Re: [PATCH][AARCH64] Fix the name mangling of va_list

[Marcus Shawcroft <marcus dot shawcroft at arm dot com>]

On 21/11/12 14:31, Yufeng Zhang wrote:
> Hi,
>
> This patch updates the AArch64 port to mangle __va_list as it is in
> namespace std in C++.  This is specified in the AArch64 AAPCS64 ABI doc.
>
> OK for the trunk?
>
> Thanks,
> Yufeng
>
> gcc/ChangeLog
>
> 2012-11-21  Yufeng Zhang  <yufeng.zhang@arm.com>
>
>           * config/aarch64/aarch64.c (aarch64_mangle_type): New function.
>           (TARGET_MANGLE_TYPE): Define.

The change to the AArch64 port itself is OK.

> gcc/testsuite/ChangeLog
>
> 2012-11-21  Yufeng Zhang  <yufeng.zhang@arm.com>
>
>           * g++.dg/abi/arm_va_list.C: Also test on aarch64*-*-*.

 // AAPCS \S 7.1.4 requires that va_list be a typedef for "struct
 // __va_list".  The mangling is as if it were "std::__va_list".
+// So is required for the AArch64 target.


The functional change in this test makes sense however the comment 
change is slightly confusing.  The original comment refers to the 
procedure call standard for AArch32: IHI0042D_aapcs.pdf.

The procedure call standard for AArch64 is defined in 
IHI0055A_aapcs.pdf.  This document also discusses va_list in chapter 
7.1.4.  Perhaps a different form of words distinguishes between the two 
different PCS documents would be better? Perhaps something along these 
lines:

// AAPCS \S 7.1.4 requires that va_list be a typedef for "struct
// __va_list".  The mangling is as if it were "std::__va_list".
// AArch64 PCS IHI0055A_aapcs64.pdf \S 7.1.4 requires that va_list
// be a typedef for "struct __va_list".  The mangling is as if it
// were "std::__va_list".

In any case I don;t believe I can OK this change to the generic part of 
the test suite. Suggest you CC Mike Stump or Janis Johnson.


Cheers

/Marcus