0 &&
-                  m_strokes[i]->m_groupId.isGrouped(true) != 0)) {
+              (currGroupId.isGrouped(true) != 0 &&
+                  m_strokes[i]->m_groupId.isGrouped(true) != 0))) {
         if (m_strokes[i]->m_groupId != currGroupId) {
           m_strokes[i]->m_groupId = currGroupId;
           changedStrokes.push_back(i);
diff --git a/toonz/sources/common/tvrender/qtofflinegl.cpp b/toonz/sources/common/tvrender/qtofflinegl.cpp
index 8ba5771..b1561a8 100644
--- a/toonz/sources/common/tvrender/qtofflinegl.cpp
+++ b/toonz/sources/common/tvrender/qtofflinegl.cpp
@@ -178,7 +178,7 @@ void QtOfflineGL::createContext(TDimension rasterSize,
   m_fbo->bind();
 
   printf("create context:%p [thread:0x%x]\n", m_context.get(),
-         QThread::currentThreadId());
+         (unsigned int)(size_t)QThread::currentThreadId());
 
   // Creo il contesto OpenGL - assicurandomi che sia effettivamente creato
   // NOTA: Se il contesto non viene creato, di solito basta ritentare qualche
diff --git a/toonz/sources/common/tvrender/tcolorstyles.cpp b/toonz/sources/common/tvrender/tcolorstyles.cpp
index 49932d6..1f1c89a 100644
--- a/toonz/sources/common/tvrender/tcolorstyles.cpp
+++ b/toonz/sources/common/tvrender/tcolorstyles.cpp
@@ -525,7 +525,7 @@ void TColorStyle::drawStroke(TFlash &flash, const TStroke *s) const {
 void TColorStyle::save(TOutputStreamInterface &os) const {
   std::wstring name = getName();
   bool numberedName =
-      !name.empty() && ('0' <= name[0] && name[0] <= '9' || name[0] == '_');
+      !name.empty() && (('0' <= name[0] && name[0] <= '9') || name[0] == '_');
 
   if (m_flags > 0 || (name.length() == 1 && numberedName))
     os << ("_" + QString::number(m_flags)).toStdString();
diff --git a/toonz/sources/common/tvrender/tglregions.cpp b/toonz/sources/common/tvrender/tglregions.cpp
index 84a9abc..43d6e17 100644
--- a/toonz/sources/common/tvrender/tglregions.cpp
+++ b/toonz/sources/common/tvrender/tglregions.cpp
@@ -655,7 +655,7 @@ rdRegions.m_alphaChannel = rdRegions.m_antiAliasing = false;*/
     int currStrokeIndex = strokeIndex;
     if (!rd.m_isIcon && vim->isInsideGroup() > 0 &&
         ((drawEnteredGroup && !vim->isEnteredGroupStroke(strokeIndex)) ||
-         !drawEnteredGroup && vim->isEnteredGroupStroke(strokeIndex))) {
+         (!drawEnteredGroup && vim->isEnteredGroupStroke(strokeIndex)))) {
       while (strokeIndex < vim->getStrokeCount() &&
              vim->sameGroup(strokeIndex, currStrokeIndex))
         strokeIndex++;
diff --git a/toonz/sources/common/tvrender/tpaletteutil.cpp b/toonz/sources/common/tvrender/tpaletteutil.cpp
index d933eb7..8e4bef9 100644
--- a/toonz/sources/common/tvrender/tpaletteutil.cpp
+++ b/toonz/sources/common/tvrender/tpaletteutil.cpp
@@ -12,7 +12,7 @@ void mergePalette(const TPaletteP &targetPalette,
 
   indexTable[0]                         = 0;
   std::set<int>::const_iterator styleIt = sourceIndices.begin();
-  for (styleIt; styleIt != sourceIndices.end(); ++styleIt) {
+  for (; styleIt != sourceIndices.end(); ++styleIt) {
     int srcStyleId = *styleIt;
     if (srcStyleId == 0) continue;
     assert(0 <= srcStyleId && srcStyleId < sourcePalette->getStyleCount());
diff --git a/toonz/sources/common/tvrender/tstrokedeformations.cpp b/toonz/sources/common/tvrender/tstrokedeformations.cpp
index 6a49806..afe1c6a 100644
--- a/toonz/sources/common/tvrender/tstrokedeformations.cpp
+++ b/toonz/sources/common/tvrender/tstrokedeformations.cpp
@@ -479,7 +479,7 @@ TThickPoint TStrokeBenderDeformation::getDisplacement(const TStroke &s,
   if (m_vect) {
     double outVal = 0.0;
 
-    if (fabs(diff) <= m_lengthOfDeformation)
+    if (fabs(diff) <= m_lengthOfDeformation) {
       if (m_versus == INNER) {
         diff *= (1.0 / m_lengthOfDeformation) * c_maxLengthOfGaussian;
         outVal = gaussianPotential(diff);
@@ -490,6 +490,7 @@ TThickPoint TStrokeBenderDeformation::getDisplacement(const TStroke &s,
                                     strokeLengthAtParameter;
         outVal = 1.0 - gaussianPotential(valForGaussian);
       }
+    }
 
     TPointD cp = convert(s.getControlPointAtParameter(w));
     TPointD p  = cp;
diff --git a/toonz/sources/common/twain/ttwain_capability.c b/toonz/sources/common/twain/ttwain_capability.c
index 2ae88ad..ceaf31f 100644
--- a/toonz/sources/common/twain/ttwain_capability.c
+++ b/toonz/sources/common/twain/ttwain_capability.c
@@ -62,10 +62,14 @@ int TTWAIN_GetCapCurrent(TW_UINT16 cap_id, TW_UINT16 conType, void *data,
 /*------------------------------------------------------------------------*/
 int TTWAIN_GetCapQuery(TW_UINT16 cap_id, TW_UINT16 *pattern) {
   int rc;
-  TW_ONEVALUE data;
+  /* GCC9 during compilation shows that this code possible call
+   * TTWAIN_GetCapability() with case TWON_TWON(TWON_RANGE, TWON_RANGE)
+   * whitch cause stack corruption, so make 'data' big enough to store
+   * TW_ONEVALUE. */
+  TW_ONEVALUE data[1 + (sizeof(TW_RANGE) / sizeof(TW_ONEVALUE))];
   rc = TTWAIN_GetCapability(MSG_QUERYSUPPORT, cap_id, TWON_ONEVALUE, &data, 0);
   if (!rc) return FALSE;
-  *pattern = (TW_UINT16)data.Item;
+  *pattern = (TW_UINT16)data[0].Item;
   return TRUE;
 }
 /*------------------------------------------------------------------------*/
diff --git a/toonz/sources/common/twain/ttwain_error.c b/toonz/sources/common/twain/ttwain_error.c
index 359b83b..e2c211f 100644
--- a/toonz/sources/common/twain/ttwain_error.c
+++ b/toonz/sources/common/twain/ttwain_error.c
@@ -98,19 +98,21 @@ void TTWAIN_RecordError(void) {
   else
     TTwainData.ErrCC = -1;
 
-  strcpy(Msg_out, "");
   if (TTwainData.ErrRC < (sizeof(RC_msg) / sizeof(RC_msg[0]))) {
-    sprintf(Msg_out, "RC: %s(%d)", RC_msg[TTwainData.ErrRC],
-            (int)TTwainData.ErrRC);
+    snprintf(Msg_out, sizeof(Msg_out), "RC: %s(%d)",
+             RC_msg[TTwainData.ErrRC], (int)TTwainData.ErrRC);
   } else {
-    sprintf(Msg_out, "RC: %s(%d)", "unknown", (int)TTwainData.ErrRC);
+    snprintf(Msg_out, sizeof(Msg_out), "RC: %s(%d)", "unknown",
+             (int)TTwainData.ErrRC);
   }
 
   if (TTwainData.ErrCC < (sizeof(CC_msg) / sizeof(CC_msg[0]))) {
-    sprintf(tmp, "CC: %s(%d)", CC_msg[TTwainData.ErrCC], (int)TTwainData.ErrCC);
+    snprintf(tmp, sizeof(tmp), "CC: %s(%d)", CC_msg[TTwainData.ErrCC],
+             (int)TTwainData.ErrCC);
     strcat(Msg_out, tmp);
   } else {
-    sprintf(tmp, "CC: %s(%d)", "unknown", (int)TTwainData.ErrCC);
+    snprintf(tmp, sizeof(tmp), "CC: %s(%d)", "unknown",
+             (int)TTwainData.ErrCC);
     strcat(Msg_out, tmp);
   }
 
diff --git a/toonz/sources/common/twain/ttwain_global_def.h b/toonz/sources/common/twain/ttwain_global_def.h
index 61db048..a46c67f 100644
--- a/toonz/sources/common/twain/ttwain_global_def.h
+++ b/toonz/sources/common/twain/ttwain_global_def.h
@@ -44,7 +44,7 @@ typedef void *TW_HANDLE;
 #define GLOBAL_LOCK(P) (P)
 #define GLOBAL_ALLOC(T, S) malloc(S)
 #define GLOBAL_FREE(P) free(P)
-#define GLOBAL_UNLOCK(P) (P)
+#define GLOBAL_UNLOCK(P)
 
 #endif
 #endif
diff --git a/toonz/sources/common/twain/ttwain_state.c b/toonz/sources/common/twain/ttwain_state.c
index 5a8b907..3925866 100644
--- a/toonz/sources/common/twain/ttwain_state.c
+++ b/toonz/sources/common/twain/ttwain_state.c
@@ -46,7 +46,11 @@ static void TTWAIN_FreeVar(void);
 
 #define CEIL(x) ((int)(x) < (x) ? (int)(x) + 1 : (int)(x))
 
+#ifndef _WIN32
+#define PRINTF(args...)
+#else
 #define PRINTF
+#endif
 /*---------------------------------------------------------------------------*/
 /* LOCAL PROTOTYPES
  */
@@ -133,7 +137,8 @@ int TTWAIN_SelectImageSource(void *hwnd) {
         TTWAIN_MGR(DG_CONTROL, DAT_IDENTITY, MSG_USERSELECT, &newSourceId);
   } else {
     char msg[2048];
-    sprintf(msg, "Unable to open Source Manager (%s)", DSM_FILENAME);
+    snprintf(msg, sizeof(msg), "Unable to open Source Manager (%s)",
+             DSM_FILENAME);
     TTWAIN_ErrorBox(msg);
     return FALSE;
   }
@@ -588,7 +593,8 @@ void *TTWAIN_AcquireNative(void *hwnd) {
     if (!TTWAIN_OpenSourceManager(hwnd)) /* Bring up to state 4 */
     {
       char msg[2048];
-      sprintf(msg, "Unable to open Source Manager (%s)", DSM_FILENAME);
+      snprintf(msg, sizeof(msg), "Unable to open Source Manager (%s)",
+               DSM_FILENAME);
       TTWAIN_ErrorBox(msg);
       return 0;
     }
@@ -642,7 +648,7 @@ static BOOL CALLBACK myHackEnumFunction(HWND hwnd, LPARAM lParam) {
   if (len && !strncmp(title, TTwainData.sourceId.ProductName, len)) {
     /*
 char dbg_str[1024];
-sprintf(dbg_str,"set focus on 0x%8x %s\n",hwnd, title);
+snprintf(dbg_str, sizeof(dbg_str), "set focus on 0x%8x %s\n",hwnd, title);
 OutputDebugString(dbg_str);
 */
     f = (MyFun *)lParam;
diff --git a/toonz/sources/common/twain/ttwain_util.c b/toonz/sources/common/twain/ttwain_util.c
index 4c16feb..6982db6 100644
--- a/toonz/sources/common/twain/ttwain_util.c
+++ b/toonz/sources/common/twain/ttwain_util.c
@@ -441,17 +441,18 @@ l'immagine)
   /*---------------------------------------------------------------------------*/
   char *TTWAIN_GetVersion(void) {
     static char version[5 + 1 + 5 + 1 + 32 + 1];
-    sprintf(version, "%d.", TTwainData.sourceId.Version.MajorNum);
-    sprintf(&version[strlen(version)], "%d ",
-            TTwainData.sourceId.Version.MinorNum);
-    strcat(version, (char *)TTwainData.sourceId.Version.Info);
+    snprintf(version, sizeof(version), "%d.%d %s",
+             TTwainData.sourceId.Version.MajorNum,
+	     TTwainData.sourceId.Version.MinorNum,
+	     (char *)TTwainData.sourceId.Version.Info);
     return version;
   }
   /*---------------------------------------------------------------------------*/
   char *TTWAIN_GetTwainVersion(void) {
     static char version[5 + 1 + 5 + 1];
-    sprintf(version, "%d.%d", TTwainData.sourceId.ProtocolMajor,
-            TTwainData.sourceId.ProtocolMinor);
+    snprintf(version, sizeof(version), "%d.%d",
+             TTwainData.sourceId.ProtocolMajor,
+             TTwainData.sourceId.ProtocolMinor);
     return version;
   }
   /*---------------------------------------------------------------------------*/
@@ -882,11 +883,13 @@ TTwainData.transferInfo.multiTransfer = status;
     TTWAIN_InitVar();
     if (TTWAIN_DSM_HasEntryPoint()) return TRUE;
 
-    if (TTwainData.twainAvailable == AVAIABLE_DONTKNOW)
-      if (TTWAIN_LoadSourceManager())
+    if (TTwainData.twainAvailable == AVAIABLE_DONTKNOW) {
+      if (TTWAIN_LoadSourceManager()) {
         TTWAIN_UnloadSourceManager();
-      else
+      } else {
         TTwainData.twainAvailable = AVAIABLE_NO;
+      }
+    }
 
     return (TTwainData.twainAvailable == AVAIABLE_YES);
   }
diff --git a/toonz/sources/common/twain/ttwain_winM.c b/toonz/sources/common/twain/ttwain_winM.c
index 81b49cf..70ec579 100644
--- a/toonz/sources/common/twain/ttwain_winM.c
+++ b/toonz/sources/common/twain/ttwain_winM.c
@@ -9,7 +9,11 @@ extern "C" {
 #include "ttwain_state.h"
 #include "ttwainP.h"
 //#define DEBUG
+#ifndef _WIN32
+#define PRINTF(args...)
+#else
 #define PRINTF
+#endif
 #if 1
 
 extern int TTWAIN_MessageHook(void *lpmsg);
@@ -147,8 +151,6 @@ void setupUI(void) {
 
 /*---------------------------------------------------------------------------*/
 
-#define PRINTF
-
 void registerTwainCallback(void) {
   if (TTWAIN_GetState() < TWAIN_SOURCE_OPEN) {
     PRINTF("%s too early!, don't register\n", __FUNCTION__);
diff --git a/toonz/sources/image/bmp/filebmp.c b/toonz/sources/image/bmp/filebmp.c
index db9b8c7..1f0a2fc 100644
--- a/toonz/sources/image/bmp/filebmp.c
+++ b/toonz/sources/image/bmp/filebmp.c
@@ -634,8 +634,9 @@ static int img_read_bmp_region(const MYSTRING fname, IMAGE **pimg, int x1,
   if ((hd->biBitCount != 1 && hd->biBitCount != 4 && hd->biBitCount != 8 &&
        hd->biBitCount != 24) ||
       hd->biPlanes != 1 || hd->biCompression > BMP_BI_RLE4) {
-    sprintf(buf, "Bogus BMP File! (bitCount=%d, Planes=%d, Compression=%d)",
-            hd->biBitCount, hd->biPlanes, hd->biCompression);
+    snprintf(buf, sizeof(buf),
+             "Bogus BMP File! (bitCount=%d, Planes=%d, Compression=%d)",
+             hd->biBitCount, hd->biPlanes, hd->biCompression);
 
     bmp_error = UNSUPPORTED_BMP_FORMAT;
     goto ERROR;
@@ -646,8 +647,9 @@ static int img_read_bmp_region(const MYSTRING fname, IMAGE **pimg, int x1,
        hd->biCompression != BMP_BI_RGB) ||
       (hd->biBitCount == 4 && hd->biCompression == BMP_BI_RLE8) ||
       (hd->biBitCount == 8 && hd->biCompression == BMP_BI_RLE4)) {
-    sprintf(buf, "Bogus BMP File!  (bitCount=%d, Compression=%d)",
-            hd->biBitCount, hd->biCompression);
+    snprintf(buf, sizeof(buf),
+             "Bogus BMP File!  (bitCount=%d, Compression=%d)",
+             hd->biBitCount, hd->biCompression);
     bmp_error = UNSUPPORTED_BMP_FORMAT;
     goto ERROR;
   }
diff --git a/toonz/sources/image/compatibility/tnz4.h b/toonz/sources/image/compatibility/tnz4.h
index 60593d6..9488ebe 100644
--- a/toonz/sources/image/compatibility/tnz4.h
+++ b/toonz/sources/image/compatibility/tnz4.h
@@ -9,8 +9,6 @@
 
 #if defined(MACOSX)
 #include <sys/malloc.h>
-#else
-#include <malloc.h>
 #endif
 
 #define UCHAR unsigned char
diff --git a/toonz/sources/image/ffmpeg/tiio_ffmpeg.cpp b/toonz/sources/image/ffmpeg/tiio_ffmpeg.cpp
index 796543a..8061153 100644
--- a/toonz/sources/image/ffmpeg/tiio_ffmpeg.cpp
+++ b/toonz/sources/image/ffmpeg/tiio_ffmpeg.cpp
@@ -301,8 +301,8 @@ TRasterImageP Ffmpeg::getImage(int frameIndex) {
       ret->yMirror();
       return TRasterImageP(ret);
     }
-  } else
-    return TRasterImageP();
+  }
+  return TRasterImageP();
 }
 
 double Ffmpeg::getFrameRate() {
diff --git a/toonz/sources/image/pli/pli_io.cpp b/toonz/sources/image/pli/pli_io.cpp
index 16e1571..8baa27e 100644
--- a/toonz/sources/image/pli/pli_io.cpp
+++ b/toonz/sources/image/pli/pli_io.cpp
@@ -582,7 +582,7 @@ ParsedPliImp::ParsedPliImp(const TFilePath &filename, bool readInfo)
                                  m_minorVersionNumber);
 
   if (m_majorVersionNumber > 5 ||
-      m_majorVersionNumber == 5 && m_minorVersionNumber >= 8)
+      (m_majorVersionNumber == 5 && m_minorVersionNumber >= 8))
     m_iChan >> m_creator;
 
   if (m_majorVersionNumber < 5) {
@@ -1055,16 +1055,16 @@ inline bool ParsedPliImp::readDinamicData(TINT32 &val, TUINT32 &bufOffs) {
     break;
   case 4:
     if (m_isIrixEndian) {
-      val = m_buf[bufOffs + 3] | (m_buf[bufOffs + 2] << 8) |
-            (m_buf[bufOffs + 1] << 16) | (m_buf[bufOffs] << 24) & 0x7fffffff;
+      val = (m_buf[bufOffs + 3] | (m_buf[bufOffs + 2] << 8) |
+            (m_buf[bufOffs + 1] << 16) | (m_buf[bufOffs] << 24)) & 0x7fffffff;
       if (m_buf[bufOffs] & 0x80) {
         val        = -val;
         isNegative = true;
       }
     } else {
-      val = m_buf[bufOffs] | (m_buf[bufOffs + 1] << 8) |
+      val = (m_buf[bufOffs] | (m_buf[bufOffs + 1] << 8) |
             (m_buf[bufOffs + 2] << 16) |
-            (m_buf[bufOffs + 3] << 24) & 0x7fffffff;
+            (m_buf[bufOffs + 3] << 24)) & 0x7fffffff;
       if (m_buf[bufOffs + 3] & 0x80) {
         val        = -val;
         isNegative = true;
diff --git a/toonz/sources/image/pli/tiio_pli.cpp b/toonz/sources/image/pli/tiio_pli.cpp
index 4878a1d..d17ff42 100644
--- a/toonz/sources/image/pli/tiio_pli.cpp
+++ b/toonz/sources/image/pli/tiio_pli.cpp
@@ -400,7 +400,7 @@ TImageP TImageReaderPli::doLoad() {
       strokeData.m_options =
           ((StrokeOutlineOptionsTag *)imageTag->m_object[i])->m_options;
       break;
-    case PliTag::AUTOCLOSE_TOLERANCE_GOBJ:
+    case PliTag::AUTOCLOSE_TOLERANCE_GOBJ: {
       // aggiunge curve quadratiche con spessore costante
       AutoCloseToleranceTag *toleranceTag =
           (AutoCloseToleranceTag *)imageTag->m_object[i];
@@ -408,6 +408,9 @@ TImageP TImageReaderPli::doLoad() {
       outVectImage->setAutocloseTolerance(
           ((double)toleranceTag->m_autoCloseTolerance) / 1000);
       break;
+    }
+    default:
+      break;
     }  // switch(groupTag->m_object[j]->m_type)
   }    // for (i=0; i<imageTag->m_numObjects; i++)
 
diff --git a/toonz/sources/image/sgi/filesgi.cpp b/toonz/sources/image/sgi/filesgi.cpp
index 9542f19..4621fe1 100644
--- a/toonz/sources/image/sgi/filesgi.cpp
+++ b/toonz/sources/image/sgi/filesgi.cpp
@@ -26,8 +26,6 @@
 
