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, 2003, 2004,
4 2007, 2009 Free Software Foundation, Inc.
5 Based on svr4.h contributed by Ron Guilmette (rfg@netcom.com).
7 This file is part of GCC.
9 GCC 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 3, or (at your option)
14 GCC 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 Under Section 7 of GPL version 3, you are granted additional
20 permissions described in the GCC Runtime Library Exception, version
21 3.1, as published by the Free Software Foundation.
23 You should have received a copy of the GNU General Public License and
24 a copy of the GCC Runtime Library Exception along with this program;
25 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
26 <http://www.gnu.org/licenses/>. */
28 #define TARGET_OBJFMT_CPP_BUILTINS() \
31 builtin_define ("__ELF__"); \
35 /* Define a symbol indicating that we are using elfos.h.
36 Some CPU specific configuration files use this. */
39 /* The prefix to add to user-visible assembler symbols.
41 For ELF systems the convention is *not* to prepend a leading
42 underscore onto user-level symbol names. */
44 #undef USER_LABEL_PREFIX
45 #define USER_LABEL_PREFIX ""
47 /* The biggest alignment supported by ELF in bits. 32-bit ELF
48 supports section alignment up to (0x80000000 * 8), while
49 64-bit ELF supports (0x8000000000000000 * 8). If this macro
50 is not defined, the default is the largest alignment supported
51 by 32-bit ELF and representable on a 32-bit host. Use this
52 macro to limit the alignment which can be specified using
53 the `__attribute__ ((aligned (N)))' construct. */
54 #ifndef MAX_OFILE_ALIGNMENT
55 #define MAX_OFILE_ALIGNMENT (((unsigned int) 1 << 28) * 8)
58 /* Use periods rather than dollar signs in special g++ assembler names. */
60 #define NO_DOLLAR_IN_LABEL
62 /* Writing `int' for a bit-field forces int alignment for the structure. */
64 #ifndef PCC_BITFIELD_TYPE_MATTERS
65 #define PCC_BITFIELD_TYPE_MATTERS 1
68 /* Handle #pragma weak and #pragma pack. */
70 #define HANDLE_SYSV_PRAGMA 1
72 /* All ELF targets can support DWARF-2. */
74 #define DWARF2_DEBUGGING_INFO 1
76 /* The GNU tools operate better with dwarf2, and it is required by some
77 psABI's. Since we don't have any native tools to be compatible with,
80 #ifndef PREFERRED_DEBUGGING_TYPE
81 #define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
84 /* All SVR4 targets use the ELF object file format. */
85 #define OBJECT_FORMAT_ELF
88 /* Output #ident as a .ident. */
90 #define ASM_OUTPUT_IDENT(FILE, NAME) \
91 fprintf (FILE, "%s\"%s\"\n", IDENT_ASM_OP, NAME);
93 #define IDENT_ASM_OP "\t.ident\t"
96 #define SET_ASM_OP "\t.set\t"
98 /* Most svr4 assemblers want a .file directive at the beginning of
100 #define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
102 /* This is how to allocate empty space in some section. The .zero
103 pseudo-op is used for this on most svr4 assemblers. */
105 #define SKIP_ASM_OP "\t.zero\t"
