1/* Output variables, constants and external declarations, for GNU compiler. 2 Copyright (C) 1988, 1994, 1995, 1996, 1997 Free Software Foundation, Inc. 3 4This file is part of GNU CC. 5 6GNU CC is free software; you can redistribute it and/or modify 7it under the terms of the GNU General Public License as published by 8the Free Software Foundation; either version 2, or (at your option) 9any later version. 10 11GNU CC is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16You should have received a copy of the GNU General Public License 17along with GNU CC; see the file COPYING. If not, write to 18the Free Software Foundation, 59 Temple Place - Suite 330, 19Boston, MA 02111-1307, USA. */ 20 21#define VMS_TARGET 22 23/* This enables certain macros in vax.h, which will make an indirect 24 reference to an external symbol an invalid address. This needs to be 25 defined before we include vax.h, since it determines which macros 26 are used for GO_IF_*. */ 27 28#define NO_EXTERNAL_INDIRECT_ADDRESS 29 30#include "vax/vax.h" 31 32#undef LIB_SPEC 33#undef CPP_PREDEFINES 34#undef TARGET_NAME 35#undef TARGET_DEFAULT 36#undef CALL_USED_REGISTERS 37#undef MAYBE_VMS_FUNCTION_PROLOGUE 38#undef STARTING_FRAME_OFFSET 39 40/* Predefine this in CPP because VMS limits the size of command options 41 and GNU CPP is not used on VMS except with GNU C. */ 42#define CPP_PREDEFINES \ 43"-Dvax -Dvms -DVMS -D__vax__ -D__vms__ -D__VMS__\ 44 -D__GNUC__=2 -D__GNUC_MINOR__=7 -Asystem(vms) -Acpu(vax) -Amachine(vax)" 45 46/* These match the definitions used in VAXCRTL, the VMS C run-time library */ 47 48#define SIZE_TYPE "unsigned int" 49#define PTRDIFF_TYPE "int" 50#define WCHAR_TYPE "unsigned int" 51#define WCHAR_TYPE_SIZE 32 /* in bits */ 52 53/* Use memcpy for structure copying, and so forth. */ 54#define TARGET_MEM_FUNCTIONS 55 56/* Strictly speaking, VMS does not use DBX at all, but the interpreter built 57 into gas only speaks straight DBX. */ 58 59#define DEFAULT_GDB_EXTENSIONS 0 60 61#define TARGET_DEFAULT 1 62#define TARGET_NAME "vax/vms" 63 64/* The structure return address arrives as an "argument" on VMS. */ 65#undef STRUCT_VALUE_REGNUM 66#define STRUCT_VALUE 0 67#undef PCC_STATIC_STRUCT_RETURN 68 69#define CALL_USED_REGISTERS {1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1} 70 71/* The run-time library routine VAXC$ESTABLISH (necessary when mixing 72 VMS exception handling and setjmp/longjmp in the same program) requires 73 that a hidden automatic variable at the top of the stack be reserved 74 for its use. We accomplish this by simply adding 4 bytes to the local 75 stack for all functions, and making sure that normal local variables 76 are 4 bytes lower on the stack then they would otherwise have been. */ 77 78#define STARTING_FRAME_OFFSET -4 79 80#define __MAIN_NAME " main(" 81/* 82 * The MAYBE_VMS_FUNCTION_PROLOGUE macro works for both gcc and g++. It 83 * first checks to see if the current routine is "main", which will only 84 * happen for GCC, and add the jsb if it is. If is not the case then try and 85 * see if __MAIN_NAME is part of current_function_name, which will only happen 86 * if we are running g++, and add the jsb if it is. In gcc there should never 87 * be a paren in the function name, and in g++ there is always a "(" in the 88 * function name, thus there should never be any confusion. 89 * 90 * Adjusting the stack pointer by 4 before calling C$MAIN_ARGS is required 91 * when linking with the VMS POSIX version of the C run-time library; using 92 * `subl2 $4,r0' is adequate but we use `clrl -(sp)' instead. The extra 4 93 * bytes could be removed after the call because STARTING_FRAME_OFFSET's 94 * setting of -4 will end up adding them right back again, but don't bother. 