From 0171e1652f153f6b2a5506cc3b7073e1f0dacfa0 Mon Sep 17 00:00:00 2001 From: Tobias Burnus Date: Thu, 11 May 2023 12:29:05 +0200 Subject: 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. (cherry picked from commit c49d51fa8134f6c7e6c7cf6e4e3007c4fea617c5) --- include/plugin-api.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'include/plugin-api.h') diff --git a/include/plugin-api.h b/include/plugin-api.h index 4e12c0320d6..85ee70e4e29 100644 --- a/include/plugin-api.h +++ b/include/plugin-api.h @@ -260,6 +260,13 @@ enum ld_plugin_status (*ld_plugin_claim_file_handler) ( const struct ld_plugin_input_file *file, int *claimed); +/* The plugin library's "claim file" handler, version 2. */ + +typedef +enum ld_plugin_status +(*ld_plugin_claim_file_handler_v2) ( + const struct ld_plugin_input_file *file, int *claimed, int known_used); + /* The plugin library's "all symbols read" handler. */ typedef @@ -278,6 +285,13 @@ typedef enum ld_plugin_status (*ld_plugin_register_claim_file) (ld_plugin_claim_file_handler handler); +/* The linker's interface for registering the "claim file" handler, + version 2. */ + +typedef +enum ld_plugin_status +(*ld_plugin_register_claim_file_v2) (ld_plugin_claim_file_handler_v2 handler); + /* The linker's interface for registering the "all symbols read" handler. */ typedef @@ -520,7 +534,8 @@ enum ld_plugin_tag LDPT_GET_INPUT_SECTION_SIZE = 30, LDPT_REGISTER_NEW_INPUT_HOOK = 31, LDPT_GET_WRAP_SYMBOLS = 32, - LDPT_ADD_SYMBOLS_V2 = 33 + LDPT_ADD_SYMBOLS_V2 = 33, + LDPT_REGISTER_CLAIM_FILE_HOOK_V2 = 35, }; /* The plugin transfer vector. */ @@ -533,6 +548,7 @@ struct ld_plugin_tv int tv_val; const char *tv_string; ld_plugin_register_claim_file tv_register_claim_file; + ld_plugin_register_claim_file_v2 tv_register_claim_file_v2; ld_plugin_register_all_symbols_read tv_register_all_symbols_read; ld_plugin_register_cleanup tv_register_cleanup; ld_plugin_add_symbols tv_add_symbols; -- cgit v1.2.1