1/* elfos.h -- operating system specific defines to be used when
2 targeting GCC for some generic ELF system
3 Copyright (C) 1991-2017 Free Software Foundation, Inc.
4 Based on svr4.h contributed by Ron Guilmette (rfg@netcom.com).
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16GNU General Public License for more details.
17
18Under Section 7 of GPL version 3, you are granted additional
19permissions described in the GCC Runtime Library Exception, version
203.1, as published by the Free Software Foundation.
21
22You should have received a copy of the GNU General Public License and
23a copy of the GCC Runtime Library Exception along with this program;
24see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25<http://www.gnu.org/licenses/>. */
26
27#define TARGET_OBJFMT_CPP_BUILTINS() \
28 do \
29 { \
30 builtin_define ("__ELF__"); \
31 } \
32 while (0)
33
34/* Define a symbol indicating that we are using elfos.h.
35 Some CPU specific configuration files use this. */
36#define USING_ELFOS_H
37
38/* The prefix to add to user-visible assembler symbols.
39
40 For ELF systems the convention is *not* to prepend a leading
41 underscore onto user-level symbol names. */
42
43#undef USER_LABEL_PREFIX
44#define USER_LABEL_PREFIX ""
45
46/* The biggest alignment supported by ELF in bits. 32-bit ELF
47 supports section alignment up to (0x80000000 * 8), while
48 64-bit ELF supports (0x8000000000000000 * 8). If this macro
49 is not defined, the default is the largest alignment supported
50 by 32-bit ELF and representable on a 32-bit host. Use this
51 macro to limit the alignment which can be specified using
52 the `__attribute__ ((aligned (N)))' construct. */
53#ifndef MAX_OFILE_ALIGNMENT
54#define MAX_OFILE_ALIGNMENT (((unsigned int) 1 << 28) * 8)
55#endif
56
57/* Use periods rather than dollar signs in special g++ assembler names. */
58
59#define NO_DOLLAR_IN_LABEL
60
61/* Writing `int' for a bit-field forces int alignment for the structure. */
62
63#ifndef PCC_BITFIELD_TYPE_MATTERS
64#define PCC_BITFIELD_TYPE_MATTERS 1
65#endif
66
67/* All ELF targets can support DWARF-2. */
68
69#define DWARF2_DEBUGGING_INFO 1
70
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,
73 default to dwarf2. */
74
75#ifndef PREFERRED_DEBUGGING_TYPE
76#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
77#endif
78
79/* All SVR4 targets use the ELF object file format. */
80#define OBJECT_FORMAT_ELF
81
82
83/* Output #ident as a .ident. */
84
85#undef TARGET_ASM_OUTPUT_IDENT
86#define TARGET_ASM_OUTPUT_IDENT default_asm_output_ident_directive
87
88#undef SET_ASM_OP
89#define SET_ASM_OP "\t.set\t"
90
91/* Most svr4 assemblers want a .file directive at the beginning of
92 their input file. */
93#define TARGET_ASM_FILE_START_FILE_DIRECTIVE true
94
95/* This is how to allocate empty space in some section. The .zero
96 pseudo-op is used for this on most svr4 assemblers. */
97
98#define SKIP_ASM_OP "\t.zero\t"