107 #undef ASM_OUTPUT_SKIP
108 #define ASM_OUTPUT_SKIP(FILE, SIZE) \
109 fprintf ((FILE), "%s"HOST_WIDE_INT_PRINT_UNSIGNED"\n",\
112 /* This is how to store into the string LABEL
113 the symbol_ref name of an internal numbered label where
114 PREFIX is the class of label and NUM is the number within the class.
115 This is suitable for output with `assemble_name'.
117 For most svr4 systems, the convention is that any symbol which begins
118 with a period is not put into the linker symbol table by the assembler. */
120 #undef ASM_GENERATE_INTERNAL_LABEL
121 #define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
124 sprintf (LABEL, "*.%s%u", PREFIX, (unsigned) (NUM)); \
128 /* Output the label which precedes a jumptable. Note that for all svr4
129 systems where we actually generate jumptables (which is to say every
130 svr4 target except i386, where we use casesi instead) we put the jump-
131 tables into the .rodata section and since other stuff could have been
132 put into the .rodata section prior to any given jumptable, we have to
133 make sure that the location counter for the .rodata section gets pro-
134 perly re-aligned prior to the actual beginning of the jump table. */
137 #define ALIGN_ASM_OP "\t.align\t"
139 #ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
140 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
141 ASM_OUTPUT_ALIGN ((FILE), 2);
144 #undef ASM_OUTPUT_CASE_LABEL
145 #define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \
148 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE) \
149 (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM); \
153 /* The standard SVR4 assembler seems to require that certain builtin
154 library routines (e.g. .udiv) be explicitly declared as .globl
155 in each assembly file where they are referenced. */
157 #define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
158 (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0))
160 /* This says how to output assembler code to declare an
161 uninitialized external linkage data object. Under SVR4,
162 the linker seems to want the alignment of data objects
163 to depend on their types. We do exactly that here. */
165 #define COMMON_ASM_OP "\t.comm\t"
167 #undef ASM_OUTPUT_ALIGNED_COMMON
168 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
171 fprintf ((FILE), "%s", COMMON_ASM_OP); \
172 assemble_name ((FILE), (NAME)); \
173 fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", \
174 (SIZE), (ALIGN) / BITS_PER_UNIT); \
178 /* This says how to output assembler code to declare an
179 uninitialized internal linkage data object. Under SVR4,
180 the linker seems to want the alignment of data objects
181 to depend on their types. We do exactly that here. */
183 #define LOCAL_ASM_OP "\t.local\t"
185 #undef ASM_OUTPUT_ALIGNED_LOCAL
186 #define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
189 fprintf ((FILE), "%s", LOCAL_ASM_OP); \
190 assemble_name ((FILE), (NAME)); \
191 fprintf ((FILE), "\n"); \
192 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \
196 /* This is the pseudo-op used to generate a contiguous sequence of byte
197 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
198 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */
200 #undef ASCII_DATA_ASM_OP
201 #define ASCII_DATA_ASM_OP "\t.ascii\t"
203 /* Support a read-only data section. */
204 #define READONLY_DATA_SECTION_ASM_OP "\t.section\t.rodata"
206 /* On svr4, we *do* have support for the .init and .fini sections, and we
207 can put stuff in there to be executed before and after `main'. We let
208 crtstuff.c and other files know this by defining the following symbols.
209 The definitions say how to change sections to the .init and .fini
210 sections. This is the same for all known svr4 assemblers. */
212 #define INIT_SECTION_ASM_OP "\t.section\t.init"
213 #define FINI_SECTION_ASM_OP "\t.section\t.fini"
215 /* Output assembly directive to move to the beginning of current section. */
216 #ifdef HAVE_GAS_SUBSECTION_ORDERING
217 # define ASM_SECTION_START_OP "\t.subsection\t-1"
218 # define ASM_OUTPUT_SECTION_START(FILE) \
219 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP)
222 #define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
224 /* Switch into a generic section. */
225 #define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
227 #undef TARGET_ASM_SELECT_RTX_SECTION
228 #define TARGET_ASM_SELECT_RTX_SECTION default_elf_select_rtx_section
229 #undef TARGET_ASM_SELECT_SECTION
230 #define TARGET_ASM_SELECT_SECTION default_elf_select_section
231 #undef TARGET_HAVE_SWITCHABLE_BSS_SECTIONS
232 #define TARGET_HAVE_SWITCHABLE_BSS_SECTIONS true
234 /* Define the strings used for the special svr4 .type and .size directives.
