Files
binutils-gdb/gas/config/obj-elf.h
H.J. Lu a8c4d40b57 ELF: Add support for unique section ID to assembler
Clang's integrated assembler supports multiple section with the same
name:

	.section .text,"ax",@progbits,unique,1
	nop
	.section .text,"ax",@progbits,unique,2
	nop

"unique,N" assigns the number, N, as the section ID, to a section.  The
valid values of the section ID are between 0 and 4294967295.  It can be
used to distinguish different sections with the same section name.

This is useful with -fno-unique-section-names -ffunction-sections.
-ffunction-sections by default generates .text.foo, .text.bar, etc.
Using the same string can save lots of space in .strtab.

This patch adds section_id to bfd_section and reuses the linker
internal bit in BFD section flags, SEC_LINKER_CREATED, for assmebler
internal use to mark valid section_id.  It also updates objdump to
compare section pointers if 2 sections comes from the same file since
2 different sections can have the same section name.

bfd/

	PR gas/25380
	* bfd-in2.h: Regenerated.
	* ecoff.c (bfd_debug_section): Add section_id.
	* section.c (bfd_section): Add section_id.
	(SEC_ASSEMBLER_SECTION_ID): New.
	(BFD_FAKE_SECTION): Add section_id.

binutils/

	PR gas/25380
	* objdump.c (sym_ok): Return FALSE if 2 sections are in the
	same file with different section pointers.

gas/

	PR gas/25380
	* config/obj-elf.c (section_match): Removed.
	(get_section): Also match SEC_ASSEMBLER_SECTION_ID and
	section_id.
	(obj_elf_change_section): Replace info and group_name arguments
	with match_p.  Also update the section ID and flags from match_p.
	(obj_elf_section): Handle "unique,N".  Update call to
	obj_elf_change_section.
	* config/obj-elf.h (elf_section_match): New.
	(obj_elf_change_section): Updated.
	* config/tc-arm.c (start_unwind_section): Update call to
	obj_elf_change_section.
	* config/tc-ia64.c (obj_elf_vms_common): Likewise.
	* config/tc-microblaze.c (microblaze_s_data): Likewise.
	(microblaze_s_sdata): Likewise.
	(microblaze_s_rdata): Likewise.
	(microblaze_s_bss): Likewise.
	* config/tc-mips.c (s_change_section): Likewise.
	* config/tc-msp430.c (msp430_profiler): Likewise.
	* config/tc-rx.c (parse_rx_section): Likewise.
	* config/tc-tic6x.c (tic6x_start_unwind_section): Likewise.
	* doc/as.texi: Document "unique,N" in .section directive.
	* testsuite/gas/elf/elf.exp: Run "unique,N" tests.
	* testsuite/gas/elf/section15.d: New file.
	* testsuite/gas/elf/section15.s: Likewise.
	* testsuite/gas/elf/section16.s: Likewise.
	* testsuite/gas/elf/section16a.d: Likewise.
	* testsuite/gas/elf/section16b.d: Likewise.
	* testsuite/gas/elf/section17.d: Likewise.
	* testsuite/gas/elf/section17.l: Likewise.
	* testsuite/gas/elf/section17.s: Likewise.
	* testsuite/gas/i386/unique.d: Likewise.
	* testsuite/gas/i386/unique.s: Likewise.
	* testsuite/gas/i386/x86-64-unique.d: Likewise.
	* testsuite/gas/i386/i386.exp: Run unique and x86-64-unique.

ld/

	PR gas/25380
	* testsuite/ld-i386/pr22001-1c.S: Use "unique,N" in .section
	directives.
	* testsuite/ld-i386/tls-gd1.S: Likewise.
	* testsuite/ld-x86-64/pr21481b.S: Likewise.
2020-02-02 17:08:01 -08:00

266 lines
7.5 KiB
C

/* ELF object file format.
Copyright (C) 1992-2020 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
/* HP PA-RISC support was contributed by the Center for Software Science
at the University of Utah. */
#ifndef _OBJ_ELF_H
#define _OBJ_ELF_H
#define OBJ_ELF 1
/* Note that all macros in this file should be wrapped in #ifndef, for
sake of obj-multi.h which includes this file. */
#ifndef OUTPUT_FLAVOR
#define OUTPUT_FLAVOR bfd_target_elf_flavour
#endif
#define BYTES_IN_WORD 4 /* for now */
#include "bfd/elf-bfd.h"
#include "targ-cpu.h"
#ifdef TC_ALPHA
#define ECOFF_DEBUGGING (alpha_flag_mdebug > 0)
extern int alpha_flag_mdebug;
#endif
/* For now, always set ECOFF_DEBUGGING for a MIPS target. */
#ifdef TC_MIPS
#define ECOFF_DEBUGGING mips_flag_mdebug
extern int mips_flag_mdebug;
#endif /* TC_MIPS */
#ifdef OBJ_MAYBE_ECOFF
#ifndef ECOFF_DEBUGGING
#define ECOFF_DEBUGGING 1
#endif
#endif
/* Additional information we keep for each symbol. */
struct elf_obj_sy
{
/* Whether the symbol has been marked as local. */
int local;
/* Use this to keep track of .size expressions that involve
differences that we can't compute yet. */
expressionS *size;
/* The name specified by the .symver directive. */
char *versioned_name;
#ifdef ECOFF_DEBUGGING
/* If we are generating ECOFF debugging information, we need some
additional fields for each symbol. */
struct efdr *ecoff_file;
struct localsym *ecoff_symbol;
valueT ecoff_extern_size;
#endif
};
/* Match section group name, the sh_info field and the section_id
field. */
struct elf_section_match
{
const char *group_name;
unsigned int info;
unsigned int section_id;
flagword flags;
};
#define OBJ_SYMFIELD_TYPE struct elf_obj_sy
#ifndef FALSE
#define FALSE 0
#define TRUE !FALSE
#endif
#ifndef obj_begin
#define obj_begin() elf_begin ()
#endif
extern void elf_begin (void);
#ifndef LOCAL_LABEL_PREFIX
#define LOCAL_LABEL_PREFIX '.'
#endif
/* should be conditional on address size! */
#define elf_symbol(asymbol) ((elf_symbol_type *) (&(asymbol)->the_bfd))
#ifndef S_GET_SIZE
#define S_GET_SIZE(S) \
(elf_symbol (symbol_get_bfdsym (S))->internal_elf_sym.st_size)
#endif
#ifndef S_SET_SIZE
#define S_SET_SIZE(S,V) \
(elf_symbol (symbol_get_bfdsym (S))->internal_elf_sym.st_size = (V))
#endif
#ifndef S_GET_ALIGN
#define S_GET_ALIGN(S) \
(elf_symbol (symbol_get_bfdsym (S))->internal_elf_sym.st_value)
#endif
#ifndef S_SET_ALIGN
#define S_SET_ALIGN(S,V) \
(elf_symbol (symbol_get_bfdsym (S))->internal_elf_sym.st_value = (V))
#endif
int elf_s_get_other (symbolS *);
#ifndef S_GET_OTHER
#define S_GET_OTHER(S) (elf_s_get_other (S))
#endif
#ifndef S_SET_OTHER
#define S_SET_OTHER(S,V) \
(elf_symbol (symbol_get_bfdsym (S))->internal_elf_sym.st_other = (V))
#endif
extern asection *gdb_section;
#ifndef obj_frob_file
#define obj_frob_file elf_frob_file
#endif
extern void elf_frob_file (void);
#ifndef obj_frob_file_before_adjust
#define obj_frob_file_before_adjust elf_frob_file_before_adjust
#endif
extern void elf_frob_file_before_adjust (void);
#ifndef obj_frob_file_after_relocs
#define obj_frob_file_after_relocs elf_frob_file_after_relocs
#endif
extern void elf_frob_file_after_relocs (void);
/* If the target doesn't have special processing for labels, take care of
dwarf2 output at the object file level. */
#ifndef tc_frob_label
#include "dwarf2dbg.h"
#define obj_frob_label dwarf2_emit_label
#endif
#ifndef obj_app_file
