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, 2002
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)
45 /* Use periods rather than dollar signs in special g++ assembler names. */
47 #define NO_DOLLAR_IN_LABEL
49 /* Writing `int' for a bit-field forces int alignment for the structure. */
51 #ifndef PCC_BITFIELD_TYPE_MATTERS
52 #define PCC_BITFIELD_TYPE_MATTERS 1
55 /* Implicit library calls should use memcpy, not bcopy, etc. */
57 #define TARGET_MEM_FUNCTIONS
59 /* Handle #pragma weak and #pragma pack. */
61 #define HANDLE_SYSV_PRAGMA 1
63 /* System V Release 4 uses DWARF debugging info. */
65 #define DWARF_DEBUGGING_INFO 1
67 /* All ELF targets can support DWARF-2. */
69 #define DWARF2_DEBUGGING_INFO 1
71 /* The GNU tools operate better with dwarf2, and it is required by some
72 psABI's. Since we don't have any native tools to be compatible with,
75 #ifndef PREFERRED_DEBUGGING_TYPE
76 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
79 /* All SVR4 targets use the ELF object file format. */
80 #define OBJECT_FORMAT_ELF
83 /* Output #ident as a .ident. */
85 #define ASM_OUTPUT_IDENT(FILE, NAME) \
86 fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);
88 #define IDENT_ASM_OP "\t.ident\t"
91 #define SET_ASM_OP "\t.set\t"
93 /* This is how to begin an assembly language file. Most svr4 assemblers want
94 at least a .file directive to come first, and some want to see a .version
95 directive come right after that. Here we just establish a default
96 which generates only the .file directive. If you need a .version
97 directive for any specific target, you should override this definition
98 in the target-specific file which includes this one. */
100 #undef ASM_FILE_START
101 #define ASM_FILE_START(FILE) \
102 output_file_directive ((FILE), main_input_filename)
104 /* This is how to allocate empty space in some section. The .zero
105 pseudo-op is used for this on most svr4 assemblers. */
107 #define SKIP_ASM_OP "\t.zero\t"
109 #undef ASM_OUTPUT_SKIP
110 #define ASM_OUTPUT_SKIP(FILE, SIZE) \
111 fprintf (FILE, "%s%u\n", SKIP_ASM_OP, (SIZE))
113 /* This is how to output an internal numbered label where
114 PREFIX is the class of label and NUM is the number within the class.
116 For most svr4 systems, the convention is that any symbol which begins
117 with a period is not put into the linker symbol table by the assembler. */
119 #undef ASM_OUTPUT_INTERNAL_LABEL
120 #define ASM_OUTPUT_INTERNAL_LABEL(FILE, PREFIX, NUM) \
123 fprintf (FILE, ".%s%u:\n", PREFIX, (unsigned) (NUM)); \
127 /* This is how to store into the string LABEL
128 the symbol_ref name of an internal numbered label where
129 PREFIX is the class of label and NUM is the number within the class.
130 This is suitable for output with `assemble_name'.
132 For most svr4 systems, the convention is that any symbol which begins
133 with a period is not put into the linker symbol table by the assembler. */
135 #undef ASM_GENERATE_INTERNAL_LABEL
136 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
139 sprintf (LABEL, "*.%s%u", PREFIX, (unsigned) (NUM)); \
143 /* Output the label which precedes a jumptable. Note that for all svr4
144 systems where we actually generate jumptables (which is to say every
145 svr4 target except i386, where we use casesi instead) we put the jump-
146 tables into the .rodata section and since other stuff could have been
147 put into the .rodata section prior to any given jumptable, we have to
148 make sure that the location counter for the .rodata section gets pro-
149 perly re-aligned prior to the actual beginning of the jump table. */
152 #define ALIGN_ASM_OP "\t.align\t"
154 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
155 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
156 ASM_OUTPUT_ALIGN ((FILE), 2);
159 #undef ASM_OUTPUT_CASE_LABEL
160 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \
163 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE) \
164 ASM_OUTPUT_INTERNAL_LABEL (FILE, PREFIX, NUM); \
168 /* The standard SVR4 assembler seems to require that certain builtin
169 library routines (e.g. .udiv) be explicitly declared as .globl
170 in each assembly file where they are referenced. */
172 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
173 (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0))
175 /* This says how to output assembler code to declare an
176 uninitialized external linkage data object. Under SVR4,
177 the linker seems to want the alignment of data objects
178 to depend on their types. We do exactly that here. */
180 #define COMMON_ASM_OP "\t.comm\t"
182 #undef ASM_OUTPUT_ALIGNED_COMMON
183 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
186 fprintf ((FILE), "%s", COMMON_ASM_OP); \
187 assemble_name ((FILE), (NAME)); \
188 fprintf ((FILE), ",%u,%u\n", (SIZE), (ALIGN) / BITS_PER_UNIT); \
192 /* This says how to output assembler code to declare an
193 uninitialized internal 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 LOCAL_ASM_OP "\t.local\t"
199 #undef ASM_OUTPUT_ALIGNED_LOCAL
200 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
203 fprintf ((FILE), "%s", LOCAL_ASM_OP); \
204 assemble_name ((FILE), (NAME)); \
205 fprintf ((FILE), "\n"); \
206 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \
210 /* This is the pseudo-op used to generate a contiguous sequence of byte
211 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
212 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */
214 #undef ASCII_DATA_ASM_OP
215 #define ASCII_DATA_ASM_OP "\t.ascii\t"
217 /* Support a read-only data section. */
218 #define READONLY_DATA_SECTION_ASM_OP "\t.section\t.rodata"
220 /* On svr4, we *do* have support for the .init and .fini sections, and we
221 can put stuff in there to be executed before and after `main'. We let
222 crtstuff.c and other files know this by defining the following symbols.
