From 039f427a3574ec75985c755108399a2bb37c2c86 Mon Sep 17 00:00:00 2001 From: Alexander Miller Date: Thu, 18 Feb 2021 03:38:56 +0100 Subject: [PATCH] Improve building with LTO Use symver attribute for symbol versioning instead of .symver assembler directive when available. Convert to use double @ syntax for default version in all cases (required when using the attribute). Add the attributes externally_visible, no_reorder if available when using assembler directives to improve the situation for < gcc-10. This is not 100% reliable, though; -flto-partition=none may still be needed in some cases. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24498 Signed-off-by: Alexander Miller --- lib/ChangeLog | 13 +++++++++ lib/eu-config.h | 65 ++++++++++++++++++++++++++++++++++-------- libdw/ChangeLog | 11 +++++++ libdw/dwarf_aggregate_size.c | 4 +-- libdw/dwarf_arrayorder.c | 2 +- libdw/dwarf_bitoffset.c | 2 +- libdw/dwarf_bitsize.c | 2 +- libdw/dwarf_bytesize.c | 2 +- libdw/dwarf_decl_column.c | 2 +- libdw/dwarf_decl_file.c | 2 +- libdw/dwarf_decl_line.c | 2 +- libdw/dwarf_srclang.c | 4 +-- libdwelf/ChangeLog | 5 ++++ libdwelf/dwelf_elf_begin.c | 2 +- libdwfl/ChangeLog | 7 +++++ libdwfl/core-file.c | 4 +-- libdwfl/dwfl_module_build_id.c | 4 +-- libdwfl/dwfl_report_elf.c | 4 +-- 18 files changed, 107 insertions(+), 30 deletions(-) diff --git a/lib/ChangeLog b/lib/ChangeLog index c72452b..8f4d4d9 100644 --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,16 @@ +2021-02-14 Alexander Miller + + * eu-config.h (used_in_asm): New macro. + (NEW_INTDEF): New macro. + (NEW_VERSION): Mark symbol as used_in_asm. Use @@ symver and change + asm name instead. New variant using symver attribute if available. + (OLD_VERSION): Update new symbol name. Indent asm directives. New + variant using symver attribute. + (COMPAT_VERSION_NEWPROTO): Mark symbol as used_in_asm. Reorder + lines. Replace asm with __asm__ in declaration. New variant using + symver attribute. + (COMPAT_VERSION): Likewise. + 2021-09-10 Colin Cross * error.c (error): Call fflush on stdout and stderr. Setup errno and diff --git a/lib/eu-config.h b/lib/eu-config.h index f0e3d07..c7d7cbb 100644 --- a/lib/eu-config.h +++ b/lib/eu-config.h @@ -176,27 +176,68 @@ asm (".section predict_data, \"aw\"; .previous\n" /* This macro is used by the tests conditionalize for standalone building. */ #define ELFUTILS_HEADER(name) +/* Don't reorder with global asm blocks or optimize away. (Doesn't reliably + keep it in the same LTO partition, though; -flto-partition=none may be + still needed for some gcc versions < 10.) */ +#ifdef __has_attribute +# if __has_attribute(no_reorder) +# define used_in_asm __attribute__ ((externally_visible, no_reorder)) +# endif +#endif +#ifndef used_in_asm +# define used_in_asm /* empty */ +#endif #ifdef SYMBOL_VERSIONING -# define OLD_VERSION(name, version) \ - asm (".globl _compat." #version "." #name "\n" \ - "_compat." #version "." #name " = " #name "\n" \ - ".symver _compat." #version "." #name "," #name "@" #version); -# define NEW_VERSION(name, version) \ - asm (".symver " #name "," #name "@@@" #version); -# define COMPAT_VERSION_NEWPROTO(name, version, prefix) \ - asm (".symver _compat." #version "." #name "," #name "@" #version); \ +# define NEW_INTDEF(name) __typeof (name) INTUSE(name) \ + __attribute__ ((alias ("_new." #name))) attribute_hidden; +# ifdef __has_attribute +# if __has_attribute(symver) +# define NEW_VERSION(name, version) \ + __typeof (name) name __asm__ ("_new." #name) \ + __attribute__ ((symver (#name "@@" #version))); +# define OLD_VERSION(name, version) _OLD_VERSION1(name, __COUNTER__, version) +# define _OLD_VERSION1(name, num, version) _OLD_VERSION2(name, num, version) +# define _OLD_VERSION2(name, num, version) \ + __typeof (name) _compat_old##num##_##name \ + __asm__ ("_compat." #version "." #name) \ + __attribute__ ((alias ("_new." #name), symver (#name "@" #version))); +# define COMPAT_VERSION_NEWPROTO(name, version, prefix) \ __typeof (_compat_##prefix##_##name) _compat_##prefix##_##name \ - asm ("_compat." #version "." #name); -# define COMPAT_VERSION(name, version, prefix) \ + __asm__ ("_compat." #version "." #name) \ + __attribute__ ((symver (#name "@" #version))); +# define COMPAT_VERSION(name, version, prefix) \ asm (".symver _compat." #version "." #name "," #name "@" #version); \ - __typeof (name) _compat_##prefix##_##name asm ("_compat." #version "." #name); + __typeof (name) _compat_##prefix##_##name \ + __asm__ ("_compat." #version "." #name) \ + __attribute__ ((symver (#name "@" #version))); +# endif +# endif +# ifndef NEW_VERSION +# define OLD_VERSION(name, version) \ + asm (".globl _compat." #version "." #name "\n\t" \ + "_compat." #version "." #name " = _new." #name "\n\t" \ + ".symver _compat." #version "." #name "," #name "@" #version); +# define NEW_VERSION(name, version) \ + __typeof (name) name __asm__ ("_new." #name) used_in_asm; \ + asm (".symver _new." #name ", " #name "@@" #version); +# define COMPAT_VERSION_NEWPROTO(name, version, prefix) \ + __typeof (_compat_##prefix##_##name) _compat_##prefix##_##name \ + __asm__ ("_compat." #version "." #name) used_in_asm; \ + asm (".symver _compat." #version "." #name ", " #name "@" #version); +# define COMPAT_VERSION(name, version, prefix) \ + __typeof (name) _compat_##prefix##_##name \ + __asm__ ("_compat." #version "." #name) used_in_asm; \ + asm (".symver _compat." #version "." #name ", " #name "@" #version); +# endif #else +# define NEW_INTDEF(name) INTDEF(name) # define OLD_VERSION(name, version) /* Nothing for static linking. */ # define NEW_VERSION(name, version) /* Nothing for static linking. */ # define COMPAT_VERSION_NEWPROTO(name, version, prefix) \ error "should use #ifdef SYMBOL_VERSIONING" -# define COMPAT_VERSION(name, version, prefix) error "should use #ifdef SYMBOL_VERSIONING" +# define COMPAT_VERSION(name, version, prefix) \ + error "should use #ifdef SYMBOL_VERSIONING" #endif #ifndef FALLTHROUGH diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 311f34b..b383683 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,14 @@ +2021-02-14 Alexander Miller + + * dwarf_aggregate_size.c (dwarf_aggregate_size): Move NEW_VERSION + before definition. Replace INTDEF with NEW_INTDEF. + * dwarf_srclang.c (dwarf_srclang): Likewise. + * dwarf_arrayorder.c (dwarf_arrayorder): Move NEW_VERSION. + * dwarf_bitoffset.c (dwarf_bitoffset): Likewise. + * dwarf_bitsize.c (dwarf_bitsize): Likewise. + * dwarf_bytesize.c (dwarf_bytesize): Likewise. + * dwarf_decl_column.c (dwarf_decl_column): Likewise. + 2021-10-18 Mark Wielaard * dwarf_aggregate_size.c (get_type): Don't pass NULL to diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c index 89f2029..8216ae4 100644 --- a/libdw/dwarf_aggregate_size.c +++ b/libdw/dwarf_aggregate_size.c @@ -241,6 +241,7 @@ aggregate_size (Dwarf_Die *die, Dwarf_Word *size, return -1; } +NEW_VERSION (dwarf_aggregate_size, ELFUTILS_0.161) int dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size) { @@ -251,6 +252,5 @@ dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size) return aggregate_size (&die_mem, size, &type_mem, 0); } -INTDEF (dwarf_aggregate_size) +NEW_INTDEF (dwarf_aggregate_size) OLD_VERSION (dwarf_aggregate_size, ELFUTILS_0.144) -NEW_VERSION (dwarf_aggregate_size, ELFUTILS_0.161) diff --git a/libdw/dwarf_arrayorder.c b/libdw/dwarf_arrayorder.c index da64f99..782e075 100644 --- a/libdw/dwarf_arrayorder.c +++ b/libdw/dwarf_arrayorder.c @@ -35,6 +35,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_arrayorder, ELFUTILS_0.143) int dwarf_arrayorder (Dwarf_Die *die) { @@ -46,4 +47,3 @@ dwarf_arrayorder (Dwarf_Die *die) &value) == 0 ? (int) value : -1; } OLD_VERSION (dwarf_arrayorder, ELFUTILS_0.122) -NEW_VERSION (dwarf_arrayorder, ELFUTILS_0.143) diff --git a/libdw/dwarf_bitoffset.c b/libdw/dwarf_bitoffset.c index c1a3a34..61a0d59 100644 --- a/libdw/dwarf_bitoffset.c +++ b/libdw/dwarf_bitoffset.c @@ -35,6 +35,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_bitoffset, ELFUTILS_0.143) int dwarf_bitoffset (Dwarf_Die *die) { @@ -46,4 +47,3 @@ dwarf_bitoffset (Dwarf_Die *die) &value) == 0 ? (int) value : -1; } OLD_VERSION (dwarf_bitoffset, ELFUTILS_0.122) -NEW_VERSION (dwarf_bitoffset, ELFUTILS_0.143) diff --git a/libdw/dwarf_bitsize.c b/libdw/dwarf_bitsize.c index 0ed9b71..35e8744 100644 --- a/libdw/dwarf_bitsize.c +++ b/libdw/dwarf_bitsize.c @@ -35,6 +35,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_bitsize, ELFUTILS_0.143) int dwarf_bitsize (Dwarf_Die *die) { @@ -46,4 +47,3 @@ dwarf_bitsize (Dwarf_Die *die) &value) == 0 ? (int) value : -1; } OLD_VERSION (dwarf_bitsize, ELFUTILS_0.122) -NEW_VERSION (dwarf_bitsize, ELFUTILS_0.143) diff --git a/libdw/dwarf_bytesize.c b/libdw/dwarf_bytesize.c index 116cd32..6d1ff9a 100644 --- a/libdw/dwarf_bytesize.c +++ b/libdw/dwarf_bytesize.c @@ -35,6 +35,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_bytesize, ELFUTILS_0.143) int dwarf_bytesize (Dwarf_Die *die) { @@ -46,4 +47,3 @@ dwarf_bytesize (Dwarf_Die *die) &value) == 0 ? (int) value : -1; } OLD_VERSION (dwarf_bytesize, ELFUTILS_0.122) -NEW_VERSION (dwarf_bytesize, ELFUTILS_0.143) diff --git a/libdw/dwarf_decl_column.c b/libdw/dwarf_decl_column.c index 08d36b8..3225fd1 100644 --- a/libdw/dwarf_decl_column.c +++ b/libdw/dwarf_decl_column.c @@ -35,10 +35,10 @@ #include "libdwP.h" +NEW_VERSION (dwarf_decl_column, ELFUTILS_0.143) int dwarf_decl_column (Dwarf_Die *decl, int *colp) { return __libdw_attr_intval (decl, colp, DW_AT_decl_column); } OLD_VERSION (dwarf_decl_column, ELFUTILS_0.122) -NEW_VERSION (dwarf_decl_column, ELFUTILS_0.143) diff --git a/libdw/dwarf_decl_file.c b/libdw/dwarf_decl_file.c index d4aa0a1..75662a3 100644 --- a/libdw/dwarf_decl_file.c +++ b/libdw/dwarf_decl_file.c @@ -36,6 +36,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_decl_file, ELFUTILS_0.143) const char * dwarf_decl_file (Dwarf_Die *die) { @@ -86,4 +87,3 @@ dwarf_decl_file (Dwarf_Die *die) return cu->files->info[idx].name; } OLD_VERSION (dwarf_decl_file, ELFUTILS_0.122) -NEW_VERSION (dwarf_decl_file, ELFUTILS_0.143) diff --git a/libdw/dwarf_decl_line.c b/libdw/dwarf_decl_line.c index 80fae6c..6b31eeb 100644 --- a/libdw/dwarf_decl_line.c +++ b/libdw/dwarf_decl_line.c @@ -37,13 +37,13 @@ #include "libdwP.h" +NEW_VERSION (dwarf_decl_line, ELFUTILS_0.143) int dwarf_decl_line (Dwarf_Die *func, int *linep) { return __libdw_attr_intval (func, linep, DW_AT_decl_line); } OLD_VERSION (dwarf_decl_line, ELFUTILS_0.122) -NEW_VERSION (dwarf_decl_line, ELFUTILS_0.143) int internal_function diff --git a/libdw/dwarf_srclang.c b/libdw/dwarf_srclang.c index f10e764..77bd58c 100644 --- a/libdw/dwarf_srclang.c +++ b/libdw/dwarf_srclang.c @@ -35,6 +35,7 @@ #include "libdwP.h" +NEW_VERSION (dwarf_srclang, ELFUTILS_0.143) int dwarf_srclang (Dwarf_Die *die) { @@ -45,6 +46,5 @@ dwarf_srclang (Dwarf_Die *die) (die, DW_AT_language, &attr_mem), &value) == 