gcc/config/openbsd.h

   1 /* Base configuration file for all OpenBSD targets.
   2    Copyright (C) 1999-2013 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* Common OpenBSD configuration.
  21    All OpenBSD architectures include this file, which is intended as
  22    a repository for common defines.
  23
  24    Some defines are common to all architectures, a few of them are
  25    triggered by OBSD_* guards, so that we won't override architecture
  26    defaults by mistakes.
  27
  28    OBSD_HAS_CORRECT_SPECS:
  29       another mechanism provides correct specs already.
  30    OBSD_NO_DYNAMIC_LIBRARIES:
  31       no implementation of dynamic libraries.
  32    OBSD_OLD_GAS:
  33       older flavor of gas which needs help for PIC.
  34    OBSD_HAS_DECLARE_FUNCTION_NAME, OBSD_HAS_DECLARE_FUNCTION_SIZE,
  35    OBSD_HAS_DECLARE_OBJECT:
  36       PIC support, FUNCTION_NAME/FUNCTION_SIZE are independent, whereas
  37       the corresponding logic for OBJECTS is necessarily coupled.
  38
  39    There are also a few `default' defines such as ASM_WEAKEN_LABEL,
  40    intended as common ground for arch that don't provide
  41    anything suitable.  */
  42
  43 /* OPENBSD_NATIVE is defined only when gcc is configured as part of
  44    the OpenBSD source tree, specifically through Makefile.bsd-wrapper.
  45
  46    In such a case the include path can be trimmed as there is no
  47    distinction between system includes and gcc includes.  */
  48
  49 /* This configuration method, namely Makefile.bsd-wrapper and
  50    OPENBSD_NATIVE is NOT recommended for building cross-compilers.  */
  51
  52 #ifdef OPENBSD_NATIVE
  53
  54 /* The compiler is configured with ONLY the gcc/g++ standard headers.  */
  55 #undef INCLUDE_DEFAULTS
  56 #define INCLUDE_DEFAULTS                        \
  57   {                                             \
  58     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1 },     \
  59     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1 }, \
  60     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1 }, \
  61     { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0 }, \
  62     { 0, 0, 0, 0 }                              \
  63   }
  64
  65 /* Under OpenBSD, the normal location of the various *crt*.o files is the
  66    /usr/lib directory.  */
  67 #undef STANDARD_STARTFILE_PREFIX
  68 #define STANDARD_STARTFILE_PREFIX       "/usr/local/lib/"
  69
  70 #endif
  71
  72 \f
  73 /* Controlling the compilation driver.  */
  74 /* TARGET_OS_CPP_BUILTINS() common to all OpenBSD targets.  */
  75 #define OPENBSD_OS_CPP_BUILTINS()               \
  76   do                                            \
  77     {                                           \
  78       builtin_define ("__OpenBSD__");           \
  79       builtin_define ("__unix__");              \
  80       builtin_define ("__ANSI_COMPAT");         \
  81       builtin_assert ("system=unix");           \
  82       builtin_assert ("system=bsd");            \
  83       builtin_assert ("system=OpenBSD");        \
  84     }                                           \
  85   while (0)
  86
  87 /* TARGET_OS_CPP_BUILTINS() common to all OpenBSD ELF targets.  */
  88 #define OPENBSD_OS_CPP_BUILTINS_ELF()           \
  89   do                                            \
  90     {                                           \
  91       OPENBSD_OS_CPP_BUILTINS();                \
  92       builtin_define ("__ELF__");               \
  93     }                                           \
  94 while (0)
  95
  96 /* TARGET_OS_CPP_BUILTINS() common to all LP64 OpenBSD targets.  */
  97 #define OPENBSD_OS_CPP_BUILTINS_LP64()          \
  98   do                                            \
  99     {                                           \
 100       builtin_define ("_LP64");                 \
 101       builtin_define ("__LP64__");              \
 102     }                                           \
 103   while (0)
 104
 105 /* CPP_SPEC appropriate for OpenBSD. We deal with -posix and -pthread.
