From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 9 Jun 2015 02:41:08 +0000 (+0000)
Subject: [MSVC Compatibility] Don't diagnose c-style cast from void-ptr to fn-ptr
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9c9126a292c1723ada0b2e16883f691963567eee;p=clang

[MSVC Compatibility] Don't diagnose c-style cast from void-ptr to fn-ptr

The machinery added to permit a static_cast from void-ptr to fn-ptr
unintentionally gets triggered for c-style casts and function-style
casts.  The observable effect was a diagnostic issued inappropriately.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@239382 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaCast.cpp b/lib/Sema/SemaCast.cpp
index 8683d03007..d9dc4df9f2 100644
--- a/lib/Sema/SemaCast.cpp
+++ b/lib/Sema/SemaCast.cpp
@@ -1084,7 +1084,8 @@ static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
 
         // Microsoft permits static_cast from 'pointer-to-void' to
         // 'pointer-to-function'.
-        if (Self.getLangOpts().MSVCCompat && DestPointee->isFunctionType()) {
+        if (!CStyle && Self.getLangOpts().MSVCCompat &&
+            DestPointee->isFunctionType()) {
           Self.Diag(OpRange.getBegin(), diag::ext_ms_cast_fn_obj) << OpRange;
           Kind = CK_BitCast;
           return TC_Success;
diff --git a/test/SemaCXX/MicrosoftCompatibility-cxx98.cpp b/test/SemaCXX/MicrosoftCompatibility-cxx98.cpp
index e72878e302..bfda837e95 100644
--- a/test/SemaCXX/MicrosoftCompatibility-cxx98.cpp
+++ b/test/SemaCXX/MicrosoftCompatibility-cxx98.cpp
@@ -7,4 +7,8 @@ ENUM *var = 0;
 ENUM var2 = (ENUM)3;
 enum ENUM1* var3 = 0;// expected-warning {{forward references to 'enum' types are a Microsoft extension}}
 
-void (*PR23733)() = static_cast<void (*)()>((void *)0); // expected-warning {{static_cast between pointer-to-function and pointer-to-object is a Microsoft extension}}
+typedef void (*FnPtrTy)();
+void (*PR23733_1)() = static_cast<FnPtrTy>((void *)0); // expected-warning {{static_cast between pointer-to-function and pointer-to-object is a Microsoft extension}}
+void (*PR23733_2)() = FnPtrTy((void *)0);
+void (*PR23733_3)() = (FnPtrTy)((void *)0);
+void (*PR23733_4)() = reinterpret_cast<FnPtrTy>((void *)0);