223 The definitions say how to change sections to the .init and .fini
224 sections. This is the same for all known svr4 assemblers. */
226 #define INIT_SECTION_ASM_OP "\t.section\t.init"
227 #define FINI_SECTION_ASM_OP "\t.section\t.fini"
229 /* Output assembly directive to move to the beginning of current section. */
230 #ifdef HAVE_GAS_SUBSECTION_ORDERING
231 # define ASM_SECTION_START_OP "\t.subsection\t-1"
232 # define ASM_OUTPUT_SECTION_START(FILE) \
233 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP)
236 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
238 /* Switch into a generic section. */
239 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
241 #undef TARGET_ASM_SELECT_RTX_SECTION
242 #define TARGET_ASM_SELECT_RTX_SECTION default_elf_select_rtx_section
243 #undef TARGET_ASM_SELECT_SECTION
244 #define TARGET_ASM_SELECT_SECTION default_elf_select_section
246 /* Define the strings used for the special svr4 .type and .size directives.
247 These strings generally do not vary from one system running svr4 to
248 another, but if a given system (e.g. m88k running svr) needs to use
249 different pseudo-op names for these, they may be overridden in the
250 file which includes this one. */
252 #define TYPE_ASM_OP "\t.type\t"
253 #define SIZE_ASM_OP "\t.size\t"
255 /* This is how we tell the assembler that a symbol is weak. */
257 #define ASM_WEAKEN_LABEL(FILE, NAME) \
260 fputs ("\t.weak\t", (FILE)); \
261 assemble_name ((FILE), (NAME)); \
262 fputc ('\n', (FILE)); \
266 /* The following macro defines the format used to output the second
267 operand of the .type assembler directive. Different svr4 assemblers
268 expect various different forms for this operand. The one given here
269 is just a default. You may need to override it in your machine-
270 specific tm.h file (depending upon the particulars of your assembler). */
272 #define TYPE_OPERAND_FMT "@%s"
274 /* Write the extra assembler code needed to declare a function's result.
275 Most svr4 assemblers don't require any special declaration of the
276 result value, but there are exceptions. */
278 #ifndef ASM_DECLARE_RESULT
279 #define ASM_DECLARE_RESULT(FILE, RESULT)
282 /* These macros generate the special .type and .size directives which
283 are used to set the corresponding fields of the linker symbol table
284 entries in an ELF object file under SVR4. These macros also output
285 the starting labels for the relevant functions/objects. */
287 /* Write the extra assembler code needed to declare a function properly.
288 Some svr4 assemblers need to also have something extra said about the
289 function's return value. We allow for that here. */
291 #ifndef ASM_DECLARE_FUNCTION_NAME
292 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
295 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \
296 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
297 ASM_OUTPUT_LABEL (FILE, NAME); \
302 /* Write the extra assembler code needed to declare an object properly. */
304 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \
307 HOST_WIDE_INT size; \
309 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \
311 size_directive_output = 0; \
312 if (!flag_inhibit_size_directive \
313 && (DECL) && DECL_SIZE (DECL)) \
315 size_directive_output = 1; \
316 size = int_size_in_bytes (TREE_TYPE (DECL)); \
317 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \
320 ASM_OUTPUT_LABEL (FILE, NAME); \
324 /* Output the size directive for a decl in rest_of_decl_compilation
325 in the case where we did not do so before the initializer.
