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author | Joseph Myers <joseph@codesourcery.com> | 2023-05-11 10:07:00 +0200 |
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committer | Tobias Burnus <tobias@codesourcery.com> | 2023-05-11 10:08:50 +0200 |
commit | c49d51fa8134f6c7e6c7cf6e4e3007c4fea617c5 (patch) | |
tree | a8c22969127dd684e5f417daf7b0620dfb70163b /lto-plugin/lto-plugin.c | |
parent | 5e05361e2fef586b0e04ee81220ad0217401cc4d (diff) | |
download | gcc-c49d51fa8134f6c7e6c7cf6e4e3007c4fea617c5.zip gcc-c49d51fa8134f6c7e6c7cf6e4e3007c4fea617c5.tar.gz gcc-c49d51fa8134f6c7e6c7cf6e4e3007c4fea617c5.tar.bz2 |
Implement LDPT_REGISTER_CLAIM_FILE_HOOK_V2 linker plugin hook [PR109128]
This is one part of the fix for PR109128, along with a corresponding
binutils's linker change. Without this patch, what happens in the
linker, when an unused object in a .a file has offload data, is that
elf_link_is_defined_archive_symbol calls bfd_link_plugin_object_p,
which ends up calling the plugin's claim_file_handler, which then
records the object as one with offload data. That is, the linker never
decides to use the object in the first place, but use of this _p
interface (called as part of trying to decide whether to use the
object) results in the plugin deciding to use its offload data (and a
consequent mismatch in the offload data present at runtime).
The new hook allows the linker plugin to distinguish calls to
claim_file_handler that know the object is being used by the linker
(from ldmain.c:add_archive_element), from calls that don't know it's
being used by the linker (from elf_link_is_defined_archive_symbol); in
the latter case, the plugin should avoid recording the object as one
with offload data.
PR middle-end/109128
include/
* plugin-api.h (ld_plugin_claim_file_handler_v2)
(ld_plugin_register_claim_file_v2)
(LDPT_REGISTER_CLAIM_FILE_HOOK_V2): New.
(struct ld_plugin_tv): Add tv_register_claim_file_v2.
lto-plugin/
* lto-plugin.c (register_claim_file_v2): New.
(claim_file_handler_v2): New.
(claim_file_handler): Wrap claim_file_handler_v2.
(onload): Handle LDPT_REGISTER_CLAIM_FILE_HOOK_V2.
Diffstat (limited to 'lto-plugin/lto-plugin.c')
-rw-r--r-- | lto-plugin/lto-plugin.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c index cc512a4..ae87089 100644 --- a/lto-plugin/lto-plugin.c +++ b/lto-plugin/lto-plugin.c @@ -173,6 +173,7 @@ static pthread_mutex_t plugin_lock; static char *arguments_file_name; static ld_plugin_register_claim_file register_claim_file; +static ld_plugin_register_claim_file_v2 register_claim_file_v2; static ld_plugin_register_all_symbols_read register_all_symbols_read; static ld_plugin_get_symbols get_symbols, get_symbols_v2, get_symbols_v3; static ld_plugin_register_cleanup register_cleanup; @@ -1191,10 +1192,15 @@ process_offload_section (void *data, const char *name, off_t offset, off_t len) } /* Callback used by a linker to check if the plugin will claim FILE. Writes - the result in CLAIMED. */ + the result in CLAIMED. If KNOWN_USED, the object is known by the linker + to be used, or an older API version is in use that does not provide that + information; otherwise, the linker is only determining whether this is + a plugin object and it should not be registered as having offload data if + not claimed by the plugin. */ static enum ld_plugin_status -claim_file_handler (const struct ld_plugin_input_file *file, int *claimed) +claim_file_handler_v2 (const struct ld_plugin_input_file *file, int *claimed, + int known_used) { enum ld_plugin_status status; struct plugin_objfile obj; @@ -1307,7 +1313,7 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed) if (*claimed && !obj.offload && offload_files_last_lto == NULL) offload_files_last_lto = offload_files_last; - if (obj.offload) + if (obj.offload && (known_used || obj.found > 0)) { /* Add file to the list. The order must be exactly the same as the final order after recompilation and linking, otherwise host and target tables @@ -1372,6 +1378,15 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed) return LDPS_OK; } +/* Callback used by a linker to check if the plugin will claim FILE. Writes + the result in CLAIMED. */ + +static enum ld_plugin_status +claim_file_handler (const struct ld_plugin_input_file *file, int *claimed) +{ + return claim_file_handler_v2 (file, claimed, true); +} + /* Parse the plugin options. */ static void @@ -1496,6 +1511,9 @@ onload (struct ld_plugin_tv *tv) case LDPT_REGISTER_CLAIM_FILE_HOOK: register_claim_file = p->tv_u.tv_register_claim_file; break; + case LDPT_REGISTER_CLAIM_FILE_HOOK_V2: + register_claim_file_v2 = p->tv_u.tv_register_claim_file_v2; + break; case LDPT_ADD_SYMBOLS_V2: add_symbols_v2 = p->tv_u.tv_add_symbols; break; @@ -1555,6 +1573,13 @@ onload (struct ld_plugin_tv *tv) check (status == LDPS_OK, LDPL_FATAL, "could not register the claim_file callback"); + if (register_claim_file_v2) + { + status = register_claim_file_v2 (claim_file_handler_v2); + check (status == LDPS_OK, LDPL_FATAL, + "could not register the claim_file_v2 callback"); + } + if (register_cleanup) { status = register_cleanup (cleanup_handler); |