 106    XXX the way threads are handled currently is not very satisfying,
 107    since all code must be compiled with -pthread to work.
 108    This two-stage defines makes it easy to pick that for targets that
 109    have subspecs.  */
 110 #ifdef CPP_CPU_SPEC
 111 #define OBSD_CPP_SPEC "%(cpp_cpu) %{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
 112 #else
 113 #define OBSD_CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
 114 #endif
 115
 116 #undef LIB_SPEC
 117 #define LIB_SPEC OBSD_LIB_SPEC
 118
 119 #ifndef OBSD_HAS_CORRECT_SPECS
 120
 121 #undef CPP_SPEC
 122 #define CPP_SPEC OBSD_CPP_SPEC
 123
 124 #ifdef OBSD_OLD_GAS
 125 /* ASM_SPEC appropriate for OpenBSD.  For some architectures, OpenBSD
 126    still uses a special flavor of gas that needs to be told when generating
 127    pic code.  */
 128 #undef ASM_SPEC
 129 #define ASM_SPEC "%{fpic|fpie:-k} %{fPIC|fPIE:-k -K}"
 130 #endif
 131
 132 /* Since we use gas, stdin -> - is a good idea.  */
 133 #define AS_NEEDS_DASH_FOR_PIPED_INPUT
 134
 135 #undef LIB_SPEC
 136 #define LIB_SPEC OBSD_LIB_SPEC
 137
 138 #if defined(HAVE_LD_EH_FRAME_HDR)
 139 #define LINK_EH_SPEC "%{!static:--eh-frame-hdr} "
 140 #endif
 141
 142 #undef LIB_SPEC
 143 #define LIB_SPEC OBSD_LIB_SPEC
 144 #endif
 145
 146 #define TARGET_POSIX_IO
 147
 148 /* All new versions of OpenBSD have C99 functions.  */
 149 #define TARGET_C99_FUNCTIONS 1
 150
 151 \f
 152 /* Runtime target specification.  */
 153
 154 /* Miscellaneous parameters.  */
 155
 156 /* Controlling debugging info: dbx options.  */
 157
 158 /* Don't use the `xsTAG;' construct in DBX output; OpenBSD systems that
 159    use DBX don't support it.  */
 160 #define DBX_NO_XREFS
 161
 162 \f
 163 /* - we use . - _func instead of a local label,
 164    - we put extra spaces in expressions such as
 165      .type _func , @function
 166      This is more readable for a human being and confuses c++filt less.  */
 167
 168 /* Assembler format: output and generation of labels.  */
 169
 170 /* Define the strings used for the .type and .size directives.
 171    These strings generally do not vary from one system running OpenBSD
 172    to another, but if a given system needs to use different pseudo-op
 173    names for these, they may be overridden in the arch specific file.  */
 174
 175 /* OpenBSD assembler is hacked to have .type & .size support even in a.out
 176    format object files.  Functions size are supported but not activated
 177    yet (look for GRACE_PERIOD_EXPIRED in gas/config/obj-aout.c).
 178    SET_ASM_OP is needed for attribute alias to work.  */
 179
 180 #undef TYPE_ASM_OP
 181 #undef SIZE_ASM_OP
 182 #undef SET_ASM_OP
 183 #undef GLOBAL_ASM_OP
 184
 185 #define TYPE_ASM_OP     "\t.type\t"
 186 #define SIZE_ASM_OP     "\t.size\t"
 187 #define SET_ASM_OP      "\t.set\t"
 188 #define GLOBAL_ASM_OP   "\t.globl\t"
 189
 190 /* The following macro defines the format used to output the second
 191    operand of the .type assembler directive.  */
 192 #undef TYPE_OPERAND_FMT
 193 #define TYPE_OPERAND_FMT        "@%s"
 194
 195 /* Provision if extra assembler code is needed to declare a function's result
 196    (taken from svr4, not needed yet actually).  */
 197 #ifndef ASM_DECLARE_RESULT
 198 #define ASM_DECLARE_RESULT(FILE, RESULT)
 199 #endif
 200
 201 /* These macros generate the special .type and .size directives which
 202    are used to set the corresponding fields of the linker symbol table
 203    entries under OpenBSD.  These macros also have to output the starting
 204    labels for the relevant functions/objects.  */
 205
 206 #ifndef OBSD_HAS_DECLARE_FUNCTION_NAME
 207 /* Extra assembler code needed to declare a function properly.
