gcc/config/linux.h

   1 /* Definitions for systems using the Linux kernel, with or without
   2    MMU, using ELF at the compiler level but possibly FLT for final
   3    linked executables and shared libraries in some no-MMU cases, and
   4    possibly with a choice of libc implementations.
   5    Copyright (C) 1995-2015 Free Software Foundation, Inc.
   6    Contributed by Eric Youngdale.
   7    Modified for stabs-in-ELF by H.J. Lu (hjl@lucon.org).
   8
   9 This file is part of GCC.
  10
  11 GCC is free software; you can redistribute it and/or modify
  12 it under the terms of the GNU General Public License as published by
  13 the Free Software Foundation; either version 3, or (at your option)
  14 any later version.
  15
  16 GCC is distributed in the hope that it will be useful,
  17 but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 GNU General Public License for more details.
  20
  21 Under Section 7 of GPL version 3, you are granted additional
  22 permissions described in the GCC Runtime Library Exception, version
  23 3.1, as published by the Free Software Foundation.
  24
  25 You should have received a copy of the GNU General Public License and
  26 a copy of the GCC Runtime Library Exception along with this program;
  27 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  28 <http://www.gnu.org/licenses/>.  */
  29
  30 /* C libraries supported on Linux.  */
  31 #ifdef SINGLE_LIBC
  32 #define OPTION_GLIBC  (DEFAULT_LIBC == LIBC_GLIBC)
  33 #define OPTION_UCLIBC (DEFAULT_LIBC == LIBC_UCLIBC)
  34 #define OPTION_BIONIC (DEFAULT_LIBC == LIBC_BIONIC)
  35 #define OPTION_MUSL   (DEFAULT_LIBC == LIBC_MUSL)
  36 #else
  37 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
  38 #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
  39 #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
  40 #define OPTION_MUSL   (linux_libc == LIBC_MUSL)
  41 #endif
  42
  43 #define GNU_USER_TARGET_OS_CPP_BUILTINS()                       \
  44     do {                                                        \
  45         if (OPTION_GLIBC)                                       \
  46           builtin_define ("__gnu_linux__");                     \
  47         builtin_define_std ("linux");                           \
  48         builtin_define_std ("unix");                            \
  49         builtin_assert ("system=linux");                        \
  50         builtin_assert ("system=unix");                         \
  51         builtin_assert ("system=posix");                        \
  52     } while (0)
  53
  54 /* Determine which dynamic linker to use depending on whether GLIBC or
  55    uClibc or Bionic or musl is the default C library and whether
  56    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change
  57    the default.  */
  58
  59 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)  \
  60   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
  61
  62 #if DEFAULT_LIBC == LIBC_GLIBC
  63 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  64   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
  65 #elif DEFAULT_LIBC == LIBC_UCLIBC
  66 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  67   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
  68 #elif DEFAULT_LIBC == LIBC_BIONIC
  69 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  70   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
  71 #elif DEFAULT_LIBC == LIBC_MUSL
  72 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  73   CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
  74 #else
  75 #error "Unsupported DEFAULT_LIBC"
  76 #endif /* DEFAULT_LIBC */
  77
  78 /* For most targets the following definitions suffice;
  79    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
  80    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
  81    supporting both 32-bit and 64-bit compilation.  */
  82 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
  83 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
  84 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
  85 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
  86 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
  87 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
  88 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
  89 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
  90 /* Should be redefined for each target that supports musl.  */
  91 #define MUSL_DYNAMIC_LINKER "/dev/null"
  92 #define MUSL_DYNAMIC_LINKER32 "/dev/null"
  93 #define MUSL_DYNAMIC_LINKER64 "/dev/null"
  94 #define MUSL_DYNAMIC_LINKERX32 "/dev/null"
  95
  96 #define GNU_USER_DYNAMIC_LINKER                                         \
  97   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
  98                          BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
  99 #define GNU_USER_DYNAMIC_LINKER32                                       \
 100   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 101                          BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
 102 #define GNU_USER_DYNAMIC_LINKER64                                       \
 103   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 104                          BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
 105 #define GNU_USER_DYNAMIC_LINKERX32                                      \
 106   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
 107                          BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
 108
 109 /* Whether we have Bionic libc runtime */
 110 #undef TARGET_HAS_BIONIC
 111 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 112
 113 /* musl avoids problematic includes by rearranging the include directories.