 #if defined(MACOSX)
 #include <sys/malloc.h>
-#else
-#include <malloc.h>
 #endif
 
 #include <assert.h>
@@ -311,7 +309,7 @@ static IMAGERGB *iopen(int fd, OpenMode openMode, unsigned int type,
 
   if ((image->tmpbuf = ibufalloc(image, BPP(image->type))) == 0) {
     char xs[1024];
-    sprintf(xs, "%d", image->xsize);
+    snprintf(xs, sizeof(xs), "%d", image->xsize);
 
     TSystem::outputDebug(string("iopen: error on tmpbuf alloc %d\n") + xs);
     return NULL;
diff --git a/toonz/sources/image/svg/tiio_svg.cpp b/toonz/sources/image/svg/tiio_svg.cpp
index d527385..42fb613 100644
--- a/toonz/sources/image/svg/tiio_svg.cpp
+++ b/toonz/sources/image/svg/tiio_svg.cpp
@@ -1870,7 +1870,7 @@ static void writeRegion(TRegion *r, TPalette *plt, QTextStream &out,
 
   out << "<path  \n";
   TPixel32 col = plt->getStyle(r->getStyle())->getMainColor();
-  if (col == TPixel::Transparent) col == TPixel::White;
+  if (col == TPixel::Transparent) col = TPixel::White;
 
   out << "style=\"fill:rgb(" << col.r << "," << col.g << "," << col.b
       << ")\" \n";
diff --git a/toonz/sources/image/tzl/tiio_tzl.cpp b/toonz/sources/image/tzl/tiio_tzl.cpp
index c94d9eb..47c6929 100644
--- a/toonz/sources/image/tzl/tiio_tzl.cpp
+++ b/toonz/sources/image/tzl/tiio_tzl.cpp
@@ -1374,7 +1374,7 @@ bool TLevelWriterTzl::optimize() {
   TLevelP level = lr->loadInfo();
   if (!level || level->getFrameCount() == 0) return false;
   TLevel::Iterator levelIt = level->begin();
-  for (levelIt; levelIt != level->end(); ++levelIt) {
+  for (; levelIt != level->end(); ++levelIt) {
     TToonzImageP img = lr->getFrameReader(levelIt->first)->load();
     assert(img);
     lw->getFrameWriter(levelIt->first)->save(img);
diff --git a/toonz/sources/image/tzp/filetzup.cpp b/toonz/sources/image/tzp/filetzup.cpp
index 6f931e5..6b55c16 100644
--- a/toonz/sources/image/tzp/filetzup.cpp
+++ b/toonz/sources/image/tzp/filetzup.cpp
@@ -454,7 +454,7 @@ height = image->pixmap.ysize;
                     tfp, TIFFTAG_XPOSITION,
                     image->pixmap.h_pos / image->pixmap.y_dpi + 8.0);
   }
-  /*sprintf(str, "TOONZ %s", versione_del_software);*/
+  /*snprintf(str, sizeof(str), "TOONZ %s", versione_del_software);*/
   TIFFSetField(tfp, TIFFTAG_SOFTWARE, str);
 
   /* Aggiungo le informazioni relative alla savebox a all'history */
diff --git a/toonz/sources/include/tcg/hpp/polyline_ops.hpp b/toonz/sources/include/tcg/hpp/polyline_ops.hpp
index 62826e3..bb85849 100644
--- a/toonz/sources/include/tcg/hpp/polyline_ops.hpp
+++ b/toonz/sources/include/tcg/hpp/polyline_ops.hpp
@@ -146,7 +146,7 @@ _QuadraticsEdgeEvaluator<Point>::furthestFrom(const quad_iterator &at) {
     const point_type &C1 = *(bt.it() + 1);
 
     // Ensure that bt is not a corner
-    if (abs(tcg::point_ops::cross(*(bt.it() - 1) - *bt, *(bt.it() + 1) - *bt)) >
+    if (std::abs(tcg::point_ops::cross(*(bt.it() - 1) - *bt, *(bt.it() + 1) - *bt)) >
         1e-3)
       break;
 
diff --git a/toonz/sources/include/tversion.h b/toonz/sources/include/tversion.h
index c8ffe75..d22470b 100644
--- a/toonz/sources/include/tversion.h
+++ b/toonz/sources/include/tversion.h
@@ -44,13 +44,13 @@ bool ToonzVersion::hasAppNote(void) {
 }
 std::string ToonzVersion::getAppVersionString(void) {
   char buffer[50];
-  sprintf(buffer, "%.1f", applicationVersion);
+  snprintf(buffer, sizeof(buffer), "%.1f", applicationVersion);
   std::string appver = std::string(buffer);
   return appver;
 }
 std::string ToonzVersion::getAppRevisionString(void) {
   char buffer[50];
-  sprintf(buffer, "%g", applicationRevision);
+  snprintf(buffer, sizeof(buffer), "%g", applicationRevision);
   std::string apprev = std::string(buffer);
   return apprev;
 }
diff --git a/toonz/sources/stdfx/backlitfx.cpp b/toonz/sources/stdfx/backlitfx.cpp
index cefc338..9e7551d 100644
--- a/toonz/sources/stdfx/backlitfx.cpp
+++ b/toonz/sources/stdfx/backlitfx.cpp
@@ -201,7 +201,7 @@ public:
   ~BacklitFx() {}
   bool doGetBBox(double frame, TRectD &bbox,
                  const TRenderSettings &info) override {
-    if (getActiveTimeRegion().contains(frame))
+    if (getActiveTimeRegion().contains(frame)) {
       if (m_light.isConnected()) {
         if (m_lighted.isConnected()) {
           TRectD b0, b1;
@@ -209,10 +209,13 @@ public:
           ret      = ret && m_lighted->doGetBBox(frame, b1, info);
           bbox     = b0.enlarge(tceil(m_value->getValue(frame))) + b1;
           return ret;
-        } else
+        } else {
           return m_light->doGetBBox(frame, bbox, info);
-      } else if (m_lighted.isConnected())
+	}
+      } else if (m_lighted.isConnected()) {
         return m_lighted->doGetBBox(frame, bbox, info);
+      }
+    }
     return false;
   }
 
diff --git a/toonz/sources/stdfx/changecolorfx.cpp b/toonz/sources/stdfx/changecolorfx.cpp
index c23048a..4fa3570 100644
--- a/toonz/sources/stdfx/changecolorfx.cpp
+++ b/toonz/sources/stdfx/changecolorfx.cpp
@@ -246,7 +246,7 @@ to_v =to_hsv[2]/255.;
         }
       }
       // premultiply(*pix);
-      *pix++;
+      pix++;
     }
   }
   raster32->unlock();
diff --git a/toonz/sources/stdfx/colorembossfx.cpp b/toonz/sources/stdfx/colorembossfx.cpp
index 248d560..94a83f5 100644
--- a/toonz/sources/stdfx/colorembossfx.cpp
+++ b/toonz/sources/stdfx/colorembossfx.cpp
@@ -136,9 +136,9 @@ void doColorEmboss(TRasterPT<PIXEL> ras, TRasterPT<PIXEL> srcraster,
                         ? (val > 0 ? (CHANNEL_TYPE)val : 0)
                         : PIXEL::maxChannelValue;
       (pixout)->m = (pix)->m;
-      *pix++;
-      *pixout++;
-      *ctrpix++;
+      pix++;
+      pixout++;
+      ctrpix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/stdfx/dissolvefx.cpp b/toonz/sources/stdfx/dissolvefx.cpp
index 9d6716e..9e9c3ac 100644
--- a/toonz/sources/stdfx/dissolvefx.cpp
+++ b/toonz/sources/stdfx/dissolvefx.cpp
@@ -57,7 +57,7 @@ void doDissolve(const TRasterPT<PIXEL> &ras, const double intensity,
           pix->r = pix->g = pix->b = pix->m = 0;
         }
       }
-      *pix++;
+      pix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/stdfx/embossfx.cpp b/toonz/sources/stdfx/embossfx.cpp
index 737c16c..87cd677 100644
--- a/toonz/sources/stdfx/embossfx.cpp
+++ b/toonz/sources/stdfx/embossfx.cpp
@@ -137,8 +137,8 @@ void doEmboss(TRasterPT<PIXEL> ras, TRasterPT<PIXEL> srcraster, double azimuth,
       (pixout)->b = pixout->r;
       (pixout)->m = (pix)->m;
       *pixout     = premultiply(*pixout);
-      *pix++;
-      *pixout++;
+      pix++;
+      pixout++;
     }
   }
 
diff --git a/toonz/sources/stdfx/freedistortfx.cpp b/toonz/sources/stdfx/freedistortfx.cpp
index 45db345..dc94019 100644
--- a/toonz/sources/stdfx/freedistortfx.cpp
+++ b/toonz/sources/stdfx/freedistortfx.cpp
@@ -590,7 +590,7 @@ void doBlur(TRasterPT<PIX> &r, double blur0, double blur1, double transp0,
   row = new PIX[std::max(lx, ly)];
   r->lock();
   bufin = r->pixels(0);
-  for (i = 0, cur_blur = blur0 + (blur1 - blur0) * (i - y0) / den, 0.0,
+  for (i = 0, cur_blur = blur0 + (blur1 - blur0) * (i - y0) / den,
       actual_blur = std::max(cur_blur, 0.0);
        i < ly; i++, bufin += wrap, cur_blur += blur_incr,
       actual_blur = std::max(cur_blur, 0.0)) {
diff --git a/toonz/sources/stdfx/glowfx.cpp b/toonz/sources/stdfx/glowfx.cpp
index 207c4b1..6bc2bd4 100644
--- a/toonz/sources/stdfx/glowfx.cpp
+++ b/toonz/sources/stdfx/glowfx.cpp
@@ -147,7 +147,7 @@ public:
 
   bool doGetBBox(double frame, TRectD &bbox,
                  const TRenderSettings &info) override {
-    if (getActiveTimeRegion().contains(frame))
+    if (getActiveTimeRegion().contains(frame)) {
       if (m_light.isConnected()) {
         TRectD b0, b1;
         bool ret = m_light->doGetBBox(frame, b0, info);
@@ -157,8 +157,10 @@ public:
           bbox += b1;
         }
         return ret;
-      } else if (m_lighted.isConnected())
+      } else if (m_lighted.isConnected()) {
         return m_lighted->doGetBBox(frame, bbox, info);
+      }
+    }
 
     return false;
   }
diff --git a/toonz/sources/stdfx/igs_motion_wind_pixel.cpp b/toonz/sources/stdfx/igs_motion_wind_pixel.cpp
index 8c96e16..d1e7bad 100644
--- a/toonz/sources/stdfx/igs_motion_wind_pixel.cpp
+++ b/toonz/sources/stdfx/igs_motion_wind_pixel.cpp
@@ -124,8 +124,8 @@ void invert_pixel_(const int channels, double *pixel) {
 void rgb_to_lightness_(const double re, const double gr, const double bl,
                        double &li) {
   li = ((re < gr) ? ((gr < bl) ? bl : gr)
-                  : ((re < bl) ? bl : re) + (gr < re) ? ((bl < gr) ? bl : gr)
-                                                      : ((bl < re) ? bl : re)) /
+                  : (((re < bl) ? bl : re) + ((gr < re) ? ((bl < gr) ? bl : gr)
+                                                        : ((bl < re) ? bl : re)))) /
        2.0;
 }
 double get_lightness_(const int channels, const double *pixel
diff --git a/toonz/sources/stdfx/iwa_adjustexposurefx.cpp b/toonz/sources/stdfx/iwa_adjustexposurefx.cpp
index ef9b74f..92d7d3a 100644
--- a/toonz/sources/stdfx/iwa_adjustexposurefx.cpp
+++ b/toonz/sources/stdfx/iwa_adjustexposurefx.cpp
@@ -121,7 +121,7 @@ void Iwa_AdjustExposureFx::doCompute_CPU(TTile &tile, double frame,
   float scale    = (float)m_scale->getValue(frame);
   float offset   = (float)m_offset->getValue(frame);
 
-  float exposureOffset = (powf(10.0f, (float)(abs(offset) / hardness)) - 1.0f) *
+  float exposureOffset = (powf(10.0f, (float)(std::abs(offset) / hardness)) - 1.0f) *
                          ((offset < 0.0f) ? -1.0f : 1.0f);
 
   float4 *pix = tile_host;
diff --git a/toonz/sources/stdfx/iwa_directionalblurfx.cpp b/toonz/sources/stdfx/iwa_directionalblurfx.cpp
index 17ed55d..636b35e 100644
--- a/toonz/sources/stdfx/iwa_directionalblurfx.cpp
+++ b/toonz/sources/stdfx/iwa_directionalblurfx.cpp
@@ -163,10 +163,10 @@ void Iwa_DirectionalBlurFx::doCompute(TTile &tile, double frame,
     maxY = (bidirectional) ? -blur.y : 0.0;
     minY = blur.y;
   }
-  int marginLeft   = (int)ceil(abs(minX));
-  int marginRight  = (int)ceil(abs(maxX));
-  int marginTop    = (int)ceil(abs(maxY));
-  int marginBottom = (int)ceil(abs(minY));
+  int marginLeft   = (int)ceil(std::abs(minX));
+  int marginRight  = (int)ceil(std::abs(maxX));
+  int marginTop    = (int)ceil(std::abs(maxY));
+  int marginBottom = (int)ceil(std::abs(minY));
 
   /*- マージンは、フィルタの上下左右を反転した寸法になる -*/
   TRectD enlargedBBox(bBox.x0 - (double)marginRight,
@@ -504,7 +504,7 @@ void Iwa_DirectionalBlurFx::makeDirectionalBlurFilter_CPU(
 
       /*- オフセット値を求める -*/
       float offset =
-          (bidirectional) ? abs(framePosRatio * 2.0 - 1.0) : framePosRatio;
+          (bidirectional) ? std::abs(framePosRatio * 2.0 - 1.0) : framePosRatio;
 
       /*- フィルタごとに分ける -*/
       float bokeAsiVal;
@@ -581,10 +581,10 @@ bool Iwa_DirectionalBlurFx::doGetBBox(double frame, TRectD &bBox,
     maxY = (bidirectional) ? -blur.y : 0.0;
     minY = blur.y;
   }
-  int marginLeft   = (int)ceil(abs(minX));
-  int marginRight  = (int)ceil(abs(maxX));
-  int marginTop    = (int)ceil(abs(maxY));
-  int marginBottom = (int)ceil(abs(minY));
+  int marginLeft   = (int)ceil(std::abs(minX));
+  int marginRight  = (int)ceil(std::abs(maxX));
+  int marginTop    = (int)ceil(std::abs(maxY));
+  int marginBottom = (int)ceil(std::abs(minY));
 
   TRectD enlargedBBox(
       bBox.x0 - (double)marginLeft, bBox.y0 - (double)marginBottom,
diff --git a/toonz/sources/stdfx/iwa_gradientwarpfx.cpp b/toonz/sources/stdfx/iwa_gradientwarpfx.cpp
index 339ac06..b387945 100644
--- a/toonz/sources/stdfx/iwa_gradientwarpfx.cpp
+++ b/toonz/sources/stdfx/iwa_gradientwarpfx.cpp
@@ -126,7 +126,7 @@ void Iwa_GradientWarpFx::doCompute(TTile &tile, double frame,
   }
 
   int margin = static_cast<int>(
-      ceil((abs(hLength) < abs(vLength)) ? abs(vLength) : abs(hLength)));
+      ceil((std::abs(hLength) < std::abs(vLength)) ? std::abs(vLength) : std::abs(hLength)));
 
   /*- 素材計算範囲を計算 -*/
   /*- 出力範囲 -*/
@@ -312,8 +312,8 @@ void Iwa_GradientWarpFx::get_render_real_hv(const double frame,
                                             double &v_maxlen) {
   /*--- ベクトルにする(プラス値) --- */
   TPointD rend_vect;
-  rend_vect.x = abs(m_h_maxlen->getValue(frame));
-  rend_vect.y = abs(m_v_maxlen->getValue(frame));
+  rend_vect.x = std::abs(m_h_maxlen->getValue(frame));
+  rend_vect.y = std::abs(m_v_maxlen->getValue(frame));
   /*--- 拡大縮小(移動回転しないで)のGeometryを反映させる ---*/
   rend_vect = rend_vect * sqrt(fabs(affine.det()));
   /*--- 方向は無視して長さを返す(プラス値) ---*/
diff --git a/toonz/sources/stdfx/iwa_motionblurfx.cpp b/toonz/sources/stdfx/iwa_motionblurfx.cpp
index 860b033..0cd2b2f 100644
--- a/toonz/sources/stdfx/iwa_motionblurfx.cpp
+++ b/toonz/sources/stdfx/iwa_motionblurfx.cpp
@@ -322,8 +322,8 @@ void Iwa_MotionBlurCompFx::makeZanzoFilter_CPU(
           continue;
 
         /* Linear interpolation with 4 neighboring pixels */
-        float xRatio = 1.0f - abs(pos.x - p0.x);
-        float yRatio = 1.0f - abs(pos.y - p0.y);
+        float xRatio = 1.0f - std::abs(pos.x - p0.x);
+        float yRatio = 1.0f - std::abs(pos.y - p0.y);
 
         /* Next, get the value of the gamma strength */
         /* Offset value of the frame of the neighbor point */
@@ -691,10 +691,10 @@ void Iwa_MotionBlurCompFx::doCompute(TTile &tile, double frame,
     if (points.at(p).y > maxY) maxY = points.at(p).y;
     if (points.at(p).y < minY) minY = points.at(p).y;
   }
-  int marginLeft   = (int)ceil(abs(minX));
-  int marginRight  = (int)ceil(abs(maxX));
-  int marginTop    = (int)ceil(abs(maxY));
-  int marginBottom = (int)ceil(abs(minY));
+  int marginLeft   = (int)ceil(std::abs(minX));
+  int marginRight  = (int)ceil(std::abs(maxX));
+  int marginTop    = (int)ceil(std::abs(maxY));
+  int marginBottom = (int)ceil(std::abs(minY));
 
   /* Return the input tile as-is if there is not movement
   * (= filter margins are all 0). */
@@ -897,10 +897,10 @@ bool Iwa_MotionBlurCompFx::doGetBBox(double frame, TRectD &bBox,
     if (points.at(p).y > maxY) maxY = points.at(p).y;
     if (points.at(p).y < minY) minY = points.at(p).y;
   }
-  int marginLeft   = (int)ceil(abs(minX));
-  int marginRight  = (int)ceil(abs(maxX));
-  int marginTop    = (int)ceil(abs(maxY));
-  int marginBottom = (int)ceil(abs(minY));
+  int marginLeft   = (int)ceil(std::abs(minX));
+  int marginRight  = (int)ceil(std::abs(maxX));
+  int marginTop    = (int)ceil(std::abs(maxY));
+  int marginBottom = (int)ceil(std::abs(minY));
 
   TRectD enlargedBBox(
       bBox.x0 - (double)marginLeft, bBox.y0 - (double)marginBottom,
diff --git a/toonz/sources/stdfx/iwa_particlesengine.cpp b/toonz/sources/stdfx/iwa_particlesengine.cpp
index 4f48de4..48e1b38 100644
--- a/toonz/sources/stdfx/iwa_particlesengine.cpp
+++ b/toonz/sources/stdfx/iwa_particlesengine.cpp
@@ -876,7 +876,7 @@ void Iwa_Particles_Engine::do_render(
     struct particles_values &values, float opacity_range, int dist_frame,
     std::map<std::pair<int, int>, float> &partScales, TTile *baseImgTile) {
   /*- カメラに対してタテになっている粒子を描かずに飛ばす -*/
-  if (abs(cosf(part->flap_phi * 3.14159f / 180.0f)) < 0.03f) {
+  if (std::abs(cosf(part->flap_phi * 3.14159f / 180.0f)) < 0.03f) {
     return;
   }
   // Retrieve the particle frame - that is, the *column frame* from which we are
@@ -923,8 +923,8 @@ void Iwa_Particles_Engine::do_render(
       float3 lightVec = {sinf(liTheta) * sinf(liPhi),
                          cosf(liTheta) * sinf(liPhi), cosf(liPhi)};
       /*- 法線ベクトルと光源ベクトルの内積の絶対値 -*/
-      illuminant = abs(normVec.x * lightVec.x + normVec.y * lightVec.y +
-                       normVec.z * lightVec.z);
+      illuminant = std::abs(normVec.x * lightVec.x + normVec.y *
+                            lightVec.y + normVec.z * lightVec.z);
     }
   }
 
