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 /* This was defined in linux.h.  Define it here also. */
  38 #undef  DEFAULT_VTABLE_THUNKS
  39 #define DEFAULT_VTABLE_THUNKS   1
  40
  41 /* Handle #pragma weak and #pragma pack.  */
  42 #define HANDLE_SYSV_PRAGMA
  43
  44 /* Now we define the strings used to build the spec file.  */
  45 #define LIB_SPEC \
  46   "%{shared: -lc} \
  47    %{!shared: %{pthread:-lpthread} \
  48         %{profile:-lc_p} %{!profile: -lc}}"
  49
  50 #define LIBGCC_SPEC "%{msoft-float:-lfloat} -lgcc"
  51
  52 /* Add the compiler's crtend, and the library's crtn.  */
  53 #define ENDFILE_SPEC "%{!shared:crtend.o%s} %{shared:crtendS.o%s} \
  54    %{pg:gcrtn.o%s}%{!pg:crtn.o%s}"
  55
  56 #define STARTFILE_SPEC "%{!shared:crt1.o%s} \
  57    crti.o%s \
  58    %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}"
  59
  60 #define LINK_SPEC "%{h*} %{version:-v} \
  61    %{b} %{Wl,*:%*} \
  62    %{static:-Bstatic} \
  63    %{shared:-shared} \
  64    %{symbolic:-Bsymbolic} \
  65    %{rdynamic:-export-dynamic} \
  66    %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2} \
  67    -X \
  68    %{mbig-endian:-EB}" \
  69    SUBTARGET_EXTRA_LINK_SPEC
  70
  71 #undef  CPP_PREDEFINES
  72 #define CPP_PREDEFINES \
  73 "-Dunix -Darm -Dlinux -Asystem(unix) -Asystem(posix) -Acpu(arm) \
  74 -Amachine(arm) -D__ELF__ -Darm_elf"
  75
  76 #ifndef SUBTARGET_DEFAULT_APCS26
  77 #undef  CPP_APCS_PC_DEFAULT_SPEC
  78 #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
  79 /* On 32-bit machine it is always safe to assume we have the "new"
  80    floating point system.  */
  81 #undef  FP_DEFAULT
  82 #define FP_DEFAULT FP_SOFT3
  83 #endif
  84
  85 /* Allow #sccs in preprocessor.  */
  86 #define SCCS_DIRECTIVE
  87
  88 #define USER_LABEL_PREFIX       ""      /* For ELF the default is no underscores */
  89 #define LOCAL_LABEL_PREFIX      "."
  90
  91 /* Attach a special .ident directive to the end of the file to identify
  92    the version of GCC which compiled this code.  */
  93 #define IDENT_ASM_OP    ".ident"
  94
  95 /* Output #ident as a .ident.  */
  96 #define ASM_OUTPUT_IDENT(FILE, NAME) \
  97   fprintf (FILE, "\t%s\t\"%s\"\n", IDENT_ASM_OP, NAME);
  98
  99 #ifdef IDENTIFY_WITH_IDENT
 100 #define ASM_IDENTIFY_GCC(FILE) /* nothing */
 101 #define ASM_IDENTIFY_LANGUAGE(FILE)                     \
 102  fprintf (FILE, "\t%s \"GCC (%s) %s\"\n", IDENT_ASM_OP, \
 103          lang_identify (), version_string)
 104 #else
 105 #define ASM_FILE_END(FILE)                                      \
 106 do {                                                            \
 107      if (!flag_no_ident)                                        \
 108         fprintf ((FILE), "\t%s\t\"GCC: (GNU) %s\"\n",           \
 109                  IDENT_ASM_OP, version_string);                 \
 110    } while (0)
 111 #endif
 112
 113 /* Support const sections and the ctors and dtors sections for g++.
