elf.h

linux下的gcc编译器

/* Definitions of target machine for GNU compiler, for DEC Alpha w/ELF.
   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
   Free Software Foundation, Inc.
   Contributed by Richard Henderson ([e-mail]).

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.    */

#undef OBJECT_FORMAT_COFF
#undef EXTENDED_COFF
#define OBJECT_FORMAT_ELF

/* ??? Move all SDB stuff from alpha.h to osf.h.  */
#undef SDB_DEBUGGING_INFO

#define DBX_DEBUGGING_INFO 1
#define DWARF2_DEBUGGING_INFO 1

#undef  PREFERRED_DEBUGGING_TYPE
#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG

#undef ASM_FINAL_SPEC

#undef  CPP_SUBTARGET_SPEC
#define CPP_SUBTARGET_SPEC "-D__ELF__"

#undef  CC1_SPEC
#define CC1_SPEC  "%{G*}"

#undef  ASM_SPEC
#define ASM_SPEC  "%{G*} %{relax:-relax} %{!gstabs*:-no-mdebug}%{gstabs*:-mdebug}"

/* Output at beginning of assembler file.  */
#undef  ASM_FILE_START
#define ASM_FILE_START(FILE)					\
do {								\
  if (write_symbols == DBX_DEBUG)				\
    {								\
      alpha_write_verstamp (FILE);				\
      output_file_directive (FILE, main_input_filename);	\
    }								\
  fprintf (FILE, "\t.set noat\n");				\
  fprintf (FILE, "\t.set noreorder\n");				\
  if (TARGET_EXPLICIT_RELOCS)					\
    fprintf (FILE, "\t.set nomacro\n");				\
  if (TARGET_BWX | TARGET_MAX | TARGET_FIX | TARGET_CIX)	\
    {								\
      fprintf (FILE, "\t.arch %s\n",				\
               (TARGET_CPU_EV6 ? "ev6"				\
                : TARGET_MAX ? "pca56" : "ev56"));		\
    }								\
} while (0)

#undef  IDENT_ASM_OP
#define IDENT_ASM_OP "\t.ident\t"

/* Output #ident as a .ident.  */
#undef  ASM_OUTPUT_IDENT
#define ASM_OUTPUT_IDENT(FILE, NAME) \
  fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);

/* This is how to allocate empty space in some section.  The .zero
   pseudo-op is used for this on most svr4 assemblers.  */

#undef  SKIP_ASM_OP
#define SKIP_ASM_OP	"\t.zero\t"

#undef  ASM_OUTPUT_SKIP
#define ASM_OUTPUT_SKIP(FILE, SIZE) \
  fprintf (FILE, "%s%u\n", SKIP_ASM_OP, (SIZE))

/* Output the label which precedes a jumptable.  Note that for all svr4
   systems where we actually generate jumptables (which is to say every
   svr4 target except i386, where we use casesi instead) we put the jump-
   tables into the .rodata section and since other stuff could have been
   put into the .rodata section prior to any given jumptable, we have to
   make sure that the location counter for the .rodata section gets pro-
   perly re-aligned prior to the actual beginning of the jump table.  */

#undef  ALIGN_ASM_OP
#define ALIGN_ASM_OP "\t.align\t"

#ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
  ASM_OUTPUT_ALIGN ((FILE), 2);
#endif

#undef  ASM_OUTPUT_CASE_LABEL
#define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE)		\
  do {									\
    ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE)		\
    ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM);			\
  } while (0)

/* The standard SVR4 assembler seems to require that certain builtin
   library routines (e.g. .udiv) be explicitly declared as .globl
   in each assembly file where they are referenced.  */

#undef  ASM_OUTPUT_EXTERNAL_LIBCALL
#define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN)				\
  (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0))

/* This says how to output assembler code to declare an
   uninitialized external linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */

#undef  COMMON_ASM_OP
#define COMMON_ASM_OP	"\t.comm\t"

#undef  ASM_OUTPUT_ALIGNED_COMMON
#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN)		\
do {									\
  fprintf ((FILE), "%s", COMMON_ASM_OP);				\
  assemble_name ((FILE), (NAME));					\
  fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT);	\
} while (0)

/* This says how to output assembler code to declare an
   uninitialized internal linkage data object.  Under SVR4,
   the linker seems to want the alignment of data objects
   to depend on their types.  We do exactly that here.  */

