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) 1995-2014 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 #else
  36 #define OPTION_GLIBC  (linux_libc == LIBC_GLIBC)
  37 #define OPTION_UCLIBC (linux_libc == LIBC_UCLIBC)
  38 #define OPTION_BIONIC (linux_libc == LIBC_BIONIC)
  39 #endif
  40
  41 #define GNU_USER_TARGET_OS_CPP_BUILTINS()                       \
  42     do {                                                        \
  43         if (OPTION_GLIBC)                                       \
  44           builtin_define ("__gnu_linux__");                     \
  45         builtin_define_std ("linux");                           \
  46         builtin_define_std ("unix");                            \
  47         builtin_assert ("system=linux");                        \
  48         builtin_assert ("system=unix");                         \
  49         builtin_assert ("system=posix");                        \
  50     } while (0)
  51
  52 /* Determine which dynamic linker to use depending on whether GLIBC or
  53    uClibc or Bionic is the default C library and whether
  54    -muclibc or -mglibc or -mbionic has been passed to change the default.  */
  55
  56 #define CHOOSE_DYNAMIC_LINKER1(LIBC1, LIBC2, LIBC3, LD1, LD2, LD3)      \
  57   "%{" LIBC2 ":" LD2 ";:%{" LIBC3 ":" LD3 ";:" LD1 "}}"
  58
  59 #if DEFAULT_LIBC == LIBC_GLIBC
  60 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
  61   CHOOSE_DYNAMIC_LINKER1 ("mglibc", "muclibc", "mbionic", G, U, B)
  62 #elif DEFAULT_LIBC == LIBC_UCLIBC
  63 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
  64   CHOOSE_DYNAMIC_LINKER1 ("muclibc", "mglibc", "mbionic", U, G, B)
  65 #elif DEFAULT_LIBC == LIBC_BIONIC
  66 #define CHOOSE_DYNAMIC_LINKER(G, U, B) \
  67   CHOOSE_DYNAMIC_LINKER1 ("mbionic", "mglibc", "muclibc", B, G, U)
  68 #else
  69 #error "Unsupported DEFAULT_LIBC"
  70 #endif /* DEFAULT_LIBC */
  71
  72 /* For most targets the following definitions suffice;
  73    GLIBC_DYNAMIC_LINKER must be defined for each target using them, or
  74    GLIBC_DYNAMIC_LINKER32 and GLIBC_DYNAMIC_LINKER64 for targets
  75    supporting both 32-bit and 64-bit compilation.  */
  76 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
  77 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
  78 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
  79 #define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
  80 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
  81 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
  82 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
  83 #define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
  84
  85 #define GNU_USER_DYNAMIC_LINKER                                         \
  86   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,   \
  87                          BIONIC_DYNAMIC_LINKER)
  88 #define GNU_USER_DYNAMIC_LINKER32                                       \
  89   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER32, UCLIBC_DYNAMIC_LINKER32, \
  90                          BIONIC_DYNAMIC_LINKER32)
  91 #define GNU_USER_DYNAMIC_LINKER64                                       \
  92   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
  93                          BIONIC_DYNAMIC_LINKER64)
  94 #define GNU_USER_DYNAMIC_LINKERX32                                      \
  95   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
  96                          BIONIC_DYNAMIC_LINKERX32)
  97
  98 /* Whether we have Bionic libc runtime */
  99 #undef TARGET_HAS_BIONIC
 100 #define TARGET_HAS_BIONIC (OPTION_BIONIC)
 101
 102 #if (DEFAULT_LIBC == LIBC_UCLIBC) && defined (SINGLE_LIBC) /* uClinux */
 103 /* This is a *uclinux* target.  We don't define below macros to normal linux
 104    versions, because doing so would require *uclinux* targets to include
 105    linux.c, linux-protos.h, linux.opt, etc.  We could, alternatively, add
 106    these files to *uclinux* targets, but that would only pollute option list
 107    (add -mglibc, etc.) without adding any useful support.  */
 108
 109 /* Define TARGET_LIBC_HAS_FUNCTION for *uclinux* targets to
 110    no_c99_libc_has_function, because uclibc does not, normally, have
 111    c99 runtime.  If, in special cases, uclibc does have c99 runtime,
 112    this should be defined to a new hook.  Also please note that for targets
 113    like *-linux-uclibc that similar check will also need to be added to
 114    linux_libc_has_function.  */
 115 # undef TARGET_LIBC_HAS_FUNCTION
 116 # define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
 117
 118 #else /* !uClinux, i.e., normal Linux */
 119
 120 /* IFUNCs are supported by glibc, but not by uClibc or Bionic.  */
 121 # undef TARGET_HAS_IFUNC_P
 122 # define TARGET_HAS_IFUNC_P linux_has_ifunc_p
 123
 124 /* Determine what functions are present at the runtime;
 125    this includes full c99 runtime and sincos.  */
 126 # undef TARGET_LIBC_HAS_FUNCTION
 127 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 128
 129 #endif