@@ -996,11 +996,13 @@ void Iwa_Particles_Engine::do_render(
 
     std::string alias;
     TRasterImageP rimg;
-    if (rimg = partLevel[part->level]->frame(ndx)) {
+    rimg = partLevel[part->level]->frame(ndx);
+    if (rimg) {
       ras = rimg->getRaster();
     } else {
       alias = "PART: " + (*part_ports[part->level])->getAlias(ndx, riNew);
-      if (rimg = TImageCache::instance()->get(alias, false)) {
+      rimg = TImageCache::instance()->get(alias, false);
+      if (rimg) {
         ras = rimg->getRaster();
 
         // Check that the raster resolution is sufficient for our purposes
@@ -1127,7 +1129,7 @@ void Iwa_Particles_Engine::fill_array(
         if (myarray[i - 1]) myarray[i] = myarray[i - 1];
       }
     }
-    *pix++;
+    pix++;
   }
 
   for (j = 1; j < ly; j++) {
@@ -1518,11 +1520,13 @@ void Iwa_Particles_Engine::renderBackground(
 
     std::string alias;
     TRasterImageP rimg;
-    if (rimg = partLevel[origin.level]->frame(ndx)) {
+    rimg = partLevel[origin.level]->frame(ndx);
+    if (rimg) {
       ras = rimg->getRaster();
     } else {
       alias = "PART: " + (*part_ports[origin.level])->getAlias(ndx, riNew);
-      if (rimg = TImageCache::instance()->get(alias, false)) {
+      rimg = TImageCache::instance()->get(alias, false);
+      if (rimg) {
         ras = rimg->getRaster();
 
         // Check that the raster resolution is sufficient for our purposes
diff --git a/toonz/sources/stdfx/iwa_soapbubblefx.cpp b/toonz/sources/stdfx/iwa_soapbubblefx.cpp
index a1d278a..5a2eccf 100644
--- a/toonz/sources/stdfx/iwa_soapbubblefx.cpp
+++ b/toonz/sources/stdfx/iwa_soapbubblefx.cpp
@@ -927,7 +927,7 @@ void Iwa_SoapBubbleFx::do_distance_transform(float* dst_p, USHORT* binarized_p,
   float* tmp_dst = dst_p;
   /* transform along rows */
   for (int j = 0; j < dim.ly; j++) {
-    for (int i = 0; i < dim.lx; i++, *tmp_dst++) {
+    for (int i = 0; i < dim.lx; i++, tmp_dst++) {
       f[i] = *tmp_dst;
     }
 
@@ -960,7 +960,7 @@ void Iwa_SoapBubbleFx::do_distance_transform(float* dst_p, USHORT* binarized_p,
 
   /* square root and normalize */
   USHORT* region_p = binarized_p;
-  for (int i = 0; i < dim.lx * dim.ly; i++, *tmp_dst++, region_p++) {
+  for (int i = 0; i < dim.lx * dim.ly; i++, tmp_dst++, region_p++) {
     if (max_val[*region_p] > 0)
       *tmp_dst = std::sqrt(*tmp_dst) / max_val[*region_p];
   }
diff --git a/toonz/sources/stdfx/iwa_textfx.cpp b/toonz/sources/stdfx/iwa_textfx.cpp
index 41892f0..d220937 100644
--- a/toonz/sources/stdfx/iwa_textfx.cpp
+++ b/toonz/sources/stdfx/iwa_textfx.cpp
@@ -75,7 +75,7 @@ void Iwa_TextFx::doCompute(TTile &tile, double frame,
   font.fromString(QString::fromStdWString(m_font->getValue()));
 
   double fac = sqrt(fabs(ri.m_affine.det()));
-  int size   = (int)(fac * fabs(font.pixelSize()));
+  int size   = (int)(fac * std::abs(font.pixelSize()));
 
   TPoint center = convert(
       fac * m_center->getValue(frame) -
diff --git a/toonz/sources/stdfx/noisefx.cpp b/toonz/sources/stdfx/noisefx.cpp
index 0679a72..59a7482 100644
--- a/toonz/sources/stdfx/noisefx.cpp
+++ b/toonz/sources/stdfx/noisefx.cpp
@@ -129,7 +129,7 @@ void doNoise(TRasterPT<PIXEL> &ras, double sigma, bool bw, bool red, bool green,
           pix->b = tcrop<int>(b, 0, pix->m);
         }
       }
-      *pix++;
+      pix++;
     }
   }
 
diff --git a/toonz/sources/stdfx/particlesengine.cpp b/toonz/sources/stdfx/particlesengine.cpp
index 5a67d75..636c79a 100644
--- a/toonz/sources/stdfx/particlesengine.cpp
+++ b/toonz/sources/stdfx/particlesengine.cpp
@@ -744,11 +744,13 @@ void Particles_Engine::do_render(
 
     std::string alias;
     TRasterImageP rimg;
-    if (rimg = partLevel[part->level]->frame(ndx)) {
+    rimg = partLevel[part->level]->frame(ndx);
+    if (rimg) {
       ras = rimg->getRaster();
     } else {
       alias = "PART: " + (*part_ports[part->level])->getAlias(ndx, riNew);
-      if (rimg = TImageCache::instance()->get(alias, false)) {
+      rimg = TImageCache::instance()->get(alias, false);
+      if (rimg) {
         ras = rimg->getRaster();
 
         // Check that the raster resolution is sufficient for our purposes
@@ -864,7 +866,7 @@ void Particles_Engine::fill_array(TTile *ctrl1, int &regioncount,
         if (myarray[i - 1]) myarray[i] = myarray[i - 1];
       }
     }
-    *pix++;
+    pix++;
   }
 
   for (j = 1; j < ly; j++) {
@@ -1035,7 +1037,7 @@ void Particles_Engine::fill_single_region(
           //           int a=0;
         }
         i++;
-        *pix++;
+        pix++;
       }
     }
   } else {
@@ -1065,7 +1067,7 @@ void Particles_Engine::fill_single_region(
         } else {
         }
         i++;
-        *pix++;
+        pix++;
       }
     }
   }
diff --git a/toonz/sources/stdfx/perlinnoisefx.cpp b/toonz/sources/stdfx/perlinnoisefx.cpp
index e2f9ab1..f4c38fd 100644
--- a/toonz/sources/stdfx/perlinnoisefx.cpp
+++ b/toonz/sources/stdfx/perlinnoisefx.cpp
@@ -124,8 +124,8 @@ void doPerlinNoise(const TRasterPT<PIXEL> &rasOut,
           pixout->b = (CHANNEL_TYPE)((pix + pixshift)->b);
           pixout->m = (CHANNEL_TYPE)((pix + pixshift)->m);
         }
-        *pix++;
-        *pixout++;
+        pix++;
+        pixout++;
       }
     }
   else
@@ -157,8 +157,8 @@ void doPerlinNoise(const TRasterPT<PIXEL> &rasOut,
           pixout->b = (CHANNEL_TYPE)((pix + pixshift)->b);
           pixout->m = (CHANNEL_TYPE)((pix + pixshift)->m);
         }
-        *pix++;
-        *pixout++;
+        pix++;
+        pixout++;
       }
     }
   rasOut->unlock();
diff --git a/toonz/sources/stdfx/pins.cpp b/toonz/sources/stdfx/pins.cpp
index 0f1edfc..59206f0 100644
--- a/toonz/sources/stdfx/pins.cpp
+++ b/toonz/sources/stdfx/pins.cpp
@@ -468,7 +468,7 @@ static int splitMatrix(double **a, int n, int *index) {
       vv[imax] = vv[j];
     }
     index[j] = imax;
-    if (fabsf(a[j][j]) <= TINY && (j != n - 1)) {
+    if (std::abs(a[j][j]) <= TINY && (j != n - 1)) {
       /*printf("Cazzo, E' singolare %f!\n", a[j][j] );*/
       return imax + 1;
     }
diff --git a/toonz/sources/stdfx/posterizefx.cpp b/toonz/sources/stdfx/posterizefx.cpp
index fcb892c..715a94a 100644
--- a/toonz/sources/stdfx/posterizefx.cpp
+++ b/toonz/sources/stdfx/posterizefx.cpp
@@ -65,7 +65,7 @@ void doPosterize(TRasterPT<PIXEL> ras, int levels) {
       pix->r = (CHANNEL_TYPE)(solarize_lut[(int)(pix->r)]);
       pix->g = (CHANNEL_TYPE)(solarize_lut[(int)(pix->g)]);
       pix->b = (CHANNEL_TYPE)(solarize_lut[(int)(pix->b)]);
-      *pix++;
+      pix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/stdfx/rgbmcutfx.cpp b/toonz/sources/stdfx/rgbmcutfx.cpp
index be812e1..06b5023 100644
--- a/toonz/sources/stdfx/rgbmcutfx.cpp
+++ b/toonz/sources/stdfx/rgbmcutfx.cpp
@@ -93,7 +93,7 @@ void doRGBMCut(TRasterPT<PIXEL> ras, double hi_m, double hi_r, double hi_g,
         pix->b = tcrop((int)pix->b, (int)lo_b, (int)hi_b);
         *pix   = premultiply(*pix);
       }
-      *pix++;
+      pix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/stdfx/saltpeppernoisefx.cpp b/toonz/sources/stdfx/saltpeppernoisefx.cpp
index 3baa53a..5ab42f7 100644
--- a/toonz/sources/stdfx/saltpeppernoisefx.cpp
+++ b/toonz/sources/stdfx/saltpeppernoisefx.cpp
@@ -65,7 +65,7 @@ void doSaltPepperNoise(const TRasterPT<PIXEL> &ras, const double intensity,
         } else if (data >= data2 && data < 0.5)
           pix->r = pix->g = pix->b = pix->m;
       }
-      *pix++;
+      pix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/stdfx/shaderfx.cpp b/toonz/sources/stdfx/shaderfx.cpp
index a427a64..b68b427 100644
--- a/toonz/sources/stdfx/shaderfx.cpp
+++ b/toonz/sources/stdfx/shaderfx.cpp
@@ -310,6 +310,8 @@ Suggestions are welcome as this is a tad beyond ridiculous...
             "This system configuration does not support OpenGL Shader "
             "Programs. Shader Fxs will not be able to render."));
         break;
+      default:
+        break;
       }
 
       sentMsg = true;
@@ -471,6 +473,8 @@ void ShaderFx::initialize() {
       case ShaderInterface::ANGLE_UI:
         param->setMeasureName(l_measureNames[ANGLE]);
         break;
+      default:
+        break;
       }
 
       m_params.push_back(param);
@@ -511,6 +515,8 @@ void ShaderFx::initialize() {
         param->getX()->setMeasureName(l_measureNames[ANGLE]);
         param->getY()->setMeasureName(l_measureNames[ANGLE]);
         break;
+      default:
+        break;
       }
 
       m_params.push_back(param);
@@ -552,6 +558,8 @@ void ShaderFx::initialize() {
                 *boost::unsafe_any_cast<TPixelParamP>(&m_params.back()));
       break;
     }
+    default:
+      break;
     }
   }
 
@@ -780,6 +788,8 @@ void ShaderFx::bindParameters(QOpenGLShaderProgram *program, double frame) {
           (GLfloat)value.m / 255.0f);
       break;
     }
+    default:
+      break;
     }
   }
 }
diff --git a/toonz/sources/stdfx/shaderinterface.cpp b/toonz/sources/stdfx/shaderinterface.cpp
index db1bf90..30e9613 100644
--- a/toonz/sources/stdfx/shaderinterface.cpp
+++ b/toonz/sources/stdfx/shaderinterface.cpp
@@ -509,6 +509,8 @@ void ShaderInterface::Parameter::saveData(TOStream &os) {
     os << (int)m_default.m_rgb[0] << (int)m_default.m_rgb[1]
        << (int)m_default.m_rgb[2];
     break;
+  default:
+    break;
   }
 
   os.closeChild();
@@ -552,6 +554,8 @@ void ShaderInterface::Parameter::saveData(TOStream &os) {
        << m_range[0].m_ivec4[2] << m_range[1].m_ivec4[2]
        << m_range[0].m_ivec4[3] << m_range[1].m_ivec4[3];
     break;
+  default:
+    break;
   }
 
   os.closeChild();
@@ -645,6 +649,8 @@ void ShaderInterface::Parameter::loadData(TIStream &is) {
   case RGB:
     m_default.m_rgb[0] = m_default.m_rgb[1] = m_default.m_rgb[2] = 255;
     break;
+  default:
+    break;
   }
 
   // Attempt loading range from file
@@ -723,6 +729,8 @@ void ShaderInterface::Parameter::loadData(TIStream &is) {
         is >> val, m_default.m_rgb[2] = val;
         break;
       }
+      default:
+        break;
       }
 
       is.closeChild();
@@ -789,6 +797,8 @@ void ShaderInterface::Parameter::loadData(TIStream &is) {
             m_range[0].m_ivec4[2] >> m_range[1].m_ivec4[2] >>
             m_range[0].m_ivec4[3] >> m_range[1].m_ivec4[3];
         break;
+      default:
+        break;
       }
 
       is.closeChild();
diff --git a/toonz/sources/stdfx/solarizefx.cpp b/toonz/sources/stdfx/solarizefx.cpp
index fccf91c..dde92e6 100644
--- a/toonz/sources/stdfx/solarizefx.cpp
+++ b/toonz/sources/stdfx/solarizefx.cpp
@@ -89,7 +89,7 @@ void doSolarize(TRasterPT<PIXEL> ras, double max, int edge) {
       pix->r = (CHANNEL_TYPE)(solarize_lut[(int)(pix->r)]);
       pix->g = (CHANNEL_TYPE)(solarize_lut[(int)(pix->g)]);
       pix->b = (CHANNEL_TYPE)(solarize_lut[(int)(pix->b)]);
-      *pix++;
+      pix++;
     }
   }
   ras->unlock();
diff --git a/toonz/sources/tcleanupper/tcleanupper.cpp b/toonz/sources/tcleanupper/tcleanupper.cpp
index 30f535d..09c121c 100644
--- a/toonz/sources/tcleanupper/tcleanupper.cpp
+++ b/toonz/sources/tcleanupper/tcleanupper.cpp
@@ -275,7 +275,7 @@ static void searchLevelsToCleanup(
             continue;
           }
           int ltype = sl->getType();
-          if (ltype == TZP_XSHLEVEL && sl->getScannedPath() != TFilePath() ||
+          if ((ltype == TZP_XSHLEVEL && sl->getScannedPath() != TFilePath()) ||
               ltype == OVL_XSHLEVEL || ltype == TZI_XSHLEVEL) {
             wstring levelName     = sl->getName();
             levelTable[levelName] = sl;
diff --git a/toonz/sources/tcomposer/tcomposer.cpp b/toonz/sources/tcomposer/tcomposer.cpp
index 08b146b..48eba05 100644
--- a/toonz/sources/tcomposer/tcomposer.cpp
+++ b/toonz/sources/tcomposer/tcomposer.cpp
@@ -799,7 +799,7 @@ int main(int argc, char *argv[]) {
 
     Sw1.start();
 
-    if (!TSystem::doesExistFileOrLevel(srcFilePath)) return false;
+    if (!TSystem::doesExistFileOrLevel(srcFilePath)) return -2;
     ToonzScene *scene = new ToonzScene();
 
     TImageStyle::setCurrentScene(scene);
diff --git a/toonz/sources/tconverter/tconverter.cpp b/toonz/sources/tconverter/tconverter.cpp
index 3a597c6..a133617 100644
--- a/toonz/sources/tconverter/tconverter.cpp
+++ b/toonz/sources/tconverter/tconverter.cpp
@@ -422,7 +422,7 @@ int main(int argc, char *argv[]) {
         exit(1);
       }
 
-      if (!TSystem::doesExistFileOrLevel(tnzFilePath)) return false;
+      if (!TSystem::doesExistFileOrLevel(tnzFilePath)) return -1;
       ToonzScene *scene = new ToonzScene();
       try {
         scene->loadTnzFile(tnzFilePath);
diff --git a/toonz/sources/tnzbase/tscanner/tscanner.cpp b/toonz/sources/tnzbase/tscanner/tscanner.cpp
index 2a3aeb8..7da7f2d 100644
--- a/toonz/sources/tnzbase/tscanner/tscanner.cpp
+++ b/toonz/sources/tnzbase/tscanner/tscanner.cpp
@@ -225,6 +225,8 @@ void TScannerParameters::saveData(TOStream &os) const {
     case RGB24:
       scanTypeString = Rgbcolors;
       break;
+    default:
+      break;
     }
     attr.clear();
     attr["value"] = scanTypeString;
diff --git a/toonz/sources/tnzbase/tscanner/tscannerepson.cpp b/toonz/sources/tnzbase/tscanner/tscannerepson.cpp
index df3e5de..8da4d15 100644
--- a/toonz/sources/tnzbase/tscanner/tscannerepson.cpp
+++ b/toonz/sources/tnzbase/tscanner/tscannerepson.cpp
@@ -73,7 +73,7 @@ static unsigned char NotReady   = 1 << 6;
 
 //-----------------------------------------------------------------------------
 
-#define log
+#define log(_str)
 
 class TScannerExpection final : public TException {
   TString m_scannerMsg;
diff --git a/toonz/sources/tnzext/ExtUtil.cpp b/toonz/sources/tnzext/ExtUtil.cpp
index 2828cc4..69b8274 100644
--- a/toonz/sources/tnzext/ExtUtil.cpp
+++ b/toonz/sources/tnzext/ExtUtil.cpp
@@ -32,12 +32,13 @@ inline bool isWGood(double first, double w, double second, const TStroke *s) {
     return false;
 
   if (s) {
-    if (s->isSelfLoop())
+    if (s->isSelfLoop()) {
       if (first > second) {
         if ((first < w && w <= 1.0) || (0.0 <= w && w < second)) return true;
       } else if (first == second) {
         if (areAlmostEqual(w, first)) return true;
       }
+    }
   }
 
   if (first < w && w < second) return true;
diff --git a/toonz/sources/tnzext/StraightCornerDeformation.cpp b/toonz/sources/tnzext/StraightCornerDeformation.cpp
index 6b9862b..3917b4c 100644
--- a/toonz/sources/tnzext/StraightCornerDeformation.cpp
+++ b/toonz/sources/tnzext/StraightCornerDeformation.cpp
@@ -73,7 +73,7 @@ bool StraightCornerDeformation::check_(const ContextStatus *status) {
   double w   = status->w_;
 
   // check extremes in another way.
-  if (!s->isSelfLoop() && areAlmostEqual(w, 0.0) || areAlmostEqual(w, 1.0)) {
+  if ((!s->isSelfLoop() && areAlmostEqual(w, 0.0)) || areAlmostEqual(w, 1.0)) {
     return isAStraightCorner(s, w, &this->getStraightsList());
   }
 
diff --git a/toonz/sources/tnztools/autofillpli.cpp b/toonz/sources/tnztools/autofillpli.cpp
index c9a51c0..0038a9f 100644
--- a/toonz/sources/tnztools/autofillpli.cpp
+++ b/toonz/sources/tnztools/autofillpli.cpp
@@ -156,12 +156,12 @@ void assignProbs(std::vector<MatchingProbs> &probVector,
 
   probs.m_barycenterProb = tround(1000 * (1 - (delta_pos / delta_pos_max)));
 
-  delta_area = abs(reference.m_area - work.m_area);
+  delta_area = std::abs(reference.m_area - work.m_area);
 
   probs.m_areaProb = tround(
       1000 * (1 - ((double)delta_area / (reference.m_area + work.m_area))));
 