#undef  ASM_OUTPUT_ALIGNED_LOCAL
#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN)		\
do {									\
  if ((SIZE) <= g_switch_value)						\
    sbss_section();							\
  else									\
    bss_section();							\
  ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");			\
  if (!flag_inhibit_size_directive)					\
    ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, SIZE);			\
  ASM_OUTPUT_ALIGN ((FILE), exact_log2((ALIGN) / BITS_PER_UNIT));	\
  ASM_OUTPUT_LABEL(FILE, NAME);						\
  ASM_OUTPUT_SKIP((FILE), (SIZE) ? (SIZE) : 1);				\
} while (0)

/* This says how to output assembler code to declare an
   uninitialized external linkage data object.  */

#undef  ASM_OUTPUT_ALIGNED_BSS
#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN)		\
do {									\
  (*targetm.asm_out.globalize_label) (FILE, NAME);	       		\
  ASM_OUTPUT_ALIGNED_LOCAL (FILE, NAME, SIZE, ALIGN);			\
} while (0)

/* Biggest alignment supported by the object file format of this
   machine.  Use this macro to limit the alignment which can be
   specified using the `__attribute__ ((aligned (N)))' construct.  If
   not defined, the default value is `BIGGEST_ALIGNMENT'. 

   This value is really 2^63.  Since gcc figures the alignment in bits,
   we could only potentially get to 2^60 on suitible hosts.  Due to other
   considerations in varasm, we must restrict this to what fits in an int.  */

#undef  MAX_OFILE_ALIGNMENT
#define MAX_OFILE_ALIGNMENT \
  (1 << (HOST_BITS_PER_INT < 64 ? HOST_BITS_PER_INT - 2 : 62))

/* This is the pseudo-op used to generate a contiguous sequence of byte
   values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
   AUTOMATICALLY APPENDED.  This is the same for most svr4 assemblers.  */

#undef  ASCII_DATA_ASM_OP
#define ASCII_DATA_ASM_OP	"\t.ascii\t"

#undef  READONLY_DATA_SECTION_ASM_OP
#define READONLY_DATA_SECTION_ASM_OP	"\t.section\t.rodata"
#undef  BSS_SECTION_ASM_OP
#define BSS_SECTION_ASM_OP	"\t.section\t.bss"
#undef  SBSS_SECTION_ASM_OP
#define SBSS_SECTION_ASM_OP	"\t.section\t.sbss,\"aw\""
#undef  SDATA_SECTION_ASM_OP
#define SDATA_SECTION_ASM_OP	"\t.section\t.sdata,\"aw\""

/* On svr4, we *do* have support for the .init and .fini sections, and we
   can put stuff in there to be executed before and after `main'.  We let
   crtstuff.c and other files know this by defining the following symbols.
   The definitions say how to change sections to the .init and .fini
   sections.  This is the same for all known svr4 assemblers.  */

#undef  INIT_SECTION_ASM_OP
#define INIT_SECTION_ASM_OP	"\t.section\t.init"
#undef  FINI_SECTION_ASM_OP
#define FINI_SECTION_ASM_OP	"\t.section\t.fini"

#ifdef HAVE_GAS_SUBSECTION_ORDERING

#define ASM_SECTION_START_OP	"\t.subsection\t-1"

/* Output assembly directive to move to the beginning of current section.  */
#define ASM_OUTPUT_SECTION_START(FILE)	\
  fprintf ((FILE), "%s\n", ASM_SECTION_START_OP)

#endif

/* A default list of other sections which we might be "in" at any given
   time.  For targets that use additional sections (e.g. .tdesc) you
   should override this definition in the target-specific file which
   includes this file.  */

#undef  EXTRA_SECTIONS
#define EXTRA_SECTIONS in_sbss, in_sdata

/* A default list of extra section function definitions.  For targets
   that use additional sections (e.g. .tdesc) you should override this
   definition in the target-specific file which includes this file.  */

#undef  EXTRA_SECTION_FUNCTIONS
#define EXTRA_SECTION_FUNCTIONS						\
  SECTION_FUNCTION_TEMPLATE(sbss_section, in_sbss, SBSS_SECTION_ASM_OP)	\
  SECTION_FUNCTION_TEMPLATE(sdata_section, in_sdata, SDATA_SECTION_ASM_OP)

extern void sbss_section		PARAMS ((void));
extern void sdata_section		PARAMS ((void));

#undef  SECTION_FUNCTION_TEMPLATE
#define SECTION_FUNCTION_TEMPLATE(FN, ENUM, OP)	\
void FN ()					\
{						\