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) 1995-2018 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 #undef OPTION_MUSL
  36 #define OPTION_MUSL   (DEFAULT_LIBC == LIBC_MUSL)
  37 #else
  38 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
  39 #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
  40 #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
  41 #undef OPTION_MUSL
  42 #define OPTION_MUSL   (linux_libc == LIBC_MUSL)
  43 #endif
  44
  45 #define GNU_USER_TARGET_OS_CPP_BUILTINS()                       \
  46     do {                                                        \
  47         if (OPTION_GLIBC)                                       \
  48           builtin_define ("__gnu_linux__");                     \
  49         builtin_define_std ("linux");                           \
  50         builtin_define_std ("unix");                            \
  51         builtin_assert ("system=linux");                        \
  52         builtin_assert ("system=unix");                         \
  53         builtin_assert ("system=posix");                        \
  54     } while (0)
  55
  56 #define GNU_USER_TARGET_D_OS_VERSIONS()                         \
  57     do {                                                        \
  58         builtin_version ("linux");                              \
  59         if (OPTION_GLIBC)                                       \
  60           builtin_version ("CRuntime_Glibc");                   \
  61         else if (OPTION_UCLIBC)                                 \
  62           builtin_version ("CRuntime_UClibc");                  \
  63         else if (OPTION_BIONIC)                                 \
  64           builtin_version ("CRuntime_Bionic");                  \
  65         else if (OPTION_MUSL)                                   \
  66           builtin_version ("CRuntime_Musl");                    \
  67     } while (0)
  68
  69 /* Determine which dynamic linker to use depending on whether GLIBC or
  70    uClibc or Bionic or musl is the default C library and whether
  71    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change
  72    the default.  */
  73
  74 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)  \
  75   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
  76
  77 #if DEFAULT_LIBC == LIBC_GLIBC
  78 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  79   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
  80 #elif DEFAULT_LIBC == LIBC_UCLIBC
  81 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  82   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
  83 #elif DEFAULT_LIBC == LIBC_BIONIC
  84 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  85   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
  86 #elif DEFAULT_LIBC == LIBC_MUSL
  87 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  88   CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
  89 #else
  90 #error "Unsupported DEFAULT_LIBC"
  91 #endif /* DEFAULT_LIBC */
  92
  93 /* For most targets the following definitions suffice;
  94    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
  95    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
  96    supporting both 32-bit and 64-bit compilation.  */
  97 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
  98 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
  99 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 100 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
 101 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
 102 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
 103 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
 104 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
 105 /* Should be redefined for each target that supports musl.  */
 106 #define MUSL_DYNAMIC_LINKER "/dev/null"
 107 #define MUSL_DYNAMIC_LINKER32 "/dev/null"
 108 #define MUSL_DYNAMIC_LINKER64 "/dev/null"
 109 #define MUSL_DYNAMIC_LINKERX32 "/dev/null"
 110
 111 #define GNU_USER_DYNAMIC_LINKER                                         \
 112   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
 113                          BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
 114 #define GNU_USER_DYNAMIC_LINKER32                                       \
 115   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 116                          BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
 117 #define GNU_USER_DYNAMIC_LINKER64                                       \
 118   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 119                          BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
 120 #define GNU_USER_DYNAMIC_LINKERX32                                      \
 121   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
 122                          BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
 123
 124 /* Whether we have Bionic libc runtime */
 125 #undef TARGET_HAS_BIONIC
 126 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 127
 128 /* musl avoids problematic includes by rearranging the include directories.
 129  * Unfortunately, this is mostly duplicated from cppdefault.c */
 130 #if DEFAULT_LIBC == LIBC_MUSL
 131 #define INCLUDE_DEFAULTS_MUSL_GPP                       \
 132     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,               \
 133       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },           \
 134     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,          \
 135       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },           \
 136     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,      \
 137       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
 138
 139 #ifdef LOCAL_INCLUDE_DIR
 140 #define INCLUDE_DEFAULTS_MUSL_LOCAL                     \
 141     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },               \
 142     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
 143 #else
 144 #define INCLUDE_DEFAULTS_MUSL_LOCAL
 145 #endif
 146
 147 #ifdef PREFIX_INCLUDE_DIR
 148 #define INCLUDE_DEFAULTS_MUSL_PREFIX                    \
 149     { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
 150 #else
 151 #define INCLUDE_DEFAULTS_MUSL_PREFIX
 152 #endif
 153
 154 #ifdef CROSS_INCLUDE_DIR
 155 #define INCLUDE_DEFAULTS_MUSL_CROSS                     \
 156     { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
 157 #else
 158 #define INCLUDE_DEFAULTS_MUSL_CROSS
 159 #endif
 160
 161 #ifdef TOOL_INCLUDE_DIR
 162 #define INCLUDE_DEFAULTS_MUSL_TOOL                      \
 163     { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
 164 #else
 165 #define INCLUDE_DEFAULTS_MUSL_TOOL
 166 #endif
 167
 168 #ifdef NATIVE_SYSTEM_HEADER_DIR
 169 #define INCLUDE_DEFAULTS_MUSL_NATIVE                    \
 170     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },        \
 171     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
 172 #else
 173 #define INCLUDE_DEFAULTS_MUSL_NATIVE
 174 #endif
 175
 176 #if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
 177 # undef INCLUDE_DEFAULTS_MUSL_LOCAL
 178 # define INCLUDE_DEFAULTS_MUSL_LOCAL
 179 # undef INCLUDE_DEFAULTS_MUSL_NATIVE
 180 # define INCLUDE_DEFAULTS_MUSL_NATIVE
 181 #else
 182 # undef INCLUDE_DEFAULTS_MUSL_CROSS
 183 # define INCLUDE_DEFAULTS_MUSL_CROSS
 184 #endif
 185
 186 #undef INCLUDE_DEFAULTS
 187 #define INCLUDE_DEFAULTS                                \
 188   {                                                     \
 189     INCLUDE_DEFAULTS_MUSL_GPP                           \
 190     INCLUDE_DEFAULTS_MUSL_LOCAL                         \
 191     INCLUDE_DEFAULTS_MUSL_PREFIX                        \
 192     INCLUDE_DEFAULTS_MUSL_CROSS                         \
 193     INCLUDE_DEFAULTS_MUSL_TOOL                          \
 194     INCLUDE_DEFAULTS_MUSL_NATIVE                        \
 195     { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },             \
 196     { 0, 0, 0, 0, 0, 0 }                                \
 197   }
 198 #endif
 199
 200 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 201 /* This is a *uclinux* target.  We don't define below macros to normal linux
 202    versions, because doing so would require *uclinux* targets to include
 203    linux.c, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 204    these files to *uclinux* targets, but that would only pollute option list
 205    (add -mglibc, etc.) without adding any useful support.  */
 206
 207 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 208    no_c99_libc_has_function, because uclibc does not, normally, have
 209    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 210    this should be defined to a new hook.  Also please note that for targets
 211    like *-linux-uclibc that similar check will also need to be added to
 212    linux_libc_has_function.  */
 213 # undef TARGET_LIBC_HAS_FUNCTION
 214 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 215
 216 #else /* !uClinux, i.e., normal Linux */
 217
 218 /* Determine what functions are present at the runtime;
 219    this includes full c99 runtime and sincos.  */
 220 # undef TARGET_LIBC_HAS_FUNCTION
 221 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 222
 223 #endif