gcc/config/openbsd.h

   1 /* Base configuration file for all OpenBSD targets.
   2    Copyright (C) 1999, 2000, 2004, 2005, 2007, 2009, 2010, 2011, 2012
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* Common OpenBSD configuration.
  22    All OpenBSD architectures include this file, which is intended as
  23    a repository for common defines.
  24
  25    Some defines are common to all architectures, a few of them are
  26    triggered by OBSD_* guards, so that we won't override architecture
  27    defaults by mistakes.
  28
  29    OBSD_HAS_CORRECT_SPECS:
  30       another mechanism provides correct specs already.
  31    OBSD_NO_DYNAMIC_LIBRARIES:
  32       no implementation of dynamic libraries.
  33    OBSD_OLD_GAS:
  34       older flavor of gas which needs help for PIC.
  35    OBSD_HAS_DECLARE_FUNCTION_NAME, OBSD_HAS_DECLARE_FUNCTION_SIZE,
  36    OBSD_HAS_DECLARE_OBJECT:
  37       PIC support, FUNCTION_NAME/FUNCTION_SIZE are independent, whereas
  38       the corresponding logic for OBJECTS is necessarily coupled.
  39
  40    There are also a few `default' defines such as ASM_WEAKEN_LABEL,
  41    intended as common ground for arch that don't provide
  42    anything suitable.  */
  43
  44 /* OPENBSD_NATIVE is defined only when gcc is configured as part of
  45    the OpenBSD source tree, specifically through Makefile.bsd-wrapper.
  46
  47    In such a case the include path can be trimmed as there is no
  48    distinction between system includes and gcc includes.  */
  49
  50 /* This configuration method, namely Makefile.bsd-wrapper and
  51    OPENBSD_NATIVE is NOT recommended for building cross-compilers.  */
  52
  53 #ifdef OPENBSD_NATIVE
  54
  55 /* The compiler is configured with ONLY the gcc/g++ standard headers.  */
  56 #undef INCLUDE_DEFAULTS
  57 #define INCLUDE_DEFAULTS                        \
  58   {                                             \
  59     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1 },     \
  60     { GPLUSPLUS_TOOL_INCLUDE_DIR, "G++", 1, 1 }, \
  61     { GPLUSPLUS_BACKWARD_INCLUDE_DIR, "G++", 1, 1 }, \
  62     { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0 }, \
  63     { 0, 0, 0, 0 }                              \
  64   }
  65
  66 /* Under OpenBSD, the normal location of the various *crt*.o files is the
  67    /usr/lib directory.  */
  68 #undef STANDARD_STARTFILE_PREFIX
  69 #define STANDARD_STARTFILE_PREFIX       "/usr/local/lib/"
  70
  71 #endif
  72
  73 \f
  74 /* Controlling the compilation driver.  */
  75 /* TARGET_OS_CPP_BUILTINS() common to all OpenBSD targets.  */
  76 #define OPENBSD_OS_CPP_BUILTINS()               \
  77   do                                            \
  78     {                                           \
  79       builtin_define ("__OpenBSD__");           \
  80       builtin_define ("__unix__");              \
  81       builtin_define ("__ANSI_COMPAT");         \
  82       builtin_assert ("system=unix");           \
  83       builtin_assert ("system=bsd");            \
  84       builtin_assert ("system=OpenBSD");        \
  85     }                                           \
  86   while (0)
  87
  88 /* TARGET_OS_CPP_BUILTINS() common to all OpenBSD ELF targets.  */
  89 #define OPENBSD_OS_CPP_BUILTINS_ELF()           \
  90   do                                            \
  91     {                                           \
  92       OPENBSD_OS_CPP_BUILTINS();                \
  93       builtin_define ("__ELF__");               \
  94     }                                           \
  95 while (0)
  96
  97 /* TARGET_OS_CPP_BUILTINS() common to all LP64 OpenBSD targets.  */
  98 #define OPENBSD_OS_CPP_BUILTINS_LP64()          \
  99   do                                            \
 100     {                                           \
 101       builtin_define ("_LP64");                 \
 102       builtin_define ("__LP64__");              \
 103     }                                           \
 104   while (0)
 105
 106 /* CPP_SPEC appropriate for OpenBSD. We deal with -posix and -pthread.