99
100#undef ASM_OUTPUT_SKIP
101#define ASM_OUTPUT_SKIP(FILE, SIZE) \
102 fprintf ((FILE), "%s" HOST_WIDE_INT_PRINT_UNSIGNED "\n",\
103 SKIP_ASM_OP, (SIZE))
104
105/* This is how to store into the string LABEL
106 the symbol_ref name of an internal numbered label where
107 PREFIX is the class of label and NUM is the number within the class.
108 This is suitable for output with `assemble_name'.
109
110 For most svr4 systems, the convention is that any symbol which begins
111 with a period is not put into the linker symbol table by the assembler. */
112
113#undef ASM_GENERATE_INTERNAL_LABEL
114#define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
115 do \
116 { \
117 char *__p; \
118 (LABEL)[0] = '*'; \
119 (LABEL)[1] = '.'; \
120 __p = stpcpy (&(LABEL)[2], PREFIX); \
121 sprint_ul (__p, (unsigned long) (NUM)); \
122 } \
123 while (0)
124
125/* Output the label which precedes a jumptable. Note that for all svr4
126 systems where we actually generate jumptables (which is to say every
127 svr4 target except i386, where we use casesi instead) we put the jump-
128 tables into the .rodata section and since other stuff could have been
129 put into the .rodata section prior to any given jumptable, we have to
130 make sure that the location counter for the .rodata section gets pro-
131 perly re-aligned prior to the actual beginning of the jump table. */
132
133#undef ALIGN_ASM_OP
134#define ALIGN_ASM_OP "\t.align\t"
135
136#ifndef ASM_OUTPUT_BEFORE_CASE_LABEL
137#define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE, PREFIX, NUM, TABLE) \
138 ASM_OUTPUT_ALIGN ((FILE), 2)
139#endif
140
141#undef ASM_OUTPUT_CASE_LABEL
142#define ASM_OUTPUT_CASE_LABEL(FILE, PREFIX, NUM, JUMPTABLE) \
143 do \
144 { \
145 ASM_OUTPUT_BEFORE_CASE_LABEL (FILE, PREFIX, NUM, JUMPTABLE); \
146 (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM); \
147 } \
148 while (0)
149
150/* The standard SVR4 assembler seems to require that certain builtin
151 library routines (e.g. .udiv) be explicitly declared as .globl
152 in each assembly file where they are referenced. */
153
154#define ASM_OUTPUT_EXTERNAL_LIBCALL(FILE, FUN) \
155 (*targetm.asm_out.globalize_label) (FILE, XSTR (FUN, 0))
156
157/* This says how to output assembler code to declare an
158 uninitialized external linkage data object. Under SVR4,
159 the linker seems to want the alignment of data objects
160 to depend on their types. We do exactly that here. */
161
162#define COMMON_ASM_OP "\t.comm\t"
163
164#undef ASM_OUTPUT_ALIGNED_COMMON
165#define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
166 do \
167 { \
168 fprintf ((FILE), "%s", COMMON_ASM_OP); \
169 assemble_name ((FILE), (NAME)); \
170 fprintf ((FILE), "," HOST_WIDE_INT_PRINT_UNSIGNED ",%u\n", \
171 (SIZE), (ALIGN) / BITS_PER_UNIT); \
172 } \
173 while (0)
174
175/* This says how to output assembler code to declare an
176 uninitialized internal 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. */
179
180#define LOCAL_ASM_OP "\t.local\t"
181
182#undef ASM_OUTPUT_ALIGNED_LOCAL
183#define ASM_OUTPUT_ALIGNED_LOCAL(FILE, NAME, SIZE, ALIGN) \
184 do \
185 { \
186 fprintf ((FILE), "%s", LOCAL_ASM_OP); \
187 assemble_name ((FILE), (NAME)); \
188 fprintf ((FILE), "\n"); \
189 ASM_OUTPUT_ALIGNED_COMMON (FILE, NAME, SIZE, ALIGN); \
190 } \
191 while (0)
192
193/* This is the pseudo-op used to generate a contiguous sequence of byte
194 values from a double-quoted string WITHOUT HAVING A TERMINATING NUL
195 AUTOMATICALLY APPENDED. This is the same for most svr4 assemblers. */
196
197#undef ASCII_DATA_ASM_OP
198#define ASCII_DATA_ASM_OP "\t.ascii\t"
199
200/* Support a read-only data section. */
201#define READONLY_DATA_SECTION_ASM_OP "\t.section\t.rodata"
202
203/* On svr4, we *do* have support for the .init and .fini sections, and we
204 can put stuff in there to be executed before and after `main'. We let
205 crtstuff.c and other files know this by defining the following symbols.
206 The definitions say how to change sections to the .init and .fini
207 sections. This is the same for all known svr4 assemblers. */
208
209#define INIT_SECTION_ASM_OP "\t.section\t.init"
210#define FINI_SECTION_ASM_OP "\t.section\t.fini"
211
212/* Output assembly directive to move to the beginning of current section. */
213#ifdef HAVE_GAS_SUBSECTION_ORDERING
214# define ASM_SECTION_START_OP "\t.subsection\t-1"
215# define ASM_OUTPUT_SECTION_START(FILE) \
216 fprintf ((FILE), "%s\n", ASM_SECTION_START_OP)
217#endif
218
219#define MAKE_DECL_ONE_ONLY(DECL) (DECL_WEAK (DECL) = 1)
220
221/* Switch into a generic section. */
222#define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
223
224#undef TARGET_ASM_SELECT_RTX_SECTION
225#define TARGET_ASM_SELECT_RTX_SECTION default_elf_select_rtx_section
226#undef TARGET_ASM_SELECT_SECTION
227#define TARGET_ASM_SELECT_SECTION default_elf_select_section
228#undef TARGET_HAVE_SWITCHABLE_BSS_SECTIONS
229#define TARGET_HAVE_SWITCHABLE_BSS_SECTIONS true
230
231/* Define the strings used for the special svr4 .type and .size directives.
