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, 2000, 2001
   3    Free Software Foundation, Inc.
   4    Contributed by Philip Blundell <philb@gnu.org>
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU CC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23 /* Run-time Target Specification.  */
  24 #define TARGET_VERSION  fputs (" (ARM GNU/Linux with ELF)", stderr);
  25
  26 /* Do not assume anything about header files.  */
  27 #define NO_IMPLICIT_EXTERN_C
  28
  29 /* Default is to use APCS-32 mode.  */
  30 #define TARGET_DEFAULT (ARM_FLAG_APCS_32 | ARM_FLAG_MMU_TRAPS)
  31 #define SUBTARGET_EXTRA_LINK_SPEC " -m armelf_linux -p"
  32 #define MULTILIB_DEFAULTS \
  33         { "marm", "mlittle-endian", "mhard-float", "mapcs-32", "mno-thumb-interwork" }
  34 #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
  35
  36 /* Handle #pragma weak and #pragma pack.  */
  37 #define HANDLE_SYSV_PRAGMA
  38
  39 /* Now we define the strings used to build the spec file.  */
  40 #define LIB_SPEC \
  41   "%{shared: -lc} \
  42    %{!shared: %{pthread:-lpthread} \
  43    %{profile:-lc_p} %{!profile: -lc}}"
  44
  45
  46 #define LIBGCC_SPEC "%{msoft-float:-lfloat} -lgcc"
  47
  48 /* Provide a STARTFILE_SPEC appropriate for GNU/Linux.  Here we add
  49    the GNU/Linux magical crtbegin.o file (see crtstuff.c) which
  50    provides part of the support for getting C++ file-scope static
  51    object constructed before entering `main'. */
  52
  53 #define STARTFILE_SPEC \
  54   "%{!shared: \
  55      %{pg:gcrt1.o%s} %{!pg:%{p:gcrt1.o%s} \
  56                        %{!p:%{profile:gcrt1.o%s} \
  57                          %{!profile:crt1.o%s}}}} \
  58    crti.o%s %{!shared:crtbegin.o%s} %{shared:crtbeginS.o%s}"
  59
  60 /* Provide a ENDFILE_SPEC appropriate for GNU/Linux.  Here we tack on
  61    the GNU/Linux magical crtend.o file (see crtstuff.c) which
  62    provides part of the support for getting C++ file-scope static
  63    object constructed before entering `main', followed by a normal
  64    GNU/Linux "finalizer" file, `crtn.o'.  */
  65
  66 #define ENDFILE_SPEC \
  67   "%{!shared:crtend.o%s} %{shared:crtendS.o%s} crtn.o%s"
  68
  69 #define LINK_SPEC "%{h*} %{version:-v} \
  70    %{b} %{Wl,*:%*} \
  71    %{static:-Bstatic} \
  72    %{shared:-shared} \
  73    %{symbolic:-Bsymbolic} \
  74    %{rdynamic:-export-dynamic} \
  75    %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2} \
  76    -X \
  77    %{mbig-endian:-EB}" \
  78    SUBTARGET_EXTRA_LINK_SPEC
  79
  80 #undef  CPP_PREDEFINES
  81 #define CPP_PREDEFINES \
  82 "-Dunix -Dlinux -D__ELF__ \
  83 -Asystem=unix -Asystem=posix -Acpu=arm -Amachine=arm"
  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 #define IDENT_ASM_OP    "\t.ident\t"
  92
  93 /* Output #ident as a .ident.  */
  94 #define ASM_OUTPUT_IDENT(FILE, NAME) \
  95   fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);
  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 #define CONST_SECTION_ASM_OP    "\t.section\t.rodata"
 121
 122 #define CONST_SECTION_FUNCTION                                          \
 123 void                                                                    \
 124 const_section ()                                                        \
 125 {                                                                       \
 126   if (!USE_CONST_SECTION)                                               \
 127     text_section ();                                                    \
 128   else if (in_section != in_const)                                      \
 129     {                                                                   \
 130       fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP);             \
 131       in_section = in_const;                                            \
 132     }                                                                   \
 133 }
 134
 135 /* Switch into a generic section.  */
 136 #define TARGET_ASM_NAMED_SECTION  arm_elf_asm_named_section
 137
 138 /* A C statement or statements to switch to the appropriate
 139    section for output of DECL.  DECL is either a `VAR_DECL' node
 140    or a constant of some sort.  RELOC indicates whether forming
 141    the initial value of DECL requires link-time relocations.  */
 142 #define SELECT_SECTION(DECL,RELOC,ALIGN)                                \
 143 {                                                                       \
 144   if (TREE_CODE (DECL) == STRING_CST)                                   \
 145     {                                                                   \
 146       if (! flag_writable_strings)                                      \
 147         const_section ();                                               \
 148       else                                                              \
 149         data_section ();                                                \
 150     }                                                                   \
 151   else if (TREE_CODE (DECL) == VAR_DECL)                                \
 152     {                                                                   \
 153       if ((flag_pic && RELOC)                                           \
 154           || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL)          \
 155           || !DECL_INITIAL (DECL)                                       \
