Question about a varasm change

Question about a varasm change

[Bernd Schmidt]

I have a question about the patch below which was applied in March.  It
appears to be causing us to generate incorrect debugging information with
static local variables in C.  The following testcase is from Fred Fish:

  void foo ()
  {
    static int funclocal = 101;
  }

The correct output is supposed to be

  .stabs "funclocal:V1",38,0,3,funclocal.3

while the current compiler produces

  .stabs "funclocal.0:V1",38,0,3,funclocal.0

The code in dbxout_symbol_name uses DECL_ASSEMBLER_NAME to print the first
string.  DECL_ASSEMBLER_NAME has the correct value ("funclocal") in the
beginning when it's created by build_decl, but it gets overwritten with
"funclocal.0" in make_decl_rtl with the change below installed.

What does the change accomplish, and do you have an idea how to fix this
problem?


Bernd

2000-03-03  Jason Merrill  <jason@casey.cygnus.com>

        * varasm.c (make_function_rtl): If we change the name used in the
	rtl, update DECL_ASSEMBLER_NAME accordingly.
	(make_decl_rtl): Likewise.

Index: varasm.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/varasm.c,v
retrieving revision 1.101
retrieving revision 1.102
diff -u -p -r1.101 -r1.102
--- varasm.c	2000/03/02 23:30:38	1.101
+++ varasm.c	2000/03/04 00:48:46	1.102
@@ -553,6 +553,7 @@ make_function_rtl (decl)
 
   if (DECL_RTL (decl) == 0)
     {
+      DECL_ASSEMBLER_NAME (decl) = get_identifier (name);
       DECL_RTL (decl)
 	= gen_rtx_MEM (DECL_MODE (decl),
 		       gen_rtx_SYMBOL_REF (Pmode, name));
@@ -792,6 +793,7 @@ make_decl_rtl (decl, asmspec, top_level)
 	      name = new_name;
 	    }
 
+	  DECL_ASSEMBLER_NAME (decl) = get_identifier (name);
 	  DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl),
 					 gen_rtx_SYMBOL_REF (Pmode, name));
 	  MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);

Re: Question about a varasm change

[Jason Merrill]

The change fixes DECL_ASSEMBLER_NAME so that it actually corresponds to the
name used in assembler output, as documented.  If the stabs backend expects
it to be the unmangled name from the source, it's looking in the wrong
place; that's what DECL_NAME is for.

Jason

Re: Question about a varasm change

[Bernd Schmidt]

On 18 Sep 2000, Jason Merrill wrote:

> The change fixes DECL_ASSEMBLER_NAME so that it actually corresponds to the
> name used in assembler output, as documented.  If the stabs backend expects
> it to be the unmangled name from the source, it's looking in the wrong
> place; that's what DECL_NAME is for.

Thanks.  Is this patch OK?  It fixes a bunch of gdb failures.


Bernd

	* dbxout.c (dbxout_symbol_name): Use DECL_NAME rather than
	DECL_ASSEMBLER_NAME.

Index: dbxout.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/dbxout.c,v
retrieving revision 1.60
diff -u -p -r1.60 dbxout.c
--- dbxout.c	2000/07/23 17:53:21	1.60
+++ dbxout.c	2000/09/18 09:31:12
@@ -2219,7 +2219,7 @@ dbxout_symbol_name (decl, suffix, letter
      class member, we must put out the mangled name instead of the
      DECL_NAME.  Note also that static member (variable) names DO NOT begin
      with underscores in .stabs directives.  */
-  const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+  const char *name = IDENTIFIER_POINTER (DECL_NAME (decl));
   if (name == 0)
     name = "(anon)";
   fprintf (asmfile, "%s \"%s%s:", ASM_STABS_OP, name,

Re: Question about a varasm change

[Jeffrey A Law]

  In message < Pine.LNX.4.21.0009181031180.1440-100000@mahatma.cygnus.co.uk >you 
write:
  > On 18 Sep 2000, Jason Merrill wrote:
  > 
  > > The change fixes DECL_ASSEMBLER_NAME so that it actually corresponds to t
  > he
  > > name used in assembler output, as documented.  If the stabs backend expec
  > ts
  > > it to be the unmangled name from the source, it's looking in the wrong
  > > place; that's what DECL_NAME is for.
  > 
  > Thanks.  Is this patch OK?  It fixes a bunch of gdb failures.
  > 
  > 
  > Bernd
  > 
  > 	* dbxout.c (dbxout_symbol_name): Use DECL_NAME rather than
  > 	DECL_ASSEMBLER_NAME.
Err, don't you need to use DECL_ASSEMBLER_NAME if the decl is a 
static class member?  According to the comment in that case we want the
mangled name.

jeff

Re: Question about a varasm change

[Bernd Schmidt]

On Mon, 18 Sep 2000, Jeffrey A Law wrote:

>   > 	* dbxout.c (dbxout_symbol_name): Use DECL_NAME rather than
>   > 	DECL_ASSEMBLER_NAME.
> Err, don't you need to use DECL_ASSEMBLER_NAME if the decl is a 
> static class member?  According to the comment in that case we want the
> mangled name.

To be honest I have no idea.  I just followed what Jason suggested.


Bernd

Re: Question about a varasm change

[Jason Merrill]

I'll check in a fix RSN.

Jason

Re: Question about a varasm change

[Jason Merrill]

I'm checking this in:

2000-09-22  Jason Merrill  <jason@redhat.com>

	* dbxout.c (dbxout_symbol_name): Just use DECL_NAME for
	function-local names.

Index: dbxout.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/dbxout.c,v
retrieving revision 1.60
diff -c -p -r1.60 dbxout.c
*** dbxout.c	2000/07/23 17:53:21	1.60
--- dbxout.c	2000/09/22 17:52:45
*************** dbxout_symbol_name (decl, suffix, letter
*** 2215,2225 ****
       const char *suffix;
       int letter;
  {
!   /* One slight hitch: if this is a VAR_DECL which is a static
!      class member, we must put out the mangled name instead of the
!      DECL_NAME.  Note also that static member (variable) names DO NOT begin
!      with underscores in .stabs directives.  */
!   const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
    if (name == 0)
      name = "(anon)";
    fprintf (asmfile, "%s \"%s%s:", ASM_STABS_OP, name,
--- 2215,2233 ----
       const char *suffix;
       int letter;
  {
!   const char *name;
! 
!   if (TYPE_P (DECL_CONTEXT (decl)))
!     /* One slight hitch: if this is a VAR_DECL which is a static
!        class member, we must put out the mangled name instead of the
!        DECL_NAME.  Note also that static member (variable) names DO NOT begin
!        with underscores in .stabs directives.  */
!     name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
!   else
!     /* ...but if we're function-local, we don't want to include the junk
!        added by ASM_FORMAT_PRIVATE_NAME.  */
!     name = IDENTIFIER_POINTER (DECL_NAME (decl));
! 
    if (name == 0)
      name = "(anon)";
    fprintf (asmfile, "%s \"%s%s:", ASM_STABS_OP, name,