-  delta_per             = abs(reference.m_perimeter - work.m_perimeter);
+  delta_per             = std::abs(reference.m_perimeter - work.m_perimeter);
   probs.m_perimeterProb = tround(
       1000 *
       (1 - ((double)delta_per / (reference.m_perimeter + work.m_perimeter))));
@@ -346,7 +346,7 @@ bool rect_autofill_apply(const TVectorImageP &imgToApply, const TRectD &rect,
       regionsReference[from].m_match = to;
       regionsWork[to].m_styleId      = regionsReference[from].m_styleId;
       TRegion *reg                   = regionsWork[to].m_region;
-      if (reg && (!selective || selective && reg->getStyle() == 0)) {
+      if (reg && (!selective || (selective && reg->getStyle() == 0))) {
         reg->setStyle(regionsWork[to].m_styleId);
         filledRegions = true;
       }
@@ -476,7 +476,7 @@ bool stroke_autofill_apply(const TVectorImageP &imgToApply, TStroke *stroke,
       regionsReference[from].m_match = to;
       regionsWork[to].m_styleId      = regionsReference[from].m_styleId;
       TRegion *reg                   = regionsWork[to].m_region;
-      if (reg && (!selective || selective && reg->getStyle() == 0)) {
+      if (reg && (!selective || (selective && reg->getStyle() == 0))) {
         reg->setStyle(regionsWork[to].m_styleId);
         filledRegions = true;
       }
diff --git a/toonz/sources/tnztools/autofilltlv.cpp b/toonz/sources/tnztools/autofilltlv.cpp
index a854c89..98cebe1 100644
--- a/toonz/sources/tnztools/autofilltlv.cpp
+++ b/toonz/sources/tnztools/autofilltlv.cpp
@@ -22,7 +22,11 @@
 #include "toonz/tscenehandle.h"
 #include "tools/tool.h"*/
 
+#ifndef _WIN32
+#define PRINTF(args...)
+#else
 #define PRINTF
+#endif
 
 struct s_segm {
   int xa, xb, region;
@@ -1010,7 +1014,7 @@ static void assign_prob3(int prob[], int i, int j)
                  BIG_TO_DOUBLE(F_work.array[j].by) / F_work.array[j].npix);
 
   delta_forma_mom =
-      abs(sqrt(delta_momx1 + delta_momy1) - sqrt(delta_momx2 + delta_momy2));
+      std::abs(sqrt(delta_momx1 + delta_momy1) - sqrt(delta_momx2 + delta_momy2));
 
   delta_forma1 = ROUNDP(
       1000 * (((double)F_reference.array[i].per / F_reference.array[i].npix -
diff --git a/toonz/sources/tnztools/cuttertool.cpp b/toonz/sources/tnztools/cuttertool.cpp
index 593aeb6..3cded97 100644
--- a/toonz/sources/tnztools/cuttertool.cpp
+++ b/toonz/sources/tnztools/cuttertool.cpp
@@ -225,38 +225,38 @@ public:
         continue;
       }
 
-      diff = abs(intersection.first - w);
+      diff = std::abs(intersection.first - w);
       if (diff < minDiff) {
         minDiff  = diff;
         nearestW = intersection.first;
       }
 
-      diff = abs(intersection.second - w);
+      diff = std::abs(intersection.second - w);
       if (diff < minDiff) {
         minDiff  = diff;
         nearestW = intersection.second;
       }
 
       if (selfStroke->isSelfLoop()) {
-        diff = abs(1 - intersection.first) + w;
+        diff = std::abs(1 - intersection.first) + w;
         if (diff < minDiff) {
           minDiff  = diff;
           nearestW = intersection.first;
         }
 
-        diff = intersection.first + abs(1 - w);
+        diff = intersection.first + std::abs(1 - w);
         if (diff < minDiff) {
           minDiff  = diff;
           nearestW = intersection.first;
         }
 
-        diff = abs(1 - intersection.second) + w;
+        diff = std::abs(1 - intersection.second) + w;
         if (diff < minDiff) {
           minDiff  = diff;
           nearestW = intersection.second;
         }
 
-        diff = intersection.second + abs(1 - w);
+        diff = intersection.second + std::abs(1 - w);
         if (diff < minDiff) {
           minDiff  = diff;
           nearestW = intersection.second;
@@ -272,20 +272,20 @@ public:
 
       intersect(selfStroke, stroke, intersections, false);
       for (auto &intersection : intersections) {
-        diff = abs(intersection.first - w);
+        diff = std::abs(intersection.first - w);
         if (diff < minDiff) {
           minDiff  = diff;
           nearestW = intersection.first;
         }
 
         if (selfStroke->isSelfLoop()) {
-          diff = abs(1 - intersection.first) + w;
+          diff = std::abs(1 - intersection.first) + w;
           if (diff < minDiff) {
             minDiff  = diff;
             nearestW = intersection.first;
           }
 
-          diff = intersection.first + abs(1 - w);
+          diff = intersection.first + std::abs(1 - w);
           if (diff < minDiff) {
             minDiff  = diff;
             nearestW = intersection.first;
diff --git a/toonz/sources/tnztools/edittool.cpp b/toonz/sources/tnztools/edittool.cpp
index a557a03..3471fdf 100644
--- a/toonz/sources/tnztools/edittool.cpp
+++ b/toonz/sources/tnztools/edittool.cpp
@@ -489,9 +489,9 @@ public:
     if (norm2(a) < eps || norm2(b) < eps) return;
 
     double fx = b.x / a.x;
-    if (fabs(fx) > 1) fx = tsign(fx) * sqrt(abs(fx));
+    if (fabs(fx) > 1) fx = tsign(fx) * sqrt(std::abs(fx));
     double fy = b.y / a.y;
-    if (fabs(fy) > 1) fy = tsign(fy) * sqrt(abs(fy));
+    if (fabs(fy) > 1) fy = tsign(fy) * sqrt(std::abs(fy));
 
     int constraint = m_constraint;
     if (constraint == ScaleConstraints::None && e.isShiftPressed())
diff --git a/toonz/sources/tnztools/edittoolgadgets.cpp b/toonz/sources/tnztools/edittoolgadgets.cpp
index ff06607..eb95383 100644
--- a/toonz/sources/tnztools/edittoolgadgets.cpp
+++ b/toonz/sources/tnztools/edittoolgadgets.cpp
@@ -1713,6 +1713,8 @@ FxGadget *FxGadgetController::allocateGadget(const TParamUIConcept &uiConcept) {
                                      uiConcept.m_params[1]);
     break;
   }
+  default:
+    break;
   }
 
   if (gadget) gadget->setLabel(uiConcept.m_label);
diff --git a/toonz/sources/tnztools/filltool.cpp b/toonz/sources/tnztools/filltool.cpp
index 15c85a8..898a66a 100644
--- a/toonz/sources/tnztools/filltool.cpp
+++ b/toonz/sources/tnztools/filltool.cpp
@@ -1906,7 +1906,7 @@ void FillTool::leftButtonDoubleClick(const TPointD &pos, const TMouseEvent &e) {
 //-----------------------------------------------------------------------------
 
 void FillTool::leftButtonDrag(const TPointD &pos, const TMouseEvent &e) {
-  if (m_fillType.getValue() != NORMALFILL && !m_onion.getValue() ||
+  if ((m_fillType.getValue() != NORMALFILL && !m_onion.getValue()) ||
       (m_colorType.getValue() == AREAS && m_onion.getValue()))
     m_rectFill->leftButtonDrag(pos, e);
   else if (!m_onion.getValue() && !m_frameRange.getValue()) {
diff --git a/toonz/sources/tnztools/fullcolorerasertool.cpp b/toonz/sources/tnztools/fullcolorerasertool.cpp
index 2b66c18..df38811 100644
--- a/toonz/sources/tnztools/fullcolorerasertool.cpp
+++ b/toonz/sources/tnztools/fullcolorerasertool.cpp
@@ -108,7 +108,7 @@ void eraseImage(const TRasterImageP &ri, const TRaster32P &image,
     TPixel32 *outPix    = workRas->pixels(y);
     TPixel32 *outEndPix = outPix + workRas->getLx();
     TPixel32 *inPix     = image->pixels(y);
-    for (outPix; outPix != outEndPix; outPix++, inPix++) {
+    for (; outPix != outEndPix; outPix++, inPix++) {
       if (outPix->m == 0) continue;
       TPixel32 pix = depremultiply(*outPix);
       pix.m =
diff --git a/toonz/sources/tnztools/geometrictool.cpp b/toonz/sources/tnztools/geometrictool.cpp
index f5d271a..bd61eea 100644
--- a/toonz/sources/tnztools/geometrictool.cpp
+++ b/toonz/sources/tnztools/geometrictool.cpp
@@ -1222,7 +1222,7 @@ TPointD Primitive::checkGuideSnapping(TPointD pos) {
     if (vGuideCount) {
       for (int j = 0; j < vGuideCount; j++) {
         double guide        = viewer->getVGuide(j);
-        double tempDistance = abs(guide - pos.y);
+        double tempDistance = std::abs(guide - pos.y);
         if (tempDistance < guideDistance &&
             (distanceToVGuide < 0 || tempDistance < distanceToVGuide)) {
           distanceToVGuide = tempDistance;
@@ -1234,7 +1234,7 @@ TPointD Primitive::checkGuideSnapping(TPointD pos) {
     if (hGuideCount) {
       for (int j = 0; j < hGuideCount; j++) {
         double guide        = viewer->getHGuide(j);
-        double tempDistance = abs(guide - pos.x);
+        double tempDistance = std::abs(guide - pos.x);
         if (tempDistance < guideDistance &&
             (distanceToHGuide < 0 || tempDistance < distanceToHGuide)) {
           distanceToHGuide = tempDistance;
@@ -1244,8 +1244,8 @@ TPointD Primitive::checkGuideSnapping(TPointD pos) {
       }
     }
     if (useGuides && m_param->m_foundSnap) {
-      double currYDistance = abs(m_param->m_snapPoint.y - pos.y);
-      double currXDistance = abs(m_param->m_snapPoint.x - pos.x);
+      double currYDistance = std::abs(m_param->m_snapPoint.y - pos.y);
+      double currXDistance = std::abs(m_param->m_snapPoint.x - pos.x);
       double hypotenuse =
           sqrt(pow(currYDistance, 2.0) + pow(currXDistance, 2.0));
       if ((distanceToVGuide >= 0 && distanceToVGuide < hypotenuse) ||
diff --git a/toonz/sources/tnztools/pinchtool.cpp b/toonz/sources/tnztools/pinchtool.cpp
index 55b5d53..81c4167 100644
--- a/toonz/sources/tnztools/pinchtool.cpp
+++ b/toonz/sources/tnztools/pinchtool.cpp
@@ -463,8 +463,8 @@ void PinchTool::mouseMove(const TPointD &pos, const TMouseEvent &event) {
   m_curr                = pos;
 
   const int pixelRange = 3;
-  if (abs(m_lastMouseEvent.m_pos.x - event.m_pos.x) < pixelRange &&
-      abs(m_lastMouseEvent.m_pos.y - event.m_pos.y) < pixelRange &&
+  if (std::abs(m_lastMouseEvent.m_pos.x - event.m_pos.x) < pixelRange &&
+      std::abs(m_lastMouseEvent.m_pos.y - event.m_pos.y) < pixelRange &&
       m_lastMouseEvent.getModifiersMask() == event.getModifiersMask())
     return;
 
diff --git a/toonz/sources/tnztools/pumptool.cpp b/toonz/sources/tnztools/pumptool.cpp
index 5c2de43..2bf1728 100644
--- a/toonz/sources/tnztools/pumptool.cpp
+++ b/toonz/sources/tnztools/pumptool.cpp
@@ -198,18 +198,22 @@ void PumpTool::draw() {
         double len = stroke->getLength(w);
 
         double len1 = len - actionLen;
-        if (len1 < 0)
-          if (stroke->isSelfLoop())
+        if (len1 < 0) {
+          if (stroke->isSelfLoop()) {
             len1 += totalLen;
-          else
+          } else {
             len1 = 0;
+	  }
+	}
 
         double len2 = len + actionLen;
-        if (len2 > totalLen)
-          if (stroke->isSelfLoop())
+        if (len2 > totalLen) {
+          if (stroke->isSelfLoop()) {
             len2 -= totalLen;
-          else
+          } else {
             len2 = totalLen;
+	  }
+	}
 
         w1 = stroke->getParameterAtLength(len1);
         w2 = stroke->getParameterAtLength(len2);
diff --git a/toonz/sources/tnztools/rulertool.cpp b/toonz/sources/tnztools/rulertool.cpp
index 6acf77a..98f1b42 100644
--- a/toonz/sources/tnztools/rulertool.cpp
+++ b/toonz/sources/tnztools/rulertool.cpp
@@ -301,7 +301,7 @@ TPointD RulerTool::getHVCoordinatedPos(TPointD p, TPointD centerPos) {
     outPoint.y = p.y;
   } else if (degree < -22.5) /*--右斜め下--*/
   {
-    if (abs(vec.x) > abs(vec.y))
+    if (std::abs(vec.x) > std::abs(vec.y))
       outPoint = centerPos + TPointD(-vec.y, vec.y);
     else
       outPoint = centerPos + TPointD(vec.x, -vec.x);
@@ -311,7 +311,7 @@ TPointD RulerTool::getHVCoordinatedPos(TPointD p, TPointD centerPos) {
     outPoint.y = centerPos.y;
   } else if (degree < 67.5) /*--右斜め上--*/
   {
-    if (abs(vec.x) > abs(vec.y))
+    if (std::abs(vec.x) > std::abs(vec.y))
       outPoint = centerPos + TPointD(vec.y, vec.y);
     else
       outPoint = centerPos + TPointD(vec.x, vec.x);
diff --git a/toonz/sources/tnztools/screenpicker.cpp b/toonz/sources/tnztools/screenpicker.cpp
index 1f3a679..c080e37 100644
--- a/toonz/sources/tnztools/screenpicker.cpp
+++ b/toonz/sources/tnztools/screenpicker.cpp
@@ -47,7 +47,10 @@ void ScreenPicker::event(QWidget *widget, QEvent *e) {
 
   case QEvent::MouseButtonRelease:
     mouseReleaseEvent(widget, static_cast<QMouseEvent *>(e));
-  };
+
+  default:
+    break;
+  }
 }
 
 //------------------------------------------------------------------
diff --git a/toonz/sources/tnztools/selectiontool.cpp b/toonz/sources/tnztools/selectiontool.cpp
index 48c302a..a911fc5 100644
--- a/toonz/sources/tnztools/selectiontool.cpp
+++ b/toonz/sources/tnztools/selectiontool.cpp
@@ -59,7 +59,7 @@ int tminPoint(std::vector<TPointD> points, bool isX) {
   TPointD p = points[0];
   for (i = 1; i < (int)points.size(); i++) {
     TPointD nextP = points[i];
-    if (isX && p.x < nextP.x || !isX && p.y < nextP.y) continue;
+    if ((isX && p.x < nextP.x) || (!isX && p.y < nextP.y)) continue;
     index = i;
   }
   return index;
@@ -1024,7 +1024,7 @@ void SelectionTool::updateAction(TPointD pos, const TMouseEvent &e) {
   m_selectedPoint = NONE;
   if ((isLevelType() || isSelectedFramesType()) && !isSameStyleType()) {
     m_what = Inside;
-    ToolCursor::LevelSelectCursor;
+    m_cursorId = ToolCursor::LevelSelectCursor;
   }
 
   if (shift) return;
diff --git a/toonz/sources/tnztools/toonzvectorbrushtool.cpp b/toonz/sources/tnztools/toonzvectorbrushtool.cpp
index cb929bc..cd5f55f 100644
--- a/toonz/sources/tnztools/toonzvectorbrushtool.cpp
+++ b/toonz/sources/tnztools/toonzvectorbrushtool.cpp
@@ -632,7 +632,7 @@ void ToonzVectorBrushTool::onActivate() {
 
 void ToonzVectorBrushTool::onDeactivate() {
   /*---
-   * �h���b�O���Ƀc�[�����؂�ւ�����ꍇ�ɔ����AonDeactivate�ɂ�MouseRelease�Ɠ����������s��
+   * ドラッグ中にツールが切り替わった場合に備え、onDeactivateにもMouseReleaseと同じ処理を行う
    * ---*/
 
   // End current stroke.
@@ -714,7 +714,7 @@ void ToonzVectorBrushTool::leftButtonDown(const TPointD &pos,
                          ? computeThickness(e.m_pressure, m_thickness, m_isPath)
                          : m_thickness.getValue().second * 0.5;
 
-  /*--- �X�g���[�N�̍ŏ���Max�T�C�Y�̉~���`����Ă��܂��s���h�~���� ---*/
+  /*--- ストロークの最初にMaxサイズの円が描かれてしまう不具合を防止する ---*/
   if (m_pressure.getValue() && e.m_pressure == 1.0)
     thickness = m_thickness.getValue().first * 0.5;
   m_currThickness = thickness;
@@ -1419,7 +1419,7 @@ void ToonzVectorBrushTool::checkGuideSnapping(bool beforeMousePress,
     if (vGuideCount) {
       for (int j = 0; j < vGuideCount; j++) {
         double guide        = viewer->getVGuide(j);
-        double tempDistance = abs(guide - m_mousePos.y);
+        double tempDistance = std::abs(guide - m_mousePos.y);
         if (tempDistance < guideDistance &&
             (distanceToVGuide < 0 || tempDistance < distanceToVGuide)) {
           distanceToVGuide = tempDistance;
@@ -1431,7 +1431,7 @@ void ToonzVectorBrushTool::checkGuideSnapping(bool beforeMousePress,
     if (hGuideCount) {
       for (int j = 0; j < hGuideCount; j++) {
         double guide        = viewer->getHGuide(j);
-        double tempDistance = abs(guide - m_mousePos.x);
+        double tempDistance = std::abs(guide - m_mousePos.x);
         if (tempDistance < guideDistance &&
             (distanceToHGuide < 0 || tempDistance < distanceToHGuide)) {
           distanceToHGuide = tempDistance;
@@ -1441,8 +1441,8 @@ void ToonzVectorBrushTool::checkGuideSnapping(bool beforeMousePress,
       }
     }
     if (useGuides && foundSnap) {
-      double currYDistance = abs(snapPoint.y - m_mousePos.y);
-      double currXDistance = abs(snapPoint.x - m_mousePos.x);
+      double currYDistance = std::abs(snapPoint.y - m_mousePos.y);
+      double currXDistance = std::abs(snapPoint.x - m_mousePos.x);
       double hypotenuse =
           sqrt(pow(currYDistance, 2.0) + pow(currXDistance, 2.0));
       if ((distanceToVGuide >= 0 && distanceToVGuide < hypotenuse) ||
@@ -1473,7 +1473,7 @@ void ToonzVectorBrushTool::checkGuideSnapping(bool beforeMousePress,
 //-------------------------------------------------------------------------------------------------------------
 
 void ToonzVectorBrushTool::draw() {
-  /*--�V���[�g�J�b�g�ł̃c�[���؂�ւ����ɐԓ_���`�����̂�h�~����--*/
+  /*--ショートカットでのツール切り替え時に赤点が描かれるのを防止する--*/
   if (m_minThick == 0 && m_maxThick == 0 &&
       !Preferences::instance()->getShow0ThickLines())
     return;
@@ -1790,7 +1790,7 @@ void ToonzVectorBrushTool::loadLastBrush() {
 }
 
 //------------------------------------------------------------------
-/*!	Brush�APaintBrush�AEraserTool��PencilMode�̂Ƃ���True��Ԃ�
+/*!	Brush、PaintBrush、EraserToolがPencilModeのときにTrueを返す
  */
 bool ToonzVectorBrushTool::isPencilModeActive() { return false; }
 
diff --git a/toonz/sources/tnztools/trackertool.cpp b/toonz/sources/tnztools/trackertool.cpp
index 6a6f449..8a37935 100644
--- a/toonz/sources/tnztools/trackertool.cpp
+++ b/toonz/sources/tnztools/trackertool.cpp
@@ -112,6 +112,7 @@ hook->setAPos(fid, hook->getBPos(fid));
 }
     makeCurrent();
 return TDataP(); */
+    return (NULL);
   }
 
