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PATCH [cygwin/mingw] Fix __attribute__((alias())) vs stdcall decoration

Hello

__attribute__((alias ("foo"))) does not work as expected with aliases
to stdcall or fastcall functions on win32 targets (which follow MS
convention and decorate the user names with @nn suffix).

The following test fails with an undefined reference to bar@4

/* alias.c */
#ifdef __cplusplus
extern "C"
#endif
void
__attribute__((stdcall))
foo(int i) { }

void
__attribute__((stdcall))  __attribute__((alias("foo@4")))
bar (int i);

int main()
{
  bar(1);
  return 0;   
}
 

The assembly shows that the DECL_ASSEMBLY_NAME for bar is being used in
set statement rather than the user label bar@4

.globl _bar@4
	.set	_bar,_foo@4

This is a regression from 2.95. The regression is present on trunk, 3.3.2
and 3.2.3.

The following fixes. Effectively the use of this
ASM_OUTPUT_DEF_FROM_DECLS in varasm.c (assemble_alias) just replaces
IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)) with
XSTR (XEXP (DECL_RTL (DECL), 0), 0) to get the decorated identifier. 

ChangeLog

2003-10-17  Danny Smith  <dannysmith@users.sourceforge.net>

	* config/i386/cygming.h (ASM_OUTPUT_DEF_FROM_DECLS): Define.


Index: cygming.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/i386/cygming.h,v
retrieving revision 1.8
diff -c -3 -p -r1.8 cygming.h
*** cygming.h	7 Oct 2003 09:36:34 -0000	1.8
--- cygming.h	16 Oct 2003 01:27:17 -0000
*************** extern int i386_pe_dllimport_name_p (con
*** 364,372 ****
--- 364,383 ----
  #ifndef SET_ASM_OP
  #define SET_ASM_OP "\t.set\t"
  #endif
+ /* This implements the `alias' attribute, keeping any stdcall or
+    fastcall decoration.  */
+ #undef	ASM_OUTPUT_DEF_FROM_DECLS
+ #define	ASM_OUTPUT_DEF_FROM_DECLS(STREAM, DECL, TARGET) 		\
+   do									\
+     {									\
+       const char *alias;						\
+       rtx rtlname = XEXP (DECL_RTL (DECL), 0);				\
+       if (GET_CODE (rtlname) == SYMBOL_REF)				\
+ 	alias = XSTR (rtlname, 0);					\
+       else								\
+ 	abort ();							\
+       ASM_OUTPUT_DEF (STREAM, alias, IDENTIFIER_POINTER (TARGET));	\
+     } while (0)
  
  #undef TREE
  
  

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