1 /* elfos.h -- operating system specific defines to be used when
2 targeting GCC for some generic ELF system
3 Copyright (C) 1991, 1994, 1995, 1999, 2000, 2001
4 Free Software Foundation, Inc.
5 Based on svr4.h contributed by Ron Guilmette (rfg@netcom.com).
7 This file is part of GNU CC.
9 GNU CC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GNU CC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GNU CC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 /* Define a symbol indicating that we are using elfos.h.
26 Some CPU specific configuration files use this. */
29 /* The prefix to add to user-visible assembler symbols.
31 For ELF systems the convention is *not* to prepend a leading
32 underscore onto user-level symbol names. */
34 #undef USER_LABEL_PREFIX
35 #define USER_LABEL_PREFIX ""
37 /* Biggest alignment supported by the object file format of this
38 machine. Use this macro to limit the alignment which can be
39 specified using the `__attribute__ ((aligned (N)))' construct. If
40 not defined, the default value is `BIGGEST_ALIGNMENT'. */
41 #ifndef MAX_OFILE_ALIGNMENT
42 #define MAX_OFILE_ALIGNMENT (32768 * 8)
46 #define ENDFILE_SPEC "crtend.o%s"
49 #define STARTFILE_SPEC "%{!shared: \
51 %{pg:gcrt0.o%s}%{!pg:%{p:mcrt0.o%s}%{!p:crt0.o%s}}}}\
54 /* Use periods rather than dollar signs in special g++ assembler names. */
56 #define NO_DOLLAR_IN_LABEL
58 /* Writing `int' for a bitfield forces int alignment for the structure. */
60 #define PCC_BITFIELD_TYPE_MATTERS 1
62 /* Implicit library calls should use memcpy, not bcopy, etc. */
64 #define TARGET_MEM_FUNCTIONS
66 /* Handle #pragma weak and #pragma pack. */
68 #define HANDLE_SYSV_PRAGMA
70 /* System V Release 4 uses DWARF debugging info. */
72 #ifndef DWARF_DEBUGGING_INFO
73 #define DWARF_DEBUGGING_INFO 1
76 /* All ELF targets can support DWARF-2. */
78 #ifndef DWARF2_DEBUGGING_INFO
79 #define DWARF2_DEBUGGING_INFO 1
82 /* Also allow them to support STABS debugging. */
86 /* The GNU tools operate better with stabs. Since we don't have
87 any native tools to be compatible with, default to stabs. */
89 #ifndef PREFERRED_DEBUGGING_TYPE
90 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
93 /* All SVR4 targets use the ELF object file format. */
94 #define OBJECT_FORMAT_ELF
97 /* Output #ident as a .ident. */
99 #define ASM_OUTPUT_IDENT(FILE, NAME) \
100 fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);
102 #define IDENT_ASM_OP "\t.ident\t"
105 #define ASM_BYTE_OP "\t.byte\t"
108 #define SET_ASM_OP "\t.set\t"
110 /* This is how to begin an assembly language file. Most svr4 assemblers want
111 at least a .file directive to come first, and some want to see a .version
112 directive come right after that. Here we just establish a default
113 which generates only the .file directive. If you need a .version
114 directive for any specific target, you should override this definition
115 in the target-specific file which includes this one. */
117 #undef ASM_FILE_START
118 #define ASM_FILE_START(FILE) \
119 output_file_directive ((FILE), main_input_filename)
121 /* This is how to allocate empty space in some section. The .zero
122 pseudo-op is used for this on most svr4 assemblers. */
124 #define SKIP_ASM_OP "\t.zero\t"
126 #undef ASM_OUTPUT_SKIP
127 #define ASM_OUTPUT_SKIP(FILE, SIZE) \
128 fprintf (FILE, "%s%u\n", SKIP_ASM_OP, (SIZE))