   TDataP pasteData(const TDataP &data) { return TDataP(); }
diff --git a/toonz/sources/tnztools/typetool.cpp b/toonz/sources/tnztools/typetool.cpp
index ff198d6..d495d25 100644
--- a/toonz/sources/tnztools/typetool.cpp
+++ b/toonz/sources/tnztools/typetool.cpp
@@ -1522,7 +1522,7 @@ void TypeTool::deleteKey() {
 
 bool TypeTool::keyDown(QKeyEvent *event) {
   QString text = event->text();
-  if ((event->modifiers() & Qt::ShiftModifier)) text.toUpper();
+  if ((event->modifiers() & Qt::ShiftModifier)) text = text.toUpper();
 
   if (QKeySequence(event->key() + event->modifiers()) == QKeySequence::Paste) {
     QClipboard *clipboard     = QApplication::clipboard();
diff --git a/toonz/sources/toonz/adjustthicknesspopup.cpp b/toonz/sources/toonz/adjustthicknesspopup.cpp
index 7296c5d..9c170d9 100644
--- a/toonz/sources/toonz/adjustthicknesspopup.cpp
+++ b/toonz/sources/toonz/adjustthicknesspopup.cpp
@@ -465,6 +465,8 @@ AdjustThicknessPopup::SelectionData::SelectionData(const TSelection *sel)
         case LevelSelection::BOUNDARY_STROKES:
           m_this->m_contentType = BOUNDARIES;
           break;
+        default:
+          break;
         }
 
         // Discriminate frames selection modes
@@ -485,6 +487,8 @@ AdjustThicknessPopup::SelectionData::SelectionData(const TSelection *sel)
           m_this->m_frameIdxs = std::move(s);
           break;
         }
+        default:
+          break;
         }
 
         resetIfInvalid();
diff --git a/toonz/sources/toonz/canvassizepopup.cpp b/toonz/sources/toonz/canvassizepopup.cpp
index a97a60c..e6ea76a 100644
--- a/toonz/sources/toonz/canvassizepopup.cpp
+++ b/toonz/sources/toonz/canvassizepopup.cpp
@@ -250,6 +250,8 @@ void PeggingWidget::createButton(QPushButton **button,
     pix = m_topRightPix.transformed(QMatrix().rotate(90),
                                     Qt::SmoothTransformation);
     break;
+  default:
+    break;
   }
   (*button)->setIcon(pix);
 }
diff --git a/toonz/sources/toonz/castviewer.cpp b/toonz/sources/toonz/castviewer.cpp
index 44ad81c..affcce6 100644
--- a/toonz/sources/toonz/castviewer.cpp
+++ b/toonz/sources/toonz/castviewer.cpp
@@ -298,11 +298,11 @@ void CastTreeViewer::dragMoveEvent(QDragMoveEvent *event) {
         (scene->isUntitled()) ? L"Untitled" : scene->getSceneName();
     rootName = rootName.fromStdWString(name);
   }
-  if (m_dropTargetItem &&
+  if ((m_dropTargetItem &&
           m_dropTargetItem->data(0, Qt::DisplayRole).toString() ==
-              AudioFolderName ||
-      m_dropFilePath != TFilePath() &&
-          m_dropTargetItem->data(0, Qt::DisplayRole).toString() == rootName)
+              AudioFolderName) ||
+      (m_dropFilePath != TFilePath() &&
+          m_dropTargetItem->data(0, Qt::DisplayRole).toString() == rootName))
     m_dropTargetItem = 0;
 
   if (!m_dropTargetItem)
diff --git a/toonz/sources/toonz/cleanuppopup.cpp b/toonz/sources/toonz/cleanuppopup.cpp
index aeb3726..0311550 100644
--- a/toonz/sources/toonz/cleanuppopup.cpp
+++ b/toonz/sources/toonz/cleanuppopup.cpp
@@ -456,7 +456,7 @@ void CleanupPopup::buildCleanupList() {
           levelsList.push_back(sl);
         }
         /*---TFrameIdを登録---*/
-        it->second.insert(cell.getFrameId()).second;
+        it->second.insert(cell.getFrameId());
       }
     }
   }
@@ -482,7 +482,7 @@ void CleanupPopup::buildCleanupList() {
           levelsList.push_back(sl);
         }
         /*---TFrameIdを登録---*/
-        it->second.insert(cell.getFrameId()).second;
+        it->second.insert(cell.getFrameId());
       }
     }
   }
@@ -563,8 +563,8 @@ bool CleanupPopup::analyzeCleanupList() {
       }
 
       // Prompt user for file conflict resolution
-      switch (clt.m_resolution =
-                  Resolution(m_overwriteDialog->execute(&clt.m_outputPath))) {
+      clt.m_resolution = Resolution(m_overwriteDialog->execute(&clt.m_outputPath));
+      switch (clt.m_resolution) {
       case CANCEL:
         return false;
 
@@ -591,6 +591,8 @@ bool CleanupPopup::analyzeCleanupList() {
           m_levelAlreadyExists[sl] = false;
           continue;
         }
+      default:
+        break;
       }
 
       TLevelP level(0);  // Current level info. Yeah the init is a shame... :(
diff --git a/toonz/sources/toonz/columncommand.cpp b/toonz/sources/toonz/columncommand.cpp
index 6195b92..f53f011 100644
--- a/toonz/sources/toonz/columncommand.cpp
+++ b/toonz/sources/toonz/columncommand.cpp
@@ -1260,9 +1260,9 @@ public:
        * -*/
       if (m_target == TARGET_UPPER && i < cc) continue;
 
-      bool negate = m_target == TARGET_CURRENT && cc != i ||
-                    m_target == TARGET_OTHER && cc == i ||
-                    m_target == TARGET_UPPER && cc == i;
+      bool negate = ((m_target == TARGET_CURRENT && cc != i) ||
+                     (m_target == TARGET_OTHER && cc == i) ||
+                     (m_target == TARGET_UPPER && cc == i));
 
       int cmd = m_cmd;
 
diff --git a/toonz/sources/toonz/comboviewerpane.cpp b/toonz/sources/toonz/comboviewerpane.cpp
index ee66a47..e10b21c 100644
--- a/toonz/sources/toonz/comboviewerpane.cpp
+++ b/toonz/sources/toonz/comboviewerpane.cpp
@@ -827,7 +827,7 @@ void ComboViewerPanel::playAudioFrame(int frame) {
                 ->getProperties()
                 ->getOutputProperties()
                 ->getFrameRate();
-    m_samplesPerFrame = m_sound->getSampleRate() / abs(m_fps);
+    m_samplesPerFrame = m_sound->getSampleRate() / std::abs(m_fps);
   }
   if (!m_sound) return;
   m_viewerFps = m_flipConsole->getCurrentFps();
diff --git a/toonz/sources/toonz/dvdirtreeview.cpp b/toonz/sources/toonz/dvdirtreeview.cpp
index 1591b26..7366a35 100644
--- a/toonz/sources/toonz/dvdirtreeview.cpp
+++ b/toonz/sources/toonz/dvdirtreeview.cpp
@@ -1475,7 +1475,7 @@ DvItemListModel::Status DvDirTreeView::getItemVersionControlStatus(
   SVNStatus s = node->getVersionControlStatus(name);
   if (s.m_path == name) {
     if (s.m_item == "missing" ||
-        s.m_item == "none" && s.m_repoStatus == "added")
+        (s.m_item == "none" && s.m_repoStatus == "added"))
       return DvItemListModel::VC_Missing;
     if (s.m_item == "unversioned") return DvItemListModel::VC_Unversioned;
     // If, for some errors, there is some item added locally but not committed
@@ -1535,7 +1535,7 @@ DvItemListModel::Status DvDirTreeView::getItemVersionControlStatus(
       TFileStatus fs(node->getPath() + levelNames.at(i).toStdWString());
 
       if (s.m_item == "missing" ||
-          s.m_item == "none" && s.m_repoStatus == "added")
+          (s.m_item == "none" && s.m_repoStatus == "added"))
         missingCount++;
       else if (s.m_item == "modified")
         modifiedCount++;
diff --git a/toonz/sources/toonz/dvitemview.cpp b/toonz/sources/toonz/dvitemview.cpp
index c5c0b96..c21252b 100644
--- a/toonz/sources/toonz/dvitemview.cpp
+++ b/toonz/sources/toonz/dvitemview.cpp
@@ -307,6 +307,9 @@ int DvItemListModel::compareData(DataType dataType, int firstIndex,
 
   case VersionControlStatus:
     return firstValue.toInt() < secondValue.toInt();
+
+  default:
+    break;
   }
 
   return 0;
@@ -818,6 +821,8 @@ void DvItemViewerPanel::setVisibility(DvItemListModel::DataType dataType,
   case DvItemListModel::VersionControlStatus:
     BrowserVersionControlStatusisVisible = value;
     break;
+  default:
+    break;
   }
 }
 
diff --git a/toonz/sources/toonz/filebrowsermodel.cpp b/toonz/sources/toonz/filebrowsermodel.cpp
index 7b6bd1f..1021323 100644
--- a/toonz/sources/toonz/filebrowsermodel.cpp
+++ b/toonz/sources/toonz/filebrowsermodel.cpp
@@ -411,7 +411,7 @@ QList<TFilePath> DvDirVersionControlNode::getMissingFiles() const {
   while (i != m_statusMap.constEnd()) {
     SVNStatus s = i.value();
     if (s.m_item == "missing" ||
-        s.m_item == "none" && s.m_repoStatus == "added") {
+        (s.m_item == "none" && s.m_repoStatus == "added")) {
       TFilePath path(getPath() + TFilePath(s.m_path.toStdWString()));
       std::string dots = path.getDots();
       if (dots != "") {
@@ -433,7 +433,7 @@ QStringList DvDirVersionControlNode::getMissingFiles(
   for (; i != m_statusMap.constEnd(); i++) {
     SVNStatus s = i.value();
     if (s.m_item == "missing" ||
-        s.m_item == "none" && s.m_repoStatus == "added") {
+        (s.m_item == "none" && s.m_repoStatus == "added")) {
       TFilePath path(s.m_path.toStdWString());
       if (!filter.exactMatch(
               QString::fromStdWString(path.withoutParentDir().getWideString())))
diff --git a/toonz/sources/toonz/filebrowserpopup.cpp b/toonz/sources/toonz/filebrowserpopup.cpp
index 5661738..4f8bf1e 100644
--- a/toonz/sources/toonz/filebrowserpopup.cpp
+++ b/toonz/sources/toonz/filebrowserpopup.cpp
@@ -189,7 +189,9 @@ void FileBrowserPopup::addFilterType(const QString &type) {
 //-----------------------------------------------------------------------------
 
 void FileBrowserPopup::setFileMode(bool isDirectoryOnly) {
-  if (m_isDirectoryOnly = isDirectoryOnly) {
+
+  m_isDirectoryOnly = isDirectoryOnly;
+  if (isDirectoryOnly) {
     m_nameFieldLabel->setText(tr("Folder name:"));
     connect(m_browser, SIGNAL(treeFolderChanged(const TFilePath &)), this,
             SLOT(onFilePathClicked(const TFilePath &)));
@@ -2133,7 +2135,7 @@ bool ReplaceParentDirectoryPopup::execute() {
       std::vector<TFrameId> frames;
       sl->getFids(frames);
       std::vector<TFrameId>::iterator f_it = frames.begin();
-      for (f_it; f_it != frames.end(); f_it++)
+      for (; f_it != frames.end(); f_it++)
         IconGenerator::instance()->invalidate(sl, *f_it);
 
       somethingChanged = true;
diff --git a/toonz/sources/toonz/filmstripcommand.cpp b/toonz/sources/toonz/filmstripcommand.cpp
index c768bab..9f04e36 100644
--- a/toonz/sources/toonz/filmstripcommand.cpp
+++ b/toonz/sources/toonz/filmstripcommand.cpp
@@ -629,7 +629,7 @@ public:
           ToonzScene *scene = TApp::instance()->getCurrentScene()->getScene();
           if (scene) {
             TCamera *camera = scene->getCurrentCamera();
-            TPointD dpi = dpi = camera->getDpi();
+            TPointD dpi = camera->getDpi();
             dpiX              = dpi.x;
             dpiY              = dpi.y;
           } else
diff --git a/toonz/sources/toonz/filmstripselection.cpp b/toonz/sources/toonz/filmstripselection.cpp
index 663d98a..a28e09e 100644
--- a/toonz/sources/toonz/filmstripselection.cpp
+++ b/toonz/sources/toonz/filmstripselection.cpp
@@ -65,7 +65,7 @@ void TFilmstripSelection::enableCommands() {
       sl->getSimpleLevel()->getFirstFid(), false);
 
   bool isNotEditableFullColorLevel =
-      (type == OVL_XSHLEVEL && path.getFrame() == TFrameId::NO_FRAME ||
+      ((type == OVL_XSHLEVEL && path.getFrame() == TFrameId::NO_FRAME) ||
        (ri && ri->isScanBW()));
 
   if (doEnable && !isNotEditableFullColorLevel) {
diff --git a/toonz/sources/toonz/flipbook.cpp b/toonz/sources/toonz/flipbook.cpp
index 4668097..412efa4 100644
--- a/toonz/sources/toonz/flipbook.cpp
+++ b/toonz/sources/toonz/flipbook.cpp
@@ -504,7 +504,7 @@ void LoadImagesPopup::onFilePathClicked(const TFilePath &fp) {
   if (!level || level->getFrameCount() == 0) goto clear;
 
   it = level->begin();
-  m_to, m_from = it->first.getNumber();
+  m_to = m_from = it->first.getNumber();
 
   for (; it != level->end(); ++it) m_to = it->first.getNumber();
 
@@ -811,6 +811,8 @@ void FlipBook::onButtonPressed(FlipConsole::EGadget button) {
   case FlipConsole::eSave:
     saveImages();
     break;
+  default:
+    break;
   }
 }
 
@@ -2237,7 +2239,7 @@ FlipBook *viewFile(const TFilePath &path, int from, int to, int step,
   if (path.getType() == "scr") return NULL;
 
   // Avi and movs may be viewed by an external viewer, depending on preferences
-  if (path.getType() == "mov" || path.getType() == "avi" && !flipbook) {
+  if ((path.getType() == "mov" || path.getType() == "avi") && !flipbook) {
     QString str;
     QSettings().value("generatedMovieViewEnabled", str);
     if (str.toInt() != 0) {
diff --git a/toonz/sources/toonz/frameheadgadget.cpp b/toonz/sources/toonz/frameheadgadget.cpp
index c3dedd0..1e799a8 100644
--- a/toonz/sources/toonz/frameheadgadget.cpp
+++ b/toonz/sources/toonz/frameheadgadget.cpp
@@ -140,7 +140,7 @@ void FrameHeadGadget::drawOnionSkinSelection(QPainter &p,
     if (i > 0 || mos > 0) {
       int ya = y;
       int yb;
-      if (i == 0 || mos > 0 && osMask.getMos(i - 1) < 0) {
+      if (i == 0 || (mos > 0 && osMask.getMos(i - 1) < 0)) {
         ya = index2y(currentRow) + 10;
         yb = index2y(currentRow + mos) + 4;
       } else
@@ -177,7 +177,7 @@ bool FrameHeadGadget::eventFilter(QObject *obj, QEvent *e) {
     int x                   = mouseEvent->pos().x();
     int y                   = mouseEvent->pos().y() - index2y(frame);
 
-    if (x > 24 || x > 12 && frame != currentFrame) return false;
+    if (x > 24 || (x > 12 && frame != currentFrame)) return false;
     if (y < 12) {
       bool isMosArea = x < 6;
       // click nel quadratino bianco.
@@ -206,7 +206,7 @@ bool FrameHeadGadget::eventFilter(QObject *obj, QEvent *e) {
     int currentFrame        = getCurrentFrame();
     int x                   = mouseEvent->pos().x();
     int y                   = mouseEvent->pos().y() - index2y(frame);
-    if (x > 24 || x > 12 && frame != currentFrame) return false;
+    if (x > 24 || (x > 12 && frame != currentFrame)) return false;
     if (mouseEvent->button() == Qt::RightButton) return false;
     if (x < 12 && y < 12 && frame == currentFrame &&
         m_buttonPressCellIndex == frame) {
diff --git a/toonz/sources/toonz/keyframemover.cpp b/toonz/sources/toonz/keyframemover.cpp
index efdb2f5..a38c753 100644
--- a/toonz/sources/toonz/keyframemover.cpp
+++ b/toonz/sources/toonz/keyframemover.cpp
@@ -213,7 +213,7 @@ bool KeyframeMover::moveKeyframes(
     } else if (m_qualifiers & eInsertKeyframes) {
       int s                           = r;
       TStageObject::Keyframe keyframe = stObj->getKeyframe(r);
-      if (!m_qualifiers & eCopyKeyframes) stObj->removeKeyframeWithoutUndo(r);
+      if (!(m_qualifiers & eCopyKeyframes)) stObj->removeKeyframeWithoutUndo(r);
       std::set<int> keyframeToShift;
       while (stObj->isKeyframe(s + dr) && s + dr != r) {
         keyframeToShift.insert(s + dr);
diff --git a/toonz/sources/toonz/levelcommand.cpp b/toonz/sources/toonz/levelcommand.cpp
index ab63c22..9abd2a4 100644
--- a/toonz/sources/toonz/levelcommand.cpp
+++ b/toonz/sources/toonz/levelcommand.cpp
@@ -189,7 +189,7 @@ bool loadFids(const TFilePath &path, TXshSimpleLevel *sl,
   if (!level || level->getFrameCount() == 0) return false;
   TLevel::Iterator levelIt         = level->begin();
   bool almostOneUnpaintedFidLoaded = false;
-  for (levelIt; levelIt != level->end(); ++levelIt) {
+  for (; levelIt != level->end(); ++levelIt) {
     TFrameId fid                          = levelIt->first;
     std::set<TFrameId>::const_iterator it = selectedFids.find(fid);
     if (it == selectedFids.end()) continue;
diff --git a/toonz/sources/toonz/levelsettingspopup.cpp b/toonz/sources/toonz/levelsettingspopup.cpp
index af3684d..f50fb5f 100644
--- a/toonz/sources/toonz/levelsettingspopup.cpp
+++ b/toonz/sources/toonz/levelsettingspopup.cpp
@@ -279,6 +279,8 @@ private:
     case WhiteTransp:
       setWhiteTransp(value.toBool());
       break;
+    default:
+      break;
     }
     // This signal is for updating the level settings
     TApp::instance()->getCurrentScene()->notifySceneChanged();
diff --git a/toonz/sources/toonz/matchlinecommand.cpp b/toonz/sources/toonz/matchlinecommand.cpp
index d1156b3..6b33ff9 100644
--- a/toonz/sources/toonz/matchlinecommand.cpp
+++ b/toonz/sources/toonz/matchlinecommand.cpp
@@ -101,7 +101,7 @@ MergeCmappedDialog::MergeCmappedDialog(TFilePath &levelPath)
 //    MergeColumns  command
 //*****************************************************************************
 
-bool isVectorColumn(const std::set<int> &columns) {
+static bool isVectorColumn(const std::set<int> &columns) {
   TXsheet *xsh = TApp::instance()->getCurrentXsheet()->getXsheet();
   std::set<int>::const_iterator column = columns.begin();
   int start, end;
diff --git a/toonz/sources/toonz/sceneviewer.cpp b/toonz/sources/toonz/sceneviewer.cpp
index ec85ddd..0168255 100644
--- a/toonz/sources/toonz/sceneviewer.cpp
+++ b/toonz/sources/toonz/sceneviewer.cpp
@@ -1116,7 +1116,7 @@ void SceneViewer::hideEvent(QHideEvent *) {
 
   disconnect(app, SIGNAL(tabletLeft()), this, SLOT(resetTabletStatus()));
 
