gcc/config/openbsd.h

   1 /* Base configuration file for all OpenBSD targets.
   2    Copyright (C) 1999, 2000 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 2, 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 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 #ifdef CPP_CPU_SPEC
  82 #define OBSD_CPP_SPEC "%(cpp_cpu) %{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
  83 #else
  84 #define OBSD_CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_POSIX_THREADS}"
  85 #endif
  86
  87 /* LIB_SPEC appropriate for OpenBSD.  Select the appropriate libc,
  88    depending on profiling and threads.  Basically,
  89    -lc(_r)?(_p)?, select _r for threads, and _p for p or pg.  */
  90 #define OBSD_LIB_SPEC "%{!shared:-lc%{pthread:_r}%{p:_p}%{!p:%{pg:_p}}}"
  91
  92 #ifndef OBSD_HAS_CORRECT_SPECS
  93
  94 #ifndef OBSD_NO_DYNAMIC_LIBRARIES
  95 #undef SWITCH_TAKES_ARG
  96 #define SWITCH_TAKES_ARG(CHAR) \
  97   (DEFAULT_SWITCH_TAKES_ARG (CHAR) \
  98    || (CHAR) == 'R')
  99 #endif
 100
 101 #undef CPP_SPEC
 102 #define CPP_SPEC OBSD_CPP_SPEC
 103
 104 #ifdef OBSD_OLD_GAS
 105 /* ASM_SPEC appropriate for OpenBSD.  For some architectures, OpenBSD
 106    still uses a special flavor of gas that needs to be told when generating
 107    pic code.  */
 108 #undef ASM_SPEC
 109 #define ASM_SPEC "%{fpic|fpie:-k} %{fPIC|fPIE:-k -K}"
 110 #endif
 111
 112 /* Since we use gas, stdin -> - is a good idea.  */
 113 #define AS_NEEDS_DASH_FOR_PIPED_INPUT
 114
 115 /* LINK_SPEC appropriate for OpenBSD.  Support for GCC options
 116    -static, -assert, and -nostdlib.  */
 117 #undef LINK_SPEC
 118 #ifdef OBSD_NO_DYNAMIC_LIBRARIES
 119 #define LINK_SPEC \
 120   "%{g:%{!nostdlib:-L/usr/lib/debug}} %{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{assert*}"
 121 #else
 122 #define LINK_SPEC \
 123   "%{g:%{!nostdlib:-L/usr/lib/debug}} %{!shared:%{!nostdlib:%{!r*:%{!e*:-e start}}}} %{shared:-Bshareable -x} -dc -dp %{R*} %{static:-Bstatic} %{assert*}"
 124 #endif
 125
 126 #undef LIB_SPEC
 127 #define LIB_SPEC OBSD_LIB_SPEC
 128 #endif
 129
 130 \f
 131 /* Runtime target specification.  */
 132
 133 /* Miscellaneous parameters.  */
 134
 135 /* Controlling debugging info: dbx options.  */
 136
 137 /* Don't use the `xsTAG;' construct in DBX output; OpenBSD systems that
 138    use DBX don't support it.  */
 139 #define DBX_NO_XREFS
 140
 141 \f
 142 /* Support of shared libraries, mostly imported from svr4.h through netbsd.  */
 143 /* Two differences from svr4.h:
 144    - we use . - _func instead of a local label,
 145    - we put extra spaces in expressions such as
 146      .type _func , @function
 147      This is more readable for a human being and confuses c++filt less.  */
 148
 149 /* Assembler format: output and generation of labels.  */
 150
 151 /* Define the strings used for the .type and .size directives.
 152    These strings generally do not vary from one system running OpenBSD
 153    to another, but if a given system needs to use different pseudo-op
 154    names for these, they may be overridden in the arch specific file.  */
 155
 156 /* OpenBSD assembler is hacked to have .type & .size support even in a.out
 157    format object files.  Functions size are supported but not activated
 158    yet (look for GRACE_PERIOD_EXPIRED in gas/config/obj-aout.c).
