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) 1995-2022 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_P(opts)    (DEFAULT_LIBC == LIBC_GLIBC)
  33 #define OPTION_UCLIBC_P(opts)   (DEFAULT_LIBC == LIBC_UCLIBC)
  34 #define OPTION_BIONIC_P(opts)   (DEFAULT_LIBC == LIBC_BIONIC)
  35 #undef OPTION_MUSL_P
  36 #define OPTION_MUSL_P(opts)     (DEFAULT_LIBC == LIBC_MUSL)
  37 #else
  38 #define OPTION_GLIBC_P(opts)    ((opts)->x_linux_libc == LIBC_GLIBC)
  39 #define OPTION_UCLIBC_P(opts)   ((opts)->x_linux_libc == LIBC_UCLIBC)
  40 #define OPTION_BIONIC_P(opts)   ((opts)->x_linux_libc == LIBC_BIONIC)
  41 #undef OPTION_MUSL_P
  42 #define OPTION_MUSL_P(opts)     ((opts)->x_linux_libc == LIBC_MUSL)
  43 #endif
  44 #define OPTION_GLIBC            OPTION_GLIBC_P (&global_options)
  45 #define OPTION_UCLIBC           OPTION_UCLIBC_P (&global_options)
  46 #define OPTION_BIONIC           OPTION_BIONIC_P (&global_options)
  47 #undef OPTION_MUSL
  48 #define OPTION_MUSL             OPTION_MUSL_P (&global_options)
  49
  50 #define GNU_USER_TARGET_OS_CPP_BUILTINS()                       \
  51     do {                                                        \
  52         if (OPTION_GLIBC)                                       \
  53           builtin_define ("__gnu_linux__");                     \
  54         builtin_define_std ("linux");                           \
  55         builtin_define_std ("unix");                            \
  56         builtin_assert ("system=linux");                        \
  57         builtin_assert ("system=unix");                         \
  58         builtin_assert ("system=posix");                        \
  59     } while (0)
  60
  61 #define GNU_USER_TARGET_D_OS_VERSIONS()                         \
  62     do {                                                        \
  63         builtin_version ("linux");                              \
  64         if (OPTION_GLIBC)                                       \
  65           builtin_version ("CRuntime_Glibc");                   \
  66         else if (OPTION_UCLIBC)                                 \
  67           builtin_version ("CRuntime_UClibc");                  \
  68         else if (OPTION_BIONIC)                                 \
  69           builtin_version ("CRuntime_Bionic");                  \
  70         else if (OPTION_MUSL)                                   \
  71           builtin_version ("CRuntime_Musl");                    \
  72     } while (0)
  73
  74 /* Determine which dynamic linker to use depending on whether GLIBC or
  75    uClibc or Bionic or musl is the default C library and whether
  76    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change
  77    the default.  */
  78
  79 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)  \
  80   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
  81
  82 #if DEFAULT_LIBC == LIBC_GLIBC
  83 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  84   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
  85 #elif DEFAULT_LIBC == LIBC_UCLIBC
  86 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  87   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
  88 #elif DEFAULT_LIBC == LIBC_BIONIC
  89 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  90   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
  91 #elif DEFAULT_LIBC == LIBC_MUSL
  92 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  93   CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
  94 #else
  95 #error "Unsupported DEFAULT_LIBC"
  96 #endif /* DEFAULT_LIBC */
  97
  98 /* For most targets the following definitions suffice;
  99    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
 100    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
 101    supporting both 32-bit and 64-bit compilation.  */
 102 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
 103 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 104 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
 105 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
 106 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
 107 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
 108 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
 109 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
 110 /* Should be redefined for each target that supports musl.  */
 111 #define MUSL_DYNAMIC_LINKER "/dev/null"
 112 #define MUSL_DYNAMIC_LINKER32 "/dev/null"
 113 #define MUSL_DYNAMIC_LINKER64 "/dev/null"
 114 #define MUSL_DYNAMIC_LINKERX32 "/dev/null"
 115
 116 #define GNU_USER_DYNAMIC_LINKER                                         \
 117   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
 118                          BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
 119 #define GNU_USER_DYNAMIC_LINKER32                                       \
 120   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 121                          BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
 122 #define GNU_USER_DYNAMIC_LINKER64                                       \
 123   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 124                          BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
 125 #define GNU_USER_DYNAMIC_LINKERX32                                      \
 126   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
 127                          BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
 128
 129 /* Whether we have Bionic libc runtime */
 130 #undef TARGET_HAS_BIONIC
 131 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 132
 133 /* musl avoids problematic includes by rearranging the include directories.
