diff mbox series

varasm: Fix up process_pending_assemble_externals [PR113182]

Message ID ZaEOgF4jwjfK6QwE@tucnak
State Unresolved
Headers
Series varasm: Fix up process_pending_assemble_externals [PR113182] |

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Context Check Description
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Commit Message

Jakub Jelinek Jan. 12, 2024, 10:03 a.m. UTC 
  Hi!

John reported that on HP-UX we no longer emit needed external libcalls.

The problem is that we didn't strip name encoding when looking up
the identifiers in assemble_external_libcall and
process_pending_assemble_externals, while
assemble_name_resolve does that:
  const char *real_name = targetm.strip_name_encoding (name);
  tree id = maybe_get_identifier (real_name);

  if (id)
    {
...
      mark_referenced (id);
The intention is that assemble_external_libcall ensures the IDENTIFIER
exists for the external libcall, then for actually emitted calls
assemble_name_resolve sees those IDENTIFIERS and sets TREE_SYMBOL_REFERENCED
on them and finally process_pending_assemble_externals looks the
IDENTIFIER up again and checks its TREE_SYMBOL_REFERENCED.

But without the strip_name_encoding call, they can look up different
identifiers and those are likely never used.

In the PR, John was discussing whether get_identifier or
maybe_get_identifier should be used, I believe in assemble_external_libcall
we definitely want to use get_identifier, we need an IDENTIFIER allocated
so that it can be actually tracked, in process_pending_assemble_externals
it doesn't matter, the IDENTIFIER should be already created.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
ok for trunk?

2024-01-12  John David Anglin  <danglin@gcc.gnu.org>
	    Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/113182
	* varasm.cc (process_pending_assemble_externals,
	assemble_external_libcall): Use targetm.strip_name_encoding
	before calling get_identifier.


	Jakub

Comments

Richard Biener Jan. 12, 2024, 11:44 a.m. UTC | #1 
On Fri, 12 Jan 2024, Jakub Jelinek wrote:

> Hi!
> 
> John reported that on HP-UX we no longer emit needed external libcalls.
> 
> The problem is that we didn't strip name encoding when looking up
> the identifiers in assemble_external_libcall and
> process_pending_assemble_externals, while
> assemble_name_resolve does that:
>   const char *real_name = targetm.strip_name_encoding (name);
>   tree id = maybe_get_identifier (real_name);
> 
>   if (id)
>     {
> ...
>       mark_referenced (id);
> The intention is that assemble_external_libcall ensures the IDENTIFIER
> exists for the external libcall, then for actually emitted calls
> assemble_name_resolve sees those IDENTIFIERS and sets TREE_SYMBOL_REFERENCED
> on them and finally process_pending_assemble_externals looks the
> IDENTIFIER up again and checks its TREE_SYMBOL_REFERENCED.
> 
> But without the strip_name_encoding call, they can look up different
> identifiers and those are likely never used.
> 
> In the PR, John was discussing whether get_identifier or
> maybe_get_identifier should be used, I believe in assemble_external_libcall
> we definitely want to use get_identifier, we need an IDENTIFIER allocated
> so that it can be actually tracked, in process_pending_assemble_externals
> it doesn't matter, the IDENTIFIER should be already created.
> 
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk?

OK.

> 2024-01-12  John David Anglin  <danglin@gcc.gnu.org>
> 	    Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR middle-end/113182
> 	* varasm.cc (process_pending_assemble_externals,
> 	assemble_external_libcall): Use targetm.strip_name_encoding
> 	before calling get_identifier.
> 
> --- gcc/varasm.cc.jj	2024-01-08 21:56:04.968516120 +0100
> +++ gcc/varasm.cc	2024-01-11 18:44:19.171399167 +0100
> @@ -2543,7 +2543,8 @@ process_pending_assemble_externals (void
>    for (rtx list = pending_libcall_symbols; list; list = XEXP (list, 1))
>      {
>        rtx symbol = XEXP (list, 0);
> -      tree id = get_identifier (XSTR (symbol, 0));
> +      const char *name = targetm.strip_name_encoding (XSTR (symbol, 0));
> +      tree id = get_identifier (name);
>        if (TREE_SYMBOL_REFERENCED (id))
>  	targetm.asm_out.external_libcall (symbol);
>      }
> @@ -2631,7 +2632,8 @@ assemble_external_libcall (rtx fun)
>           reference to it will mark its tree node as referenced, via
>           assemble_name_resolve.  These are eventually emitted, if
>           used, in process_pending_assemble_externals. */
> -      get_identifier (XSTR (fun, 0));
> +      const char *name = targetm.strip_name_encoding (XSTR (fun, 0));
> +      get_identifier (name);
>        pending_libcall_symbols = gen_rtx_EXPR_LIST (VOIDmode, fun,
>  						   pending_libcall_symbols);
>      }
> 
> 	Jakub
> 
>
diff mbox series

Patch

--- gcc/varasm.cc.jj	2024-01-08 21:56:04.968516120 +0100
+++ gcc/varasm.cc	2024-01-11 18:44:19.171399167 +0100
@@ -2543,7 +2543,8 @@  process_pending_assemble_externals (void
   for (rtx list = pending_libcall_symbols; list; list = XEXP (list, 1))
     {
       rtx symbol = XEXP (list, 0);
-      tree id = get_identifier (XSTR (symbol, 0));
+      const char *name = targetm.strip_name_encoding (XSTR (symbol, 0));
+      tree id = get_identifier (name);
       if (TREE_SYMBOL_REFERENCED (id))
 	targetm.asm_out.external_libcall (symbol);
     }
@@ -2631,7 +2632,8 @@  assemble_external_libcall (rtx fun)
          reference to it will mark its tree node as referenced, via
          assemble_name_resolve.  These are eventually emitted, if
          used, in process_pending_assemble_externals. */
-      get_identifier (XSTR (fun, 0));
+      const char *name = targetm.strip_name_encoding (XSTR (fun, 0));
+      get_identifier (name);
       pending_libcall_symbols = gen_rtx_EXPR_LIST (VOIDmode, fun,
 						   pending_libcall_symbols);
     }