gcc/config/linux.h

   1 /* Definitions for Linux-based GNU systems with ELF format
   2    Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2003, 2004, 2005, 2006
   3    Free Software Foundation, Inc.
   4    Contributed by Eric Youngdale.
   5    Modified for stabs-in-ELF by H.J. Lu (hjl@lucon.org).
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 GCC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  22 Boston, MA 02110-1301, USA.  */
  23
  24 /* Don't assume anything about the header files.  */
  25 #define NO_IMPLICIT_EXTERN_C
  26
  27 #undef ASM_APP_ON
  28 #define ASM_APP_ON "#APP\n"
  29
  30 #undef ASM_APP_OFF
  31 #define ASM_APP_OFF "#NO_APP\n"
  32
  33 #undef MD_EXEC_PREFIX
  34 #undef MD_STARTFILE_PREFIX
  35
  36 /* Provide a STARTFILE_SPEC appropriate for GNU/Linux.  Here we add
  37    the GNU/Linux magical crtbegin.o file (see crtstuff.c) which
  38    provides part of the support for getting C++ file-scope static
  39    object constructed before entering `main'.  */
  40
  41 #undef  STARTFILE_SPEC
  42 #if defined HAVE_LD_PIE
  43 #define STARTFILE_SPEC \
  44   "%{!shared: %{pg|p|profile:gcrt1.o%s;pie:Scrt1.o%s;:crt1.o%s}} \
  45    crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}"
  46 #else
  47 #define STARTFILE_SPEC \
  48   "%{!shared: %{pg|p|profile:gcrt1.o%s;:crt1.o%s}} \
  49    crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}"
  50 #endif
  51
  52 /* Provide a ENDFILE_SPEC appropriate for GNU/Linux.  Here we tack on
  53    the GNU/Linux magical crtend.o file (see crtstuff.c) which
  54    provides part of the support for getting C++ file-scope static
  55    object constructed before entering `main', followed by a normal
  56    GNU/Linux "finalizer" file, `crtn.o'.  */
  57
  58 #undef  ENDFILE_SPEC
  59 #define ENDFILE_SPEC \
  60   "%{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s"
  61
  62 /* This is for -profile to use -lc_p instead of -lc.  */
  63 #ifndef CC1_SPEC
  64 #define CC1_SPEC "%{profile:-p}"
  65 #endif
  66
  67 /* The GNU C++ standard library requires that these macros be defined.  */
  68 #undef CPLUSPLUS_CPP_SPEC
  69 #define CPLUSPLUS_CPP_SPEC "-D_GNU_SOURCE %(cpp)"
  70
  71 #undef  LIB_SPEC
  72 #define LIB_SPEC \
  73   "%{pthread:-lpthread} \
  74    %{shared:-lc} \
  75    %{!shared:%{mieee-fp:-lieee} %{profile:-lc_p}%{!profile:-lc}}"
  76
  77 #define LINUX_TARGET_OS_CPP_BUILTINS()                          \
  78     do {                                                        \
  79         builtin_define ("__gnu_linux__");                       \
  80         builtin_define_std ("linux");                           \
  81         builtin_define_std ("unix");                            \
  82         builtin_assert ("system=linux");                        \
  83         builtin_assert ("system=unix");                         \
  84         builtin_assert ("system=posix");                        \
  85     } while (0)
  86
  87 #if defined(HAVE_LD_EH_FRAME_HDR)
  88 #define LINK_EH_SPEC "%{!static:--eh-frame-hdr} "
  89 #endif
  90
  91 /* Define this so we can compile MS code for use with WINE.  */
  92 #define HANDLE_PRAGMA_PACK_PUSH_POP
  93
  94 #define LINK_GCC_C_SEQUENCE_SPEC \
  95   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
  96
  97 /* Use --as-needed -lgcc_s for eh support.  */
  98 #ifdef HAVE_LD_AS_NEEDED
  99 #define USE_LD_AS_NEEDED 1
 100 #endif
 101
 102 /* Determine which dynamic linker to use depending on whether GLIBC or
 103    uClibc is the default C library and whether -muclibc or -mglibc has
 104    been passed to change the default.  */
 105 #if UCLIBC_DEFAULT
 106 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{mglibc:%{muclibc:%e-mglibc and -muclibc used together}" G ";:" U "}"
 107 #else
 108 #define CHOOSE_DYNAMIC_LINKER(G, U) "%{muclibc:%{mglibc:%e-mglibc and -muclibc used together}" U ";:" G "}"
 109 #endif
 110
 111 /* For most targets the following definitions suffice;
 112    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
 113    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
 114    supporting both 32-bit and 64-bit compilation.  */
 115 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
 116 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 117 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 118 #define LINUX_DYNAMIC_LINKER \
 119   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER)
 120 #define LINUX_DYNAMIC_LINKER32 \
 121   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32)
 122 #define LINUX_DYNAMIC_LINKER64 \
 123   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64)
 124
 125 /* Determine whether the entire c99 runtime
 126    is present in the runtime library.  */
 127 #define TARGET_C99_FUNCTIONS (OPTION_GLIBC)
 128
 129 #define TARGET_POSIX_IO