235 These strings generally do not vary from one system running svr4 to
236 another, but if a given system (e.g. m88k running svr) needs to use
237 different pseudo-op names for these, they may be overridden in the
238 file which includes this one. */
240 #define TYPE_ASM_OP "\t.type\t"
241 #define SIZE_ASM_OP "\t.size\t"
243 /* This is how we tell the assembler that a symbol is weak. */
245 #define ASM_WEAKEN_LABEL(FILE, NAME) \
248 fputs ("\t.weak\t", (FILE)); \
249 assemble_name ((FILE), (NAME)); \
250 fputc ('\n', (FILE)); \
254 /* The following macro defines the format used to output the second
255 operand of the .type assembler directive. Different svr4 assemblers
256 expect various different forms for this operand. The one given here
257 is just a default. You may need to override it in your machine-
258 specific tm.h file (depending upon the particulars of your assembler). */
260 #define TYPE_OPERAND_FMT "@%s"
262 /* Write the extra assembler code needed to declare a function's result.
263 Most svr4 assemblers don't require any special declaration of the
264 result value, but there are exceptions. */
266 #ifndef ASM_DECLARE_RESULT
267 #define ASM_DECLARE_RESULT(FILE, RESULT)
270 /* These macros generate the special .type and .size directives which
271 are used to set the corresponding fields of the linker symbol table
272 entries in an ELF object file under SVR4. These macros also output
273 the starting labels for the relevant functions/objects. */
275 /* Write the extra assembler code needed to declare a function properly.
276 Some svr4 assemblers need to also have something extra said about the
277 function's return value. We allow for that here. */
279 #ifndef ASM_DECLARE_FUNCTION_NAME
280 #define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
283 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \
284 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
285 ASM_OUTPUT_LABEL (FILE, NAME); \
290 /* Write the extra assembler code needed to declare an object properly. */
292 #ifdef HAVE_GAS_GNU_UNIQUE_OBJECT
293 #define USE_GNU_UNIQUE_OBJECT 1
295 #define USE_GNU_UNIQUE_OBJECT 0
298 #define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \
301 HOST_WIDE_INT size; \
303 /* For template static data member instantiations or \
304 inline fn local statics, use gnu_unique_object so that \
305 they will be combined even under RTLD_LOCAL. */ \
306 if (USE_GNU_UNIQUE_OBJECT \
307 && !DECL_ARTIFICIAL (DECL) && DECL_ONE_ONLY (DECL)) \
308 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \
310 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \
312 size_directive_output = 0; \
313 if (!flag_inhibit_size_directive \
314 && (DECL) && DECL_SIZE (DECL)) \
316 size_directive_output = 1; \
317 size = int_size_in_bytes (TREE_TYPE (DECL)); \
318 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \
321 ASM_OUTPUT_LABEL (FILE, NAME); \
325 /* Output the size directive for a decl in rest_of_decl_compilation
326 in the case where we did not do so before the initializer.
327 Once we find the error_mark_node, we know that the value of
328 size_directive_output was set
329 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */
331 #undef ASM_FINISH_DECLARE_OBJECT
332 #define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\
335 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \
336 HOST_WIDE_INT size; \
338 if (!flag_inhibit_size_directive \
339 && DECL_SIZE (DECL) \
340 && ! AT_END && TOP_LEVEL \
341 && DECL_INITIAL (DECL) == error_mark_node \
342 && !size_directive_output) \
344 size_directive_output = 1; \
345 size = int_size_in_bytes (TREE_TYPE (DECL)); \
346 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \
351 /* This is how to declare the size of a function. */
352 #ifndef ASM_DECLARE_FUNCTION_SIZE
353 #define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
356 if (!flag_inhibit_size_directive) \
357 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \
362 /* A table of bytes codes used by the ASM_OUTPUT_ASCII and
363 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table
364 corresponds to a particular byte value [0..255]. For any
365 given byte value, if the value in the corresponding table
366 position is zero, the given character can be output directly.
367 If the table value is 1, the byte must be output as a \ooo
368 octal escape. If the tables value is anything else, then the
369 byte value should be output as a \ followed by the value
370 in the table. Note that we can use standard UN*X escape
371 sequences for many control characters, but we don't use
372 \a to represent BEL because some svr4 assemblers (e.g. on
373 the i386) don't know about that. Also, we don't use \v
374 since some versions of gas, such as 2.2 did not accept it. */
377 "\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\
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\
379 \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\
380 \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\
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\
383 \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 \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"
386 /* Some svr4 assemblers have a limit on the number of characters which
387 can appear in the operand of a .string directive. If your assembler
388 has such a limitation, you should define STRING_LIMIT to reflect that
389 limit. Note that at least some svr4 assemblers have a limit on the
390 actual number of bytes in the double-quoted string, and that they
391 count each character in an escape sequence as one byte. Thus, an
392 escape sequence like \377 would count as four bytes.