-  if (!m_stopMotion == NULL) {
+  if (m_stopMotion) {
     disconnect(m_stopMotion, SIGNAL(newImageReady()), this,
                SLOT(onNewStopMotionImageReady()));
     disconnect(m_stopMotion, SIGNAL(liveViewStopped()), this,
@@ -1526,7 +1526,7 @@ void SceneViewer::drawPreview() {
   }
 
   if (!previewer->isFrameReady(row) ||
-      app->getCurrentFrame()->isPlaying() && previewer->isBusy()) {
+      (app->getCurrentFrame()->isPlaying() && previewer->isBusy())) {
     glColor3d(1, 0, 0);
 
     tglDrawRect(frameRect);
@@ -1560,8 +1560,8 @@ void SceneViewer::drawOverlay() {
   if (!m_drawCameraTest) {
     // draw grid & guides
     if (viewGuideToggle.getStatus() &&
-        (m_vRuler && m_vRuler->getGuideCount() ||
-         m_hRuler && m_hRuler->getGuideCount())) {
+        ((m_vRuler && m_vRuler->getGuideCount()) ||
+         (m_hRuler && m_hRuler->getGuideCount()))) {
       glPushMatrix();
       tglMultMatrix(getViewMatrix());
       ViewerDraw::drawGridAndGuides(
@@ -2374,16 +2374,18 @@ void SceneViewer::zoomQt(const QPoint &center, double factor) {
       TAffine &viewAff = m_viewAff[i];
       double scale2    = fabs(viewAff.det());
       if ((scale2 < 100000 || factor < 1) &&
-          (scale2 > 0.001 * 0.05 || factor > 1))
-        if (i == m_viewMode)
+          (scale2 > 0.001 * 0.05 || factor > 1)) {
+        if (i == m_viewMode) {
           // viewAff = TTranslation(delta) * TScale(factor) *
           // TTranslation(-delta) * viewAff;
           setViewMatrix(TTranslation(delta) * TScale(factor) *
                             TTranslation(-delta) * viewAff,
                         i);
-        else
+        } else {
           // viewAff = TScale(factor) * viewAff;
           setViewMatrix(TScale(factor) * viewAff, i);
+	}
+      }
     }
   }
 
diff --git a/toonz/sources/toonz/sceneviewerevents.cpp b/toonz/sources/toonz/sceneviewerevents.cpp
index 20cf63c..f64c80c 100644
--- a/toonz/sources/toonz/sceneviewerevents.cpp
+++ b/toonz/sources/toonz/sceneviewerevents.cpp
@@ -235,6 +235,8 @@ void SceneViewer::onButtonPressed(FlipConsole::EGadget button) {
   case FlipConsole::eResetView:
     resetSceneViewer();
     break;
+  default:
+    break;
   }
 }
 
@@ -499,11 +501,11 @@ void SceneViewer::onMove(const TMouseEvent &event) {
   // if the "compare with snapshot" mode is activated, change the mouse cursor
   // on the border handle
   if (m_visualSettings.m_doCompare && isPreviewEnabled()) {
-    if (abs(curPos.x() - width() * m_compareSettings.m_compareX) < 20) {
+    if (std::abs(curPos.x() - width() * m_compareSettings.m_compareX) < 20) {
       cursorSet = true;
       setToolCursor(this, ToolCursor::ScaleHCursor);
-    } else if (abs((height() - curPos.y()) -
-                   height() * m_compareSettings.m_compareY) < 20) {
+    } else if (std::abs((height() - curPos.y()) -
+                         height() * m_compareSettings.m_compareY) < 20) {
       cursorSet = true;
       setToolCursor(this, ToolCursor::ScaleVCursor);
     }
@@ -703,7 +705,7 @@ void SceneViewer::onPress(const TMouseEvent &event) {
     if (!PreviewSubCameraManager::instance()->mousePressEvent(this, event))
       return;
   } else if (m_mouseButton == Qt::LeftButton && m_visualSettings.m_doCompare) {
-    if (abs(m_pos.x() - width() * m_compareSettings.m_compareX) < 20) {
+    if (std::abs(m_pos.x() - width() * m_compareSettings.m_compareX) < 20) {
       m_compareSettings.m_dragCompareX = true;
       m_compareSettings.m_dragCompareY = false;
       m_compareSettings.m_compareY     = ImagePainter::DefaultCompareValue;
@@ -711,8 +713,8 @@ void SceneViewer::onPress(const TMouseEvent &event) {
       m_tabletEvent = false;
       m_tabletState = None;
       return;
-    } else if (abs((height() - m_pos.y()) -
-                   height() * m_compareSettings.m_compareY) < 20) {
+    } else if (std::abs((height() - m_pos.y()) -
+                         height() * m_compareSettings.m_compareY) < 20) {
       m_compareSettings.m_dragCompareY = true;
       m_compareSettings.m_dragCompareX = false;
       m_compareSettings.m_compareX     = ImagePainter::DefaultCompareValue;
@@ -1036,7 +1038,7 @@ void SceneViewer::gestureEvent(QGestureEvent *e) {
         TPointD center = aff * TPointD(0, 0);
         if (!m_rotating && !m_zooming) {
           m_rotationDelta += rotationDelta;
-          double absDelta = abs(m_rotationDelta);
+          double absDelta = std::abs(m_rotationDelta);
           if (absDelta >= 10) {
             m_rotating = true;
           }
@@ -1310,7 +1312,7 @@ public:
 
 bool changeFrameSkippingHolds(QKeyEvent *e) {
   if ((e->modifiers() & Qt::ShiftModifier) == 0 ||
-      e->key() != Qt::Key_Down && e->key() != Qt::Key_Up)
+      (e->key() != Qt::Key_Down && e->key() != Qt::Key_Up))
     return false;
   TApp *app        = TApp::instance();
   TFrameHandle *fh = app->getCurrentFrame();
diff --git a/toonz/sources/toonz/subcameramanager.cpp b/toonz/sources/toonz/subcameramanager.cpp
index 59a0199..560ad0b 100644
--- a/toonz/sources/toonz/subcameramanager.cpp
+++ b/toonz/sources/toonz/subcameramanager.cpp
@@ -136,8 +136,8 @@ bool PreviewSubCameraManager::mouseMoveEvent(SceneViewer *viewer,
   QPointF curPos(event.mousePos() * getDevPixRatio());
   if (event.buttons() == Qt::LeftButton) {
     if (!bitwiseContains(m_dragType, INNER)) {
-      if (abs(curPos.x() - m_mousePressPos.x()) > 10 ||
-          abs(curPos.y() - m_mousePressPos.y()) > 10)
+      if (std::abs(curPos.x() - m_mousePressPos.x()) > 10 ||
+          std::abs(curPos.y() - m_mousePressPos.y()) > 10)
         m_clickAndDrag = true;
     }
 
diff --git a/toonz/sources/toonz/svnupdatedialog.cpp b/toonz/sources/toonz/svnupdatedialog.cpp
index 13a84e9..c178773 100644
--- a/toonz/sources/toonz/svnupdatedialog.cpp
+++ b/toonz/sources/toonz/svnupdatedialog.cpp
@@ -226,7 +226,7 @@ void SVNUpdateDialog::checkFiles() {
              s.m_repoStatus == "modified" || s.m_repoStatus == "modified") {
       if (s.m_path.endsWith(".tnz") &&
           (s.m_item == "missing" ||
-           s.m_item == "none" && s.m_repoStatus == "added")) {
+           (s.m_item == "none" && s.m_repoStatus == "added"))) {
         TFilePath scenePath =
             TFilePath(m_workingDir.toStdWString()) + s.m_path.toStdWString();
         TFilePath iconPath = ToonzScene::getIconPath(scenePath);
diff --git a/toonz/sources/toonz/versioncontrol.cpp b/toonz/sources/toonz/versioncontrol.cpp
index c99423f..f22677a 100644
--- a/toonz/sources/toonz/versioncontrol.cpp
+++ b/toonz/sources/toonz/versioncontrol.cpp
@@ -318,7 +318,7 @@ VersionControlManager *VersionControlManager::instance() {
 }
 
 //-----------------------------------------------------------------------------
-void setVersionControlCredentials(QString currentPath) {
+static void setVersionControlCredentials(QString currentPath) {
   VersionControl *vc                = VersionControl::instance();
   QList<SVNRepository> repositories = vc->getRepositories();
   int repoCount                     = repositories.size();
diff --git a/toonz/sources/toonz/viewerdraw.cpp b/toonz/sources/toonz/viewerdraw.cpp
index e8ffe02..9b97047 100644
--- a/toonz/sources/toonz/viewerdraw.cpp
+++ b/toonz/sources/toonz/viewerdraw.cpp
@@ -284,7 +284,7 @@ void ViewerDraw::drawGridAndGuides(SceneViewer *viewer, double sc, Ruler *vr,
   double ymax = std::max({p00.y, p01.y, p10.y, p11.y});
 
   double step  = 10;
-  double absSc = abs(sc);
+  double absSc = std::abs(sc);
   if (absSc * step < 4)
     while (absSc * step < 4) step *= 5;
   else if (absSc * step > 20)
diff --git a/toonz/sources/toonz/viewerpane.cpp b/toonz/sources/toonz/viewerpane.cpp
index b77e071..f7f4138 100644
--- a/toonz/sources/toonz/viewerpane.cpp
+++ b/toonz/sources/toonz/viewerpane.cpp
@@ -708,7 +708,7 @@ void SceneViewerPanel::playAudioFrame(int frame) {
                 ->getProperties()
                 ->getOutputProperties()
                 ->getFrameRate();
-    m_samplesPerFrame = m_sound->getSampleRate() / abs(m_fps);
+    m_samplesPerFrame = m_sound->getSampleRate() / std::abs(m_fps);
   }
   if (!m_sound) return;
   m_viewerFps = m_flipConsole->getCurrentFps();
diff --git a/toonz/sources/toonz/xdtsio.cpp b/toonz/sources/toonz/xdtsio.cpp
index 5d298f9..9e1a1a3 100644
--- a/toonz/sources/toonz/xdtsio.cpp
+++ b/toonz/sources/toonz/xdtsio.cpp
@@ -128,7 +128,7 @@ void XdtsFieldTrackItem::write(QJsonObject &json) const {
 }
 //-----------------------------------------------------------------------------
 
-bool frameLessThan(const QPair<int, int> &v1, const QPair<int, int> &v2) {
+static bool frameLessThan(const QPair<int, int> &v1, const QPair<int, int> &v2) {
   return v1.first < v2.first;
 }
 
diff --git a/toonz/sources/toonz/xshcellviewer.cpp b/toonz/sources/toonz/xshcellviewer.cpp
index 5456acc..d55cbe4 100644
--- a/toonz/sources/toonz/xshcellviewer.cpp
+++ b/toonz/sources/toonz/xshcellviewer.cpp
@@ -978,11 +978,11 @@ void RenameCellField::keyPressEvent(QKeyEvent *event) {
     cellSelection->selectCells(r0, c0, r1 + offset.frame(),
                                c1 + offset.layer());
   } else {
-    CellPosition offset(offset * stride);
-    int movedR0 = std::max(0, r0 + offset.frame());
+    CellPosition offset_(offset * stride);
+    int movedR0 = std::max(0, r0 + offset_.frame());
     int firstCol =
         Preferences::instance()->isXsheetCameraColumnVisible() ? -1 : 0;
-    int movedC0   = std::max(firstCol, c0 + offset.layer());
+    int movedC0   = std::max(firstCol, c0 + offset_.layer());
     int diffFrame = movedR0 - r0;
     int diffLayer = movedC0 - c0;
     // It needs to be discussed - I made not to rename cell with arrow key.
@@ -990,8 +990,8 @@ void RenameCellField::keyPressEvent(QKeyEvent *event) {
     // renameCell();
     cellSelection->selectCells(r0 + diffFrame, c0 + diffLayer, r1 + diffFrame,
                                c1 + diffLayer);
-    int newRow = std::max(0, m_row + offset.frame());
-    int newCol = std::max(firstCol, m_col + offset.layer());
+    int newRow = std::max(0, m_row + offset_.frame());
+    int newCol = std::max(firstCol, m_col + offset_.layer());
     showInRowCol(newRow, newCol, c1 - c0 > 0);
   }
   m_viewer->updateCells();
diff --git a/toonz/sources/toonzfarm/tfarmcontroller/tfarmcontroller.cpp b/toonz/sources/toonzfarm/tfarmcontroller/tfarmcontroller.cpp
index 53ef038..f758638 100644
--- a/toonz/sources/toonzfarm/tfarmcontroller/tfarmcontroller.cpp
+++ b/toonz/sources/toonzfarm/tfarmcontroller/tfarmcontroller.cpp
@@ -1155,8 +1155,8 @@ CtrlFarmTask *FarmController::getTaskToStart(FarmServerProxy *server) {
     CtrlFarmTask *task = itTask->second;
     if ((!server || (task->m_platform == NoPlatform ||
                      task->m_platform == server->m_platform)) &&
-        ((task->m_status == Waiting && task->m_priority > maxPriority) ||
-         (task->m_status == Aborted && task->m_failureCount < 3) &&
+        (((task->m_status == Waiting && task->m_priority > maxPriority) ||
+          (task->m_status == Aborted && task->m_failureCount < 3)) &&
              task->m_parentId != "")) {
       bool dependenciesCompleted = true;
 
@@ -2171,7 +2171,7 @@ void FarmController::activateReadyServers() {
     ServerState state = queryServerState2(server->getId());
     int tasksCount    = server->m_tasks.size();
     if (state == Ready ||
-        state == Busy && tasksCount < server->m_maxTaskCount) {
+        (state == Busy && tasksCount < server->m_maxTaskCount)) {
       for (int i = 0; i < (server->m_maxTaskCount - tasksCount); ++i) {
         // cerca un task da sottomettere al server
         CtrlFarmTask *task = getTaskToStart(server);
diff --git a/toonz/sources/toonzfarm/tfarmserver/tfarmserver.cpp b/toonz/sources/toonzfarm/tfarmserver/tfarmserver.cpp
index d40e6c0..6b2cacc 100644
--- a/toonz/sources/toonzfarm/tfarmserver/tfarmserver.cpp
+++ b/toonz/sources/toonzfarm/tfarmserver/tfarmserver.cpp
@@ -542,7 +542,7 @@ QString FarmServer::execute(const vector<QString> &argv) {
         reply += ",";
       }
 
-      if (!reply.isEmpty()) reply.left(reply.size() - 1);
+      if (!reply.isEmpty()) reply = reply.left(reply.size() - 1);
 
       return reply;
     } else if (argv[0] == "queryHwInfo") {
@@ -727,14 +727,17 @@ std::string getLine(std::istream &is) {
 
   while (!is.eof()) {
     is.get(c);
-    if (c != '\r')
-      if (c != '\n')
-        if (!is.fail())
+    if (c != '\r') {
+      if (c != '\n') {
+        if (!is.fail()) {
           out.append(1, c);
-        else
+        } else {
           break;
-      else
+	}
+      } else {
         break;
+      }
+    }
   }
   return out;
 }
diff --git a/toonz/sources/toonzlib/autoclose.cpp b/toonz/sources/toonzlib/autoclose.cpp
index 48220e7..d41317c 100644
--- a/toonz/sources/toonzlib/autoclose.cpp
+++ b/toonz/sources/toonzlib/autoclose.cpp
@@ -399,11 +399,13 @@ int intersect_triangle(int x1a, int y1a, int x2a, int y2a, int x3a, int y3a,
 
     intersect_segment(x1a, y1a, x2a, y2a, i, &xamin);
 
-    if (intersect_segment(x1a, y1a, x3a, y3a, i, &val))
-      if (xamin)
+    if (intersect_segment(x1a, y1a, x3a, y3a, i, &val)) {
+      if (xamin) {
         xamax = val;
-      else
+      } else {
         xamin = val;
+      }
+    }
 
     if (!xamax) intersect_segment(x2a, y2a, x3a, y3a, i, &xamax);
 
@@ -413,11 +415,13 @@ int intersect_triangle(int x1a, int y1a, int x2a, int y2a, int x3a, int y3a,
 
     intersect_segment(x1b, y1b, x2b, y2b, i, &xbmin);
 
-    if (intersect_segment(x1b, y1b, x3b, y3b, i, &val))
-      if (xbmin)
+    if (intersect_segment(x1b, y1b, x3b, y3b, i, &val)) {
+      if (xbmin) {
         xbmax = val;
-      else
+      } else {
         xbmin = val;
+      }
+    }
 
     if (!xbmax) intersect_segment(x2b, y2b, x3b, y3b, i, &xbmax);
 
diff --git a/toonz/sources/toonzlib/boardsettings.cpp b/toonz/sources/toonzlib/boardsettings.cpp
index e910b3c..dc38fea 100644
--- a/toonz/sources/toonzlib/boardsettings.cpp
+++ b/toonz/sources/toonzlib/boardsettings.cpp
@@ -113,6 +113,8 @@ QString BoardItem::getContentText(ToonzScene *scene) {
     TOutputProperties *oprop = scene->getProperties()->getOutputProperties();
     return scene->decodeFilePath(oprop->getPath()).getQString();
   } break;
+  default:
+    break;
   }
   return QString();
 }
diff --git a/toonz/sources/toonzlib/mypaintbrushstyle.cpp b/toonz/sources/toonzlib/mypaintbrushstyle.cpp
index b299c10..eecc712 100644
--- a/toonz/sources/toonzlib/mypaintbrushstyle.cpp
+++ b/toonz/sources/toonzlib/mypaintbrushstyle.cpp
@@ -107,7 +107,7 @@ TFilePath TMyPaintBrushStyle::decodePath(const TFilePath &path) const {
 }
 
 //-----------------------------------------------------------------------------
-std::string mybToVersion3(std::string origStr) {
+static std::string mybToVersion3(std::string origStr) {
   std::string outStr   = "";
   std::string comment  = "";
   bool settingsStarted = false;
diff --git a/toonz/sources/toonzlib/preferences.cpp b/toonz/sources/toonzlib/preferences.cpp
index 8212ccf..f29260e 100644
--- a/toonz/sources/toonzlib/preferences.cpp
+++ b/toonz/sources/toonzlib/preferences.cpp
@@ -317,14 +317,12 @@ void Preferences::initializeOptions() {
   try {
     TSystem::readDirectory(room_fpset, room_path, true, false);
     TFilePathSet::iterator it = room_fpset.begin();
-    int i                     = 0;
-    for (it; it != room_fpset.end(); it++) {
+    for (int i = 0; it != room_fpset.end(); it++, i++) {
       TFilePath newPath = *it;
       if (newPath == room_path) continue;
       if (TFileStatus(newPath).isDirectory()) {
         QString string = QString::fromStdWString(newPath.getWideName());
         m_roomMaps[i]  = string;
-        i++;
       }
     }
   } catch (...) {
diff --git a/toonz/sources/toonzlib/sandor_fxs/BlurMatrix.cpp b/toonz/sources/toonzlib/sandor_fxs/BlurMatrix.cpp
index 7ad5196..b167a8c 100644
--- a/toonz/sources/toonzlib/sandor_fxs/BlurMatrix.cpp
+++ b/toonz/sources/toonzlib/sandor_fxs/BlurMatrix.cpp
@@ -235,7 +235,8 @@ void CBlurMatrix::print() const {
                    for( vector<SXYD>::const_iterator pp=m_m[0][i].begin();
                             pp!=m_m[0][i].end();
                             ++pp,++j ) {
-                          sprintf(s,"(%d,%d,%d,%d) ",i,j,pp->x,pp->y);
+                          snprintf(s, sizeof(s),
+                            "(%d,%d,%d,%d) ",i,j,pp->x,pp->y);
                           OutputDebugString(s);
                   }
                   OutputDebugString("\n");
diff --git a/toonz/sources/toonzlib/sandor_fxs/Params.h b/toonz/sources/toonzlib/sandor_fxs/Params.h
index 7e8ad87..c656df3 100644
--- a/toonz/sources/toonzlib/sandor_fxs/Params.h
+++ b/toonz/sources/toonzlib/sandor_fxs/Params.h
@@ -41,12 +41,12 @@ void print()
   int i;
 
