Fix crash on noreturn conversion in unprototyped function type. Thanks to Keith

Walker for spotting the bug.

llvm-svn: 284673

2 files changed, 13 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 0c7ef74a248..db97f3d57f5 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1432,7 +1432,7 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
   const auto *FromFn = cast<FunctionType>(CanFrom);
   FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
 
-  const auto *ToFn = dyn_cast<FunctionProtoType>(CanTo);
+  const auto *ToFn = cast<FunctionType>(CanTo);
   FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
 
   bool Changed = false;
@@ -1445,7 +1445,7 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
 
   // Drop 'noexcept' if not present in target type.
   if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
-    const auto *ToFPT = dyn_cast<FunctionProtoType>(ToFn);
+    const auto *ToFPT = cast<FunctionProtoType>(ToFn);
     if (FromFPT->isNothrow(Context) && !ToFPT->isNothrow(Context)) {
       FromFn = cast<FunctionType>(
           Context.getFunctionType(FromFPT->getReturnType(),
diff --git a/clang/test/Sema/initialize-noreturn.c b/clang/test/Sema/initialize-noreturn.c
index b90d46d6beb..21ff29585ff 100644
--- a/clang/test/Sema/initialize-noreturn.c
+++ b/clang/test/Sema/initialize-noreturn.c
@@ -4,13 +4,24 @@
 typedef void (*Fn_noret)(void) __attribute__((noreturn));
 typedef void (*Fn_ret)(void);
 
+typedef void (*Fn_noret_noproto)() __attribute__((noreturn));
+typedef void (*Fn_ret_noproto)();
+
 void foo(void);
 void foo_noret(void)  __attribute__((noreturn));
 
+void foo_noproto();
+void foo_noret_noproto()  __attribute__((noreturn));
+
 void test() {
   Fn_noret fn2 = &foo; // expected-warning {{incompatible function pointer types initializing 'Fn_noret'}}
   Fn_noret fn3 = &foo_noret; 
   Fn_ret fn4 = &foo_noret; 
   Fn_ret fn5 = &foo;
+
+  Fn_noret_noproto fn6 = &foo_noproto; // expected-warning {{incompatible function pointer types initializing 'Fn_noret_noproto'}}
+  Fn_noret_noproto fn7 = &foo_noret_noproto; 
+  Fn_ret_noproto fn8 = &foo_noret_noproto; 
+  Fn_ret_noproto fn9 = &foo_noproto;
 }