232 These strings generally do not vary from one system running svr4 to
233 another, but if a given system (e.g. m88k running svr) needs to use
234 different pseudo-op names for these, they may be overridden in the
235 file which includes this one. */
236
237#define TYPE_ASM_OP "\t.type\t"
238#define SIZE_ASM_OP "\t.size\t"
239
240/* This is how we tell the assembler that a symbol is weak. */
241
242#define ASM_WEAKEN_LABEL(FILE, NAME) \
243 do \
244 { \
245 fputs ("\t.weak\t", (FILE)); \
246 assemble_name ((FILE), (NAME)); \
247 fputc ('\n', (FILE)); \
248 } \
249 while (0)
250
251/* The following macro defines the format used to output the second
252 operand of the .type assembler directive. Different svr4 assemblers
253 expect various different forms for this operand. The one given here
254 is just a default. You may need to override it in your machine-
255 specific tm.h file (depending upon the particulars of your assembler). */
256
257#define TYPE_OPERAND_FMT "@%s"
258
259/* Write the extra assembler code needed to declare a function's result.
260 Most svr4 assemblers don't require any special declaration of the
261 result value, but there are exceptions. */
262
263#ifndef ASM_DECLARE_RESULT
264#define ASM_DECLARE_RESULT(FILE, RESULT)
265#endif
266
267/* These macros generate the special .type and .size directives which
268 are used to set the corresponding fields of the linker symbol table
269 entries in an ELF object file under SVR4. These macros also output
270 the starting labels for the relevant functions/objects. */
271
272/* Write the extra assembler code needed to declare a function properly.
273 Some svr4 assemblers need to also have something extra said about the
274 function's return value. We allow for that here. */
275
276#ifndef ASM_DECLARE_FUNCTION_NAME
277#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \
278 do \
279 { \
280 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \
281 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
282 ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL); \
283 } \
284 while (0)
285#endif
286
287/* Write the extra assembler code needed to declare the name of a
288 cold function partition properly. Some svr4 assemblers need to also
289 have something extra said about the function's return value. We
290 allow for that here. */
291
292#ifndef ASM_DECLARE_COLD_FUNCTION_NAME
293#define ASM_DECLARE_COLD_FUNCTION_NAME(FILE, NAME, DECL) \
294 do \
295 { \
296 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \
297 ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \
298 ASM_OUTPUT_FUNCTION_LABEL (FILE, NAME, DECL); \
299 } \
300 while (0)
301#endif
302
303/* Write the extra assembler code needed to declare an object properly. */
304
305#ifdef HAVE_GAS_GNU_UNIQUE_OBJECT
306#define USE_GNU_UNIQUE_OBJECT flag_gnu_unique
307#else
308#define USE_GNU_UNIQUE_OBJECT 0
309#endif
310
311#define ASM_DECLARE_OBJECT_NAME(FILE, NAME, DECL) \
312 do \
313 { \
314 HOST_WIDE_INT size; \
315 \
316 /* For template static data member instantiations or \
317 inline fn local statics and their guard variables, use \
318 gnu_unique_object so that they will be combined even under \
319 RTLD_LOCAL. Don't use gnu_unique_object for typeinfo, \
320 vtables and other read-only artificial decls. */ \
321 if (USE_GNU_UNIQUE_OBJECT && DECL_ONE_ONLY (DECL) \
322 && (!DECL_ARTIFICIAL (DECL) || !TREE_READONLY (DECL))) \
323 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \
324 else \
325 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \
326 \
327 size_directive_output = 0; \
328 if (!flag_inhibit_size_directive \
329 && (DECL) && DECL_SIZE (DECL)) \
330 { \
331 size_directive_output = 1; \
332 size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \
333 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, size); \
334 } \
335 \
336 ASM_OUTPUT_LABEL (FILE, NAME); \
337 } \
338 while (0)
339
340/* Output the size directive for a decl in rest_of_decl_compilation
341 in the case where we did not do so before the initializer.
