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) 1995-2023 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 /* Determine which dynamic linker to use depending on whether GLIBC or
  62    uClibc or Bionic or musl is the default C library and whether
  63    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change
  64    the default.  */
  65
  66 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)  \
  67   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
  68
  69 #if DEFAULT_LIBC == LIBC_GLIBC
  70 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  71   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
  72 #elif DEFAULT_LIBC == LIBC_UCLIBC
  73 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  74   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
  75 #elif DEFAULT_LIBC == LIBC_BIONIC
  76 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  77   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
  78 #elif DEFAULT_LIBC == LIBC_MUSL
  79 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  80   CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
  81 #else
  82 #error "Unsupported DEFAULT_LIBC"
  83 #endif /* DEFAULT_LIBC */
  84
  85 /* For most targets the following definitions suffice;
  86    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
  87    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
  88    supporting both 32-bit and 64-bit compilation.  */
  89 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
  90 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
  91 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
  92 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
  93 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
  94 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
  95 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
  96 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
  97 /* Should be redefined for each target that supports musl.  */
  98 #define MUSL_DYNAMIC_LINKER "/dev/null"
  99 #define MUSL_DYNAMIC_LINKER32 "/dev/null"
 100 #define MUSL_DYNAMIC_LINKER64 "/dev/null"
 101 #define MUSL_DYNAMIC_LINKERX32 "/dev/null"
 102
 103 #define GNU_USER_DYNAMIC_LINKER                                         \
 104   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
 105                          BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
 106 #define GNU_USER_DYNAMIC_LINKER32                                       \
 107   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 108                          BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
 109 #define GNU_USER_DYNAMIC_LINKER64                                       \
 110   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 111                          BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
 112 #define GNU_USER_DYNAMIC_LINKERX32                                      \
 113   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
 114                          BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
 115
 116 /* Whether we have Bionic libc runtime */
 117 #undef TARGET_HAS_BIONIC
 118 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 119
 120 /* musl avoids problematic includes by rearranging the include directories.
 121  * Unfortunately, this is mostly duplicated from cppdefault.cc */
 122 #if DEFAULT_LIBC == LIBC_MUSL
 123 #define INCLUDE_DEFAULTS_MUSL_GPP                       \
 124     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,               \
 125       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },           \
 126     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,          \
 127       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },           \
 128     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,      \
 129       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
 130
 131 #ifdef LOCAL_INCLUDE_DIR
 132 #define INCLUDE_DEFAULTS_MUSL_LOCAL                     \
 133     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },               \
 134     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
 135 #else
 136 #define INCLUDE_DEFAULTS_MUSL_LOCAL
 137 #endif
 138
 139 #ifdef PREFIX_INCLUDE_DIR
 140 #define INCLUDE_DEFAULTS_MUSL_PREFIX                    \
 141     { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
 142 #else
 143 #define INCLUDE_DEFAULTS_MUSL_PREFIX
 144 #endif
 145
 146 #ifdef CROSS_INCLUDE_DIR
 147 #define INCLUDE_DEFAULTS_MUSL_CROSS                     \
 148     { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
 149 #else
 150 #define INCLUDE_DEFAULTS_MUSL_CROSS
 151 #endif
 152
 153 #ifdef TOOL_INCLUDE_DIR
 154 #define INCLUDE_DEFAULTS_MUSL_TOOL                      \
 155     { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
 156 #else
 157 #define INCLUDE_DEFAULTS_MUSL_TOOL
 158 #endif
 159
 160 #ifdef NATIVE_SYSTEM_HEADER_DIR
 161 #define INCLUDE_DEFAULTS_MUSL_NATIVE                    \
 162     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },        \
 163     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
 164 #else
 165 #define INCLUDE_DEFAULTS_MUSL_NATIVE
 166 #endif
 167
 168 #if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
 169 # undef INCLUDE_DEFAULTS_MUSL_LOCAL
 170 # define INCLUDE_DEFAULTS_MUSL_LOCAL
 171 # undef INCLUDE_DEFAULTS_MUSL_NATIVE
 172 # define INCLUDE_DEFAULTS_MUSL_NATIVE
 173 #else
 174 # undef INCLUDE_DEFAULTS_MUSL_CROSS
 175 # define INCLUDE_DEFAULTS_MUSL_CROSS
 176 #endif
 177
 178 #undef INCLUDE_DEFAULTS
 179 #define INCLUDE_DEFAULTS                                \
 180   {                                                     \
 181     INCLUDE_DEFAULTS_MUSL_GPP                           \
 182     INCLUDE_DEFAULTS_MUSL_LOCAL                         \
 183     INCLUDE_DEFAULTS_MUSL_PREFIX                        \
 184     INCLUDE_DEFAULTS_MUSL_CROSS                         \
 185     INCLUDE_DEFAULTS_MUSL_TOOL                          \
 186     INCLUDE_DEFAULTS_MUSL_NATIVE                        \
 187     { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },             \
 188     { 0, 0, 0, 0, 0, 0 }                                \
 189   }
 190 #endif
 191
 192 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 193 /* This is a *uclinux* target.  We don't define below macros to normal linux
 194    versions, because doing so would require *uclinux* targets to include
 195    linux.cc, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 196    these files to *uclinux* targets, but that would only pollute option list
 197    (add -mglibc, etc.) without adding any useful support.  */
 198
 199 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 200    no_c99_libc_has_function, because uclibc does not, normally, have
 201    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 202    this should be defined to a new hook.  Also please note that for targets
 203    like *-linux-uclibc that similar check will also need to be added to
 204    linux_libc_has_function.  */
 205 # undef TARGET_LIBC_HAS_FUNCTION
 206 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 207
 208 #else /* !uClinux, i.e., normal Linux */
 209
 210 /* Determine what functions are present at the runtime;
 211    this includes full c99 runtime and sincos.  */
 212 # undef TARGET_LIBC_HAS_FUNCTION
 213 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 214
 215 # undef TARGET_LIBM_FUNCTION_MAX_ERROR
 216 # define TARGET_LIBM_FUNCTION_MAX_ERROR linux_libm_function_max_error
 217
 218 #endif