   OutputDebugString("===== PARAMS =====\n");
-  sprintf(s,"Scale=%f\n",m_scale);
+  snprintf(s, sizeof(s), "Scale=%f\n",m_scale);
   OutputDebugString(s);
   i=0;
   for( vector<EParam>::iterator p=m_params.begin();
           p!=m_params.end(); ++p,++i ){
-          sprintf(s,"--- %d. Param ---\n",i);
+          snprintf(s, sizeof(s), "--- %d. Param ---\n",i);
           OutputDebugString(s);
           p->print();
   }
diff --git a/toonz/sources/toonzlib/sandor_fxs/Pattern.cpp b/toonz/sources/toonzlib/sandor_fxs/Pattern.cpp
index 5cd0882..b05d4d9 100644
--- a/toonz/sources/toonzlib/sandor_fxs/Pattern.cpp
+++ b/toonz/sources/toonzlib/sandor_fxs/Pattern.cpp
@@ -202,7 +202,7 @@ void CPattern::optimalizeSize() {
     std::unique_ptr<UC_PIXEL[]> nPat(new UC_PIXEL[nLX * nLY]);
     if (!nPat) {
       char s[200];
-      sprintf(s, "in Pattern Optimalization \n");
+      snprintf(s, sizeof(s), "in Pattern Optimalization \n");
       throw SMemAllocError(s);
     }
     for (int y = bb.y0; y <= bb.y1; y++)
@@ -239,7 +239,7 @@ void CPattern::rotate(const double angle) {
   std::unique_ptr<UC_PIXEL[]> nPat(new UC_PIXEL[nLXY * nLXY]);
   if (!nPat) {
     char s[200];
-    sprintf(s, "in Pattern Rotation \n");
+    snprintf(s, sizeof(s), "in Pattern Rotation \n");
     throw SMemAllocError(s);
   }
   eraseBuffer(nLXY, nLXY, nPat.get());
diff --git a/toonz/sources/toonzlib/sandor_fxs/PatternPosition.cpp b/toonz/sources/toonzlib/sandor_fxs/PatternPosition.cpp
index 3aac31d..a20af3a 100644
--- a/toonz/sources/toonzlib/sandor_fxs/PatternPosition.cpp
+++ b/toonz/sources/toonzlib/sandor_fxs/PatternPosition.cpp
@@ -57,7 +57,7 @@ void CPatternPosition::makeRandomPositions(const int nbPat, const int nbPixel,
         }
   } catch (exception) {
     char s[50];
-    sprintf(s, "in Pattern Position Generation");
+    snprintf(s, sizeof(s), "in Pattern Position Generation");
     throw SMemAllocError(s);
   }
 }
@@ -157,7 +157,7 @@ void CPatternPosition::prepareCircle(vector<SPOINT> &v, const double r) {
         }
   } catch (exception) {
     char s[50];
-    sprintf(s, "Position Generation");
+    snprintf(s, sizeof(s), "Position Generation");
     throw SMemAllocError(s);
   }
 }
@@ -188,7 +188,7 @@ void CPatternPosition::makeDDPositions(const int lX, const int lY, UCHAR *sel,
   std::unique_ptr<UCHAR[]> lSel(new UCHAR[lX * lY]);
   if (!lSel) {
     char s[50];
-    sprintf(s, "in Pattern Position Generation");
+    snprintf(s, sizeof(s), "in Pattern Position Generation");
     throw SMemAllocError(s);
   }
   memcpy(lSel.get(), sel, lX * lY * sizeof(UCHAR));
@@ -209,7 +209,7 @@ void CPatternPosition::makeDDPositions(const int lX, const int lY, UCHAR *sel,
     }
   } catch (exception) {
     char s[50];
-    sprintf(s, "in Pattern Position Generation");
+    snprintf(s, sizeof(s), "in Pattern Position Generation");
     throw SMemAllocError(s);
   }
   //	memcpy(sel,lSel,lX*lY);
diff --git a/toonz/sources/toonzlib/sandor_fxs/STColSelPic.h b/toonz/sources/toonzlib/sandor_fxs/STColSelPic.h
index 06d1262..8811926 100644
--- a/toonz/sources/toonzlib/sandor_fxs/STColSelPic.h
+++ b/toonz/sources/toonzlib/sandor_fxs/STColSelPic.h
@@ -45,8 +45,8 @@ public:
       if (!m_sel) throw SMemAllocError(" in initColorSelection");
     } else {
       char s[200];
-      sprintf(s, " in initColorSelection lXY=(%d,%d)\n", CSTPic<P>::m_lX,
-              CSTPic<P>::m_lY);
+      snprintf(s, sizeof(s), " in initColorSelection lXY=(%d,%d)\n",
+               CSTPic<P>::m_lX, CSTPic<P>::m_lY);
       throw SMemAllocError(s);
     }
   }
diff --git a/toonz/sources/toonzlib/sandor_fxs/STPic.h b/toonz/sources/toonzlib/sandor_fxs/STPic.h
index d6135e7..d7c8623 100644
--- a/toonz/sources/toonzlib/sandor_fxs/STPic.h
+++ b/toonz/sources/toonzlib/sandor_fxs/STPic.h
@@ -131,7 +131,7 @@ public:
       lock();
     } else {
       char s[200];
-      sprintf(s, "in initPic lXY=(%d,%d)\n", m_lX, m_lY);
+      snprintf(s, sizeof(s), "in initPic lXY=(%d,%d)\n", m_lX, m_lY);
       throw SMemAllocError(s);
     }
   }
@@ -322,7 +322,9 @@ public:
         ip.b = (int)pLL.b;
         ip.m = (int)pLL.m;
         break;
-      }
+      default:
+         break;
+     }
     } else
       ip.r = ip.g = ip.b = ip.m = 0;
   }
@@ -358,6 +360,8 @@ public:
         pS->b = (USHORT)ip.b;
         pS->m = (USHORT)ip.m;
         break;
+      default:
+         break;
       }
     }
   }
@@ -467,6 +471,8 @@ public:
                 p->m = PIX_USHORT_FROM_BYTE((UCHAR)ip.m);
               }
               break;
+            default:
+              break;
             }
           }
       }
diff --git a/toonz/sources/toonzlib/sandor_fxs/YOMBParam.cpp b/toonz/sources/toonzlib/sandor_fxs/YOMBParam.cpp
index d42b73b..ef0f7e9 100644
--- a/toonz/sources/toonzlib/sandor_fxs/YOMBParam.cpp
+++ b/toonz/sources/toonzlib/sandor_fxs/YOMBParam.cpp
@@ -30,27 +30,28 @@ void CYOMBParam::print() {
   char s[1024];
 
   OutputDebugString("   ----- YOMB Param -----\n");
-  sprintf(s,"   Name=%s\n",m_name.c_str());
+  snprintf(s, sizeof(s), "   Name=%s\n",m_name.c_str());
   OutputDebugString(s);
-  sprintf(s,"   RandomSampling=%d\n",m_isRandomSampling);
+  snprintf(s, sizeof(s), "   RandomSampling=%d\n",m_isRandomSampling);
   OutputDebugString(s);
-  sprintf(s,"   ShowSelection=%d\n",m_isShowSelection);
+  snprintf(s, sizeof(s), "   ShowSelection=%d\n",m_isShowSelection);
   OutputDebugString(s);
-  sprintf(s,"   StopAtContour=%d\n",m_isStopAtContour);
+  snprintf(s, sizeof(s), "   StopAtContour=%d\n",m_isStopAtContour);
   OutputDebugString(s);
-  sprintf(s,"   dSample=%f\n",m_dSample);
+  snprintf(s, sizeof(s), "   dSample=%f\n",m_dSample);
   OutputDebugString(s);
-  sprintf(s,"   nbSample=%d\n",m_nbSample);
+  snprintf(s, sizeof(s), "   nbSample=%d\n",m_nbSample);
   OutputDebugString(s);
-  sprintf(s,"   dA=%f\n",m_dA);
+  snprintf(s, sizeof(s), "   dA=%f\n",m_dA);
   OutputDebugString(s);
-  sprintf(s,"   dAB=%f\n",m_dAB);
+  snprintf(s, sizeof(s), "   dAB=%f\n",m_dAB);
   OutputDebugString(s);
 
   for( vector<I_PIXEL>::iterator p=m_color.begin();
            p!=m_color.end();
            ++p ) {
-          sprintf(s,"   RGBM=(%d,%d,%d,%d)\n",p->r,p->g,p->b,p->m);
+          snprintf(s, sizeof(s), "   RGBM=(%d,%d,%d,%d)\n",
+            p->r,p->g,p->b,p->m);
           OutputDebugString(s);
   }
   OutputDebugString("   ----------------------\n");
diff --git a/toonz/sources/toonzlib/sandor_fxs/YOMBParam.h b/toonz/sources/toonzlib/sandor_fxs/YOMBParam.h
index f049c86..12e93f7 100644
--- a/toonz/sources/toonzlib/sandor_fxs/YOMBParam.h
+++ b/toonz/sources/toonzlib/sandor_fxs/YOMBParam.h
@@ -166,7 +166,7 @@ public:
       int y = yy + xyd->y;
       if (x >= 0 && y >= 0 && x < pic.m_lX && y < pic.m_lY) {
         int xy = y * pic.m_lX + x;
-        if (*(pic.m_sel + xy) > (UCHAR)0)
+        if (*(pic.m_sel + xy) > (UCHAR)0) {
           if (bm.m_isSAC) {
             if (!isContourOnPath(xx, yy, pBS, pic)) {
               addPixel(p, pic, xxyy, xy);
@@ -176,6 +176,7 @@ public:
             addPixel(p, pic, xxyy, xy);
             nb++;
           }
+	}
       }
     }
 
diff --git a/toonz/sources/toonzlib/scenefx.cpp b/toonz/sources/toonzlib/scenefx.cpp
index 64672fb..077fbeb 100644
--- a/toonz/sources/toonzlib/scenefx.cpp
+++ b/toonz/sources/toonzlib/scenefx.cpp
@@ -785,8 +785,8 @@ PlacedFx FxBuilder::makePF(TLevelColumnFx *lcfx) {
     /*-- ParticleFxのTextureポートに繋がっていない場合 --*/
     if (m_particleDescendentCount == 0) {
       if (!xl ||
-          xl->getType() != PLI_XSHLEVEL && xl->getType() != TZP_XSHLEVEL &&
-              xl->getType() != CHILD_XSHLEVEL)
+          (xl->getType() != PLI_XSHLEVEL && xl->getType() != TZP_XSHLEVEL &&
+              xl->getType() != CHILD_XSHLEVEL))
         return PlacedFx();
     }
     /*-- ParticleFxのTextureポートに繋がっている場合 --*/
diff --git a/toonz/sources/toonzlib/stagevisitor.cpp b/toonz/sources/toonzlib/stagevisitor.cpp
index 7480003..b73077e 100644
--- a/toonz/sources/toonzlib/stagevisitor.cpp
+++ b/toonz/sources/toonzlib/stagevisitor.cpp
@@ -701,7 +701,7 @@ void RasterPainter::drawRasterImages(QPainter &p, QPolygon cameraPol) {
   p.setClipRegion(QRegion(cameraPol));
   for (i = 0; i < (int)m_nodes.size(); i++) {
     if (m_nodes[i].m_onionMode != Node::eOnionSkinNone) continue;
-    p.resetMatrix();
+    p.resetTransform();
     TRasterP ras = m_nodes[i].m_raster;
     TAffine aff  = TTranslation(-rect.x0, -rect.y0) * flipY * m_nodes[i].m_aff;
     QMatrix matrix(aff.a11, aff.a21, aff.a12, aff.a22, aff.a13, aff.a23);
@@ -711,7 +711,7 @@ void RasterPainter::drawRasterImages(QPainter &p, QPolygon cameraPol) {
     p.drawImage(rect.getP00().x, rect.getP00().y, image);
   }
 
-  p.resetMatrix();
+  p.resetTransform();
   m_nodes.clear();
 }
 
diff --git a/toonz/sources/toonzlib/tcenterlineadjustments.cpp b/toonz/sources/toonzlib/tcenterlineadjustments.cpp
index 9489fd4..b15a12b 100644
--- a/toonz/sources/toonzlib/tcenterlineadjustments.cpp
+++ b/toonz/sources/toonzlib/tcenterlineadjustments.cpp
@@ -70,12 +70,15 @@ void organizeGraphs(SkeletonList *skeleton, VectorizerCoreGlobals &g) {
     // Discriminate between graphs, two-endpoint single sequences, and circular
     // ones
     bool has1DegreePoint = 0;
-    for (i = 0; i < currGraph.getNodesCount(); ++i)
-      if (currGraph.getNode(i).degree() != 2)
-        if (currGraph.getNode(i).degree() == 1)
+    for (i = 0; i < currGraph.getNodesCount(); ++i) {
+      if (currGraph.getNode(i).degree() != 2) {
+        if (currGraph.getNode(i).degree() == 1) {
           has1DegreePoint = 1;
-        else
+        } else {
           goto _graph;
+	}
+      }
+    }
 
     if (has1DegreePoint)
       goto _two_endpoint;
diff --git a/toonz/sources/toonzlib/tcenterlinepolygonizer.cpp b/toonz/sources/toonzlib/tcenterlinepolygonizer.cpp
index d829435..efb7dae 100644
--- a/toonz/sources/toonzlib/tcenterlinepolygonizer.cpp
+++ b/toonz/sources/toonzlib/tcenterlinepolygonizer.cpp
@@ -378,7 +378,7 @@ static RawBorder *extractPath(Signaturemap &ras, int x0, int y0, int pathType,
 
   // If the inner region's overall area is under a given threshold,
   // then erase it (intended as image noise).
-  if (abs(area) < despeckling) {
+  if (std::abs(area) < despeckling) {
     setSignature(ras, *path, invalid);
     delete path;
     path = 0;
@@ -416,11 +416,13 @@ static BorderList *extractBorders(const TRasterP &ras, int threshold,
         if ((signature = byteImage.getSignature(x, y)) == none) {
           // We've found a border
           if ((foundPath = extractPath(byteImage, x, y, !enteredRegionType,
-                                       xOuterPixel, despeckling)))
-            if (enteredRegionType == outer)
+                                       xOuterPixel, despeckling))) {
+            if (enteredRegionType == outer) {
               innerBorders.push_back(foundPath);
-            else
+            } else {
               outerBorders.push_back(foundPath);
+	    }
+          }
         }
 
         // If leaving a white region, remember it - in order to establish
diff --git a/toonz/sources/toonzlib/tcenterlineskeletonizer.cpp b/toonz/sources/toonzlib/tcenterlineskeletonizer.cpp
index 5fdadc4..2f5b219 100644
--- a/toonz/sources/toonzlib/tcenterlineskeletonizer.cpp
+++ b/toonz/sources/toonzlib/tcenterlineskeletonizer.cpp
@@ -1229,6 +1229,8 @@ inline bool Event::process() {
       }
 
       break;
+    default:
+      break;
     }
   }
 
diff --git a/toonz/sources/toonzlib/tcenterlinevectorizer.cpp b/toonz/sources/toonzlib/tcenterlinevectorizer.cpp
index 65992fd..2118f18 100644
--- a/toonz/sources/toonzlib/tcenterlinevectorizer.cpp
+++ b/toonz/sources/toonzlib/tcenterlinevectorizer.cpp
@@ -177,7 +177,8 @@ TVectorImageP VectorizerCore::centerlineVectorize(
       converter.setPalette(palette);
 
       QList<int> dummy;
-      if (ti = converter.makeTlv(true, dummy))  // Transparent synthetic inks
+      ti = converter.makeTlv(true, dummy);
+      if (ti)  // Transparent synthetic inks
       {
         image = ti;
         ras   = ti->getRaster();
diff --git a/toonz/sources/toonzlib/tcleanupper.cpp b/toonz/sources/toonzlib/tcleanupper.cpp
index d813cc1..3c69ba8 100644
--- a/toonz/sources/toonzlib/tcleanupper.cpp
+++ b/toonz/sources/toonzlib/tcleanupper.cpp
@@ -412,8 +412,8 @@ bool TCleanupper::getResampleValues(const TRasterImageP &image, TAffine &aff,
   TRect saveBox          = image->getSavebox();
   bool raster_is_savebox = true;
   if (saveBox == TRect() &&
-      (saveBox.getLx() > 0 && saveBox.getLx() < rasterLx ||
-       saveBox.getLy() > 0 && saveBox.getLy() < rasterLy))
+      ((saveBox.getLx() > 0 && saveBox.getLx() < rasterLx) ||
+       (saveBox.getLy() > 0 && saveBox.getLy() < rasterLy)))
     raster_is_savebox = false;
 
   // Use the same source dpi throughout the level
diff --git a/toonz/sources/toonzlib/tdistort.cpp b/toonz/sources/toonzlib/tdistort.cpp
index c208fc3..098a701 100644
--- a/toonz/sources/toonzlib/tdistort.cpp
+++ b/toonz/sources/toonzlib/tdistort.cpp
@@ -993,33 +993,41 @@ inline void updateResult(const TPointD &srcCorner, const TPointD &xDer,
   if (jacobianSign > 0) {
     hasPositiveResults = true;
 
-    if (sideDerXAgainstRectSideX != -sideDerXAgainstRectSideY)
+    if (sideDerXAgainstRectSideX != -sideDerXAgainstRectSideY) {
       // Rect lies on one side of the derivative line extension. Therefore, the
       // inverted rect can be updated.
-      if (sideDerXAgainstRectSideX > 0 || sideDerXAgainstRectSideY > 0)
+      if (sideDerXAgainstRectSideX > 0 || sideDerXAgainstRectSideY > 0) {
         posResult.y0 = std::min(posResult.y0, srcCorner.y - securityAddendum);
-      else
+      } else {
         posResult.y1 = std::max(posResult.y1, srcCorner.y + securityAddendum);
+      }
+    }
 
-    if (sideDerYAgainstRectSideX != -sideDerYAgainstRectSideY)
-      if (sideDerYAgainstRectSideX > 0 || sideDerYAgainstRectSideY > 0)
+    if (sideDerYAgainstRectSideX != -sideDerYAgainstRectSideY) {
+      if (sideDerYAgainstRectSideX > 0 || sideDerYAgainstRectSideY > 0) {
         posResult.x1 = std::max(posResult.x1, srcCorner.x + securityAddendum);
-      else
+      } else {
         posResult.x0 = std::min(posResult.x0, srcCorner.x - securityAddendum);
+      }
+    }
   } else if (jacobianSign < 0) {
     hasNegativeResults = true;
 
-    if (sideDerXAgainstRectSideX != -sideDerXAgainstRectSideY)
-      if (sideDerXAgainstRectSideX > 0 || sideDerXAgainstRectSideY > 0)
+    if (sideDerXAgainstRectSideX != -sideDerXAgainstRectSideY) {
+      if (sideDerXAgainstRectSideX > 0 || sideDerXAgainstRectSideY > 0) {
         negResult.y1 = std::max(posResult.y1, srcCorner.y + securityAddendum);
-      else
+      } else {
         negResult.y0 = std::min(posResult.y0, srcCorner.y - securityAddendum);
+      }
+    }
 