394 If your target assembler doesn't support the .string directive, you
395 should define this to zero.
398 #define STRING_LIMIT ((unsigned) 256)
400 #define STRING_ASM_OP "\t.string\t"
402 /* The routine used to output NUL terminated strings. We use a special
403 version of this for most svr4 targets because doing so makes the
404 generated assembly code more compact (and thus faster to assemble)
405 as well as more readable, especially for targets like the i386
406 (where the only alternative is to output character sequences as
407 comma separated lists of numbers). */
409 #define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \
412 register const unsigned char *_limited_str = \
413 (const unsigned char *) (STR); \
414 register unsigned ch; \
416 fprintf ((FILE), "%s\"", STRING_ASM_OP); \
418 for (; (ch = *_limited_str); _limited_str++) \
420 register int escape; \
422 switch (escape = ESCAPES[ch]) \
428 fprintf ((FILE), "\\%03o", ch); \
431 putc ('\\', (FILE)); \
432 putc (escape, (FILE)); \
437 fprintf ((FILE), "\"\n"); \
441 /* The routine used to output sequences of byte values. We use a special
442 version of this for most svr4 targets because doing so makes the
443 generated assembly code more compact (and thus faster to assemble)
444 as well as more readable. Note that if we find subparts of the
445 character sequence which end with NUL (and which are shorter than
446 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */
448 #undef ASM_OUTPUT_ASCII
449 #define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \
452 const unsigned char *_ascii_bytes = \
453 (const unsigned char *) (STR); \
454 const unsigned char *limit = _ascii_bytes + (LENGTH); \
455 const unsigned char *last_null = NULL; \
456 unsigned bytes_in_chunk = 0; \
458 for (; _ascii_bytes < limit; _ascii_bytes++) \
460 const unsigned char *p; \
462 if (bytes_in_chunk >= 60) \
464 fprintf ((FILE), "\"\n"); \
465 bytes_in_chunk = 0; \
468 if (_ascii_bytes > last_null) \
470 for (p = _ascii_bytes; p < limit && *p != '\0'; p++) \
477 if (p < limit && (p - _ascii_bytes) <= (long)STRING_LIMIT) \
479 if (bytes_in_chunk > 0) \
481 fprintf ((FILE), "\"\n"); \
482 bytes_in_chunk = 0; \
485 ASM_OUTPUT_LIMITED_STRING ((FILE), _ascii_bytes); \
490 register int escape; \
491 register unsigned ch; \
493 if (bytes_in_chunk == 0) \
494 fprintf ((FILE), "%s\"", ASCII_DATA_ASM_OP); \
496 switch (escape = ESCAPES[ch = *_ascii_bytes]) \
503 fprintf ((FILE), "\\%03o", ch); \
504 bytes_in_chunk += 4; \
507 putc ('\\', (FILE)); \
508 putc (escape, (FILE)); \
509 bytes_in_chunk += 2; \
515 if (bytes_in_chunk > 0) \
516 fprintf ((FILE), "\"\n"); \
520 /* Allow the use of the -frecord-gcc-switches switch via the
521 elf_record_gcc_switches function defined in varasm.c. */
522 #undef TARGET_ASM_RECORD_GCC_SWITCHES
523 #define TARGET_ASM_RECORD_GCC_SWITCHES elf_record_gcc_switches
525 /* A C statement (sans semicolon) to output to the stdio stream STREAM
526 any text necessary for declaring the name of an external symbol
527 named NAME which is referenced in this compilation but not defined.
528 It is needed to properly support non-default visibility. */
530 #ifndef ASM_OUTPUT_EXTERNAL
531 #define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
532 default_elf_asm_output_external (FILE, DECL, NAME)