Patchwork [AARCH64] Fix the name mangling of va_list

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Submitter Yufeng Zhang
Date Nov. 21, 2012, 2:31 p.m.
Message ID <50ACE5A7.1080204@arm.com>
Download mbox | patch
Permalink /patch/200780/
State New
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Comments

Yufeng Zhang - Nov. 21, 2012, 2:31 p.m.
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.

gcc/testsuite/ChangeLog

2012-11-21  Yufeng Zhang  <yufeng.zhang@arm.com>

         * g++.dg/abi/arm_va_list.C: Also test on aarch64*-*-*.
Marcus Shawcroft - Nov. 26, 2012, 9:55 a.m.
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

Patch

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 4437fef..792b086 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -5859,6 +5859,20 @@  aarch64_preferred_simd_mode (enum machine_mode mode)
   return word_mode;
 }
 
+/* Implement TARGET_MANGLE_TYPE.  */
+
+const char *
+aarch64_mangle_type (const_tree type)
+{
+  /* The AArch64 ABI documents say that "__va_list" has to be
+     managled as if it is in the "std" namespace.  */
+  if (lang_hooks.types_compatible_p (CONST_CAST_TREE (type), va_list_type))
+    return "St9__va_list";
+
+  /* Use the default mangling.  */
+  return NULL;
+}
+
 /* Legitimize a memory reference for sync primitive implemented using
    LDXR/STXR instructions.  We currently force the form of the reference
    to be indirect without offset.  */
@@ -6923,6 +6937,9 @@  aarch64_c_mode_for_suffix (char suffix)
 #undef TARGET_LIBGCC_CMP_RETURN_MODE
 #define TARGET_LIBGCC_CMP_RETURN_MODE aarch64_libgcc_cmp_return_mode
 
+#undef TARGET_MANGLE_TYPE
+#define TARGET_MANGLE_TYPE aarch64_mangle_type
+
 #undef TARGET_MEMORY_MOVE_COST
 #define TARGET_MEMORY_MOVE_COST aarch64_memory_move_cost
 
diff --git a/gcc/testsuite/g++.dg/abi/arm_va_list.C b/gcc/testsuite/g++.dg/abi/arm_va_list.C
index 45a426a..d983ee1 100644
--- a/gcc/testsuite/g++.dg/abi/arm_va_list.C
+++ b/gcc/testsuite/g++.dg/abi/arm_va_list.C
@@ -1,9 +1,10 @@ 
-// { dg-do compile }
+// { dg-do compile { target { aarch64*-*-* arm*-*-* } } }
 // { dg-options "-Wno-abi" }
-// { dg-require-effective-target arm_eabi }
+// { dg-require-effective-target arm_eabi { target arm*-*-* } }
 
 // 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.
 // #include <stdarg.h>
 typedef __builtin_va_list va_list;