342 Once we find the error_mark_node, we know that the value of
343 size_directive_output was set
344 by ASM_DECLARE_OBJECT_NAME when it was run for the same decl. */
345
346#undef ASM_FINISH_DECLARE_OBJECT
347#define ASM_FINISH_DECLARE_OBJECT(FILE, DECL, TOP_LEVEL, AT_END)\
348 do \
349 { \
350 const char *name = XSTR (XEXP (DECL_RTL (DECL), 0), 0); \
351 HOST_WIDE_INT size; \
352 \
353 if (!flag_inhibit_size_directive \
354 && DECL_SIZE (DECL) \
355 && ! AT_END && TOP_LEVEL \
356 && DECL_INITIAL (DECL) == error_mark_node \
357 && !size_directive_output) \
358 { \
359 size_directive_output = 1; \
360 size = tree_to_uhwi (DECL_SIZE_UNIT (DECL)); \
361 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, name, size); \
362 } \
363 } \
364 while (0)
365
366/* This is how to declare the size of a function. */
367#ifndef ASM_DECLARE_FUNCTION_SIZE
368#define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
369 do \
370 { \
371 if (!flag_inhibit_size_directive) \
372 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \
373 } \
374 while (0)
375#endif
376
377/* This is how to declare the size of a cold function partition. */
378#ifndef ASM_DECLARE_COLD_FUNCTION_SIZE
379#define ASM_DECLARE_COLD_FUNCTION_SIZE(FILE, FNAME, DECL) \
380 do \
381 { \
382 if (!flag_inhibit_size_directive) \
383 ASM_OUTPUT_MEASURED_SIZE (FILE, FNAME); \
384 } \
385 while (0)
386#endif
387
388/* A table of bytes codes used by the ASM_OUTPUT_ASCII and
389 ASM_OUTPUT_LIMITED_STRING macros. Each byte in the table
390 corresponds to a particular byte value [0..255]. For any
391 given byte value, if the value in the corresponding table
392 position is zero, the given character can be output directly.
393 If the table value is 1, the byte must be output as a \ooo
394 octal escape. If the tables value is anything else, then the
395 byte value should be output as a \ followed by the value
396 in the table. Note that we can use standard UN*X escape
397 sequences for many control characters, but we don't use
398 \a to represent BEL because some svr4 assemblers (e.g. on
399 the i386) don't know about that. Also, we don't use \v
400 since some versions of gas, such as 2.2 did not accept it. */
401
402#define ELF_ASCII_ESCAPES \
403"\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\
404\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\
405\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\
406\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\
407\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\
408\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\
409\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\
410\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"
411
412/* Some svr4 assemblers have a limit on the number of characters which
413 can appear in the operand of a .string directive. If your assembler
414 has such a limitation, you should define STRING_LIMIT to reflect that
415 limit. Note that at least some svr4 assemblers have a limit on the
416 actual number of bytes in the double-quoted string, and that they
417 count each character in an escape sequence as one byte. Thus, an
418 escape sequence like \377 would count as four bytes.
419
420 If your target assembler doesn't support the .string directive, you
421 should define this to zero.
422*/
423
424#define ELF_STRING_LIMIT ((unsigned) 256)
425
426#define STRING_ASM_OP "\t.string\t"
427
428/* The routine used to output NUL terminated strings. We use a special
429 version of this for most svr4 targets because doing so makes the
430 generated assembly code more compact (and thus faster to assemble)
431 as well as more readable, especially for targets like the i386
432 (where the only alternative is to output character sequences as
433 comma separated lists of numbers). */
434
435#define ASM_OUTPUT_LIMITED_STRING(FILE, STR) \
436 default_elf_asm_output_limited_string ((FILE), (STR))
437
438/* The routine used to output sequences of byte values. We use a special
439 version of this for most svr4 targets because doing so makes the
440 generated assembly code more compact (and thus faster to assemble)
441 as well as more readable. Note that if we find subparts of the
442 character sequence which end with NUL (and which are shorter than
443 STRING_LIMIT) we output those using ASM_OUTPUT_LIMITED_STRING. */
444
445#undef ASM_OUTPUT_ASCII
446#define ASM_OUTPUT_ASCII(FILE, STR, LENGTH) \
447 default_elf_asm_output_ascii ((FILE), (STR), (LENGTH))
448
449/* Allow the use of the -frecord-gcc-switches switch via the
450 elf_record_gcc_switches function defined in varasm.c. */
451#undef TARGET_ASM_RECORD_GCC_SWITCHES
452#define TARGET_ASM_RECORD_GCC_SWITCHES elf_record_gcc_switches
453
454/* A C statement (sans semicolon) to output to the stdio stream STREAM
455 any text necessary for declaring the name of an external symbol
456 named NAME which is referenced in this compilation but not defined.
457 It is needed to properly support non-default visibility. */
458
459#ifndef ASM_OUTPUT_EXTERNAL
460#define ASM_OUTPUT_EXTERNAL(FILE, DECL, NAME) \
461 default_elf_asm_output_external (FILE, DECL, NAME)
462#endif
463
464#undef TARGET_LIBC_HAS_FUNCTION
465#define TARGET_LIBC_HAS_FUNCTION no_c99_libc_has_function
466