130 /* This is how to output an internal numbered label where
131 PREFIX is the class of label and NUM is the number within the class.
133 For most svr4 systems, the convention is that any symbol which begins
134 with a period is not put into the linker symbol table by the assembler. */
136 #undef ASM_OUTPUT_INTERNAL_LABEL
137 #define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM) \
140 fprintf (FILE, ".%s%d:\n", PREFIX, NUM); \
144 /* This is how to store into the string LABEL
145 the symbol_ref name of an internal numbered label where
146 PREFIX is the class of label and NUM is the number within the class.
147 This is suitable for output with `assemble_name'.
149 For most svr4 systems, the convention is that any symbol which begins
150 with a period is not put into the linker symbol table by the assembler. */
152 #undef ASM_GENERATE_INTERNAL_LABEL
153 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
156 sprintf (LABEL, "*.%s%u", PREFIX, (unsigned) (NUM)); \
160 /* Output the label which precedes a jumptable. Note that for all svr4
161 systems where we actually generate jumptables (which is to say every
162 svr4 target except i386, where we use casesi instead) we put the jump-
163 tables into the .rodata section and since other stuff could have been
164 put into the .rodata section prior to any given jumptable, we have to
165 make sure that the location counter for the .rodata section gets pro-
166 perly re-aligned prior to the actual beginning of the jump table. */
169 #define ALIGN_ASM_OP "\t.align\t"
171 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
172 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
173 ASM_OUTPUT_ALIGN ((FILE), 2);
176 #undef ASM_OUTPUT_CASE_LABEL
177 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \
180 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE) \
181 ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM); \
185 /* The standard SVR4 assembler seems to require that certain builtin
186 library routines (e.g. .udiv) be explicitly declared as .globl
187 in each assembly file where they are referenced. */
189 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
190 ASM_GLOBALIZE_LABEL (FILE, XSTR (FUN, 0))
192 /* This says how to output assembler code to declare an
193 uninitialized external linkage data object. Under SVR4,
194 the linker seems to want the alignment of data objects
195 to depend on their types. We do exactly that here. */
197 #define COMMON_ASM_OP "\t.comm\t"
199 #undef ASM_OUTPUT_ALIGNED_COMMON
200 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
203 fprintf ((FILE), "%s", COMMON_ASM_OP); \
204 assemble_name ((FILE), (NAME)); \
205 fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT); \
209 /* This says how to output assembler code to declare an
210 uninitialized internal linkage data object. Under SVR4,
211 the linker seems to want the alignment of data objects
212 to depend on their types. We do exactly that here. */
214 #define LOCAL_ASM_OP "\t.local\t"
216 #undef ASM_OUTPUT_ALIGNED_LOCAL
217 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
220 fprintf ((FILE), "%s", LOCAL_ASM_OP); \
221 assemble_name ((FILE), (NAME)); \
222 fprintf ((FILE), "\n"); \
223 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \
227 /* This is the pseudo-op used to generate a contiguous sequence of byte
228 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
229 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */
231 #undef ASCII_DATA_ASM_OP
232 #define ASCII_DATA_ASM_OP "\t.ascii\t"
234 /* Support const sections and the ctors and dtors sections for g++.
235 Note that there appears to be two different ways to support const
236 sections at the moment. You can either #define the symbol
237 READONLY_DATA_SECTION (giving it some code which switches to the
238 readonly data section) or else you can #define the symbols
239 EXTRA_SECTIONS, EXTRA_SECTION_FUNCTIONS, SELECT_SECTION, and
240 SELECT_RTX_SECTION. We do both here just to be on the safe side. */
242 #define USE_CONST_SECTION 1
244 #define CONST_SECTION_ASM_OP "\t.section\t.rodata"
246 /* On svr4, we *do* have support for the .init and .fini sections, and we
247 can put stuff in there to be executed before and after `main'. We let
248 crtstuff.c and other files know this by defining the following symbols.