 159    SET_ASM_OP is needed for attribute alias to work.  */
 160
 161 #undef TYPE_ASM_OP
 162 #undef SIZE_ASM_OP
 163 #undef SET_ASM_OP
 164 #undef GLOBAL_ASM_OP
 165
 166 #define TYPE_ASM_OP     "\t.type\t"
 167 #define SIZE_ASM_OP     "\t.size\t"
 168 #define SET_ASM_OP      "\t.set\t"
 169 #define GLOBAL_ASM_OP   "\t.globl\t"
 170
 171 /* The following macro defines the format used to output the second
 172    operand of the .type assembler directive.  */
 173 #undef TYPE_OPERAND_FMT
 174 #define TYPE_OPERAND_FMT        "@%s"
 175
 176 /* Provision if extra assembler code is needed to declare a function's result
 177    (taken from svr4, not needed yet actually).  */
 178 #ifndef ASM_DECLARE_RESULT
 179 #define ASM_DECLARE_RESULT(FILE, RESULT)
 180 #endif
 181
 182 /* These macros generate the special .type and .size directives which
 183    are used to set the corresponding fields of the linker symbol table
 184    entries under OpenBSD.  These macros also have to output the starting
 185    labels for the relevant functions/objects.  */
 186
 187 #ifndef OBSD_HAS_DECLARE_FUNCTION_NAME
 188 /* Extra assembler code needed to declare a function properly.
 189    Some assemblers may also need to also have something extra said
 190    about the function's return value.  We allow for that here.  */
 191 #undef ASM_DECLARE_FUNCTION_NAME
 192 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL)                     \
 193   do {                                                                  \
 194     ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function");                 \
 195     ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL));                      \
 196     ASM_OUTPUT_LABEL(FILE, NAME);                                       \
 197   } while (0)
 198 #endif
 199
 200 #ifndef OBSD_HAS_DECLARE_FUNCTION_SIZE
 201 /* Declare the size of a function.  */
 202 #undef ASM_DECLARE_FUNCTION_SIZE
 203 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)            \
 204   do {                                                          \
 205     if (!flag_inhibit_size_directive)                           \
 206       ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME);                   \
 207   } while (0)
 208 #endif
 209
 210 #ifndef OBSD_HAS_DECLARE_OBJECT
 211 /* Extra assembler code needed to declare an object properly.  */
 212 #undef ASM_DECLARE_OBJECT_NAME
 213 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL)               \
 214   do {                                                          \
 215       HOST_WIDE_INT size;                                       \
 216       ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");         \
 217       size_directive_output = 0;                                \
 218       if (!flag_inhibit_size_directive                          \
 219           && (DECL) && DECL_SIZE (DECL))                        \
 220         {                                                       \
 221           size_directive_output = 1;                            \
 222           size = int_size_in_bytes (TREE_TYPE (DECL));          \
 223           ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size);         \
 224         }                                                       \
 225       ASM_OUTPUT_LABEL (FILE, NAME);                            \
 226   } while (0)
 227
 228 /* Output the size directive for a decl in rest_of_decl_compilation
 229    in the case where we did not do so before the initializer.
 230    Once we find the error_mark_node, we know that the value of
 231    size_directive_output was set by ASM_DECLARE_OBJECT_NAME
 232    when it was run for the same decl.  */
 233 #undef ASM_FINISH_DECLARE_OBJECT
 234 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)         \
 235 do {                                                                     \
 236      const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0);             \
 237      HOST_WIDE_INT size;                                                 \
 238      if (!flag_inhibit_size_directive && DECL_SIZE (DECL)                \
 239          && ! AT_END && TOP_LEVEL                                        \
 240          && DECL_INITIAL (DECL) == error_mark_node                       \
 241          && !size_directive_output)                                      \
 242        {                                                                 \
 243          size_directive_output = 1;                                      \
 244          size = int_size_in_bytes (TREE_TYPE (DECL));                    \
 245          ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size);                   \
 246        }                                                                 \
 247    } while (0)
 248 #endif
 249
 250 \f
 251 /* Those are `generic' ways to weaken/globalize a label. We shouldn't need
 252    to override a processor specific definition. Hence, #ifndef ASM_*
 253    In case overriding turns out to be needed, one can always #undef ASM_*
 254    before including this file.  */
 255
 256 /* Tell the assembler that a symbol is weak.  */
 257 /* Note: netbsd arm32 assembler needs a .globl here. An override may
 258    be needed when/if we go for arm32 support.  */
 259 #ifndef ASM_WEAKEN_LABEL
 260 #define ASM_WEAKEN_LABEL(FILE,NAME) \
 261   do { fputs ("\t.weak\t", FILE); assemble_name (FILE, NAME); \
 262        fputc ('\n', FILE); } while (0)
 263 #endif
 264 \f
 265 /* Storage layout.  */
 266
 267 \f
 268 /* Otherwise, since we support weak, gthr.h erroneously tries to use
 269    #pragma weak.  */
 270 #define GTHREAD_USE_WEAK 0
 271
 272 /* bug work around: we don't want to support #pragma weak, but the current
 273    code layout needs HANDLE_PRAGMA_WEAK asserted for __attribute((weak)) to
 274    work.  On the other hand, we don't define HANDLE_PRAGMA_WEAK directly,
 275    as this depends on a few other details as well...  */
 276 #define HANDLE_SYSV_PRAGMA 1
 277