elf.h   [plain text]


/* Definitions of target machine for GNU compiler.  MIPS R3000 version with
   GOFAST floating point library.
   Copyright (C) 1994, 1997, 1999, 2000, 2002 Free Software Foundation, Inc.

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.  */

/* Use ELF.  */
#undef  OBJECT_FORMAT_COFF
#undef  EXTENDED_COFF

/* ??? Move all SDB stuff into separate header file.  */
#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  SUBTARGET_ASM_DEBUGGING_SPEC
#define SUBTARGET_ASM_DEBUGGING_SPEC "-g0"

/* 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'.  */

#undef  MAX_OFILE_ALIGNMENT
#define MAX_OFILE_ALIGNMENT (32768*8)

/* Switch into a generic section.  */
#undef  TARGET_ASM_NAMED_SECTION
#define TARGET_ASM_NAMED_SECTION  default_elf_asm_named_section

/* Given that Irix has it's own headers, not having TARGET_GAS here
   seems a mistake.  If we actually need to be prepared for file
   switching, then we need a custom TARGET_ASM_NAMED_SECTION too.  */

#undef  TEXT_SECTION
#define TEXT_SECTION()				\
do {						\
  if (TARGET_FILE_SWITCHING)			\
    abort ();					\
  fputs (TEXT_SECTION_ASM_OP, asm_out_file);	\
  fputc ('\n', asm_out_file);			\
} while (0)

/* The following macro defines the format used to output the second
   operand of the .type assembler directive.  Different svr4 assemblers
   expect various different forms for this operand.  The one given here
   is just a default.  You may need to override it in your machine-
   specific tm.h file (depending upon the particulars of your assembler).  */

#define TYPE_OPERAND_FMT        "@%s"

/* Define the strings used for the special svr4 .type and .size directives.
   These strings generally do not vary from one system running svr4 to
   another, but if a given system (e.g. m88k running svr) needs to use
   different pseudo-op names for these, they may be overridden in the
   file which includes this one.  */

#undef TYPE_ASM_OP
#undef SIZE_ASM_OP
#define TYPE_ASM_OP	"\t.type\t"
#define SIZE_ASM_OP	"\t.size\t"

/* If defined, a C expression whose value is a string containing the
   assembler operation to identify the following data as
   uninitialized global data.  If not defined, and neither
   `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined,
   uninitialized global data will be output in the data section if
   `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be
   used.  */

#ifndef BSS_SECTION_ASM_OP
#define BSS_SECTION_ASM_OP	"\t.section\t.bss"
#endif

#undef  SBSS_SECTION_ASM_OP
#define SBSS_SECTION_ASM_OP	"\t.section .sbss"

/* Like `ASM_OUTPUT_BSS' except takes the required alignment as a
   separate, explicit argument.  If you define this macro, it is used
   in place of `ASM_OUTPUT_BSS', and gives you more flexibility in
   handling the required alignment of the variable.  The alignment is
   specified as the number of bits.

   Try to use function `asm_output_aligned_bss' defined in file
   `varasm.c' when defining this macro.  */
#ifndef ASM_OUTPUT_ALIGNED_BSS
#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
do {									\
  (*targetm.asm_out.globalize_label) (FILE, NAME);			\
  if (SIZE > 0 && SIZE <= mips_section_threshold)			\
    sbss_section ();							\
  else									\
    bss_section ();							\
  ASM_OUTPUT_ALIGN (FILE, floor_log2 (ALIGN / BITS_PER_UNIT));		\
  last_assemble_variable_decl = DECL;					\
  ASM_DECLARE_OBJECT_NAME (FILE, NAME, DECL);				\
  ASM_OUTPUT_SKIP (FILE, SIZE ? SIZE : 1);				\
} while (0)
#endif

/* These macros generate the special .type and .size directives which
   are used to set the corresponding fields of the linker symbol table
   entries in an ELF object file under SVR4.  These macros also output
   the starting labels for the relevant functions/objects.  */

