r291253 - Make ASTContext::getDeclAlign return the correct alignment for

[Akira Hatanaka via cfe-commits]

Author: ahatanak
Date: Fri Jan  6 11:56:15 2017
New Revision: 291253

URL: http://llvm.org/viewvc/llvm-project?rev=291253&view=rev
Log:
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

Modified:
    cfe/trunk/lib/AST/ASTContext.cpp
    cfe/trunk/test/Sema/warn-cast-align.c

Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=291253&r1=291252&r2=291253&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Fri Jan  6 11:56:15 2017
@@ -1458,7 +1458,9 @@ CharUnits ASTContext::getDeclAlign(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)) {

Modified: cfe/trunk/test/Sema/warn-cast-align.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-cast-align.c?rev=291253&r1=291252&r2=291253&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-cast-align.c (original)
+++ cfe/trunk/test/Sema/warn-cast-align.c Fri Jan  6 11:56:15 2017
@@ -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;
+}