 134  * Unfortunately, this is mostly duplicated from cppdefault.cc */
 135 #if DEFAULT_LIBC == LIBC_MUSL
 136 #define INCLUDE_DEFAULTS_MUSL_GPP                       \
 137     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,               \
 138       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },           \
 139     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,          \
 140       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },           \
 141     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,      \
 142       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
 143
 144 #ifdef LOCAL_INCLUDE_DIR
 145 #define INCLUDE_DEFAULTS_MUSL_LOCAL                     \
 146     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },               \
 147     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
 148 #else
 149 #define INCLUDE_DEFAULTS_MUSL_LOCAL
 150 #endif
 151
 152 #ifdef PREFIX_INCLUDE_DIR
 153 #define INCLUDE_DEFAULTS_MUSL_PREFIX                    \
 154     { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
 155 #else
 156 #define INCLUDE_DEFAULTS_MUSL_PREFIX
 157 #endif
 158
 159 #ifdef CROSS_INCLUDE_DIR
 160 #define INCLUDE_DEFAULTS_MUSL_CROSS                     \
 161     { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
 162 #else
 163 #define INCLUDE_DEFAULTS_MUSL_CROSS
 164 #endif
 165
 166 #ifdef TOOL_INCLUDE_DIR
 167 #define INCLUDE_DEFAULTS_MUSL_TOOL                      \
 168     { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
 169 #else
 170 #define INCLUDE_DEFAULTS_MUSL_TOOL
 171 #endif
 172
 173 #ifdef NATIVE_SYSTEM_HEADER_DIR
 174 #define INCLUDE_DEFAULTS_MUSL_NATIVE                    \
 175     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },        \
 176     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
 177 #else
 178 #define INCLUDE_DEFAULTS_MUSL_NATIVE
 179 #endif
 180
 181 #if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
 182 # undef INCLUDE_DEFAULTS_MUSL_LOCAL
 183 # define INCLUDE_DEFAULTS_MUSL_LOCAL
 184 # undef INCLUDE_DEFAULTS_MUSL_NATIVE
 185 # define INCLUDE_DEFAULTS_MUSL_NATIVE
 186 #else
 187 # undef INCLUDE_DEFAULTS_MUSL_CROSS
 188 # define INCLUDE_DEFAULTS_MUSL_CROSS
 189 #endif
 190
 191 #undef INCLUDE_DEFAULTS
 192 #define INCLUDE_DEFAULTS                                \
 193   {                                                     \
 194     INCLUDE_DEFAULTS_MUSL_GPP                           \
 195     INCLUDE_DEFAULTS_MUSL_LOCAL                         \
 196     INCLUDE_DEFAULTS_MUSL_PREFIX                        \
 197     INCLUDE_DEFAULTS_MUSL_CROSS                         \
 198     INCLUDE_DEFAULTS_MUSL_TOOL                          \
 199     INCLUDE_DEFAULTS_MUSL_NATIVE                        \
 200     { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },             \
 201     { 0, 0, 0, 0, 0, 0 }                                \
 202   }
 203 #endif
 204
 205 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 206 /* This is a *uclinux* target.  We don't define below macros to normal linux
 207    versions, because doing so would require *uclinux* targets to include
 208    linux.cc, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 209    these files to *uclinux* targets, but that would only pollute option list
 210    (add -mglibc, etc.) without adding any useful support.  */
 211
 212 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 213    no_c99_libc_has_function, because uclibc does not, normally, have
 214    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 215    this should be defined to a new hook.  Also please note that for targets
 216    like *-linux-uclibc that similar check will also need to be added to
 217    linux_libc_has_function.  */
 218 # undef TARGET_LIBC_HAS_FUNCTION
 219 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 220
 221 #else /* !uClinux, i.e., normal Linux */
 222
 223 /* Determine what functions are present at the runtime;
 224    this includes full c99 runtime and sincos.  */
 225 # undef TARGET_LIBC_HAS_FUNCTION
 226 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 227
 228 #endif