95 */ 96#define MAYBE_VMS_FUNCTION_PROLOGUE(FILE) \ 97{ extern char *current_function_name; \ 98 char *p = current_function_name; \ 99 int is_main = strcmp ("main", p) == 0; \ 100 while (!is_main && *p != '\0') \ 101 { \ 102 if (*p == *__MAIN_NAME \ 103 && strncmp (p, __MAIN_NAME, sizeof __MAIN_NAME - sizeof "") == 0) \ 104 is_main = 1; \ 105 else \ 106 p++; \ 107 } \ 108 if (is_main) \ 109 fprintf (FILE, "\t%s\n\t%s\n", "clrl -(sp)", "jsb _C$MAIN_ARGS"); \ 110} 111 112/* This macro definition sets up a default value for `main' to return. */ 113#define DEFAULT_MAIN_RETURN c_expand_return (integer_one_node) 114 115/* This makes use of a hook in varasm.c to mark all external variables 116 for us. We use this to make sure that external variables are correctly 117 addressed. Under VMS there is some brain damage in the linker that requires 118 us to do this. */ 119 120#define ENCODE_SECTION_INFO(decl) \ 121 if (DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)) \ 122 SYMBOL_REF_FLAG (XEXP (DECL_RTL (decl), 0)) = 1; 123 124/* This is how to output a command to make the user-level label named NAME 125 defined for reference from other files. */ 126 127#undef ASM_GLOBALIZE_LABEL 128#define ASM_GLOBALIZE_LABEL(FILE,NAME) \ 129 do { fputs (".globl ", FILE); \ 130 assemble_name (FILE, NAME); \ 131 fputs ("\n", FILE); \ 132 vms_check_external (NULL_TREE, NAME, 0); \ 133 } while (0) 134 135/* Under VMS we write the actual size of the storage to be allocated even 136 though the symbol is external. Although it is possible to give external 137 symbols a size of 0 (as unix does), the VMS linker does not make the 138 distinction between a variable definition and an external reference of a 139 variable, and thus the linker will not complain about a missing definition. 140 If we followed the unix example of giving external symbols a size of 141 zero, you tried to link a program where a given variable was externally 142 defined but none of the object modules contained a non-extern definition, 143 the linker would allocate 0 bytes for the variable, and any attempt to 144 use that variable would use the storage allocated to some other variable. 145 146 We must also select either const_section or data_section: this will indicate 147 whether or not the variable will get the readonly bit set. Since the 148 VMS linker does not distinguish between a variable's definition and an 149 external reference, all usages of a given variable must have the readonly 150 bit set the same way, or the linker will get confused and give warning 151 messages. */ 152 153/* We used to round the size up to a multiple of 4, 154 but that causes linker errors sometimes when the variable was initialized 155 since the size of its definition was not likewise rounded up. */ 156 157/* Note: the original ASM_OUTPUT_EXTERNAL code has been moved into 158 vms_check_external and vms_flush_pending_externals. */ 159 160#define ASM_OUTPUT_EXTERNAL(FILE,DECL,NAME) \ 161{ if (DECL_INITIAL (DECL) == 0 && TREE_CODE (DECL) != FUNCTION_DECL) \ 162 vms_check_external ((DECL), (NAME), 1); \ 163} 164 165/* ASM_OUTPUT_EXTERNAL will have wait until after an initializer is 166 completed in order to switch sections for an external object, so 167 use the DECLARE_OBJECT hooks to manage deferred declarations. */ 168 169/* This is the default action for ASM_DECLARE_OBJECT_NAME, but if it 170 is explicitly defined, then ASM_FINISH_DECLARE_OBJECT will be used. */ 171 172#define ASM_DECLARE_OBJECT_NAME(ASM_OUT_FILE,NAME,DECL) \ 173 ASM_OUTPUT_LABEL ((ASM_OUT_FILE), (NAME)) 174 175/* We don't need to do anything special to finish the current object, but it 176 should now be safe to output any deferred external global declarations. */ 177 178#define ASM_FINISH_DECLARE_OBJECT(FILE,DECL,TOPLVL,ATEND) \ 179 vms_flush_pending_externals(FILE) 180 181/* Anything still pending must be flushed at the very end. */ 182 183#define ASM_FILE_END(STREAM) \ 184 vms_flush_pending_externals(STREAM) 185 186/* Here we redefine ASM_OUTPUT_COMMON to select the data_section or the 187 const_section before writing the ".const" assembler directive. 