 107    XXX the way threads are handled currently is not very satisfying,
 108    since all code must be compiled with -pthread to work.
 109    This two-stage defines makes it easy to pick that for targets that
 110    have subspecs.  */
 111 #ifdef CPP_CPU_SPEC
 112 #define OBSD_CPP_SPEC "%(cpp_cpu) %{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
 113 #else
 114 #define OBSD_CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
 115 #endif
 116
 117 #undef LIB_SPEC
 118 #define LIB_SPEC OBSD_LIB_SPEC
 119
 120 #ifndef OBSD_HAS_CORRECT_SPECS
 121
 122 #undef CPP_SPEC
 123 #define CPP_SPEC OBSD_CPP_SPEC
 124
 125 #ifdef OBSD_OLD_GAS
 126 /* ASM_SPEC appropriate for OpenBSD.  For some architectures, OpenBSD
 127    still uses a special flavor of gas that needs to be told when generating
 128    pic code.  */
 129 #undef ASM_SPEC
 130 #define ASM_SPEC "%{fpic|fpie:-k} %{fPIC|fPIE:-k -K}"
 131 #endif
 132
 133 /* Since we use gas, stdin -> - is a good idea.  */
 134 #define AS_NEEDS_DASH_FOR_PIPED_INPUT
 135
 136 #undef LIB_SPEC
 137 #define LIB_SPEC OBSD_LIB_SPEC
 138
 139 #if defined(HAVE_LD_EH_FRAME_HDR)
 140 #define LINK_EH_SPEC "%{!static:--eh-frame-hdr} "
 141 #endif
 142
 143 #undef LIB_SPEC
 144 #define LIB_SPEC OBSD_LIB_SPEC
 145 #endif
 146
 147 #define TARGET_POSIX_IO
 148
 149 /* All new versions of OpenBSD have C99 functions.  */
 150 #define TARGET_C99_FUNCTIONS 1
 151
 152 \f
 153 /* Runtime target specification.  */
 154
 155 /* Miscellaneous parameters.  */
 156
 157 /* Controlling debugging info: dbx options.  */
 158
 159 /* Don't use the `xsTAG;' construct in DBX output; OpenBSD systems that
 160    use DBX don't support it.  */
 161 #define DBX_NO_XREFS
 162
 163 \f
 164 /* - we use . - _func instead of a local label,
 165    - we put extra spaces in expressions such as
 166      .type _func , @function
 167      This is more readable for a human being and confuses c++filt less.  */
 168
 169 /* Assembler format: output and generation of labels.  */
 170
 171 /* Define the strings used for the .type and .size directives.
 172    These strings generally do not vary from one system running OpenBSD
 173    to another, but if a given system needs to use different pseudo-op
 174    names for these, they may be overridden in the arch specific file.  */
 175
 176 /* OpenBSD assembler is hacked to have .type & .size support even in a.out
 177    format object files.  Functions size are supported but not activated
 178    yet (look for GRACE_PERIOD_EXPIRED in gas/config/obj-aout.c).