 208    Some assemblers may also need to also have something extra said
 209    about the function's return value.  We allow for that here.  */
 210 #undef ASM_DECLARE_FUNCTION_NAME
 211 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)                     \
 212   do {                                                                  \
 213     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function");                 \
 214     ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                      \
 215     ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL);                       \
 216   } while (0)
 217 #endif
 218
 219 #ifndef OBSD_HAS_DECLARE_FUNCTION_SIZE
 220 /* Declare the size of a function.  */
 221 #undef ASM_DECLARE_FUNCTION_SIZE
 222 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
 223   do {                                                          \
 224     if (!flag_inhibit_size_directive)                           \
 225       ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME);                   \
 226   } while (0)
 227 #endif
 228
 229 #ifndef OBSD_HAS_DECLARE_OBJECT
 230 /* Extra assembler code needed to declare an object properly.  */
 231 #undef ASM_DECLARE_OBJECT_NAME
 232 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)               \
 233   do {                                                          \
 234       HOST_WIDE_INT size;                                       \
 235       ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");         \
 236       size_directive_output = 0;                                \
 237       if (!flag_inhibit_size_directive                          \
 238           && (DECL) && DECL_SIZE (DECL))                        \
 239         {                                                       \
 240           size_directive_output = 1;                            \
 241           size = int_size_in_bytes (TREE_TYPE (DECL));          \
 242           ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size);         \
 243         }                                                       \
 244       ASM_OUTPUT_LABEL (FILE, NAME);                            \
 245   } while (0)
 246
 247 /* Output the size directive for a decl in rest_of_decl_compilation
 248    in the case where we did not do so before the initializer.
 249    Once we find the error_mark_node, we know that the value of
 250    size_directive_output was set by ASM_DECLARE_OBJECT_NAME
 251    when it was run for the same decl.  */
 252 #undef ASM_FINISH_DECLARE_OBJECT
 253 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 254 do {                                                                     \
 255      const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);             \
 256      HOST_WIDE_INT size;                                                 \
 257      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 258          && ! AT_END && TOP_LEVEL                                        \
 259          && DECL_INITIAL (DECL) == error_mark_node                       \
 260          && !size_directive_output)                                      \
 261        {                                                                 \
 262          size_directive_output = 1;                                      \
 263          size = int_size_in_bytes (TREE_TYPE (DECL));                    \
 264          ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size);                   \
 265        }                                                                 \
 266    } while (0)
 267 #endif
 268
 269 \f
 270 /* Those are `generic' ways to weaken/globalize a label. We shouldn't need
 271    to override a processor specific definition. Hence, #ifndef ASM_*
 272    In case overriding turns out to be needed, one can always #undef ASM_*
 273    before including this file.  */
 274
 275 /* Tell the assembler that a symbol is weak.  */
 276 /* Note: netbsd arm32 assembler needs a .globl here. An override may
 277    be needed when/if we go for arm32 support.  */
 278 #ifndef ASM_WEAKEN_LABEL
 279 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 280   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 281        fputc ('\n', FILE); } while (0)
 282 #endif
 283 \f
 284 /* Storage layout.  */
 285
 286 \f
 287 #define HAVE_ENABLE_EXECUTE_STACK