249 The definitions say how to change sections to the .init and .fini
250 sections. This is the same for all known svr4 assemblers. */
252 #define INIT_SECTION_ASM_OP "\t.section\t.init"
253 #define FINI_SECTION_ASM_OP "\t.section\t.fini"
255 #ifdef HAVE_GAS_SUBSECTION_ORDERING
257 #define ASM_SECTION_START_OP "\t.subsection\t-1"
259 /* Output assembly directive to move to the beginning of current section. */
260 #define ASM_OUTPUT_SECTION_START(FILE) \
261 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP)
265 /* A default list of other sections which we might be "in" at any given
266 time. For targets that use additional sections (e.g. .tdesc) you
267 should override this definition in the target-specific file which
268 includes this file. */
270 #undef EXTRA_SECTIONS
271 #define EXTRA_SECTIONS in_const
273 /* A default list of extra section function definitions. For targets
274 that use additional sections (e.g. .tdesc) you should override this
275 definition in the target-specific file which includes this file. */
277 #undef EXTRA_SECTION_FUNCTIONS
278 #define EXTRA_SECTION_FUNCTIONS \
279 CONST_SECTION_FUNCTION
281 #define READONLY_DATA_SECTION() const_section ()
283 #define CONST_SECTION_FUNCTION \
287 if (!USE_CONST_SECTION) \
289 else if (in_section != in_const) \
291 fprintf (asm_out_file, "%s\n", CONST_SECTION_ASM_OP); \
292 in_section = in_const; \
296 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
298 #define UNIQUE_SECTION(DECL, RELOC) \
305 const char *prefix; \
306 static const char *const prefixes[4][2] = \
308 { ".text.", ".gnu.linkonce.t." }, \
309 { ".rodata.", ".gnu.linkonce.r." }, \
310 { ".data.", ".gnu.linkonce.d." }, \
311 { ".bss.", ".gnu.linkonce.b." } \
314 if (TREE_CODE (DECL) == FUNCTION_DECL) \
316 else if (DECL_INITIAL (DECL) == 0 \
317 || DECL_INITIAL (DECL) == error_mark_node) \
319 else if (DECL_READONLY_SECTION (DECL, RELOC)) \
324 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)); \
325 /* Strip off any encoding in name. */ \
326 STRIP_NAME_ENCODING (name, name); \
327 prefix = prefixes[sec][DECL_ONE_ONLY(DECL)]; \
328 len = strlen (name) + strlen (prefix); \
329 string = alloca (len + 1); \
331 sprintf (string, "%s%s", prefix, name); \
333 DECL_SECTION_NAME (DECL) = build_string (len, string); \
337 /* Switch into a generic section. */
338 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
340 /* A C statement or statements to switch to the appropriate
341 section for output of RTX in mode MODE. RTX is some kind
342 of constant in RTL. The argument MODE is redundant except
343 in the case of a `const_int' rtx.
344 If assembler supports SHF_MERGE sections, put it into
345 a .rodata.cstN section where N is size of the constant,
346 otherwise into const section. */
348 #undef SELECT_RTX_SECTION
349 #define SELECT_RTX_SECTION(MODE, RTX, ALIGN) \
350 mergeable_constant_section ((MODE), (ALIGN), 0)
352 /* A C statement or statements to switch to the appropriate
353 section for output of DECL. DECL is either a `VAR_DECL' node
354 or a constant of some sort. RELOC indicates whether forming
355 the initial value of DECL requires link-time relocations. */
357 #undef SELECT_SECTION
358 #define SELECT_SECTION(DECL, RELOC, ALIGN) \
360 if (TREE_CODE (DECL) == STRING_CST) \
362 if (! flag_writable_strings) \
363 mergeable_string_section ((DECL), (ALIGN), 0); \
367 else if (TREE_CODE (DECL) == VAR_DECL) \
369 if ((flag_pic && RELOC) \
370 || !TREE_READONLY (DECL) || TREE_SIDE_EFFECTS (DECL) \
371 || !DECL_INITIAL (DECL) \
372 || (DECL_INITIAL (DECL) != error_mark_node \
373 && !TREE_CONSTANT (DECL_INITIAL (DECL)))) \
375 else if (flag_merge_constants < 2) \
376 /* C and C++ don't allow different variables to share \
377 the same location. -fmerge-all-constants allows \
378 even that (at the expense of not conforming). */ \
380 else if (TREE_CODE (DECL_INITIAL (DECL)) == STRING_CST) \
381 mergeable_string_section (DECL_INITIAL (DECL), (ALIGN), \
384 mergeable_constant_section (DECL_MODE (DECL), (ALIGN), \
387 else if (TREE_CODE (DECL) == CONSTRUCTOR) \
389 if ((flag_pic && RELOC) \
390 || TREE_SIDE_EFFECTS (DECL) \
391 || ! TREE_CONSTANT (DECL)) \
400 /* Define the strings used for the special svr4 .type and .size directives.
