gcc/config/vax/vms.h

   1 /* Output variables, constants and external declarations, for GNU compiler.
   2    Copyright (C) 1988, 1994, 1995, 1996, 1997, 1999, 2001, 2002
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC 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 2, or (at your option)
  10 any later version.
  11
  12 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #define TARGET_EXECUTABLE_SUFFIX ".exe"
  23 #define TARGET_OBJECT_SUFFIX ".obj"
  24
  25 /* This enables certain macros in vax.h, which will make an indirect
  26    reference to an external symbol an invalid address.  This needs to be
  27    defined before we include vax.h, since it determines which macros
  28    are used for GO_IF_*.  */
  29
  30 #define NO_EXTERNAL_INDIRECT_ADDRESS
  31
  32 #include "vax/vax.h"
  33
  34 #undef VMS_TARGET
  35 #define VMS_TARGET 1
  36
  37 #undef LIB_SPEC
  38 #undef TARGET_NAME
  39 #undef TARGET_DEFAULT
  40 #undef CALL_USED_REGISTERS
  41 #undef STARTING_FRAME_OFFSET
  42
  43 #define TARGET_OS_CPP_BUILTINS()                \
  44   do                                            \
  45     {                                           \
  46       builtin_define_std ("vms");               \
  47       builtin_define_std ("VMS");               \
  48       builtin_assert ("system=vms");            \
  49                                                 \
  50       builtin_define_std ("vax");               \
  51       if (TARGET_G_FLOAT)                       \
  52         builtin_define_std ("GFLOAT");          \
  53     }                                           \
  54   while (0)
  55
  56 /* These match the definitions used in VAXCRTL, the VMS C run-time library */
  57
  58 #define SIZE_TYPE       "unsigned int"
  59 #define PTRDIFF_TYPE    "int"
  60 #define WCHAR_TYPE      "unsigned int"
  61 #define WCHAR_TYPE_SIZE 32      /* in bits */
  62
  63 /* Use memcpy for structure copying, and so forth.  */
  64 #define TARGET_MEM_FUNCTIONS
  65
  66 /* Strictly speaking, VMS does not use DBX at all, but the interpreter built
  67    into gas only speaks straight DBX.  */
  68
  69 #define DEFAULT_GDB_EXTENSIONS 0
  70
  71 #define TARGET_DEFAULT 1
  72 #define TARGET_NAME "vax/vms"
  73
  74 /* The structure return address arrives as an "argument" on VMS.  */
  75 #undef STRUCT_VALUE_REGNUM
  76 #define STRUCT_VALUE 0
  77 #undef PCC_STATIC_STRUCT_RETURN
  78
  79 #define CALL_USED_REGISTERS {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1}
  80
  81 /* The run-time library routine VAXC$ESTABLISH (necessary when mixing
  82    VMS exception handling and setjmp/longjmp in the same program) requires
  83    that a hidden automatic variable at the top of the stack be reserved
  84    for its use.  We accomplish this by simply adding 4 bytes to the local
  85    stack for all functions, and making sure that normal local variables
  86    are 4 bytes lower on the stack then they would otherwise have been.  */
  87
  88 #define STARTING_FRAME_OFFSET -4
  89
  90 /* This macro definition sets up a default value for `main' to return.  */
  91 #define DEFAULT_MAIN_RETURN  c_expand_return (integer_one_node)
  92 \f
  93 /* This is how to output a command to make the user-level label named NAME
  94    defined for reference from other files.  */
  95
  96 #undef ASM_GLOBALIZE_LABEL
  97 #define ASM_GLOBALIZE_LABEL(FILE,NAME)          \
  98   do { fputs (".globl ", FILE);                 \
  99        assemble_name (FILE, NAME);              \
 100        fputs ("\n", FILE);                      \
 101        vms_check_external (NULL_TREE, NAME, 0); \
 102      } while (0)
 103
 104 /* Under VMS we write the actual size of the storage to be allocated even
 105    though the symbol is external.  Although it is possible to give external
 106    symbols a size of 0 (as unix does), the VMS linker does not make the
 107    distinction between a variable definition and an external reference of a
 108    variable, and thus the linker will not complain about a missing definition.
 109    If we followed the unix example of giving external symbols a size of
 110    zero, you tried to link a program where a given variable was externally
 111    defined but none of the object modules contained a non-extern definition,
 112    the linker would allocate 0 bytes for the variable, and any attempt to
 113    use that variable would use the storage allocated to some other variable.
