[binutils-gdb] PE+: Remove the stdcall fixup machinery
Jan Beulich
jbeulich@sourceware.org
Fri Sep 4 09:48:51 GMT 2026
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=534e9a794c4d63e27519ec16489de53ada7bb2fd
commit 534e9a794c4d63e27519ec16489de53ada7bb2fd
Author: Oleg Tolmatcev <oleg.tolmatcev@gmail.com>
Date: Fri Sep 4 11:44:50 2026 +0200
PE+: Remove the stdcall fixup machinery
Win64 has a single calling convention, so symbols never carry the @nn
stdcall decoration. The stdcall fixup pass in pep.em can therefore
never find a match, and neither can --kill-at or --add-stdcall-alias,
both of which only act on names containing '@'.
Remove the stdcall fixup pass. Besides being dead code, it traversed
the whole link hash table once per undefined cdecl symbol, so it was
quadratic.
The four affected options are still parsed, and now simply ignored, so
that command lines shared with i386 PE targets keep working. They are
no longer listed in --help, and ld.texi records that they have no
effect on PE+ targets.
ld/ChangeLog:
* emultempl/pep.em (pep_enable_stdcall_fixup, pep_undef_found_sym)
(pep_undef_cdecl_match, set_decoration, pep_fixup_stdcalls):
Remove.
(gld${EMULATION_NAME}_list_options): Don't list --add-stdcall-alias,
--disable-stdcall-fixup, --enable-stdcall-fixup or --kill-at.
(gld${EMULATION_NAME}_handle_option): Accept and ignore
OPTION_KILL_ATS, OPTION_STDCALL_ALIASES,
OPTION_ENABLE_STDCALL_FIXUP and OPTION_DISABLE_STDCALL_FIXUP.
(gld${EMULATION_NAME}_after_open): Don't call pep_fixup_stdcalls.
* ld.texi (--add-stdcall-alias, --enable-stdcall-fixup)
(--kill-at): Note that these have no effect on PE+ targets.
Signed-off-by: Oleg Tolmatcev <oleg.tolmatcev@gmail.com>
Diff:
---
ld/emultempl/pep.em | 146 +---------------------------------------------------
ld/ld.texi | 6 +++
2 files changed, 8 insertions(+), 144 deletions(-)
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em
index 3ba29401821..a20b5c7dc0d 100644
--- a/ld/emultempl/pep.em
+++ b/ld/emultempl/pep.em
@@ -194,7 +194,6 @@ static char *pdb_name;
#endif
#ifdef DLL_SUPPORT
-static int pep_enable_stdcall_fixup = 1; /* 0=disable 1=enable (default). */
static char * pep_out_def_filename = NULL;
static int pep_enable_auto_image_base = 0;
static char * pep_dll_search_prefix = NULL;
@@ -425,9 +424,6 @@ gld${EMULATION_NAME}_list_options (FILE *file)
fprintf (file, _(" --[no-]insert-timestamp Use a real timestamp rather than zero (default)\n"));
fprintf (file, _(" This makes binaries non-deterministic\n"));
#ifdef DLL_SUPPORT
- fprintf (file, _(" --add-stdcall-alias Export symbols with and without @nn\n"));
- fprintf (file, _(" --disable-stdcall-fixup Don't link _sym to _sym@nn\n"));
- fprintf (file, _(" --enable-stdcall-fixup Link _sym to _sym@nn without warnings\n"));
fprintf (file, _(" --exclude-symbols sym,sym,... Exclude symbols from automatic export\n"));
fprintf (file, _(" --exclude-all-symbols Exclude all symbols from automatic export\n"));
fprintf (file, _(" --exclude-libs lib,lib,... Exclude libraries from automatic export\n"));
@@ -435,7 +431,6 @@ gld${EMULATION_NAME}_list_options (FILE *file)
fprintf (file, _(" Exclude objects, archive members from auto\n"));
fprintf (file, _(" export, place into import library instead\n"));
fprintf (file, _(" --export-all-symbols Automatically export all globals to DLL\n"));
- fprintf (file, _(" --kill-at Remove @nn from exported symbols\n"));
fprintf (file, _(" --output-def <file> Generate a .DEF file for the built DLL\n"));
fprintf (file, _(" --warn-duplicate-exports Warn about duplicate exports\n"));
fprintf (file, _(" --compat-implib Create backward compatible import libs;\n\
@@ -768,16 +763,11 @@ gld${EMULATION_NAME}_handle_option (int optc)
pep_dll_add_excludes (optarg, EXCLUDEFORIMPLIB);
break;
case OPTION_KILL_ATS:
- pep_dll_kill_ats = 1;
- break;
case OPTION_STDCALL_ALIASES:
- pep_dll_stdcall_aliases = 1;
- break;
case OPTION_ENABLE_STDCALL_FIXUP:
- pep_enable_stdcall_fixup = 1;
- break;
case OPTION_DISABLE_STDCALL_FIXUP:
- pep_enable_stdcall_fixup = 0;
+ /* Ignored: stdcall and cdecl are unsupported on platforms using
+ Win64's ABI. */
break;
case OPTION_WARN_DUPLICATE_EXPORTS:
pep_dll_warn_dup_exports = 1;
@@ -1031,132 +1021,6 @@ gld${EMULATION_NAME}_after_parse (void)
}
#ifdef DLL_SUPPORT
-static struct bfd_link_hash_entry *pep_undef_found_sym;
-
-static bool
-pep_undef_cdecl_match (struct bfd_link_hash_entry *h, void *inf)
-{
- int sl;
- char *string = inf;
- const char *hs = h->root.string;
-
- sl = strlen (string);
- if (h->type == bfd_link_hash_defined
- && ((*hs == '@' && *string == '_'
- && strncmp (hs + 1, string + 1, sl - 1) == 0)
- || strncmp (hs, string, sl) == 0)
- && h->root.string[sl] == '@')
- {
- pep_undef_found_sym = h;
- return false;
- }
- return true;
-}
-
-static void
-set_decoration (const char *undecorated_name,
- struct bfd_link_hash_entry * decoration)
-{