 114  * Unfortunately, this is mostly duplicated from cppdefault.c */
 115 #if DEFAULT_LIBC == LIBC_MUSL
 116 #define INCLUDE_DEFAULTS_MUSL_GPP                       \
 117     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,               \
 118       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },           \
 119     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,          \
 120       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },           \
 121     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,      \
 122       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
 123
 124 #ifdef LOCAL_INCLUDE_DIR
 125 #define INCLUDE_DEFAULTS_MUSL_LOCAL                     \
 126     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },               \
 127     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
 128 #else
 129 #define INCLUDE_DEFAULTS_MUSL_LOCAL
 130 #endif
 131
 132 #ifdef PREFIX_INCLUDE_DIR
 133 #define INCLUDE_DEFAULTS_MUSL_PREFIX                    \
 134     { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
 135 #else
 136 #define INCLUDE_DEFAULTS_MUSL_PREFIX
 137 #endif
 138
 139 #ifdef CROSS_INCLUDE_DIR
 140 #define INCLUDE_DEFAULTS_MUSL_CROSS                     \
 141     { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
 142 #else
 143 #define INCLUDE_DEFAULTS_MUSL_CROSS
 144 #endif
 145
 146 #ifdef TOOL_INCLUDE_DIR
 147 #define INCLUDE_DEFAULTS_MUSL_TOOL                      \
 148     { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
 149 #else
 150 #define INCLUDE_DEFAULTS_MUSL_TOOL
 151 #endif
 152
 153 #ifdef NATIVE_SYSTEM_HEADER_DIR
 154 #define INCLUDE_DEFAULTS_MUSL_NATIVE                    \
 155     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },        \
 156     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
 157 #else
 158 #define INCLUDE_DEFAULTS_MUSL_NATIVE
 159 #endif
 160
 161 #if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
 162 # undef INCLUDE_DEFAULTS_MUSL_LOCAL
 163 # define INCLUDE_DEFAULTS_MUSL_LOCAL
 164 # undef INCLUDE_DEFAULTS_MUSL_NATIVE
 165 # define INCLUDE_DEFAULTS_MUSL_NATIVE
 166 #else
 167 # undef INCLUDE_DEFAULTS_MUSL_CROSS
 168 # define INCLUDE_DEFAULTS_MUSL_CROSS
 169 #endif
 170
 171 #undef INCLUDE_DEFAULTS
 172 #define INCLUDE_DEFAULTS                                \
 173   {                                                     \
 174     INCLUDE_DEFAULTS_MUSL_GPP                           \
 175     INCLUDE_DEFAULTS_MUSL_PREFIX                        \
 176     INCLUDE_DEFAULTS_MUSL_CROSS                         \
 177     INCLUDE_DEFAULTS_MUSL_TOOL                          \
 178     INCLUDE_DEFAULTS_MUSL_NATIVE                        \
 179     { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },             \
 180     { 0, 0, 0, 0, 0, 0 }                                \
 181   }
 182 #endif
 183
 184 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 185 /* This is a *uclinux* target.  We don't define below macros to normal linux
 186    versions, because doing so would require *uclinux* targets to include
 187    linux.c, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 188    these files to *uclinux* targets, but that would only pollute option list
 189    (add -mglibc, etc.) without adding any useful support.  */
 190
 191 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 192    no_c99_libc_has_function, because uclibc does not, normally, have
 193    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 194    this should be defined to a new hook.  Also please note that for targets
 195    like *-linux-uclibc that similar check will also need to be added to
 196    linux_libc_has_function.  */
 197 # undef TARGET_LIBC_HAS_FUNCTION
 198 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 199
 200 #else /* !uClinux, i.e., normal Linux */
 201
 202 /* Determine what functions are present at the runtime;
 203    this includes full c99 runtime and sincos.  */
 204 # undef TARGET_LIBC_HAS_FUNCTION
 205 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 206
 207 #endif