[CStringSyntaxChecker] Fix build bot builds != x86 archs

[devnexen]

Summary

Adding more unit tests

[devnexen]

The buildbots broke because of the miscalculation of the buffer array size.

[devnexen]

Adding darwin 32 bits

[george.karpenkov]

Could you explain what was crashing?

[devnexen]

Example on arm http://lab.llvm.org:8011/builders/clang-cmake-armv8-quick/builds/4848/steps/ninja%20check%201/logs/FAIL%3A%20Clang%3A%3Acstring-syntax.c

[NoQ]

Looks good, please commit!

When you think that a fix for buildbots requires review, please revert first! Reviews have a much longer turnaround than acceptable buildbot downtime.

The new code does indeed look more correct, but yeah, i agree with @george.karpenkov that explaining what's going on when posting code on review is a good idea.

[mikhail.ramalho]

Still crashes for me in the same place (CStringSyntaxChecker.cpp:164) when analyzing tmux.

[devnexen]

In D49588#1170259, @mikhail.ramalho wrote:

Still crashes for me in the same place (CStringSyntaxChecker.cpp:164) when analyzing tmux.

Why I did not commit yet. I m testing a newer slightly version. Still building.

[devnexen]

@mikhail.ramalho could you try again with this change pls ?

cfe/trunk/lib/StaticAnalyzer/Checkers/CStringSyntaxChecker.cpp

 }
 
 bool WalkAST::containsBadStrlcpyPattern(const CallExpr *CE) {
   if (CE->getNumArgs() != 3)
     return false;
   const Expr *DstArg = CE->getArg(0);
   const Expr *LenArg = CE->getArg(2);
 
-  const auto *DstArgDecl = dyn_cast<DeclRefExpr>(DstArg->IgnoreParenCasts());
+  const auto *DstArgDecl = dyn_cast<DeclRefExpr>(DstArg->IgnoreParenImpCasts());
   const auto *LenArgDecl = dyn_cast<DeclRefExpr>(LenArg->IgnoreParenLValueCasts());
   // - size_t dstlen = sizeof(dst)
   if (LenArgDecl) {
     const auto *LenArgVal = dyn_cast<VarDecl>(LenArgDecl->getDecl());
     if (LenArgVal->getInit())
       LenArg = LenArgVal->getInit();
   }
 
   // - integral value
   // We try to figure out if the last argument is possibly longer
   // than the destination can possibly handle if its size can be defined
-  if (const auto *IL = dyn_cast<IntegerLiteral>(LenArg->IgnoreParenCasts())) {
+  if (const auto *IL = dyn_cast<IntegerLiteral>(LenArg->IgnoreParenImpCasts())) {
     uint64_t ILRawVal = IL->getValue().getZExtValue();
+    if (DstArgDecl) {
       if (const auto *Buffer = dyn_cast<ConstantArrayType>(DstArgDecl->getType())) {
         ASTContext &C = BR.getContext();
-      uint64_t Usize = C.getTypeSizeInChars(DstArg->getType()).getQuantity();
-      uint64_t BufferLen = BR.getContext().getTypeSize(Buffer) / Usize;
+        uint64_t BufferLen = C.getTypeSize(Buffer) / 8;
         if (BufferLen < ILRawVal)
           return true;
       }
     }
+  }
 
   return false;
 }
 
 void WalkAST::VisitCallExpr(CallExpr *CE) {
   const FunctionDecl *FD = CE->getDirectCallee();
   if (!FD)
     return;

cfe/trunk/test/Analysis/cstring-syntax.c

 // RUN: %clang_analyze_cc1 -analyzer-checker=unix.cstring.BadSizeArg -analyzer-store=region -Wno-strncat-size -Wno-strlcpy-strlcat-size -Wno-sizeof-array-argument -Wno-sizeof-pointer-memaccess -verify %s
+// RUN: %clang_analyze_cc1 -triple armv7-a15-linux -analyzer-checker=unix.cstring.BadSizeArg -analyzer-store=region -Wno-strncat-size -Wno-strlcpy-strlcat-size -Wno-sizeof-array-argument -Wno-sizeof-pointer-memaccess -verify %s
+// RUN: %clang_analyze_cc1 -triple aarch64_be-none-linux-gnu -analyzer-checker=unix.cstring.BadSizeArg -analyzer-store=region -Wno-strncat-size -Wno-strlcpy-strlcat-size -Wno-sizeof-array-argument -Wno-sizeof-pointer-memaccess -verify %s
+// RUN: %clang_analyze_cc1 -triple i386-apple-darwin10 -analyzer-checker=unix.cstring.BadSizeArg -analyzer-store=region -Wno-strncat-size -Wno-strlcpy-strlcat-size -Wno-sizeof-array-argument -Wno-sizeof-pointer-memaccess -verify %s
 
 typedef __SIZE_TYPE__ size_t;
 char  *strncat(char *, const char *, size_t);
 size_t strlen (const char *s);
 size_t strlcpy(char *, const char *, size_t);
 
 void testStrncat(const char *src) {
   char dest[10];
void testStrlcpy(const char *src) {
   size_t badlen = 20;
   size_t ulen;
   strlcpy(dest, src, sizeof(dest));
   strlcpy(dest, src, destlen);
   strlcpy(dest, src, 10);
   strlcpy(dest, src, 20); // expected-warning {{The third argument is larger than the size of the input buffer. Replace with the value 'sizeof(dest)` or lower}}
   strlcpy(dest, src, badlen); // expected-warning {{The third argument is larger than the size of the input buffer. Replace with the value 'sizeof(dest)` or lower}}
   strlcpy(dest, src, ulen);
+  strlcpy(dest + 5, src, 5);
 }