c: assignment/init of a function pointer whose function(s)

return to one which does not return (has noreturn attribute) 
should warn as it is an unsafe assignment. // rdar://10095762
c++ already handles this. This is the c version.

llvm-svn: 141141

2 files changed, 8 insertions, 5 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 5e0c78409da..6f68c2dc2f4 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5543,13 +5543,13 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
   if (lbaseInfo.getProducesResult() != rbaseInfo.getProducesResult())
     return QualType();
 
-  // It's noreturn if either type is.
-  // FIXME: some uses, e.g. conditional exprs, really want this to be 'both'.
-  bool NoReturn = lbaseInfo.getNoReturn() || rbaseInfo.getNoReturn();
-  if (NoReturn != lbaseInfo.getNoReturn())
+  // functypes which return are preferred over those that do not.
+  if (lbaseInfo.getNoReturn() && !rbaseInfo.getNoReturn())
     allLTypes = false;
-  if (NoReturn != rbaseInfo.getNoReturn())
+  else if (!lbaseInfo.getNoReturn() && rbaseInfo.getNoReturn())
     allRTypes = false;
+  // FIXME: some uses, e.g. conditional exprs, really want this to be 'both'.
+  bool NoReturn = lbaseInfo.getNoReturn() || rbaseInfo.getNoReturn();
 
   FunctionType::ExtInfo einfo = lbaseInfo.withNoReturn(NoReturn);
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 707d577f613..242fcfacde5 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5277,6 +5277,9 @@ checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) {
     // General pointer incompatibility takes priority over qualifiers.
     return Sema::IncompatiblePointer;
   }
+  if (!S.getLangOptions().CPlusPlus &&
+      S.IsNoReturnConversion(ltrans, rtrans, ltrans))
+    return Sema::IncompatiblePointer;
   return ConvTy;
 }