Fix printf format string checking for '%lc' (which expects a wint_t or compatible argument). Fixes PR 7981.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111978 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 0 deletions

diff --git a/lib/Analysis/FormatString.cpp b/lib/Analysis/FormatString.cpp
index a6cfba228e..388b9d34a2 100644
--- a/lib/Analysis/FormatString.cpp
+++ b/lib/Analysis/FormatString.cpp
@@ -277,6 +277,23 @@ bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
         C.getCanonicalType(PT->getPointeeType()).getUnqualifiedType();
       return pointeeTy == C.getWCharType();
     }
+    
+    case WIntTy: {
+      // Instead of doing a lookup for the definition of 'wint_t' (which
+      // is defined by the system headers) instead see if wchar_t and
+      // the argument type promote to the same type.
+      QualType PromoWChar =
+        C.getWCharType()->isPromotableIntegerType() 
+          ? C.getPromotedIntegerType(C.getWCharType()) : C.getWCharType();
+      QualType PromoArg = 
+        argTy->isPromotableIntegerType()
+          ? C.getPromotedIntegerType(argTy) : argTy;
+      
+      PromoWChar = C.getCanonicalType(PromoWChar).getUnqualifiedType();
+      PromoArg = C.getCanonicalType(PromoArg).getUnqualifiedType();
+      
+      return PromoWChar == PromoArg;
+    }
 
     case CPointerTy:
       return argTy->getAs<PointerType>() != NULL ||
@@ -308,6 +325,10 @@ QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
       return C.ObjCBuiltinIdTy;
     case CPointerTy:
       return C.VoidPtrTy;
+    case WIntTy: {
+      QualType WC = C.getWCharType();
+      return WC->isPromotableIntegerType() ? C.getPromotedIntegerType(WC) : WC;
+    }
   }
 
   // FIXME: Should be unreachable, but Clang is currently emitting
diff --git a/lib/Analysis/PrintfFormatString.cpp b/lib/Analysis/PrintfFormatString.cpp
index 727de2934f..b8c327cdeb 100644
--- a/lib/Analysis/PrintfFormatString.cpp
+++ b/lib/Analysis/PrintfFormatString.cpp
@@ -281,6 +281,14 @@ ArgTypeResult PrintfSpecifier::getArgType(ASTContext &Ctx) const {
   if (!CS.consumesDataArgument())
     return ArgTypeResult::Invalid();
 
+  if (CS.getKind() == ConversionSpecifier::cArg)
+    switch (LM.getKind()) {
+      case LengthModifier::None: return Ctx.IntTy;
+      case LengthModifier::AsLong: return ArgTypeResult::WIntTy;
+      default:
+        return ArgTypeResult::Invalid();
+    }
+  
   if (CS.isIntArg())
     switch (LM.getKind()) {
       case LengthModifier::AsLongDouble: