From: Akira Hatanaka <ahatanaka@apple.com>
Date: Fri, 6 Jan 2017 17:56:15 +0000 (+0000)
Subject: Make ASTContext::getDeclAlign return the correct alignment for
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6ad43775258405f22d7db3fe6d76f33621b8ba83;p=clang

Make ASTContext::getDeclAlign return the correct alignment for
FunctionDecls.

This commit silences an incorrect warning that is issued when a function
pointer is cast to another function pointer type. The warning gets
issued because alignments of the source and destination do not match in
Sema::CheckCastAlign, which happens because ASTContext::getTypeInfoImpl
and ASTContext::getDeclAlign return different values for functions (the
former returns 4 while the latter returns 1).

This should fix PR31558.

rdar://problem/29533528

Differential Revision: https://reviews.llvm.org/D27478


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@291253 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 1b5988d019..d03c22af5b 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -1458,7 +1458,9 @@ CharUnits ASTContext::getDeclAlign(const Decl *D, bool ForAlignof) const {
         T = getPointerType(RT->getPointeeType());
     }
     QualType BaseT = getBaseElementType(T);
-    if (!BaseT->isIncompleteType() && !T->isFunctionType()) {
+    if (T->isFunctionType())
+      Align = getTypeInfoImpl(T.getTypePtr()).Align;
+    else if (!BaseT->isIncompleteType()) {
       // Adjust alignments of declarations with array type by the
       // large-array alignment on the target.
       if (const ArrayType *arrayType = getAsArrayType(T)) {
diff --git a/test/Sema/warn-cast-align.c b/test/Sema/warn-cast-align.c
index e8f85bc14d..389c0c17d2 100644
--- a/test/Sema/warn-cast-align.c
+++ b/test/Sema/warn-cast-align.c
@@ -59,3 +59,11 @@ void test4() {
   i = (int *)&s.s0;
   i = (int *)a;
 }
+
+// No warnings.
+typedef int (*FnTy)(void);
+unsigned int func5(void);
+
+FnTy test5(void) {
+  return (FnTy)&func5;
+}