gcc/config/openbsd.h

   1 /* Base configuration file for all OpenBSD targets.
   2    Copyright (C) 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC 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 2, or (at your option)
   9 any later version.
  10
  11 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  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 #undef GCC_INCLUDE_DIR
  56 #define GCC_INCLUDE_DIR "/usr/include"
  57
  58 /* The compiler is configured with ONLY the gcc/g++ standard headers.  */
  59 #undef INCLUDE_DEFAULTS
  60 #define INCLUDE_DEFAULTS                        \
  61   {                                             \
  62     { GPLUSPLUS_INCLUDE_DIR, "G++", 1, 1 },     \
  63     { GCC_INCLUDE_DIR, "GCC", 0, 0 },           \
  64     { 0, 0, 0, 0 }                              \
  65   }
  66
  67 /* Under OpenBSD, the normal location of the various *crt*.o files is the
  68    /usr/lib directory.  */
  69 #define STANDARD_STARTFILE_PREFIX       "/usr/lib/"
  70
  71 #endif
  72
  73 \f
  74 /* Controlling the compilation driver.  */
  75
  76 /* CPP_SPEC appropriate for OpenBSD. We deal with -posix and -pthread.
  77    XXX the way threads are handling currently is not very satisfying,
  78    since all code must be compiled with -pthread to work.
  79    This two-stage defines makes it easy to pick that for targets that
  80    have subspecs.  */
  81 #define OBSD_CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
  82
  83 /* LIB_SPEC appropriate for OpenBSD.  Select the appropriate libc,
  84    depending on profiling and threads.  Basically,
  85    -lc(_r)?(_p)?, select _r for threads, and _p for p or pg.  */
  86 #define OBSD_LIB_SPEC "-lc%{pthread:_r}%{p:_p}%{!p:%{pg:_p}}"
  87
  88 #ifndef OBSD_HAS_CORRECT_SPECS
  89
  90 #ifndef OBSD_NO_DYNAMIC_LIBRARIES
  91 #undef SWITCH_TAKES_ARG
  92 #define SWITCH_TAKES_ARG(CHAR) \
  93   (DEFAULT_SWITCH_TAKES_ARG (CHAR) \
  94    || (CHAR) == 'R')
  95 #endif
  96
  97 #undef CPP_SPEC
  98 #define CPP_SPEC OBSD_CPP_SPEC
  99
 100 #ifdef OBSD_OLD_GAS
 101 /* ASM_SPEC appropriate for OpenBSD.  For some architectures, OpenBSD
 102    still uses a special flavor of gas that needs to be told when generating
 103    pic code.  */
 104 #undef ASM_SPEC
 105 #define ASM_SPEC "%{fpic:-k} %{fPIC:-k -K} %|"
 106 #else
 107 /* Since we use gas, stdin -> - is a good idea, but we don't want to
 108    override native specs just for that.  */
 109 #ifndef ASM_SPEC
 110 #define ASM_SPEC "%|"
 111 #endif
 112 #endif
 113
 114 /* LINK_SPEC appropriate for OpenBSD.  Support for GCC options
 115    -static, -assert, and -nostdlib.  */
 116 #undef LINK_SPEC
 117 #ifdef OBSD_NO_DYNAMIC_LIBRARIES
 118 #define LINK_SPEC \
 119   "%{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{assert*}"
 120 #else
 121 #define LINK_SPEC \
 122   "%{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{R*} %{static:-Bstatic} %{assert*}"
 123 #endif
 124
 125 #undef LIB_SPEC
 126 #define LIB_SPEC OBSD_LIB_SPEC
 127 #endif
 128
 129 \f
 130 /* Runtime target specification.  */
 131
 132 /* You must redefine CPP_PREDEFINES in any arch specific file.  */
 133 #undef CPP_PREDEFINES
 134
 135 /* Implicit calls to library routines.  */
 136
 137 /* Use memcpy and memset instead of bcopy and bzero.  */
 138 #define TARGET_MEM_FUNCTIONS
 139
 140 /* Miscellaneous parameters.  */
 141
 142 /* Controlling debugging info: dbx options.  */
 143
 144 /* Don't use the `xsTAG;' construct in DBX output; OpenBSD systems that
 145    use DBX don't support it.  */
 146 #define DBX_NO_XREFS
 147
 148 \f
 149 /* Support of shared libraries, mostly imported from svr4.h through netbsd.  */
 150 /* Two differences from svr4.h:
 151    - we use . - _func instead of a local label,
 152    - we put extra spaces in expressions such as
 153      .type _func , @function
 154      This is more readable for a human being and confuses c++filt less.  */
 155
 156 /* Assembler format: output and generation of labels.  */
 157
 158 /* Define the strings used for the .type and .size directives.
