gcc/config/arm/linux-elf.h

   1 /* Definitions for ARM running Linux-based GNU systems using ELF
   2    Copyright (C) 1993, 1994, 1997, 1998, 1999 Free Software Foundation, Inc.
   3    Contributed by Philip Blundell <philb@gnu.org>
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* Run-time Target Specification.  */
  23 #define TARGET_VERSION  fputs (" (ARM GNU/Linux with ELF)", stderr);
  24
  25 /* We have libgcc2.  */
  26 #define HAVE_ATEXIT
  27
  28 /* Default is to use APCS-32 mode.  */
  29 #ifndef SUBTARGET_DEFAULT_APCS26
  30 #define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_SHORT_BYTE)
  31 #define SUBTARGET_EXTRA_LINK_SPEC       \
  32         " %{mapcs-26:-m elf32arm26} %{!mapcs-26:-m elf32arm}"
  33 #define SUBTARGET_EXTRA_ASM_SPEC        \
  34         " %{mapcs-26:-mapcs-26} %(!mapcs-26:-mapcs-32}"
  35 #endif
  36
  37 /* Now we define the strings used to build the spec file.  */
  38 #define LIB_SPEC "%{!shared:%{!symbolic:-lc}}"
  39
  40 /* Add the compiler's crtend, and the library's crtn.  */
  41 #define ENDFILE_SPEC "%{!shared:crtend.o%s} %{shared:crtendS.o%s} \
  42    %{pg:gcrtn.o%s}%{!pg:crtn.o%s}"
  43
  44 #define STARTFILE_SPEC "%{!shared:crt1.o%s} \
  45    crti.o%s \
  46    %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}"
  47
  48 #define LINK_SPEC "%{h*} %{version:-v} \
  49    %{b} %{Wl,*:%*} \
  50    %{static:-Bstatic} \
  51    %{shared:-shared} \
  52    %{symbolic:-Bsymbolic} \
  53    %{rdynamic:-export-dynamic} \
  54    %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2} \
  55    -X \
  56    %{mbig-endian:-EB}" \
  57    SUBTARGET_EXTRA_LINK_SPEC
  58
  59 #undef  CPP_PREDEFINES
  60 #define CPP_PREDEFINES \
  61 "-Dunix -Darm -Dlinux -Asystem(unix) -Asystem(posix) -Acpu(arm) \
  62 -Amachine(arm) -D__ELF__ -Darm_elf"
  63
  64 #ifndef SUBTARGET_DEFAULT_APCS26
  65 #undef  CPP_APCS_PC_DEFAULT_SPEC
  66 #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
  67 #endif
  68
  69 /* Allow #sccs in preprocessor.  */
  70 #define SCCS_DIRECTIVE
  71
  72 #define USER_LABEL_PREFIX       ""      /* For ELF the default is no underscores */
  73 #define LOCAL_LABEL_PREFIX      "."
  74
  75 /* Attach a special .ident directive to the end of the file to identify
  76    the version of GCC which compiled this code.  */
  77 #define IDENT_ASM_OP    ".ident"
  78
  79 /* Output #ident as a .ident.  */
  80 #define ASM_OUTPUT_IDENT(FILE, NAME) \
  81   fprintf (FILE, "\t%s\t\"%s\"\n", IDENT_ASM_OP, NAME);
  82
  83 #ifdef IDENTIFY_WITH_IDENT
  84 #define ASM_IDENTIFY_GCC(FILE) /* nothing */
  85 #define ASM_IDENTIFY_LANGUAGE(FILE)                     \
  86  fprintf (FILE, "\t%s \"GCC (%s) %s\"\n", IDENT_ASM_OP, \
  87          lang_identify (), version_string)
  88 #else
  89 #define ASM_FILE_END(FILE)                                      \
  90 do {                                                            \
  91      if (!flag_no_ident)                                        \
  92         fprintf ((FILE), "\t%s\t\"GCC: (GNU) %s\"\n",           \
  93                  IDENT_ASM_OP, version_string);                 \
  94    } while (0)
  95 #endif
  96
  97 /* Support const sections and the ctors and dtors sections for g++.