 156           || (DECL_INITIAL (DECL) != error_mark_node                    \
 157               && !TREE_CONSTANT (DECL_INITIAL (DECL))))                 \
 158         data_section ();                                                \
 159       else                                                              \
 160         const_section ();                                               \
 161     }                                                                   \
 162   else                                                                  \
 163     const_section ();                                                   \
 164 }
 165
 166 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
 167 #define UNIQUE_SECTION(DECL, RELOC)                             \
 168   do                                                            \
 169     {                                                           \
 170       int len;                                                  \
 171       char * name;                                              \
 172       char * string;                                            \
 173       char * prefix;                                            \
 174                                                                 \
 175       name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL));   \
 176                                                                 \
 177       if (! DECL_ONE_ONLY (DECL))                               \
 178         {                                                       \
 179           prefix = ".";                                         \
 180           if (TREE_CODE (DECL) == FUNCTION_DECL)                \
 181             prefix = ".text.";                                  \
 182           else if (DECL_READONLY_SECTION (DECL, RELOC))         \
 183             prefix = ".rodata.";                                \
 184           else                                                  \
 185             prefix = ".data.";                                  \
 186         }                                                       \
 187       else if (TREE_CODE (DECL) == FUNCTION_DECL)               \
 188         prefix = ".gnu.linkonce.t.";                            \
 189       else if (DECL_READONLY_SECTION (DECL, RELOC))             \
 190         prefix = ".gnu.linkonce.r.";                            \
 191       else                                                      \
 192         prefix = ".gnu.linkonce.d.";                            \
 193                                                                 \
 194       len = strlen (name) + strlen (prefix);                    \
 195       string = alloca (len + 1);                                \
 196       sprintf (string, "%s%s", prefix, name);                   \
 197                                                                 \
 198       DECL_SECTION_NAME (DECL) = build_string (len, string);    \
 199     }                                                           \
 200   while (0)
 201
 202 /* A C statement or statements to switch to the appropriate
 203    section for output of RTX in mode MODE.  RTX is some kind
 204    of constant in RTL.  The argument MODE is redundant except
 205    in the case of a `const_int' rtx.  Currently, these always
 206    go into the const section.  */
 207 #define SELECT_RTX_SECTION(MODE,RTX,ALIGN) const_section ()
 208
 209 /* On svr4, we *do* have support for the .init and .fini sections, and we
 210    can put stuff in there to be executed before and after `main'.  We let
 211    crtstuff.c and other files know this by defining the following symbols.
 212    The definitions say how to change sections to the .init and .fini
 213    sections.  This is the same for all known svr4 assemblers.  */
 214 #define INIT_SECTION_ASM_OP     "\t.section\t.init"
 215 #define FINI_SECTION_ASM_OP     "\t.section\t.fini"
 216
 217
 218 /* This is how we tell the assembler that a symbol is weak.  */
 219 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 220   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 221        fputc ('\n', FILE); } while (0)
 222
 223 /* This is how we tell the assembler that two symbols have the same value.  */
 224
 225 #define ASM_OUTPUT_DEF(FILE,NAME1,NAME2) \
 226   do { assemble_name (FILE, NAME1);      \
 227        fputs (" = ", FILE);              \
 228        assemble_name (FILE, NAME2);      \
 229        fputc ('\n', FILE); } while (0)
 230
 231 /* Make DWARF2 an option, but keep DBX as the default for now.
 232    Use -gdwarf-2 to turn on DWARF2.  */
 233 #define DWARF2_DEBUGGING_INFO
 234 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
 235
 236 /* Get the standard ELF stabs definitions.  */
 237 #include "dbxelf.h"
 238
 239 #include "arm/elf.h"
 240 #include "arm/linux-gas.h"
 241
 242 /* NWFPE always understands FPA instructions.  */
 243 #undef  FP_DEFAULT
 244 #define FP_DEFAULT FP_SOFT3
 245
 246 /* Call the function profiler with a given profile label.  */
 247 #undef  ARM_FUNCTION_PROFILER
 248 #define ARM_FUNCTION_PROFILER(STREAM, LABELNO)                          \
 249 {                                                                       \
 250   fprintf (STREAM, "\tbl\tmcount%s\n", NEED_PLT_RELOC ? "(PLT)" : "");  \
 251 }
 252
 253 #undef  CC1_SPEC
 254 #define CC1_SPEC "%{profile:-p}"