401 These strings generally do not vary from one system running svr4 to
402 another, but if a given system (e.g. m88k running svr) needs to use
403 different pseudo-op names for these, they may be overridden in the
404 file which includes this one. */
406 #define TYPE_ASM_OP "\t.type\t"
407 #define SIZE_ASM_OP "\t.size\t"
409 /* This is how we tell the assembler that a symbol is weak. */
411 #define ASM_WEAKEN_LABEL(FILE, NAME) \
414 fputs ("\t.weak\t", (FILE)); \
415 assemble_name ((FILE), (NAME)); \
416 fputc ('\n', (FILE)); \
420 /* The following macro defines the format used to output the second
421 operand of the .type assembler directive. Different svr4 assemblers
422 expect various different forms for this operand. The one given here
423 is just a default. You may need to override it in your machine-
424 specific tm.h file (depending upon the particulars of your assembler). */
426 #define TYPE_OPERAND_FMT "@%s"
428 /* Write the extra assembler code needed to declare a function's result.
429 Most svr4 assemblers don't require any special declaration of the
430 result value, but there are exceptions. */
432 #ifndef ASM_DECLARE_RESULT
433 #define ASM_DECLARE_RESULT(FILE, RESULT)
436 /* These macros generate the special .type and .size directives which
437 are used to set the corresponding fields of the linker symbol table
438 entries in an ELF object file under SVR4. These macros also output
439 the starting labels for the relevant functions/objects. */
441 /* Write the extra assembler code needed to declare a function properly.
442 Some svr4 assemblers need to also have something extra said about the
443 function's return value. We allow for that here. */
445 #ifndef ASM_DECLARE_FUNCTION_NAME
446 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
449 fprintf (FILE, "%s", TYPE_ASM_OP); \
450 assemble_name (FILE, NAME); \
452 fprintf (FILE, TYPE_OPERAND_FMT, "function"); \
455 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
456 ASM_OUTPUT_LABEL(FILE, NAME); \
461 /* Write the extra assembler code needed to declare an object properly. */
463 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \
466 fprintf (FILE, "%s", TYPE_ASM_OP); \
467 assemble_name (FILE, NAME); \
469 fprintf (FILE, TYPE_OPERAND_FMT, "object"); \
472 size_directive_output = 0; \
474 if (!flag_inhibit_size_directive \
475 && (DECL) && DECL_SIZE (DECL)) \
477 size_directive_output = 1; \
478 fprintf (FILE, "%s", SIZE_ASM_OP); \
479 assemble_name (FILE, NAME); \
481 fprintf (FILE, HOST_WIDE_INT_PRINT_DEC, \
482 int_size_in_bytes (TREE_TYPE (DECL))); \
483 fputc ('\n', FILE); \
486 ASM_OUTPUT_LABEL (FILE, NAME); \
490 /* Output the size directive for a decl in rest_of_decl_compilation
491 in the case where we did not do so before the initializer.
492 Once we find the error_mark_node, we know that the value of
493 size_directive_output was set
494 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */
496 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\
499 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \
501 if (!flag_inhibit_size_directive \
502 && DECL_SIZE (DECL) \
503 && ! AT_END && TOP_LEVEL \
504 && DECL_INITIAL (DECL) == error_mark_node \
505 && !size_directive_output) \
507 size_directive_output = 1; \
508 fprintf (FILE, "%s", SIZE_ASM_OP); \
509 assemble_name (FILE, name); \
511 fprintf (FILE, HOST_WIDE_INT_PRINT_DEC, \
512 int_size_in_bytes (TREE_TYPE (DECL))); \
513 fputc ('\n', FILE); \
518 /* This is how to declare the size of a function. */
519 #ifndef ASM_DECLARE_FUNCTION_SIZE
520 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
523 if (!flag_inhibit_size_directive) \
526 static int labelno; \
530 ASM_GENERATE_INTERNAL_LABEL (label, "Lfe", labelno); \
531 ASM_OUTPUT_INTERNAL_LABEL (FILE, "Lfe", labelno); \
533 fprintf (FILE, "%s", SIZE_ASM_OP); \
534 assemble_name (FILE, (FNAME)); \
535 fprintf (FILE, ","); \
536 assemble_name (FILE, label); \
537 fprintf (FILE, "-"); \
538 assemble_name (FILE, (FNAME)); \
545 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and
546 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table
547 corresponds to a particular byte value [0..255]. For any
548 given byte value, if the value in the corresponding table
549 position is zero, the given character can be output directly.