 114
 115    We must also select either const_section or data_section: this will indicate
 116    whether or not the variable will get the readonly bit set.  Since the
 117    VMS linker does not distinguish between a variable's definition and an
 118    external reference, all usages of a given variable must have the readonly
 119    bit set the same way, or the linker will get confused and give warning
 120    messages.  */
 121
 122 /* We used to round the size up to a multiple of 4,
 123    but that causes linker errors sometimes when the variable was initialized
 124    since the size of its definition was not likewise rounded up.  */
 125
 126 /* Note:  the original ASM_OUTPUT_EXTERNAL code has been moved into
 127    vms_check_external and vms_flush_pending_externals.  */
 128
 129 #define ASM_OUTPUT_EXTERNAL(FILE,DECL,NAME)                             \
 130 { if (DECL_INITIAL (DECL) == 0 && TREE_CODE (DECL) != FUNCTION_DECL)    \
 131     vms_check_external ((DECL), (NAME), 1);                             \
 132 }
 133
 134 /* ASM_OUTPUT_EXTERNAL will have wait until after an initializer is
 135    completed in order to switch sections for an external object, so
 136    use the DECLARE_OBJECT hooks to manage deferred declarations.  */
 137
 138 /* This is the default action for ASM_DECLARE_OBJECT_NAME, but if it
 139    is explicitly defined, then ASM_FINISH_DECLARE_OBJECT will be used.  */
 140
 141 #define ASM_DECLARE_OBJECT_NAME(ASM_OUT_FILE,NAME,DECL)         \
 142   ASM_OUTPUT_LABEL ((ASM_OUT_FILE), (NAME))
 143
 144 /* We don't need to do anything special to finish the current object, but it
 145    should now be safe to output any deferred external global declarations.  */
 146
 147 #define ASM_FINISH_DECLARE_OBJECT(FILE,DECL,TOPLVL,ATEND)               \
 148   vms_flush_pending_externals(FILE)
 149
 150 /* Anything still pending must be flushed at the very end.  */
 151
 152 #define ASM_FILE_END(STREAM)                                            \
 153   vms_flush_pending_externals(STREAM)
 154
 155 /* Here we redefine ASM_OUTPUT_COMMON to select the data_section or the
 156    const_section before writing the ".const" assembler directive.
 157    If we were specifying a size of zero for external variables, we would
 158    not have to select a section, since the assembler can assume that
 159    when the size > 0, the storage is for a non-external, uninitialized
 160    variable (for which a "const" declaration would be senseless),
 161    and the assembler can make the storage read/write.
 162
 163    Since the ".const" directive specifies the actual size of the storage used
 164    for both external and non-external variables, the assembler cannot
 165    make this assumption, and thus it has no way of deciding if storage should
 166    be read/write or read-only.  To resolve this, we give the assembler some
 167    assistance, in the form of a ".const" or a ".data" directive.
 168
 169    Under GCC 1.40, external variables were declared with a size of zero.
 170    The GNU assembler, GAS, will recognize the "-2" switch when built for VMS;
 171    when compiling programs with GCC 2.n this switch should be used or the
 172    assembler will not give the read-only attribute to external constants.
 173    Failure to use this switch will result in linker warning messages about
 174    mismatched psect attributes.  */
 175
 176 #undef ASM_OUTPUT_COMMON
 177
 178 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)            \
 179 ( ((TREE_READONLY (decl) && ! TREE_THIS_VOLATILE (decl))        \
 180    ? (const_section (), 0) : (data_section (), 0)),             \
 181   fputs (".comm ", (FILE)),                                     \
 182   assemble_name ((FILE), (NAME)),                               \
 183   fprintf ((FILE), ",%u\n", (SIZE)))
 184
 185 /* We define this to prevent the name mangler from putting dollar signs into
 186    function names.  This isn't really needed, but it has been here for
 187    some time and  removing it would cause the object files generated by the
 188    compiler to be incompatible with the object files from a compiler that
 189    had this defined.  Since it does no harm, we leave it in.  */
 190
 191 #define NO_DOLLAR_IN_LABEL
 192
 193 /* Add a "const" section.  This is viewed by the assembler as being nearly
 194    the same as the "data" section, with the only difference being that a
 195    flag is set for variables declared while in the const section.  This
 196    flag is used to determine whether or not the read/write bit should be
 197    set in the Psect definition.  */
 198
 199 #define EXTRA_SECTIONS in_const
 200
 201 #define EXTRA_SECTION_FUNCTIONS                         \
 202 void                                                    \
 203 const_section ()                                        \
 204 {                                                       \
 205   if (in_section != in_const) {                         \
 206     fprintf(asm_out_file,".const\n");                   \
 207     in_section = in_const;                              \
 208   }                                                     \
 209 }
 210
 211 /* This is used by a hook in varasm.c to write the assembler directives
 212    that are needed to tell the startup code which constructors need to
 213    be run.  */
 214
 215 #define TARGET_ASM_CONSTRUCTOR  vms_asm_out_constructor
 216 #define TARGET_ASM_DESTRUCTOR   vms_asm_out_destructor
 217
 218 /* The following definitions are used in libgcc2.c with the __main
 219    function.  The _SHR symbol is used when the sharable image library
 220    for the C++ library is used - this is picked up automatically by the linker
 221    and this symbol points to the start of __CTOR_LIST__ from the C++ library.