#define obj_app_file elf_file_symbol
#endif
extern void elf_file_symbol (const char *, int);
extern void obj_elf_section_change_hook (void);
extern void obj_elf_section (int);
extern const char * obj_elf_section_name (void);
extern void obj_elf_previous (int);
extern void obj_elf_version (int);
extern void obj_elf_common (int);
extern void obj_elf_data (int);
extern void obj_elf_text (int);
extern void obj_elf_change_section
(const char *, unsigned int, bfd_vma, int, struct elf_section_match *,
int, int);
extern void obj_elf_vtable_inherit (int);
extern void obj_elf_vtable_entry (int);
extern struct fix * obj_elf_get_vtable_inherit (void);
extern struct fix * obj_elf_get_vtable_entry (void);
extern bfd_boolean obj_elf_seen_attribute
(int, unsigned int);
extern int obj_elf_vendor_attribute (int);
/* BFD wants to write the udata field, which is a no-no for the
predefined section symbols in bfd/section.c. They are read-only. */
#ifndef obj_sec_sym_ok_for_reloc
#define obj_sec_sym_ok_for_reloc(SEC) ((SEC)->owner != 0)
#endif
void elf_obj_read_begin_hook (void);
#ifndef obj_read_begin_hook
#define obj_read_begin_hook elf_obj_read_begin_hook
#endif
void elf_obj_symbol_new_hook (symbolS *);
#ifndef obj_symbol_new_hook
#define obj_symbol_new_hook elf_obj_symbol_new_hook
#endif
void elf_copy_symbol_attributes (symbolS *, symbolS *);
#ifndef OBJ_COPY_SYMBOL_ATTRIBUTES
#define OBJ_COPY_SYMBOL_ATTRIBUTES(DEST, SRC) \
(elf_copy_symbol_attributes (DEST, SRC))
#endif
void elf_adjust_symtab (void);
#ifndef obj_adjust_symtab
#define obj_adjust_symtab elf_adjust_symtab
#endif
#ifndef SEPARATE_STAB_SECTIONS
/* Avoid ifndef each separate macro setting by wrapping the whole of the
stab group on the assumption that whoever sets SEPARATE_STAB_SECTIONS
caters to ECOFF_DEBUGGING and the right setting of INIT_STAB_SECTIONS
and OBJ_PROCESS_STAB too, without needing the tweaks below. */
/* Stabs go in a separate section. */
#define SEPARATE_STAB_SECTIONS 1
/* We need 12 bytes at the start of the section to hold some initial
information. */
extern void obj_elf_init_stab_section (segT);
#define INIT_STAB_SECTION(seg) obj_elf_init_stab_section (seg)
#ifdef ECOFF_DEBUGGING
/* We smuggle stabs in ECOFF rather than using a separate section.
The Irix linker can not handle a separate stabs section. */
#undef SEPARATE_STAB_SECTIONS
#define SEPARATE_STAB_SECTIONS (!ECOFF_DEBUGGING)
#undef INIT_STAB_SECTION
#define INIT_STAB_SECTION(seg) \
((void) (ECOFF_DEBUGGING ? 0 : (obj_elf_init_stab_section (seg), 0)))
#undef OBJ_PROCESS_STAB
#define OBJ_PROCESS_STAB(seg, what, string, type, other, desc) \
if (ECOFF_DEBUGGING) \
ecoff_stab ((seg), (what), (string), (type), (other), (desc))
#endif /* ECOFF_DEBUGGING */
#endif /* SEPARATE_STAB_SECTIONS not defined. */
extern void elf_frob_symbol (symbolS *, int *);
#ifndef obj_frob_symbol
#define obj_frob_symbol(symp, punt) elf_frob_symbol (symp, &punt)
#endif
extern void elf_pop_insert (void);
#ifndef obj_pop_insert
#define obj_pop_insert() elf_pop_insert()
#endif
#ifndef OBJ_MAYBE_ELF
/* If OBJ_MAYBE_ELF then obj-multi.h will define obj_ecoff_set_ext. */
#define obj_ecoff_set_ext elf_ecoff_set_ext
struct ecoff_extr;
extern void elf_ecoff_set_ext (symbolS *, struct ecoff_extr *);
#endif
extern asection *elf_com_section_ptr;
extern symbolS * elf_common_parse (int ignore ATTRIBUTE_UNUSED, symbolS *symbolP,
addressT size);
#endif /* _OBJ_ELF_H */