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) 1995-2017 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 /* Determine which dynamic linker to use depending on whether GLIBC or
  57    uClibc or Bionic or musl is the default C library and whether
  58    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change
  59    the default.  */
  60
  61 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LIBC4, LD1, LD2, LD3, LD4)  \
  62   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:%{" LIBC4 ":" LD4 ";:" LD1 "}}}"
  63
  64 #if DEFAULT_LIBC == LIBC_GLIBC
  65 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  66   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", "mmusl", G, U, B, M)
  67 #elif DEFAULT_LIBC == LIBC_UCLIBC
  68 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  69   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", "mmusl", U, G, B, M)
  70 #elif DEFAULT_LIBC == LIBC_BIONIC
  71 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  72   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", "mmusl", B, G, U, M)
  73 #elif DEFAULT_LIBC == LIBC_MUSL
  74 #define CHOOSE_DYNAMIC_LINKER(G, U, B, M) \
  75   CHOOSE_DYNAMIC_LINKER1 ("mmusl", "mglibc", "muclibc", "mbionic", M, G, U, B)
  76 #else
  77 #error "Unsupported DEFAULT_LIBC"
  78 #endif /* DEFAULT_LIBC */
  79
  80 /* For most targets the following definitions suffice;
  81    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
  82    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
  83    supporting both 32-bit and 64-bit compilation.  */
  84 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
  85 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
  86 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
  87 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
  88 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
  89 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
  90 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
  91 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
  92 /* Should be redefined for each target that supports musl.  */
  93 #define MUSL_DYNAMIC_LINKER "/dev/null"
  94 #define MUSL_DYNAMIC_LINKER32 "/dev/null"
  95 #define MUSL_DYNAMIC_LINKER64 "/dev/null"
  96 #define MUSL_DYNAMIC_LINKERX32 "/dev/null"
  97
  98 #define GNU_USER_DYNAMIC_LINKER                                         \
  99   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
 100                          BIONIC_DYNAMIC_LINKER, MUSL_DYNAMIC_LINKER)
 101 #define GNU_USER_DYNAMIC_LINKER32                                       \
 102   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
 103                          BIONIC_DYNAMIC_LINKER32, MUSL_DYNAMIC_LINKER32)
 104 #define GNU_USER_DYNAMIC_LINKER64                                       \
 105   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 106                          BIONIC_DYNAMIC_LINKER64, MUSL_DYNAMIC_LINKER64)
 107 #define GNU_USER_DYNAMIC_LINKERX32                                      \
 108   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
 109                          BIONIC_DYNAMIC_LINKERX32, MUSL_DYNAMIC_LINKERX32)
 110
 111 /* Whether we have Bionic libc runtime */
 112 #undef TARGET_HAS_BIONIC
 113 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 114
 115 /* musl avoids problematic includes by rearranging the include directories.
 116  * Unfortunately, this is mostly duplicated from cppdefault.c */
 117 #if DEFAULT_LIBC == LIBC_MUSL
 118 #define INCLUDE_DEFAULTS_MUSL_GPP                       \
 119     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1,               \
 120       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },           \
 121     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1,          \
 122       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 1 },           \
 123     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1,      \
 124       GPLUSPLUS_INCLUDE_DIR_ADD_SYSROOT, 0 },
 125
 126 #ifdef LOCAL_INCLUDE_DIR
 127 #define INCLUDE_DEFAULTS_MUSL_LOCAL                     \
 128     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 2 },               \
 129     { LOCAL_INCLUDE_DIR, 0, 0, 1, 1, 0 },
 130 #else
 131 #define INCLUDE_DEFAULTS_MUSL_LOCAL
 132 #endif
 133
 134 #ifdef PREFIX_INCLUDE_DIR
 135 #define INCLUDE_DEFAULTS_MUSL_PREFIX                    \
 136     { PREFIX_INCLUDE_DIR, 0, 0, 1, 0, 0},
 137 #else
 138 #define INCLUDE_DEFAULTS_MUSL_PREFIX
 139 #endif
 140
 141 #ifdef CROSS_INCLUDE_DIR
 142 #define INCLUDE_DEFAULTS_MUSL_CROSS                     \
 143     { CROSS_INCLUDE_DIR, "GCC", 0, 0, 0, 0},
 144 #else
 145 #define INCLUDE_DEFAULTS_MUSL_CROSS
 146 #endif
 147
 148 #ifdef TOOL_INCLUDE_DIR
 149 #define INCLUDE_DEFAULTS_MUSL_TOOL                      \
 150     { TOOL_INCLUDE_DIR, "BINUTILS", 0, 1, 0, 0},
 151 #else
 152 #define INCLUDE_DEFAULTS_MUSL_TOOL
 153 #endif
 154
 155 #ifdef NATIVE_SYSTEM_HEADER_DIR
 156 #define INCLUDE_DEFAULTS_MUSL_NATIVE                    \
 157     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 2 },        \
 158     { NATIVE_SYSTEM_HEADER_DIR, 0, 0, 0, 1, 0 },
 159 #else
 160 #define INCLUDE_DEFAULTS_MUSL_NATIVE
 161 #endif
 162
 163 #if defined (CROSS_DIRECTORY_STRUCTURE) && !defined (TARGET_SYSTEM_ROOT)
 164 # undef INCLUDE_DEFAULTS_MUSL_LOCAL
 165 # define INCLUDE_DEFAULTS_MUSL_LOCAL
 166 # undef INCLUDE_DEFAULTS_MUSL_NATIVE
 167 # define INCLUDE_DEFAULTS_MUSL_NATIVE
 168 #else
 169 # undef INCLUDE_DEFAULTS_MUSL_CROSS
 170 # define INCLUDE_DEFAULTS_MUSL_CROSS
 171 #endif
 172
 173 #undef INCLUDE_DEFAULTS
 174 #define INCLUDE_DEFAULTS                                \
 175   {                                                     \
 176     INCLUDE_DEFAULTS_MUSL_GPP                           \
 177     INCLUDE_DEFAULTS_MUSL_LOCAL                         \
 178     INCLUDE_DEFAULTS_MUSL_PREFIX                        \
 179     INCLUDE_DEFAULTS_MUSL_CROSS                         \
 180     INCLUDE_DEFAULTS_MUSL_TOOL                          \
 181     INCLUDE_DEFAULTS_MUSL_NATIVE                        \
 182     { GCC_INCLUDE_DIR, "GCC", 0, 1, 0, 0 },             \
 183     { 0, 0, 0, 0, 0, 0 }                                \
 184   }
 185 #endif
 186
 187 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 188 /* This is a *uclinux* target.  We don't define below macros to normal linux
 189    versions, because doing so would require *uclinux* targets to include
 190    linux.c, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 191    these files to *uclinux* targets, but that would only pollute option list
 192    (add -mglibc, etc.) without adding any useful support.  */
 193
 194 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 195    no_c99_libc_has_function, because uclibc does not, normally, have
 196    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 197    this should be defined to a new hook.  Also please note that for targets
 198    like *-linux-uclibc that similar check will also need to be added to
 199    linux_libc_has_function.  */
 200 # undef TARGET_LIBC_HAS_FUNCTION
 201 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 202
 203 #else /* !uClinux, i.e., normal Linux */
 204
 205 /* Determine what functions are present at the runtime;
 206    this includes full c99 runtime and sincos.  */
 207 # undef TARGET_LIBC_HAS_FUNCTION
 208 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 209
 210 #endif