188 If we were specifying a size of zero for external variables, we would 189 not have to select a section, since the assembler can assume that 190 when the size > 0, the storage is for a non-external, uninitialized 191 variable (for which a "const" declaration would be senseless), 192 and the assembler can make the storage read/write. 193 194 Since the ".const" directive specifies the actual size of the storage used 195 for both external and non-external variables, the assembler cannot 196 make this assumption, and thus it has no way of deciding if storage should 197 be read/write or read-only. To resolve this, we give the assembler some 198 assistance, in the form of a ".const" or a ".data" directive. 199 200 Under GCC 1.40, external variables were declared with a size of zero. 201 The GNU assembler, GAS, will recognize the "-2" switch when built for VMS; 202 when compiling programs with GCC 2.n this switch should be used or the 203 assembler will not give the read-only attribute to external constants. 204 Failure to use this switch will result in linker warning messages about 205 mismatched psect attributes. */ 206 207#undef ASM_OUTPUT_COMMON 208 209#define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED) \ 210( ((TREE_READONLY (decl) && ! TREE_THIS_VOLATILE (decl)) \ 211 ? (const_section (), 0) : (data_section (), 0)), \ 212 fputs (".comm ", (FILE)), \ 213 assemble_name ((FILE), (NAME)), \ 214 fprintf ((FILE), ",%u\n", (SIZE))) 215 216/* We define this to prevent the name mangler from putting dollar signs into 217 function names. This isn't really needed, but it has been here for 218 some time and removing it would cause the object files generated by the 219 compiler to be incompatible with the object files from a compiler that 220 had this defined. Since it does no harm, we leave it in. */ 221 222#define NO_DOLLAR_IN_LABEL 223 224/* Add a "const" section. This is viewed by the assembler as being nearly 225 the same as the "data" section, with the only difference being that a 226 flag is set for variables declared while in the const section. This 227 flag is used to determine whether or not the read/write bit should be 228 set in the Psect definition. */ 229 230#define EXTRA_SECTIONS in_const 231 232#define EXTRA_SECTION_FUNCTIONS \ 233void \ 234const_section () \ 235{ \ 236 if (in_section != in_const) { \ 237 fprintf(asm_out_file,".const\n"); \ 238 in_section = in_const; \ 239 } \ 240} 241 242/* This macro contains the logic to decide which section a variable 243 should be stored in. Static constant variables go in the text_section, 244 non-const variables go in the data_section, and non-static const 245 variables go in the const_section. 246 247 Since this macro is used in a number of places, we must also be able 248 to decide where to place string constants. */ 249 250#define SELECT_SECTION(T,RELOC) \ 251{ \ 252 if (TREE_CODE (T) == VAR_DECL) \ 253 { \ 254 if (TREE_READONLY (T) && ! TREE_THIS_VOLATILE (T) \ 255 && DECL_INITIAL (T) \ 256 && (DECL_INITIAL (T) == error_mark_node \ 257 || TREE_CONSTANT (DECL_INITIAL (T)))) \ 258 { \ 259 if (TREE_PUBLIC (T)) \ 260 const_section (); \ 261 else \ 262 text_section (); \ 263 } \ 264 else \ 265 data_section (); \ 266 } \ 267 if (TREE_CODE_CLASS (TREE_CODE (T)) == 'c') \ 