-    if (sideDerYAgainstRectSideX != -sideDerYAgainstRectSideY)
-      if (sideDerYAgainstRectSideX > 0 || sideDerYAgainstRectSideY > 0)
+    if (sideDerYAgainstRectSideX != -sideDerYAgainstRectSideY) {
+      if (sideDerYAgainstRectSideX > 0 || sideDerYAgainstRectSideY > 0) {
         negResult.x0 = std::min(posResult.x0, srcCorner.x - securityAddendum);
-      else
+      } else {
         negResult.x1 = std::max(posResult.x1, srcCorner.x + securityAddendum);
+      }
+    }
   }
 }
 
diff --git a/toonz/sources/toonzlib/tframehandle.cpp b/toonz/sources/toonzlib/tframehandle.cpp
index 12f7cce..73aea2d 100644
--- a/toonz/sources/toonzlib/tframehandle.cpp
+++ b/toonz/sources/toonzlib/tframehandle.cpp
@@ -14,6 +14,7 @@
 
 namespace {
 
+#if 0
 /* int getCurrentSceneFrameCount()
   {
     return 100; //
@@ -34,6 +35,7 @@ namespace {
 /*   r0 = 0;
     r1 = getCurrentSceneFrameCount()-1;
   }*/
+#endif
 
 bool getCurrentLevelFids(std::vector<TFrameId> &fids) {
   /*
diff --git a/toonz/sources/toonzlib/toonzimageutils.cpp b/toonz/sources/toonzlib/toonzimageutils.cpp
index 7f9302e..4f40dc1 100644
--- a/toonz/sources/toonzlib/toonzimageutils.cpp
+++ b/toonz/sources/toonzlib/toonzimageutils.cpp
@@ -724,7 +724,7 @@ void ToonzImageUtils::eraseImage(const TToonzImageP &ti,
     TPixelCM32 *outPix    = workRas->pixels(y);
     TPixelCM32 *outEndPix = outPix + workRas->getLx();
     TPixel32 *inPix       = image->pixels(y);
-    for (outPix; outPix != outEndPix; outPix++, inPix++) {
+    for (; outPix != outEndPix; outPix++, inPix++) {
       bool canEraseInk =
           !selective || (selective && styleId == outPix->getInk());
       bool canErasePaint =
diff --git a/toonz/sources/toonzlib/toonzscene.cpp b/toonz/sources/toonzlib/toonzscene.cpp
index 2b08313..6f66006 100644
--- a/toonz/sources/toonzlib/toonzscene.cpp
+++ b/toonz/sources/toonzlib/toonzscene.cpp
@@ -1043,6 +1043,8 @@ static LevelType getLevelType(const TFilePath &fp) {
   case TFileType::MESH_LEVEL:
     ret.m_ltype = MESH_XSHLEVEL;
     break;
+  default:
+    break;
   }
 
   return ret;
diff --git a/toonz/sources/toonzlib/toutlinevectorizer.cpp b/toonz/sources/toonzlib/toutlinevectorizer.cpp
index c8196b0..c75858e 100644
--- a/toonz/sources/toonzlib/toutlinevectorizer.cpp
+++ b/toonz/sources/toonzlib/toutlinevectorizer.cpp
@@ -496,7 +496,7 @@ void OutlineVectorizer::createOutlineStrokes() {
 
   std::list<std::vector<TThickPoint>>::iterator it_outlines =
       m_protoOutlines.begin();
-  for (it_outlines; it_outlines != m_protoOutlines.end(); it_outlines++) {
+  for (; it_outlines != m_protoOutlines.end(); it_outlines++) {
     if (it_outlines->size() > 3) {
       std::vector<TThickPoint> points;
       std::vector<TThickPoint>::iterator it;
diff --git a/toonz/sources/toonzlib/txsheetexpr.cpp b/toonz/sources/toonzlib/txsheetexpr.cpp
index 8dd475c..fd904d0 100644
--- a/toonz/sources/toonzlib/txsheetexpr.cpp
+++ b/toonz/sources/toonzlib/txsheetexpr.cpp
@@ -228,9 +228,9 @@ public:
     int i = (int)previousTokens.size();
     if (i == 0)
       return matchObjectName(token) != TStageObjectId::NoneId;
-    else if (i == 1 && token.getText() == "." ||
-             i == 3 && token.getText() == "(" ||
-             i == 5 && token.getText() == ")")
+    else if ((i == 1 && token.getText() == ".") ||
+             (i == 3 && token.getText() == "(") ||
+             (i == 5 && token.getText() == ")"))
       return true;
     else if (i == 2) {
       if (matchChannelName(token) < TStageObject::T_ChannelCount)
diff --git a/toonz/sources/toonzlib/txshsimplelevel.cpp b/toonz/sources/toonzlib/txshsimplelevel.cpp
index f04f13a..cf2ff70 100644
--- a/toonz/sources/toonzlib/txshsimplelevel.cpp
+++ b/toonz/sources/toonzlib/txshsimplelevel.cpp
@@ -996,7 +996,7 @@ public:
 
   bool match(const TFrameId &fid) const {
     /*-- ↓SubSequent範囲内にある条件		↓全部ロードする場合 --*/
-    return m_fromFid <= fid && fid <= m_toFid || m_fromFid > m_toFid;
+    return ((m_fromFid <= fid && fid <= m_toFid) || m_fromFid > m_toFid);
   }
   bool isEnabled() const { return m_fromFid <= m_toFid; }
   void reset() {
diff --git a/toonz/sources/toonzqt/docklayout.cpp b/toonz/sources/toonzqt/docklayout.cpp
index 3ebe00f..f0ccdac 100644
--- a/toonz/sources/toonzqt/docklayout.cpp
+++ b/toonz/sources/toonzqt/docklayout.cpp
@@ -540,7 +540,7 @@ void Region::insertSubRegion(Region *subRegion, int idx) {
 Region *Region::insertItem(DockWidget *item, int idx) {
   Region *newRegion = new Region(m_owner, item);
 
-  if (this) insertSubRegion(newRegion, idx);
+  insertSubRegion(newRegion, idx);
 
   return newRegion;
 }
diff --git a/toonz/sources/toonzqt/expressionfield.cpp b/toonz/sources/toonzqt/expressionfield.cpp
index 88cba01..3a6dc12 100644
--- a/toonz/sources/toonzqt/expressionfield.cpp
+++ b/toonz/sources/toonzqt/expressionfield.cpp
@@ -235,7 +235,7 @@ void ExpressionField::keyPressEvent(QKeyEvent *e) {
     QTextEdit::keyPressEvent(e);
     if (m_completerPopup->isVisible()) {
       updateCompleterPopup();
-    } else if (Qt::Key_A <= e->key() && e->key() <= Qt::Key_Z ||
+    } else if ((Qt::Key_A <= e->key() && e->key() <= Qt::Key_Z) ||
                std::string("+&|!*/=?,:-").find(e->key()) != std::string::npos) {
       openCompleterPopup();
     }
@@ -371,9 +371,9 @@ int ExpressionField::computeSuggestions() {
     start--;
     while (start > 0) {
       char c = text[start - 1];
-      if (isascii(c) && isalpha(c) || c == '_' ||
-          c == '.' && (start - 2 < 0 ||
-                       isascii(text[start - 2]) && isalpha(text[start - 2]))) {
+      if ((isascii(c) && isalpha(c)) || c == '_' ||
+          (c == '.' && (start - 2 < 0 ||
+                        (isascii(text[start - 2]) && isalpha(text[start - 2]))))) {
       } else
         break;
       start--;
diff --git a/toonz/sources/toonzqt/flipconsole.cpp b/toonz/sources/toonzqt/flipconsole.cpp
index 94eef12..37abca3 100644
--- a/toonz/sources/toonzqt/flipconsole.cpp
+++ b/toonz/sources/toonzqt/flipconsole.cpp
@@ -672,24 +672,27 @@ void FlipConsole::enableButton(UINT button, bool enable, bool doShowHide) {
   if (!m_playToolBar) return;
 
   QList<QAction *> list = m_playToolBar->actions();
-  int i;
-  for (i = 0; i < (int)list.size(); i++)
+  for (size_t i = 0; i < list.size(); i++)
     if (list[i]->data().toUInt() == button) {
-      if (button == eSound)
-        if (doShowHide)
+      if (button == eSound) {
+        if (doShowHide) {
           m_soundSep->setVisible(enable);
-        else
+        } else {
           m_soundSep->setEnabled(enable);
+	}
+      }
       if (button == eHisto) {
-        if (doShowHide)
+        if (doShowHide) {
           m_histoSep->setVisible(enable && m_customizeMask & eShowHisto);
-        else
+        } else {
           m_histoSep->setEnabled(enable);
+	}
       }
-      if (doShowHide)
+      if (doShowHide) {
         list[i]->setVisible(enable);
-      else
+      } else {
         list[i]->setEnabled(enable);
+      }
       if (!enable && list[i]->isChecked()) pressButton((EGadget)button);
 
       return;
@@ -707,6 +710,8 @@ void FlipConsole::enableButton(UINT button, bool enable, bool doShowHide) {
   case eGBlue:
     if (m_doubleBlue) m_doubleBlue->setEnabledSecondButton(enable);
     break;
+  default:
+    break;
   }
 }
 
diff --git a/toonz/sources/toonzqt/functionpanel.cpp b/toonz/sources/toonzqt/functionpanel.cpp
index bd7ed8c..4cc6612 100644
--- a/toonz/sources/toonzqt/functionpanel.cpp
+++ b/toonz/sources/toonzqt/functionpanel.cpp
@@ -755,6 +755,8 @@ void FunctionPanel::updateGadgets(TDoubleParam *curve) {
         m_gadgets.push_back(Gadget(EaseInPercentage, i, q, 6, 15));
         break;
       }
+      default:
+        break;
       }
 
       // Right handle
@@ -784,6 +786,8 @@ void FunctionPanel::updateGadgets(TDoubleParam *curve) {
           m_gadgets.push_back(Gadget(EaseOutPercentage, i, q, 6, 15));
           break;
         }
+        default:
+          break;
         }
       }
     }
@@ -993,6 +997,8 @@ void FunctionPanel::drawCurrentCurve(QPainter &painter) {
       painter.setPen(isHighlighted ? QColor(255, 126, 0) : m_selectedColor);
       painter.drawLine(p.x(), p.y() - 15, p.x(), p.y() + 15);
       break;
+    default:
+      break;
     }
   }
 
@@ -1055,6 +1061,8 @@ void FunctionPanel::drawGroupKeyframes(QPainter &painter) {
       pp.lineTo(p + QPointF(d, h));
       painter.drawPath(pp);
       break;
+    default:
+      break;
     }
   }
   painter.setPen(m_textColor);
@@ -1227,8 +1235,8 @@ void FunctionPanel::mousePressEvent(QMouseEvent *e) {
   FunctionTreeModel::Channel *currentChannel =
       m_functionTreeModel ? m_functionTreeModel->getCurrentChannel() : 0;
   if (!currentChannel ||
-      getCurveDistance(currentChannel->getParam(), winPos) > maxDistance &&
-          closestGadgetId < 0) {
+      (getCurveDistance(currentChannel->getParam(), winPos) > maxDistance &&
+          closestGadgetId < 0)) {
     // if current channel is undefined or its curve is too far from the clicked
     // point
     // the user is possibly trying to select a different curve
diff --git a/toonz/sources/toonzqt/fxschematicnode.cpp b/toonz/sources/toonzqt/fxschematicnode.cpp
index 5affb29..a9cd864 100644
--- a/toonz/sources/toonzqt/fxschematicnode.cpp
+++ b/toonz/sources/toonzqt/fxschematicnode.cpp
@@ -554,6 +554,8 @@ FxPainter::FxPainter(FxSchematicNode *parent, double width, double height,
     }
     break;
   }
+  default:
+    break;
   }
 }
 
@@ -784,8 +786,8 @@ void FxPainter::contextMenuEvent(QGraphicsSceneContextMenuEvent *cme) {
     else
       menu.addAction(connectToXSheet);
     menu.addAction(duplicateFx);
-    if (zsrc && zsrc->getZeraryFx() &&
-            zsrc->getZeraryFx()->getLinkedFx() != zsrc->getZeraryFx() ||
+    if ((zsrc && zsrc->getZeraryFx() &&
+            zsrc->getZeraryFx()->getLinkedFx() != zsrc->getZeraryFx()) ||
         fx->getLinkedFx() != fx)
       menu.addAction(unlinkFx);
   }
@@ -2441,6 +2443,8 @@ FxSchematicNormalFxNode::FxSchematicNormalFxNode(FxSchematicScene *scene,
     else
       setToolTip(m_name);
   }
+  default:
+    break;
   }
 
   m_nameItem = new SchematicName(this, 72, 20);  // for rename
@@ -2601,6 +2605,8 @@ void FxSchematicNormalFxNode::onNameChanged() {
     else
       setToolTip(m_name);
   }
+  default:
+    break;
   }
 
   setFlag(QGraphicsItem::ItemIsSelectable, true);
diff --git a/toonz/sources/toonzqt/fxschematicscene.cpp b/toonz/sources/toonzqt/fxschematicscene.cpp
index 2ada469..533b260 100644
--- a/toonz/sources/toonzqt/fxschematicscene.cpp
+++ b/toonz/sources/toonzqt/fxschematicscene.cpp
@@ -1468,29 +1468,31 @@ void FxSchematicScene::onUncacheFx() { setEnableCache(false); }
 
 void FxSchematicScene::setEnableCache(bool toggle) {
   QList<TFxP> selectedFxs = m_selection->getFxs();
-  int i;
-  for (i = 0; i < selectedFxs.size(); i++) {
+  for (int i = 0; i < selectedFxs.size(); i++) {
     TFx *fx               = selectedFxs[i].getPointer();
     TZeraryColumnFx *zcfx = dynamic_cast<TZeraryColumnFx *>(fx);
     if (zcfx) fx          = zcfx->getZeraryFx();
     TFxAttributes *attr   = fx->getAttributes();
-    if (!attr->isGrouped() || attr->isGroupEditing())
-      if (toggle)
+    if (!attr->isGrouped() || attr->isGroupEditing()) {
+      if (toggle) {
         TPassiveCacheManager::instance()->enableCache(fx);
-      else
+      } else {
         TPassiveCacheManager::instance()->disableCache(fx);
-    else {
+      }
+    } else {
       QMap<int, FxGroupNode *>::iterator it;
       for (it = m_groupedTable.begin(); it != m_groupedTable.end(); it++) {
         FxGroupNode *group = it.value();
         QList<TFxP> roots  = group->getRootFxs();
-        int j;
-        for (j = 0; j < roots.size(); j++)
-          if (fx == roots[j].getPointer())
-            if (toggle)
+        for (int j = 0; j < roots.size(); j++) {
+          if (fx == roots[j].getPointer()) {
+            if (toggle) {
               TPassiveCacheManager::instance()->enableCache(fx);
-            else
+            } else {
               TPassiveCacheManager::instance()->disableCache(fx);
+	    }
+	  }
+	}
         group->update();
       }
     }
diff --git a/toonz/sources/toonzqt/intfield.cpp b/toonz/sources/toonzqt/intfield.cpp
index 300d0ad..9445115 100644
--- a/toonz/sources/toonzqt/intfield.cpp
+++ b/toonz/sources/toonzqt/intfield.cpp
@@ -443,7 +443,7 @@ void IntField::onEditingFinished() {
   // Controllo necessario per evitare che il segnale di cambiamento venga emesso
   // piu' volte.
   if ((pos2value(m_slider->value()) == value && m_slider->isVisible()) ||
-      (int)m_roller->getValue() == value && m_roller->isVisible())
+      ((int)m_roller->getValue() == value && m_roller->isVisible()))
     return;
   m_slider->setValue(value2pos(value));
   m_roller->setValue((double)value);
diff --git a/toonz/sources/toonzqt/keyframenavigator.cpp b/toonz/sources/toonzqt/keyframenavigator.cpp
index 6a1b29a..24925b8 100644
--- a/toonz/sources/toonzqt/keyframenavigator.cpp
+++ b/toonz/sources/toonzqt/keyframenavigator.cpp
@@ -595,7 +595,7 @@ void FxKeyframeNavigator::toggle() {
   if (!isKeyframe) isFullKeyframe = false;
 
   // modifico lo stato: nokeyframe->full, full->no, partial->full
-  bool on = !isKeyframe || isKeyframe && !isFullKeyframe;
+  bool on = (!isKeyframe || (isKeyframe && !isFullKeyframe));
   for (i = 0; i < fx->getParams()->getParamCount();
        i++) {  // TODO. spostare questo codice in TParam
     TParamP param = fx->getParams()->getParam(i);
diff --git a/toonz/sources/toonzqt/menubarcommand.cpp b/toonz/sources/toonzqt/menubarcommand.cpp
index 2ab4af3..16d51c9 100644
--- a/toonz/sources/toonzqt/menubarcommand.cpp
+++ b/toonz/sources/toonzqt/menubarcommand.cpp
@@ -124,8 +124,8 @@ void CommandManager::define(CommandId id, CommandType type,
   node->m_type    = type;
   node->m_qaction = qaction;
   node->m_qaction->setEnabled(
-      node->m_enabled &&
-          (!!node->m_handler || node->m_qaction->actionGroup() != 0) ||
+      (node->m_enabled &&
+          (node->m_handler || node->m_qaction->actionGroup() != 0)) ||
       node->m_type == MiscCommandType ||
       node->m_type == ToolModifierCommandType);
 
diff --git a/toonz/sources/toonzqt/plugin_param_traits.h b/toonz/sources/toonzqt/plugin_param_traits.h
index e59ed45..8960680 100644
--- a/toonz/sources/toonzqt/plugin_param_traits.h
+++ b/toonz/sources/toonzqt/plugin_param_traits.h
@@ -52,7 +52,7 @@ inline F &get_func_b(RT *t) {
 template <>
 inline TDoubleParamP &get_func_a<TRangeParam, TDoubleParamP>(TRangeParam *t) {
   printf("get_func_a< TRangeParam, TDoubleParamP& >(TRangeParam* t)\n");
-  return std::mem_fun(&TRangeParam::getMin)(t);
+  return std::mem_fn(&TRangeParam::getMin)(t);
 }
 
 template <>
@@ -62,7 +62,7 @@ inline TDoubleParamP &get_func_b<TRangeParam, TDoubleParamP>(TRangeParam *t)
 // t)
 {
   printf("get_func_b< TRangeParam, TDoubleParamP& >(TRangeParam* t)\n");
-  return std::mem_fun(&TRangeParam::getMax)(t);
+  return std::mem_fn(&TRangeParam::getMax)(t);
 }
 
 /* TPointParam */
@@ -73,7 +73,7 @@ inline TDoubleParamP &get_func_a<TPointParam, TDoubleParamP>(TPointParam *t)
 // t)
 {
   printf("get_func_a< TPointParam, TDoubleParamP& >(TPointParam* t)\n");
-  return std::mem_fun(&TPointParam::getX)(t);
+  return std::mem_fn(&TPointParam::getX)(t);
 }
 
 template <>
@@ -83,7 +83,7 @@ inline TDoubleParamP &get_func_b<TPointParam, TDoubleParamP>(TPointParam *t)
 // t)
 {
   printf("get_func_b< TPointParam, TDoubleParamP& >(TPointParam* t)\n");
-  return std::mem_fun(&TPointParam::getY)(t);
+  return std::mem_fn(&TPointParam::getY)(t);
 }
 
 /* valuetype が集約型の場合、 スカラを取得するための関数 */
diff --git a/toonz/sources/toonzqt/styleeditor.cpp b/toonz/sources/toonzqt/styleeditor.cpp
index 8556bf0..77e49fc 100644
--- a/toonz/sources/toonzqt/styleeditor.cpp
+++ b/toonz/sources/toonzqt/styleeditor.cpp
@@ -236,6 +236,8 @@ void ColorModel::setValues(ColorChannel channel, int v, int u) {
     setValue(eHue, v);
     setValue(eSaturation, u);
     break;
+  default:
+    break;
   }
 }
 
@@ -274,6 +276,8 @@ void ColorModel::getValues(ColorChannel channel, int &u, int &v) {
     u = getValue(eHue);
     v = getValue(eSaturation);
     break;
+  default:
+    break;
   }
 }
 
diff --git a/toonz/sources/toonzqt/swatchviewer.cpp b/toonz/sources/toonzqt/swatchviewer.cpp
index 0e89f69..55782b5 100644
--- a/toonz/sources/toonzqt/swatchviewer.cpp
+++ b/toonz/sources/toonzqt/swatchviewer.cpp
@@ -197,10 +197,10 @@ double ZoomFactors[ZOOMLEVELS] = {
     1,     2,     3,      4,      5,     6,     7,    8,     12,   16};
 
 double getQuantizedZoomFactor(double zf, bool forward) {
-  if (forward && zf > ZoomFactors[ZOOMLEVELS - 1] ||
+  if ((forward && zf > ZoomFactors[ZOOMLEVELS - 1]) ||
       areAlmostEqual(zf, ZoomFactors[ZOOMLEVELS - 1], 1e-5))
     return zf;
-  else if (!forward && zf < ZoomFactors[0] ||
+  else if ((!forward && zf < ZoomFactors[0]) ||
            areAlmostEqual(zf, ZoomFactors[0], 1e-5))
     return zf;
 
diff --git a/toonz/sources/toonzqt/tonecurvefield.cpp b/toonz/sources/toonzqt/tonecurvefield.cpp
index 0dd016f..f8b766b 100644
--- a/toonz/sources/toonzqt/tonecurvefield.cpp
+++ b/toonz/sources/toonzqt/tonecurvefield.cpp
@@ -29,8 +29,8 @@ double getPercentAtPoint(QPointF point, QPainterPath path) {
   for (i = 1; i < 100; i++) {
     double p          = double(i) * 0.01;
     QPointF pathPoint = path.pointAtPercent(p);
-    if (abs(pathPoint.x() - point.x()) < 3 &&
-        abs(pathPoint.y() - point.y()) < 3)
+    if (std::abs(pathPoint.x() - point.x()) < 3 &&
+        std::abs(pathPoint.y() - point.y()) < 3)
       return p;
   }
   return 0;
@@ -457,13 +457,13 @@ void ChennelCurveEditor::addControlPoint(double percent) {
 
   QPointF p0 = checkPoint(m_points.at(beforeControlPointIndex));
   // Se sono troppo vicino al punto di controllo precedente ritorno
-  if (abs(p.x() - p0.x()) <= cpMargin) return;
+  if (std::abs(p.x() - p0.x()) <= cpMargin) return;
   double beforeControlPointPercent = getPercentAtPoint(p0, path);
   QPointF p1 = checkPoint(m_points.at(beforeControlPointIndex + 1));
   QPointF p2 = checkPoint(m_points.at(beforeControlPointIndex + 2));
   QPointF p3 = checkPoint(m_points.at(beforeControlPointIndex + 3));
   // Se sono troppo vicino al punto di controllo successivo ritorno
-  if (abs(p3.x() - p.x()) <= cpMargin) return;
+  if (std::abs(p3.x() - p.x()) <= cpMargin) return;
   double nextControlPointPercent = getPercentAtPoint(p3, path);
 
   // Calcolo la velocita' e quindi il coiffciente angolare.