- static bool gave_warning_message = false;
- struct decoration_hash_entry *entry;
-
- if (is_underscoring () && undecorated_name[0] == '_')
- undecorated_name++;
-
- entry = (struct decoration_hash_entry *)
- bfd_hash_lookup (&(coff_hash_table (&link_info)->decoration_hash),
- undecorated_name, true /* create */, false /* copy */);
-
- if (entry->decorated_link != NULL && !gave_warning_message)
- {
- einfo (_("%P: warning: overwriting decorated name %s with %s\n"),
- entry->decorated_link->root.string, undecorated_name);
- gave_warning_message = true;
- }
-
- entry->decorated_link = decoration;
-}
-
-static void
-pep_fixup_stdcalls (void)
-{
- static int gave_warning_message = 0;
- struct bfd_link_hash_entry *undef, *sym;
-
- if (pep_dll_extra_pe_debug)
- printf ("%s\n", __func__);
-
- for (undef = link_info.hash->undefs; undef; undef=undef->u.undef.next)
- if (undef->type == bfd_link_hash_undefined)
- {
- const char* at = strchr (undef->root.string, '@');
- int lead_at = (*undef->root.string == '@');
- if (lead_at)
- at = strchr (undef->root.string + 1, '@');
- if (at || lead_at)
- {
- /* The symbol is a stdcall symbol, so let's look for a
- cdecl symbol with the same name and resolve to that. */
- char *cname = xstrdup (undef->root.string);
- char *at2;
-
- if (lead_at)
- *cname = '_';
- at2 = strchr (cname, '@');
- if (at2)
- *at2 = 0;
- sym = bfd_link_hash_lookup (link_info.hash, cname, 0, 0, 1);
-
- if (sym && sym->type == bfd_link_hash_defined)
- {
- undef->type = bfd_link_hash_defined;
- undef->u.def.value = sym->u.def.value;
- undef->u.def.section = sym->u.def.section;
-
- if (pep_enable_stdcall_fixup == -1)
- {
- einfo (_("warning: resolving %s by linking to %s\n"),
- undef->root.string, cname);
- if (! gave_warning_message)
- {
- gave_warning_message = 1;
- einfo (_("Use --enable-stdcall-fixup to disable these warnings\n"));
- einfo (_("Use --disable-stdcall-fixup to disable these fixups\n"));
- }
- }
- }
- }
- else
- {
- /* The symbol is a cdecl symbol, so we look for stdcall
- symbols - which means scanning the whole symbol table. */
- pep_undef_found_sym = 0;
- bfd_link_hash_traverse (link_info.hash, pep_undef_cdecl_match,
- (char *) undef->root.string);
- sym = pep_undef_found_sym;
- if (sym)
- {
- undef->type = bfd_link_hash_defined;
- undef->u.def.value = sym->u.def.value;
- undef->u.def.section = sym->u.def.section;
- set_decoration (undef->root.string, sym);
-
- if (pep_enable_stdcall_fixup == -1)
- {
- einfo (_("warning: resolving %s by linking to %s\n"),
- undef->root.string, sym->root.string);
- if (! gave_warning_message)
- {
- gave_warning_message = 1;
- einfo (_("Use --enable-stdcall-fixup to disable these warnings\n"));
- einfo (_("Use --disable-stdcall-fixup to disable these fixups\n"));
- }
- }
- }
- }
- }
-}
-
static bfd_vma
read_addend (arelent *rel, asection *s)
{
@@ -1598,12 +1462,6 @@ gld${EMULATION_NAME}_after_open (void)
if (link_info.pei386_auto_import) /* -1=warn or 1=enable */
pep_find_data_imports (U ("_head_"), make_import_fixup);
- /* The implementation of the feature is rather dumb and would cause the
- compilation time to go through the roof if there are many undefined
- symbols in the link, so it needs to be run after auto-import. */
- if (pep_enable_stdcall_fixup) /* -1=warn or 1=enable */
- pep_fixup_stdcalls ();
-
#if !defined(TARGET_IS_i386pep) && !defined(COFF_WITH_peAArch64)
if (bfd_link_pic (&link_info))
#else
diff --git a/ld/ld.texi b/ld/ld.texi
index 9d6618a4307..90c84c8d3c1 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -3471,6 +3471,8 @@ values by either a space or an equals sign.
@item --add-stdcall-alias
If given, symbols with a stdcall suffix (@@@var{nn}) will be exported
as-is and also with the suffix stripped.
+Because PE+ targets have a single calling convention, symbols there
+are never decorated and this option is accepted but has no effect.
[This option is specific to PE targeted ports of the linker]
@kindex --base-file
@@ -3526,6 +3528,8 @@ to be usable. If you specify @option{--enable-stdcall-fixup}, this
feature is fully enabled and warnings are not printed. If you specify
@option{--disable-stdcall-fixup}, this feature is disabled and such
mismatches are considered to be errors.
+Because PE+ targets have a single calling convention, symbols there
+are never decorated and these options are accepted but have no effect.
[This option is specific to PE targeted ports of the linker]
@kindex --leading-underscore
@@ -3595,6 +3599,8 @@ committed.
@item --kill-at
If given, the stdcall suffixes (@@@var{nn}) will be stripped from
symbols before they are exported.
+Because PE+ targets have a single calling convention, symbols there
+are never decorated and this option is accepted but has no effect.
[This option is specific to PE targeted ports of the linker]
@kindex --large-address-aware
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