326 Once we find the error_mark_node, we know that the value of
327 size_directive_output was set
328 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */
330 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\
333 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \
334 HOST_WIDE_INT size; \
336 if (!flag_inhibit_size_directive \
337 && DECL_SIZE (DECL) \
338 && ! AT_END && TOP_LEVEL \
339 && DECL_INITIAL (DECL) == error_mark_node \
340 && !size_directive_output) \
342 size_directive_output = 1; \
343 size = int_size_in_bytes (TREE_TYPE (DECL)); \
344 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \
349 /* This is how to declare the size of a function. */
350 #ifndef ASM_DECLARE_FUNCTION_SIZE
351 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
354 if (!flag_inhibit_size_directive) \
355 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \
360 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and
361 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table
362 corresponds to a particular byte value [0..255]. For any
363 given byte value, if the value in the corresponding table
364 position is zero, the given character can be output directly.
365 If the table value is 1, the byte must be output as a \ooo
366 octal escape. If the tables value is anything else, then the
367 byte value should be output as a \ followed by the value
368 in the table. Note that we can use standard UN*X escape
369 sequences for many control characters, but we don't use
370 \a to represent BEL because some svr4 assemblers (e.g. on
371 the i386) don't know about that. Also, we don't use \v
372 since some versions of gas, such as 2.2 did not accept it. */
375 "\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\
376 \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\
377 \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\
378 \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\
379 \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\
380 \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\
381 \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\
382 \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"
384 /* Some svr4 assemblers have a limit on the number of characters which
385 can appear in the operand of a .string directive. If your assembler
386 has such a limitation, you should define STRING_LIMIT to reflect that
387 limit. Note that at least some svr4 assemblers have a limit on the
388 actual number of bytes in the double-quoted string, and that they
389 count each character in an escape sequence as one byte. Thus, an
390 escape sequence like \377 would count as four bytes.
392 If your target assembler doesn't support the .string directive, you
393 should define this to zero.
396 #define STRING_LIMIT ((unsigned) 256)
398 #define STRING_ASM_OP "\t.string\t"
400 /* The routine used to output NUL terminated strings. We use a special
401 version of this for most svr4 targets because doing so makes the
402 generated assembly code more compact (and thus faster to assemble)
403 as well as more readable, especially for targets like the i386
404 (where the only alternative is to output character sequences as
405 comma separated lists of numbers). */
407 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \
410 register const unsigned char *_limited_str = \
411 (const unsigned char *) (STR); \
412 register unsigned ch; \
414 fprintf ((FILE), "%s\"", STRING_ASM_OP); \
416 for (; (ch = *_limited_str); _limited_str++) \
418 register int escape; \
420 switch (escape = ESCAPES[ch]) \
426 fprintf ((FILE), "\\%03o", ch); \
429 putc ('\\', (FILE)); \
430 putc (escape, (FILE)); \
435 fprintf ((FILE), "\"\n"); \
439 /* The routine used to output sequences of byte values. We use a special
440 version of this for most svr4 targets because doing so makes the
441 generated assembly code more compact (and thus faster to assemble)
442 as well as more readable. Note that if we find subparts of the
443 character sequence which end with NUL (and which are shorter than
444 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */
446 #undef ASM_OUTPUT_ASCII
447 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \
450 register const unsigned char *_ascii_bytes = \
451 (const unsigned char *) (STR); \
452 register const unsigned char *limit = _ascii_bytes + (LENGTH); \
453 register unsigned bytes_in_chunk = 0; \
455 for (; _ascii_bytes < limit; _ascii_bytes++) \
457 register const unsigned char *p; \
459 if (bytes_in_chunk >= 60) \
461 fprintf ((FILE), "\"\n"); \
462 bytes_in_chunk = 0; \
465 for (p = _ascii_bytes; p < limit && *p != '\0'; p++) \
468 if (p < limit && (p - _ascii_bytes) <= (long)STRING_LIMIT) \
470 if (bytes_in_chunk > 0) \
472 fprintf ((FILE), "\"\n"); \
473 bytes_in_chunk = 0; \
476 ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes); \
481 register int escape; \
482 register unsigned ch; \
484 if (bytes_in_chunk == 0) \
485 fprintf ((FILE), "%s\"", ASCII_DATA_ASM_OP); \
487 switch (escape = ESCAPES[ch = *_ascii_bytes]) \
494 fprintf ((FILE), "\\%03o", ch); \
495 bytes_in_chunk += 4; \
498 putc ('\\', (FILE)); \
499 putc (escape, (FILE)); \
500 bytes_in_chunk += 2; \
506 if (bytes_in_chunk > 0) \
507 fprintf ((FILE), "\"\n"); \