0 ? (int) value : -1; } -INTDEF (dwarf_srclang) +NEW_INTDEF (dwarf_srclang) OLD_VERSION (dwarf_srclang, ELFUTILS_0.122) -NEW_VERSION (dwarf_srclang, ELFUTILS_0.143) diff --git a/libdwelf/ChangeLog b/libdwelf/ChangeLog index 1abee0e..5f7fb4e 100644 --- a/libdwelf/ChangeLog +++ b/libdwelf/ChangeLog @@ -1,3 +1,8 @@ +2021-02-14 Alexander Miller + + * dwelf_elf_begin.c (dwelf_elf_begin): Move NEW_VERSION before + definition. + 2021-09-06 Dmitry V. Levin * dwelf_strtab.c (dwelf_strtab_init): Remove cast of calloc return diff --git a/libdwelf/dwelf_elf_begin.c b/libdwelf/dwelf_elf_begin.c index c7d63a1..c3cfe63 100644 --- a/libdwelf/dwelf_elf_begin.c +++ b/libdwelf/dwelf_elf_begin.c @@ -36,6 +36,7 @@ #include +NEW_VERSION (dwelf_elf_begin, ELFUTILS_0.177) Elf * dwelf_elf_begin (int fd) { @@ -61,4 +62,3 @@ dwelf_elf_begin (int fd) return NULL; } OLD_VERSION (dwelf_elf_begin, ELFUTILS_0.175) -NEW_VERSION (dwelf_elf_begin, ELFUTILS_0.177) diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index d35674c..f7e24a2 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,10 @@ +2021-02-14 Alexander Miller + + * core-file.c (dwfl_core_file_report): Move NEW_VERSION before + definition. Replace INTDEF with NEW_INTDEF. + * dwfl_module_build_id.c (dwfl_module_build_id): Likewise. + * dwfl_report_elf.c (dwfl_report_elf): Likewise. + 2021-09-06 Dmitry V. Levin * linux-pid-attach.c (read_cached_memory): Remove cast of malloc diff --git a/libdwfl/core-file.c b/libdwfl/core-file.c index a0ccc9b..4e4c9b3 100644 --- a/libdwfl/core-file.c +++ b/libdwfl/core-file.c @@ -440,6 +440,7 @@ __libdwfl_dynamic_vaddr_get (Elf *elf, GElf_Addr *vaddrp) return false; } +NEW_VERSION (dwfl_core_file_report, ELFUTILS_0.158) int dwfl_core_file_report (Dwfl *dwfl, Elf *elf, const char *executable) { @@ -625,8 +626,7 @@ dwfl_core_file_report (Dwfl *dwfl, Elf *elf, const char *executable) error rather than just nothing found. */ return listed > 0 ? listed : retval; } -INTDEF (dwfl_core_file_report) -NEW_VERSION (dwfl_core_file_report, ELFUTILS_0.158) +NEW_INTDEF (dwfl_core_file_report) #ifdef SYMBOL_VERSIONING int _compat_without_executable_dwfl_core_file_report (Dwfl *dwfl, Elf *elf); diff --git a/libdwfl/dwfl_module_build_id.c b/libdwfl/dwfl_module_build_id.c index 6ca9376..0c198f2 100644 --- a/libdwfl/dwfl_module_build_id.c +++ b/libdwfl/dwfl_module_build_id.c @@ -77,6 +77,7 @@ __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf) return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr); } +NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138) int dwfl_module_build_id (Dwfl_Module *mod, const unsigned char **bits, GElf_Addr *vaddr) @@ -102,8 +103,7 @@ dwfl_module_build_id (Dwfl_Module *mod, *vaddr = mod->build_id_vaddr; return mod->build_id_len; } -INTDEF (dwfl_module_build_id) -NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138) +NEW_INTDEF (dwfl_module_build_id) #ifdef SYMBOL_VERSIONING COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end) diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c index 9da8669..a5f0e5e 100644 --- a/libdwfl/dwfl_report_elf.c +++ b/libdwfl/dwfl_report_elf.c @@ -287,6 +287,7 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, return m; } +NEW_VERSION (dwfl_report_elf, ELFUTILS_0.156) Dwfl_Module * dwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, int fd, GElf_Addr base, bool add_p_vaddr) @@ -322,8 +323,7 @@ dwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, int fd, return mod; } -INTDEF (dwfl_report_elf) -NEW_VERSION (dwfl_report_elf, ELFUTILS_0.156) +NEW_INTDEF (dwfl_report_elf) #ifdef SYMBOL_VERSIONING Dwfl_Module * -- 2.7.4