 179    SET_ASM_OP is needed for attribute alias to work.  */
 180
 181 #undef TYPE_ASM_OP
 182 #undef SIZE_ASM_OP
 183 #undef SET_ASM_OP
 184 #undef GLOBAL_ASM_OP
 185
 186 #define TYPE_ASM_OP     "\t.type\t"
 187 #define SIZE_ASM_OP     "\t.size\t"
 188 #define SET_ASM_OP      "\t.set\t"
 189 #define GLOBAL_ASM_OP   "\t.globl\t"
 190
 191 /* The following macro defines the format used to output the second
 192    operand of the .type assembler directive.  */
 193 #undef TYPE_OPERAND_FMT
 194 #define TYPE_OPERAND_FMT        "@%s"
 195
 196 /* Provision if extra assembler code is needed to declare a function's result
 197    (taken from svr4, not needed yet actually).  */
 198 #ifndef ASM_DECLARE_RESULT
 199 #define ASM_DECLARE_RESULT(FILE, RESULT)
 200 #endif
 201
 202 /* These macros generate the special .type and .size directives which
 203    are used to set the corresponding fields of the linker symbol table
 204    entries under OpenBSD.  These macros also have to output the starting
 205    labels for the relevant functions/objects.  */
 206
 207 #ifndef OBSD_HAS_DECLARE_FUNCTION_NAME
 208 /* Extra assembler code needed to declare a function properly.
 209    Some assemblers may also need to also have something extra said
 210    about the function's return value.  We allow for that here.  */
 211 #undef ASM_DECLARE_FUNCTION_NAME
 212 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)                     \
 213   do {                                                                  \
 214     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function");                 \
 215     ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                      \
 216     ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL);                       \
 217   } while (0)
 218 #endif
 219
 220 #ifndef OBSD_HAS_DECLARE_FUNCTION_SIZE
 221 /* Declare the size of a function.  */
 222 #undef ASM_DECLARE_FUNCTION_SIZE
 223 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
 224   do {                                                          \
 225     if (!flag_inhibit_size_directive)                           \
 226       ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME);                   \
 227   } while (0)
 228 #endif
 229
 230 #ifndef OBSD_HAS_DECLARE_OBJECT
 231 /* Extra assembler code needed to declare an object properly.  */
 232 #undef ASM_DECLARE_OBJECT_NAME
 233 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)               \
 234   do {                                                          \
 235       HOST_WIDE_INT size;                                       \
 236       ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");         \
 237       size_directive_output = 0;                                \
 238       if (!flag_inhibit_size_directive                          \
 239           && (DECL) && DECL_SIZE (DECL))                        \
 240         {                                                       \
 241           size_directive_output = 1;                            \
 242           size = int_size_in_bytes (TREE_TYPE (DECL));          \
 243           ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size);         \
 244         }                                                       \
 245       ASM_OUTPUT_LABEL (FILE, NAME);                            \
 246   } while (0)
 247
 248 /* Output the size directive for a decl in rest_of_decl_compilation
 249    in the case where we did not do so before the initializer.
 250    Once we find the error_mark_node, we know that the value of
 251    size_directive_output was set by ASM_DECLARE_OBJECT_NAME
 252    when it was run for the same decl.  */
 253 #undef ASM_FINISH_DECLARE_OBJECT
 254 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 255 do {                                                                     \
 256      const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);             \
 257      HOST_WIDE_INT size;                                                 \
 258      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 259          && ! AT_END && TOP_LEVEL                                        \
 260          && DECL_INITIAL (DECL) == error_mark_node                       \
 261          && !size_directive_output)                                      \
 262        {                                                                 \
 263          size_directive_output = 1;                                      \
 264          size = int_size_in_bytes (TREE_TYPE (DECL));                    \
 265          ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size);                   \
 266        }                                                                 \
 267    } while (0)
 268 #endif
 269
 270 \f
 271 /* Those are `generic' ways to weaken/globalize a label. We shouldn't need
 272    to override a processor specific definition. Hence, #ifndef ASM_*
 273    In case overriding turns out to be needed, one can always #undef ASM_*
 274    before including this file.  */
 275
 276 /* Tell the assembler that a symbol is weak.  */
 277 /* Note: netbsd arm32 assembler needs a .globl here. An override may
 278    be needed when/if we go for arm32 support.  */
 279 #ifndef ASM_WEAKEN_LABEL
 280 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 281   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 282        fputc ('\n', FILE); } while (0)
 283 #endif
 284 \f
 285 /* Storage layout.  */
 286
 287 \f
 288 #define HAVE_ENABLE_EXECUTE_STACK