From: Fariborz Jahanian <fjahanian@apple.com>
Date: Wed, 5 Oct 2011 00:05:34 +0000 (+0000)
Subject: c: assignment/init of a function pointer whose function(s)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=53c8167d7a007daae87f342c0fedd03f1dcf1b62;p=clang

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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141141 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 5e0c78409d..6f68c2dc2f 100644
--- a/lib/AST/ASTContext.cpp
+++ b/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/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 707d577f61..242fcfacde 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/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;
 }
 
diff --git a/test/Sema/initialize-noreturn.c b/test/Sema/initialize-noreturn.c
new file mode 100644
index 0000000000..5557862871
--- /dev/null
+++ b/test/Sema/initialize-noreturn.c
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 %s -fsyntax-only -verify
+// rdar://10095762
+
+typedef void (*Fn_noret)(void) __attribute__((noreturn));
+typedef void (*Fn_ret)(void);
+
+void foo(void);
+void foo_noret(void)  __attribute__((noreturn));
+
+void test() {
+  Fn_noret fn2 = &foo; // expected-warning {{incompatible pointer types initializing 'Fn_noret'}}
+  Fn_noret fn3 = &foo_noret; 
+  Fn_ret fn4 = &foo_noret; 
+  Fn_ret fn5 = &foo;
+}
+