550 If the table value is 1, the byte must be output as a \ooo
551 octal escape. If the tables value is anything else, then the
552 byte value should be output as a \ followed by the value
553 in the table. Note that we can use standard UN*X escape
554 sequences for many control characters, but we don't use
555 \a to represent BEL because some svr4 assemblers (e.g. on
556 the i386) don't know about that. Also, we don't use \v
557 since some versions of gas, such as 2.2 did not accept it. */
560 "\1\1\1\1\1\1\1\1btn\1fr\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\
561 \0\0\"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
562 \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\\\0\0\0\
563 \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1\
564 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\
565 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\
566 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\
567 \1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1\1"
569 /* Some svr4 assemblers have a limit on the number of characters which
570 can appear in the operand of a .string directive. If your assembler
571 has such a limitation, you should define STRING_LIMIT to reflect that
572 limit. Note that at least some svr4 assemblers have a limit on the
573 actual number of bytes in the double-quoted string, and that they
574 count each character in an escape sequence as one byte. Thus, an
575 escape sequence like \377 would count as four bytes.
577 If your target assembler doesn't support the .string directive, you
578 should define this to zero.
581 #define STRING_LIMIT ((unsigned) 256)
583 #define STRING_ASM_OP "\t.string\t"
585 /* The routine used to output NUL terminated strings. We use a special
586 version of this for most svr4 targets because doing so makes the
587 generated assembly code more compact (and thus faster to assemble)
588 as well as more readable, especially for targets like the i386
589 (where the only alternative is to output character sequences as
590 comma separated lists of numbers). */
592 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \
595 register const unsigned char *_limited_str = \
596 (const unsigned char *) (STR); \
597 register unsigned ch; \
599 fprintf ((FILE), "%s\"", STRING_ASM_OP); \
601 for (; (ch = *_limited_str); _limited_str++) \
603 register int escape; \
605 switch (escape = ESCAPES[ch]) \
611 fprintf ((FILE), "\\%03o", ch); \
614 putc ('\\', (FILE)); \
615 putc (escape, (FILE)); \
620 fprintf ((FILE), "\"\n"); \
624 /* The routine used to output sequences of byte values. We use a special
625 version of this for most svr4 targets because doing so makes the
626 generated assembly code more compact (and thus faster to assemble)
627 as well as more readable. Note that if we find subparts of the
628 character sequence which end with NUL (and which are shorter than
629 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */
631 #undef ASM_OUTPUT_ASCII
632 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \
635 register const unsigned char *_ascii_bytes = \
636 (const unsigned char *) (STR); \
637 register const unsigned char *limit = _ascii_bytes + (LENGTH); \
638 register unsigned bytes_in_chunk = 0; \
640 for (; _ascii_bytes < limit; _ascii_bytes++) \
642 register const unsigned char *p; \
644 if (bytes_in_chunk >= 60) \
646 fprintf ((FILE), "\"\n"); \
647 bytes_in_chunk = 0; \
650 for (p = _ascii_bytes; p < limit && *p != '\0'; p++) \
653 if (p < limit && (p - _ascii_bytes) <= (long)STRING_LIMIT) \
655 if (bytes_in_chunk > 0) \
657 fprintf ((FILE), "\"\n"); \
658 bytes_in_chunk = 0; \
661 ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes); \
666 register int escape; \
667 register unsigned ch; \
669 if (bytes_in_chunk == 0) \
670 fprintf ((FILE), "%s\"", ASCII_DATA_ASM_OP); \
672 switch (escape = ESCAPES[ch = *_ascii_bytes]) \
679 fprintf ((FILE), "\\%03o", ch); \
680 bytes_in_chunk += 4; \
683 putc ('\\', (FILE)); \
684 putc (escape, (FILE)); \
685 bytes_in_chunk += 2; \
691 if (bytes_in_chunk > 0) \
692 fprintf ((FILE), "\"\n"); \