[cfe-commits] r114044 - in /cfe/trunk: lib/Sema/SemaExpr.cpp test/Sema/self-comparison.c

[Ted Kremenek]

Author: kremenek
Date: Wed Sep 15 19:03:01 2010
New Revision: 114044

URL: http://llvm.org/viewvc/llvm-project?rev=114044&view=rev
Log:
For self-comparison warning, check the source location of both the LHS and RHS to see if they
are expanded from macros (and if so, omit the warning).  Previously we were just looking at the
location of the binary expression.

Fixes <rdar://problem/8435950>.

Modified:
    cfe/trunk/lib/Sema/SemaExpr.cpp
    cfe/trunk/test/Sema/self-comparison.c

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=114044&r1=114043&r2=114044&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Wed Sep 15 19:03:01 2010
@@ -5437,7 +5437,9 @@
   QualType rType = rex->getType();
 
   if (!lType->hasFloatingRepresentation() &&
-      !(lType->isBlockPointerType() && isRelational)) {
+      !(lType->isBlockPointerType() && isRelational) &&
+      !lex->getLocStart().isMacroID() &&
+      !rex->getLocStart().isMacroID()) {
     // For non-floating point types, check for self-comparisons of the form
     // x == x, x != x, x < x, etc.  These always evaluate to a constant, and
     // often indicate logic errors in the program.
@@ -5452,7 +5454,7 @@
     Expr *RHSStripped = rex->IgnoreParens();
     if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) {
       if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) {
-        if (DRL->getDecl() == DRR->getDecl() && !Loc.isMacroID() &&
+        if (DRL->getDecl() == DRR->getDecl() &&
             !IsWithinTemplateSpecialization(DRL->getDecl())) {
           DiagRuntimeBehavior(Loc, PDiag(diag::warn_comparison_always)
                               << 0 // self-

Modified: cfe/trunk/test/Sema/self-comparison.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/self-comparison.c?rev=114044&r1=114043&r2=114044&view=diff
==============================================================================
--- cfe/trunk/test/Sema/self-comparison.c (original)
+++ cfe/trunk/test/Sema/self-comparison.c Wed Sep 15 19:03:01 2010
@@ -75,3 +75,14 @@
 
 }
 
+// Don't issue a warning when either the left or right side of the comparison
+// results from a macro expansion.  <rdar://problem/8435950>
+#define R8435950_A i 
+#define R8435950_B i 
+
+int R8435950(int i) {
+  if (R8435950_A == R8435950_B) // no-warning
+   return 0;
+  return 1;
+}
+