 159    These strings generally do not vary from one system running OpenBSD
 160    to another, but if a given system needs to use different pseudo-op
 161    names for these, they may be overridden in the arch specific file.  */
 162
 163 /* OpenBSD assembler is hacked to have .type & .size support even in a.out
 164    format object files.  Functions size are supported but not activated
 165    yet (look for GRACE_PERIOD_EXPIRED in gas/config/obj-aout.c).
 166    SET_ASM_OP is needed for attribute alias to work.  */
 167
 168 #undef TYPE_ASM_OP
 169 #undef SIZE_ASM_OP
 170 #undef SET_ASM_OP
 171
 172 #define TYPE_ASM_OP     ".type"
 173 #define SIZE_ASM_OP     ".size"
 174 #define SET_ASM_OP      ".set"
 175
 176 /* The following macro defines the format used to output the second
 177    operand of the .type assembler directive.  */
 178 #undef TYPE_OPERAND_FMT
 179 #define TYPE_OPERAND_FMT        "@%s"
 180
 181 /* Provision if extra assembler code is needed to declare a function's result
 182    (taken from svr4, not needed yet actually).  */
 183 #ifndef ASM_DECLARE_RESULT
 184 #define ASM_DECLARE_RESULT(FILE, RESULT)
 185 #endif
 186
 187 /* These macros generate the special .type and .size directives which
 188    are used to set the corresponding fields of the linker symbol table
 189    entries under OpenBSD.  These macros also have to output the starting
 190    labels for the relevant functions/objects.  */
 191
 192 #ifndef OBSD_HAS_DECLARE_FUNCTION_NAME
 193 /* Extra assembler code needed to declare a function properly.
 194    Some assemblers may also need to also have something extra said
 195    about the function's return value.  We allow for that here.  */
 196 #undef ASM_DECLARE_FUNCTION_NAME
 197 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)                     \
 198   do {                                                                  \
 199     fprintf (FILE, "\t%s\t", TYPE_ASM_OP);                              \
 200     assemble_name (FILE, NAME);                                         \
 201     fputs (" , ", FILE);                                                \
 202     fprintf (FILE, TYPE_OPERAND_FMT, "function");                       \
 203     putc ('\n', FILE);                                                  \
 204     ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                      \
 205     ASM_OUTPUT_LABEL(FILE, NAME);                                       \
 206   } while (0)
 207 #endif
 208
 209 #ifndef OBSD_HAS_DECLARE_FUNCTION_SIZE
 210 /* Declare the size of a function.  */
 211 #undef ASM_DECLARE_FUNCTION_SIZE
 212 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)                    \
 213   do {                                                                  \
 214     if (!flag_inhibit_size_directive)                                   \
 215       {                                                                 \
 216         fprintf (FILE, "\t%s\t", SIZE_ASM_OP);                          \
 217         assemble_name (FILE, (FNAME));                                  \
 218         fputs (" , . - ", FILE);                                        \
 219         assemble_name (FILE, (FNAME));                                  \
 220         putc ('\n', FILE);                                              \
 221       }                                                                 \
 222   } while (0)
 223 #endif
 224
 225 #ifndef OBSD_HAS_DECLARE_OBJECT
 226 /* Extra assembler code needed to declare an object properly.  */
 227 #undef ASM_DECLARE_OBJECT_NAME
 228 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)                       \
 229   do {                                                                  \
 230     fprintf (FILE, "\t%s\t ", TYPE_ASM_OP);                             \
 231     assemble_name (FILE, NAME);                                         \
 232     fputs (" , ", FILE);                                                \
 233     fprintf (FILE, TYPE_OPERAND_FMT, "object");                         \
 234     putc ('\n', FILE);                                                  \
 235     size_directive_output = 0;                                          \
 236     if (!flag_inhibit_size_directive && DECL_SIZE (DECL))               \
 237       {                                                                 \
 238         size_directive_output = 1;                                      \
 239         fprintf (FILE, "\t%s\t", SIZE_ASM_OP);                          \
 240         assemble_name (FILE, NAME);                                     \
 241         fprintf (FILE, " , %d\n", int_size_in_bytes (TREE_TYPE (DECL)));\
 242       }                                                                 \
 243     ASM_OUTPUT_LABEL (FILE, NAME);                                      \
 244   } while (0)
 245
 246 /* Output the size directive for a decl in rest_of_decl_compilation
 247    in the case where we did not do so before the initializer.
