[PATCH] D19654: PR27132: Proper mangling for __unaligned qualifier (now with PR27367 fixed)

[David Majnemer via cfe-commits]

majnemer added inline comments.

================
Comment at: lib/AST/MicrosoftMangle.cpp:1583-1584
@@ -1579,2 +1582,4 @@
   case QMM_Result:
+    // Presence of __unaligned qualifier shouldn't affect mangling here.
+    Quals.removeUnaligned();
     if ((!IsPointer && Quals) || isa<TagType>(T)) {
----------------
rnk wrote:
> majnemer wrote:
> > andreybokhanko wrote:
> > > majnemer wrote:
> > > > andreybokhanko wrote:
> > > > > Done. Test added.
> > > > Hmm, can you give a concrete example why we need this line?
> > > Sure. An example is:
> > > 
> > > __unaligned int unaligned_foo3() { return 0; }
> > > 
> > > MS mangles it as
> > > 
> > > ?unaligned_foo3@@YAHXZ
> > > 
> > > However, if __unaligned is taken into account, "if ((!IsPointer && Quals) || isa<TagType>(T))" computes to true and clang adds "?A", resulting to
> > > 
> > > ?unaligned_foo3@@YA?AHXZ
> > > 
> > > Yours,
> > > Andrey
> > > 
> > Wait, I thought __unaligned can only apply to pointer types.  Is this not so?!
> > Does `__unaligned int x;` really keep it's `__unaligned` qualifier?
> Yeah it does:
>   $ cat t.cpp
>   __unaligned int x;
>   $ cl -nologo -c t.cpp && dumpbin /symbols t.obj  | grep ?x
>   t.cpp
>   008 00000000 SECT3  notype       External     | ?x@@3HFA (int __unaligned x)
Woah.  So if you do:

> __unaligned int unaligned_foo3() { return 0; }
> auto z = foo3();

How is `z` mangled?


http://reviews.llvm.org/D19654