-Wformat: better handling of qualifiers on pointer arguments

Warn about using pointers to const-qualified types as arguments to
scanf. Ignore the volatile qualifier when checking if types match.

llvm-svn: 161052

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
index a68b9bb3240..f03a84fb523 100644
--- a/clang/lib/Analysis/FormatString.cpp
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -262,6 +262,13 @@ bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
         argTy = ETy->getDecl()->getIntegerType();
       argTy = C.getCanonicalType(argTy).getUnqualifiedType();
 
+      if (const PointerType *PTy = argTy->getAs<PointerType>()) {
+        // Strip volatile qualifier from pointee type.
+        QualType Pointee = PTy->getPointeeType();
+        Pointee.removeLocalVolatile();
+        argTy = C.getPointerType(Pointee);
+      }
+
       if (T == argTy)
         return true;
       // Check for "compatible types".