/* Write the extra assembler code needed to declare an object properly.  */

#undef  ASM_DECLARE_OBJECT_NAME
#define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)			\
  do {									\
    HOST_WIDE_INT size;							\
    ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");			\
    size_directive_output = 0;						\
    if (!flag_inhibit_size_directive && DECL_SIZE (DECL))		\
      {									\
	size_directive_output = 1;					\
	size = int_size_in_bytes (TREE_TYPE (DECL));			\
	ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size);			\
      }									\
    mips_declare_object (FILE, NAME, "", ":\n", 0);			\
  } while (0)

/* Output the size directive for a decl in rest_of_decl_compilation
   in the case where we did not do so before the initializer.
   Once we find the error_mark_node, we know that the value of
   size_directive_output was set
   by ASM_DECLARE_OBJECT_NAME when it was run for the same decl.  */

#undef  ASM_FINISH_DECLARE_OBJECT
#define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)	 \
do {									 \
     const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);		 \
     HOST_WIDE_INT size;						 \
									 \
     if (!flag_inhibit_size_directive && DECL_SIZE (DECL)		 \
         && ! AT_END && TOP_LEVEL					 \
	 && DECL_INITIAL (DECL) == error_mark_node			 \
	 && !size_directive_output)					 \
       {								 \
	 size_directive_output = 1;					 \
	 size = int_size_in_bytes (TREE_TYPE (DECL));			 \
	 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size);			 \
       }								 \
   } while (0)

#define ASM_OUTPUT_DEF(FILE,LABEL1,LABEL2)                            \
 do { fputc ( '\t', FILE);                                            \
      assemble_name (FILE, LABEL1);                                   \
      fputs ( " = ", FILE);                                           \
      assemble_name (FILE, LABEL2);                                   \
      fputc ( '\n', FILE);                                            \
 } while (0)

/* Note about .weak vs. .weakext
   The mips native assemblers support .weakext, but not .weak.
   mips-elf gas supports .weak, but not .weakext.
   mips-elf gas has been changed to support both .weak and .weakext,
   but until that support is generally available, the 'if' below
   should serve.  */

#undef  ASM_WEAKEN_LABEL
#define ASM_WEAKEN_LABEL(FILE,NAME) ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,0)
#define ASM_OUTPUT_WEAK_ALIAS(FILE,NAME,VALUE)	\
 do {						\
  if (TARGET_GAS)                               \
      fputs ("\t.weak\t", FILE);		\
  else                                          \
      fputs ("\t.weakext\t", FILE);		\
  assemble_name (FILE, NAME);			\
  if (VALUE)					\
    {						\
      fputc (' ', FILE);			\
      assemble_name (FILE, VALUE);		\
    }						\
  fputc ('\n', FILE);				\
 } while (0)

#define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)

#define TARGET_ASM_UNIQUE_SECTION  mips_unique_section

/* A list of other sections which the compiler might be "in" at any
   given time.  */
#undef  EXTRA_SECTIONS
#define EXTRA_SECTIONS in_sdata, in_sbss

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

#define SECTION_FUNCTION_TEMPLATE(FN, ENUM, OP)                               \
void FN ()                                                            \
{                                                                     \
  if (in_section != ENUM)                                             \
    {                                                                 \
      fprintf (asm_out_file, "%s\n", OP);                             \
      in_section = ENUM;                                              \
    }                                                                 \
}

/* On elf, 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 elf 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"

/* Don't set the target flags, this is done by the linker script */
#undef  LIB_SPEC
#define LIB_SPEC ""

#undef  STARTFILE_SPEC
#if defined(HAVE_MIPS_LIBGLOSS_STARTUP_DIRECTIVES) \
    || (MIPS_ABI_DEFAULT == ABI_MEABI)
#define STARTFILE_SPEC "crti%O%s crtbegin%O%s"
#else
#define STARTFILE_SPEC "crti%O%s crtbegin%O%s %{!mno-crt0:crt0%O%s}"
#endif

#undef  ENDFILE_SPEC
#define ENDFILE_SPEC "crtend%O%s crtn%O%s"

/* We support #pragma.  */
#define HANDLE_SYSV_PRAGMA 1