 114    Note that there appears to be two different ways to support const
 115    sections at the moment.  You can either #define the symbol
 116    READONLY_DATA_SECTION (giving it some code which switches to the
 117    readonly data section) or else you can #define the symbols
 118    EXTRA_SECTIONS, EXTRA_SECTION_FUNCTIONS, SELECT_SECTION, and
 119    SELECT_RTX_SECTION.  We do both here just to be on the safe side.  */
 120 #define USE_CONST_SECTION       1
 121
 122 /* Support for Constructors and Destructors.  */
 123 #define READONLY_DATA_SECTION() const_section ()
 124
 125 /* A default list of other sections which we might be "in" at any given
 126    time.  For targets that use additional sections (e.g. .tdesc) you
 127    should override this definition in the target-specific file which
 128    includes this file.  */
 129 #define SUBTARGET_EXTRA_SECTIONS in_const,
 130
 131 /* A default list of extra section function definitions.  For targets
 132    that use additional sections (e.g. .tdesc) you should override this
 133    definition in the target-specific file which includes this file.  */
 134 #define SUBTARGET_EXTRA_SECTION_FUNCTIONS       CONST_SECTION_FUNCTION
 135
 136 extern void text_section ();
 137
 138 #define CONST_SECTION_ASM_OP    ".section\t.rodata"
 139
 140 #define CONST_SECTION_FUNCTION                                          \
 141 void                                                                    \
 142 const_section ()                                                        \
 143 {                                                                       \
 144   if (!USE_CONST_SECTION)                                               \
 145     text_section ();                                                    \
 146   else if (in_section != in_const)                                      \
 147     {                                                                   \
 148       fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP);             \
 149       in_section = in_const;                                            \
 150     }                                                                   \
 151 }
 152
 153 /* Switch into a generic section.
 154    This is currently only used to support section attributes.
 155
 156    We make the section read-only and executable for a function decl,
 157    read-only for a const data decl, and writable for a non-const data decl.  */
 158 #define ASM_OUTPUT_SECTION_NAME(FILE, DECL, NAME, RELOC) \
 159   fprintf (FILE, ".section\t%s,\"%s\",%%progbits\n", NAME, \
 160            (DECL) && TREE_CODE (DECL) == FUNCTION_DECL ? "ax" : \
 161            (DECL) && DECL_READONLY_SECTION (DECL, RELOC) ? "a" : "aw")
 162
 163 /* A C statement or statements to switch to the appropriate
 164    section for output of DECL.  DECL is either a `VAR_DECL' node
 165    or a constant of some sort.  RELOC indicates whether forming
 166    the initial value of DECL requires link-time relocations.  */
 167 #define SELECT_SECTION(DECL,RELOC)                                      \
 168 {                                                                       \
 169   if (TREE_CODE (DECL) == STRING_CST)                                   \
 170     {                                                                   \
 171       if (! flag_writable_strings)                                      \
 172         const_section ();                                               \
 173       else                                                              \
 174         data_section ();                                                \
 175     }                                                                   \
 176   else if (TREE_CODE (DECL) == VAR_DECL)                                \
 177     {                                                                   \
 178       if ((flag_pic && RELOC)                                           \
 179           || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL)          \
 180           || !DECL_INITIAL (DECL)                                       \
 181           || (DECL_INITIAL (DECL) != error_mark_node                    \
 182               && !TREE_CONSTANT (DECL_INITIAL (DECL))))                 \
 183         data_section ();                                                \
 184       else                                                              \
 185         const_section ();                                               \
 186     }                                                                   \
 187   else                                                                  \
 188     const_section ();                                                   \
 189 }
 190
 191 /* A C statement or statements to switch to the appropriate
 192    section for output of RTX in mode MODE.  RTX is some kind
 193    of constant in RTL.  The argument MODE is redundant except
 194    in the case of a `const_int' rtx.  Currently, these always
 195    go into the const section.  */
 196 #define SELECT_RTX_SECTION(MODE,RTX) const_section ()
 197
 198 /* On svr4, we *do* have support for the .init and .fini sections, and we
 199    can put stuff in there to be executed before and after `main'.  We let
 200    crtstuff.c and other files know this by defining the following symbols.
 201    The definitions say how to change sections to the .init and .fini
 202    sections.  This is the same for all known svr4 assemblers.  */
 203 #define INIT_SECTION_ASM_OP     ".section\t.init"
 204 #define FINI_SECTION_ASM_OP     ".section\t.fini"
 205
 206
 207 /* This is how we tell the assembler that a symbol is weak.  */
 208 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 209   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 210        fputc ('\n', FILE); } while (0)
 211
 212 /* This is how we tell the assembler that two symbols have the same value.  */
 213
 214 #define ASM_OUTPUT_DEF(FILE,NAME1,NAME2) \
 215   do { assemble_name (FILE, NAME1);      \
 216        fputs (" = ", FILE);              \
 217        assemble_name (FILE, NAME2);      \
 218        fputc ('\n', FILE); } while (0)
 219
 220 /* Make DWARF2 an option, but keep DBX as the default for now.
 221    Use -gdwarf2 to turn on DWARF2.  */
 222 #define DWARF2_DEBUGGING_INFO
 223 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
 224
 225 #include "arm/elf.h"
 226 #include "arm/linux-gas.h"