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    2007, 2009, 2010 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 3, 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 Under Section 7 of GPL version 3, you are granted additional
  20 permissions described in the GCC Runtime Library Exception, version
  21 3.1, as published by the Free Software Foundation.
  22
  23 You should have received a copy of the GNU General Public License and
  24 a copy of the GCC Runtime Library Exception along with this program;
  25 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  26 <http://www.gnu.org/licenses/>.  */
  27
  28 /* Don't assume anything about the header files.  */
  29 #define NO_IMPLICIT_EXTERN_C
  30
  31 #undef ASM_APP_ON
  32 #define ASM_APP_ON "#APP\n"
  33
  34 #undef ASM_APP_OFF
  35 #define ASM_APP_OFF "#NO_APP\n"
  36
  37 /* Provide a STARTFILE_SPEC appropriate for GNU/Linux.  Here we add
  38    the GNU/Linux magical crtbegin.o file (see crtstuff.c) which
  39    provides part of the support for getting C++ file-scope static
  40    object constructed before entering `main'.  */
  41
  42 #if defined HAVE_LD_PIE
  43 #define LINUX_TARGET_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 LINUX_TARGET_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 #undef  STARTFILE_SPEC
  52 #define STARTFILE_SPEC LINUX_TARGET_STARTFILE_SPEC
  53
  54 /* Provide a ENDFILE_SPEC appropriate for GNU/Linux.  Here we tack on
  55    the GNU/Linux magical crtend.o file (see crtstuff.c) which
  56    provides part of the support for getting C++ file-scope static
  57    object constructed before entering `main', followed by a normal
  58    GNU/Linux "finalizer" file, `crtn.o'.  */
  59
  60 #define LINUX_TARGET_ENDFILE_SPEC \
  61   "%{shared|pie:crtendS.o%s;:crtend.o%s} crtn.o%s"
  62 #undef  ENDFILE_SPEC
  63 #define ENDFILE_SPEC LINUX_TARGET_ENDFILE_SPEC
  64
  65 /* This is for -profile to use -lc_p instead of -lc.  */
  66 #define LINUX_TARGET_CC1_SPEC "%{profile:-p}"
  67 #ifndef CC1_SPEC
  68 #define CC1_SPEC LINUX_TARGET_CC1_SPEC
  69 #endif
  70
  71 /* The GNU C++ standard library requires that these macros be defined.  */
  72 #undef CPLUSPLUS_CPP_SPEC
  73 #define CPLUSPLUS_CPP_SPEC "-D_GNU_SOURCE %(cpp)"
  74
  75 #define LINUX_TARGET_LIB_SPEC \
  76   "%{pthread:-lpthread} \
  77    %{shared:-lc} \
  78    %{!shared:%{mieee-fp:-lieee} %{profile:-lc_p}%{!profile:-lc}}"
  79 #undef  LIB_SPEC
  80 #define LIB_SPEC LINUX_TARGET_LIB_SPEC
  81
  82 /* C libraries supported on Linux.  */
  83 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
  84 #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
  85 #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
  86
  87 #define LINUX_TARGET_OS_CPP_BUILTINS()                          \
  88     do {                                                        \
  89         if (OPTION_GLIBC)                                       \
  90           builtin_define ("__gnu_linux__");                     \
  91         builtin_define_std ("linux");                           \
  92         builtin_define_std ("unix");                            \
  93         builtin_assert ("system=linux");                        \
  94         builtin_assert ("system=unix");                         \
  95         builtin_assert ("system=posix");                        \
  96     } while (0)
  97
  98 #if defined(HAVE_LD_EH_FRAME_HDR)
  99 #define LINK_EH_SPEC "%{!static:--eh-frame-hdr} "
 100 #endif
 101
 102 #undef LINK_GCC_C_SEQUENCE_SPEC
 103 #define LINK_GCC_C_SEQUENCE_SPEC \
 104   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
 105
 106 /* Use --as-needed -lgcc_s for eh support.  */
 107 #ifdef HAVE_LD_AS_NEEDED
 108 #define USE_LD_AS_NEEDED 1
 109 #endif
 110
 111 /* Determine which dynamic linker to use depending on whether GLIBC or
 112    uClibc or Bionic is the default C library and whether
 113    -muclibc or -mglibc or -mbionic has been passed to change the default.  */
 114
 115 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LD1, LD2, LD3)      \
 116   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:" LD1 "}}"
 117
 118 #if DEFAULT_LIBC == LIBC_GLIBC
 119 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
 120   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", G, U, B)
 121 #elif DEFAULT_LIBC == LIBC_UCLIBC
 122 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
 123   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", U, G, B)
 124 #elif DEFAULT_LIBC == LIBC_BIONIC
 125 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
 126   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", B, G, U)
 127 #else
 128 #error "Unsupported DEFAULT_LIBC"
 129 #endif /* DEFAULT_LIBC */
 130
 131 /* For most targets the following definitions suffice;
 132    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
 133    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
 134    supporting both 32-bit and 64-bit compilation.  */
 135 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
 136 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 137 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 138 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
 139 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
 140 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
 141
 142 #define LINUX_DYNAMIC_LINKER                                            \
 143   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
 144                          BIONIC_DYNAMIC_LINKER)
 145 #define LINUX_DYNAMIC_LINKER32                                          \
 146   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 147                          BIONIC_DYNAMIC_LINKER32)
 148 #define LINUX_DYNAMIC_LINKER64                                          \
 149   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 150                          BIONIC_DYNAMIC_LINKER64)
 151
 152 /* Determine whether the entire c99 runtime
 153    is present in the runtime library.  */
 154 #define TARGET_C99_FUNCTIONS (OPTION_GLIBC)
 155
 156 /* Whether we have sincos that follows the GNU extension.  */
 157 #define TARGET_HAS_SINCOS (OPTION_GLIBC || OPTION_BIONIC)
 158
 159 #define TARGET_POSIX_IO