268 { \ 269 if ((TREE_CODE (T) == STRING_CST && flag_writable_strings)) \ 270 data_section (); \ 271 else \ 272 text_section (); \ 273 } \ 274} 275 276/* This is used by a hook in varasm.c to write the assembler directives 277 that are needed to tell the startup code which constructors need to 278 be run. */ 279 280#define ASM_OUTPUT_CONSTRUCTOR(FILE,NAME) \ 281{ \ 282 fprintf ((FILE),".globl $$PsectAttributes_NOOVR$$__gxx_init_1\n"); \ 283 data_section(); \ 284 fprintf ((FILE),"$$PsectAttributes_NOOVR$$__gxx_init_1:\n\t.long\t"); \ 285 assemble_name ((FILE), (NAME)); \ 286 fputc ('\n', (FILE)); \ 287} 288 289/* This is used by a hook in varasm.c to write the assembler directives 290 that are needed to tell the startup code which destructors need to 291 be run. */ 292 293#define ASM_OUTPUT_DESTRUCTOR(FILE,NAME) \ 294{ \ 295 fprintf ((FILE),".globl $$PsectAttributes_NOOVR$$__gxx_clean_1\n"); \ 296 data_section(); \ 297 fprintf ((FILE),"$$PsectAttributes_NOOVR$$__gxx_clean_1:\n\t.long\t");\ 298 assemble_name ((FILE), (NAME)); \ 299 fputc ('\n', (FILE)); \ 300} 301 302/* True for VMS V4.6 and later. */ 303#define HAVE_ATEXIT 304 305/* The following definitions are used in libgcc2.c with the __main 306 function. The _SHR symbol is used when the sharable image library 307 for the C++ library is used - this is picked up automatically by the linker 308 and this symbol points to the start of __CTOR_LIST__ from the C++ library. 309 If the C++ library is not used, then __CTOR_LIST_SHR__ occurs just after 310 __CTOR_LIST__, and essentially points to the same list as __CTOR_LIST. */ 311 312#ifdef L__main 313 314#define __CTOR_LIST__ __gxx_init_0 315#define __CTOR_LIST_END__ __gxx_init_2 316 317#define __CTOR_LIST_SHR__ $$PsectAttributes_NOSHR$$__gxx_init_0_shr 318#define __CTOR_LIST_SHR_END__ $$PsectAttributes_NOSHR$$__gxx_init_2_shr 319 320#define DO_GLOBAL_CTORS_BODY \ 321do { \ 322 func_ptr *p; \ 323 extern func_ptr __CTOR_LIST__[1], __CTOR_LIST_END__[1]; \ 324 extern func_ptr __CTOR_LIST_SHR__[1], __CTOR_LIST_SHR_END__[1]; \ 325 if (&__CTOR_LIST_SHR__[0] != &__CTOR_LIST__[1]) \ 326 for (p = __CTOR_LIST_SHR__ + 1; p < __CTOR_LIST_SHR_END__ ; p++ ) \ 327 if (*p) (*p) (); \ 328 for (p = __CTOR_LIST__ + 1; p < __CTOR_LIST_END__ ; p++ ) \ 329 if (*p) (*p) (); \ 330 do { /* arrange for `return' from main() to pass through exit() */ \ 331 __label__ foo; \ 332 int *callers_caller_fp = (int *) __builtin_frame_address (3); \ 333 register int retval asm ("r0"); \ 334 callers_caller_fp[4] = (int) && foo; \ 335 break; /* out of do-while block */ \ 336 foo: \ 337 exit (retval); \ 338 } while (0); \ 339} while (0) 340 341#define __DTOR_LIST__ __gxx_clean_0 342#define __DTOR_LIST_END__ __gxx_clean_2 343 344#define __DTOR_LIST_SHR__ $$PsectAttributes_NOSHR$$__gxx_clean_0_shr 345#define __DTOR_LIST_SHR_END__ $$PsectAttributes_NOSHR$$__gxx_clean_2_shr 346 347#define DO_GLOBAL_DTORS_BODY \ 348do { \ 349 func_ptr *p; \ 350 extern func_ptr __DTOR_LIST__[1], __DTOR_LIST_END__[1]; \ 351 extern func_ptr __DTOR_LIST_SHR__[1], __DTOR_LIST_SHR_END__[1]; \ 352 for (p = __DTOR_LIST__ + 1; p < __DTOR_LIST_END__ ; p++ ) \ 353 if (*p) (*p) (); \ 354 if (&__DTOR_LIST_SHR__[0] != &__DTOR_LIST__[1]) \ 355 for (p = __DTOR_LIST_SHR__ + 1; p < __DTOR_LIST_SHR_END__ ; p++ ) \ 356 if (*p) (*p) (); \ 357} while (0) 358 359#endif /* L__main */ 360 361/* Specify the list of include file directories. */ 362#define INCLUDE_DEFAULTS \ 363{ \ 364 { "GNU_GXX_INCLUDE:", "G++", 1, 1 }, \ 365 { "GNU_CC_INCLUDE:", "GCC", 0, 0 }, /* GNU includes */ \ 366 { "SYS$SYSROOT:[SYSLIB.]", 0, 0, 0 }, /* VAX-11 "C" includes */ \ 367 { ".", 0, 0, 1 }, /* Make normal VMS filespecs work. */ \ 368 { 0, 0, 0, 0 } \ 369} 370