  98    Note that there appears to be two different ways to support const
  99    sections at the moment.  You can either #define the symbol
 100    READONLY_DATA_SECTION (giving it some code which switches to the
 101    readonly data section) or else you can #define the symbols
 102    EXTRA_SECTIONS, EXTRA_SECTION_FUNCTIONS, SELECT_SECTION, and
 103    SELECT_RTX_SECTION.  We do both here just to be on the safe side.  */
 104 #define USE_CONST_SECTION       1
 105
 106 /* Support for Constructors and Destructors.  */
 107 #define READONLY_DATA_SECTION() const_section ()
 108
 109 /* A default list of other sections which we might be "in" at any given
 110    time.  For targets that use additional sections (e.g. .tdesc) you
 111    should override this definition in the target-specific file which
 112    includes this file.  */
 113 #define SUBTARGET_EXTRA_SECTIONS in_const,
 114
 115 /* A default list of extra section function definitions.  For targets
 116    that use additional sections (e.g. .tdesc) you should override this
 117    definition in the target-specific file which includes this file.  */
 118 #define SUBTARGET_EXTRA_SECTION_FUNCTIONS       CONST_SECTION_FUNCTION
 119
 120 extern void text_section ();
 121
 122 #define CONST_SECTION_ASM_OP    ".section\t.rodata"
 123
 124 #define CONST_SECTION_FUNCTION                                          \
 125 void                                                                    \
 126 const_section ()                                                        \
 127 {                                                                       \
 128   if (!USE_CONST_SECTION)                                               \
 129     text_section ();                                                    \
 130   else if (in_section != in_const)                                      \
 131     {                                                                   \
 132       fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP);             \
 133       in_section = in_const;                                            \
 134     }                                                                   \
 135 }
 136
 137 /* Switch into a generic section.
 138    This is currently only used to support section attributes.
 139
 140    We make the section read-only and executable for a function decl,
 141    read-only for a const data decl, and writable for a non-const data decl.  */
 142 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC) \
 143   fprintf (FILE, ".section\t%s,\"%s\",%%progbits\n", NAME, \
 144            (DECL) && TREE_CODE (DECL) == FUNCTION_DECL ? "ax" : \
 145            (DECL) && DECL_READONLY_SECTION (DECL, RELOC) ? "a" : "aw")
 146
 147 /* A C statement or statements to switch to the appropriate
 148    section for output of DECL.  DECL is either a `VAR_DECL' node
 149    or a constant of some sort.  RELOC indicates whether forming
 150    the initial value of DECL requires link-time relocations.  */
 151 #define SELECT_SECTION(DECL,RELOC)                                      \
 152 {                                                                       \
 153   if (TREE_CODE (DECL) == STRING_CST)                                   \
 154     {                                                                   \
 155       if (! flag_writable_strings)                                      \
 156         const_section ();                                               \
 157       else                                                              \
 158         data_section ();                                                \
 159     }                                                                   \
 160   else if (TREE_CODE (DECL) == VAR_DECL)                                \
 161     {                                                                   \
 162       if ((flag_pic && RELOC)                                           \
 163           || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL)          \
 164           || !DECL_INITIAL (DECL)                                       \
 165           || (DECL_INITIAL (DECL) != error_mark_node                    \
 166               && !TREE_CONSTANT (DECL_INITIAL (DECL))))                 \
 167         data_section ();                                                \
 168       else                                                              \
 169         const_section ();                                               \
 170     }                                                                   \
 171   else                                                                  \
 172     const_section ();                                                   \
 173 }
 174
 175 /* A C statement or statements to switch to the appropriate
 176    section for output of RTX in mode MODE.  RTX is some kind
 177    of constant in RTL.  The argument MODE is redundant except
 178    in the case of a `const_int' rtx.  Currently, these always
 179    go into the const section.  */
 180 #define SELECT_RTX_SECTION(MODE,RTX) const_section ()
 181
 182 /* On svr4, we *do* have support for the .init and .fini sections, and we
 183    can put stuff in there to be executed before and after `main'.  We let
 184    crtstuff.c and other files know this by defining the following symbols.
 185    The definitions say how to change sections to the .init and .fini
 186    sections.  This is the same for all known svr4 assemblers.  */
 187 #define INIT_SECTION_ASM_OP     ".section\t.init"
 188 #define FINI_SECTION_ASM_OP     ".section\t.fini"
 189
 190
 191 /* This is how we tell the assembler that a symbol is weak.  */
 192 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 193   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 194        fputc ('\n', FILE); } while (0)
 195
 196 /* This is how we tell the assembler that two symbols have the same value.  */
 197
 198 #define ASM_OUTPUT_DEF(FILE,NAME1,NAME2) \
 199   do { assemble_name (FILE, NAME1);      \
 200        fputs (" = ", FILE);              \
 201        assemble_name (FILE, NAME2);      \
 202        fputc ('\n', FILE); } while (0)
 203
 204 #include "arm/elf.h"
 205 #include "arm/linux-gas.h"