 248    Once we find the error_mark_node, we know that the value of
 249    size_directive_output was set by ASM_DECLARE_OBJECT_NAME
 250    when it was run for the same decl.  */
 251 #undef ASM_FINISH_DECLARE_OBJECT
 252 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 253 do {                                                                     \
 254      char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);                   \
 255      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 256          && ! AT_END && TOP_LEVEL                                        \
 257          && DECL_INITIAL (DECL) == error_mark_node                       \
 258          && !size_directive_output)                                      \
 259        {                                                                 \
 260          size_directive_output = 1;                                      \
 261          fprintf (FILE, "\t%s\t", SIZE_ASM_OP);                  \
 262          assemble_name (FILE, name);                                     \
 263          fprintf (FILE, " , %d\n", int_size_in_bytes (TREE_TYPE (DECL)));\
 264        }                                                                 \
 265    } while (0)
 266 #endif
 267
 268 \f
 269 /* Those are `generic' ways to weaken/globalize a label. We shouldn't need
 270    to override a processor specific definition. Hence, #ifndef ASM_*
 271    In case overriding turns out to be needed, one can always #undef ASM_*
 272    before including this file.  */
 273
 274 /* Tell the assembler that a symbol is weak.  */
 275 /* Note: netbsd arm32 assembler needs a .globl here. An override may
 276    be needed when/if we go for arm32 support.  */
 277 #ifndef ASM_WEAKEN_LABEL
 278 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 279   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 280        fputc ('\n', FILE); } while (0)
 281 #endif
 282
 283 /* Tell the assembler that a symbol is global.  */
 284 #ifndef ASM_GLOBALIZE_LABEL
 285 #define ASM_GLOBALIZE_LABEL(FILE,NAME) \
 286   do { fputs ("\t.globl\t", FILE); assemble_name (FILE, NAME); \
 287        fputc ('\n', FILE); } while(0)
 288 #endif
 289
 290 \f
 291 /* Storage layout.  */
 292
 293 /* We don't have to worry about binary compatibility with older C++ code,
 294    but there is a big known bug with vtable thunks which has not been
 295    fixed yet, so DON'T activate it by default.  */
 296 /* #define DEFAULT_VTABLE_THUNKS 1 */
 297
 298 \f
 299 /* Otherwise, since we support weak, gthr.h erroneously tries to use
 300    #pragma weak.  */
 301 #define GTHREAD_USE_WEAK 0
 302
 303 /* bug work around: we don't want to support #pragma weak, but the current
 304    code layout needs HANDLE_PRAGMA_WEAK asserted for __attribute((weak)) to
 305    work.  On the other hand, we don't define HANDLE_PRAGMA_WEAK directly,
 306    as this depends on a few other details as well...  */
 307 #define HANDLE_SYSV_PRAGMA
 308