 222    If the C++ library is not used, then __CTOR_LIST_SHR__ occurs just after
 223    __CTOR_LIST__, and essentially points to the same list as __CTOR_LIST.  */
 224
 225 #ifdef L__main
 226
 227 #define __CTOR_LIST__ __gxx_init_0
 228 #define __CTOR_LIST_END__ __gxx_init_2
 229
 230 #define __CTOR_LIST_SHR__ $$PsectAttributes_NOSHR$$__gxx_init_0_shr
 231 #define __CTOR_LIST_SHR_END__ $$PsectAttributes_NOSHR$$__gxx_init_2_shr
 232
 233 #define DO_GLOBAL_CTORS_BODY                                            \
 234 do {                                                                    \
 235   func_ptr *p;                                                          \
 236   extern func_ptr __CTOR_LIST__[1], __CTOR_LIST_END__[1];               \
 237   extern func_ptr __CTOR_LIST_SHR__[1], __CTOR_LIST_SHR_END__[1];       \
 238   if (&__CTOR_LIST_SHR__[0] != &__CTOR_LIST__[1])                       \
 239     for (p = __CTOR_LIST_SHR__ + 1; p < __CTOR_LIST_SHR_END__ ; p++ )   \
 240       if (*p) (*p) ();                                                  \
 241   for (p = __CTOR_LIST__ + 1; p < __CTOR_LIST_END__ ; p++ )             \
 242     if (*p) (*p) ();                                                    \
 243   do {  /* arrange for `return' from main() to pass through exit() */   \
 244       __label__ foo;                                                    \
 245       int *callers_caller_fp = (int *) __builtin_frame_address (3);     \
 246       register int retval asm ("r0");                                   \
 247       callers_caller_fp[4] = (int) && foo;                              \
 248       break;            /* out of do-while block */                     \
 249     foo:                                                                \
 250       exit (retval);                                                    \
 251   } while (0);                                                          \
 252 } while (0)
 253
 254 #define __DTOR_LIST__ __gxx_clean_0
 255 #define __DTOR_LIST_END__ __gxx_clean_2
 256
 257 #define __DTOR_LIST_SHR__ $$PsectAttributes_NOSHR$$__gxx_clean_0_shr
 258 #define __DTOR_LIST_SHR_END__ $$PsectAttributes_NOSHR$$__gxx_clean_2_shr
 259
 260 #define DO_GLOBAL_DTORS_BODY                                            \
 261 do {                                                                    \
 262   func_ptr *p;                                                          \
 263   extern func_ptr __DTOR_LIST__[1], __DTOR_LIST_END__[1];               \
 264   extern func_ptr __DTOR_LIST_SHR__[1], __DTOR_LIST_SHR_END__[1];       \
 265   for (p = __DTOR_LIST__ + 1; p < __DTOR_LIST_END__ ; p++ )             \
 266     if (*p) (*p) ();                                                    \
 267   if (&__DTOR_LIST_SHR__[0] != &__DTOR_LIST__[1])                       \
 268     for (p = __DTOR_LIST_SHR__ + 1; p < __DTOR_LIST_SHR_END__ ; p++ )   \
 269       if (*p) (*p) ();                                                  \
 270 } while (0)
 271
 272 #endif /* L__main */
 273
 274 /* Specify the list of include file directories.  */
 275 #define INCLUDE_DEFAULTS \
 276 {                                                                       \
 277   { "GNU_GXX_INCLUDE:", "G++", 1, 1 },                                  \
 278   { "GNU_CC_INCLUDE:", "GCC", 0, 0 },   /* GNU includes */              \
 279   { "SYS$SYSROOT:[SYSLIB.]", 0, 0, 0 }, /* VAX-11 "C" includes */       \
 280   { ".", 0, 0, 1 },             /* Make normal VMS filespecs work.  */  \
 281   { 0, 0, 0, 0 }                                                        \
 282 }