1 /* Declarations for insn-output.cc and other code to write to asm_out_file.
2 These functions are defined in final.cc, and varasm.cc.
3 Copyright (C) 1987-2022 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
24 /* Initialize data in final at the beginning of a compilation. */
25 extern void init_final (const char *);
27 /* Enable APP processing of subsequent output.
28 Used before the output from an `asm' statement. */
29 extern void app_enable (void);
31 /* Disable APP processing of subsequent output.
32 Called from varasm.cc before most kinds of output. */
33 extern void app_disable (void);
35 /* Return the number of slots filled in the current
36 delayed branch sequence (we don't count the insn needing the
37 delay slot). Zero if not in a delayed branch sequence. */
38 extern int dbr_sequence_length (void);
40 /* Indicate that branch shortening hasn't yet been done. */
41 extern void init_insn_lengths (void);
43 /* Obtain the current length of an insn. If branch shortening has been done,
44 get its actual length. Otherwise, get its maximum length. */
45 extern int get_attr_length (rtx_insn *);
47 /* Obtain the current length of an insn. If branch shortening has been done,
48 get its actual length. Otherwise, get its minimum length. */
49 extern int get_attr_min_length (rtx_insn *);
51 /* Make a pass over all insns and compute their actual lengths by shortening
52 any branches of variable length if possible. */
53 extern void shorten_branches (rtx_insn *);
55 const char *get_some_local_dynamic_name ();
57 /* Output assembler code for the start of a function,
58 and initialize some of the variables in this file
59 for the new function. The label for the function and associated
60 assembler pseudo-ops have already been output in
61 `assemble_start_function'. */
62 extern void final_start_function (rtx_insn *, FILE *, int);
64 /* Output assembler code for the end of a function.
65 For clarity, args are same as those of `final_start_function'
66 even though not all of them are needed. */
67 extern void final_end_function (void);
69 /* Output assembler code for some insns: all or part of a function. */
70 extern void final (rtx_insn *, FILE *, int);
72 /* The final scan for one insn, INSN. Args are same as in `final', except
73 that INSN is the insn being scanned. Value returned is the next insn to
75 extern rtx_insn *final_scan_insn (rtx_insn *, FILE *, int, int, int *);
77 /* Replace a SUBREG with a REG or a MEM, based on the thing it is a
79 extern rtx alter_subreg (rtx *, bool);
81 /* Print an operand using machine-dependent assembler syntax. */
82 extern void output_operand (rtx, int);
84 /* Report inconsistency between the assembler template and the operands.
85 In an `asm', it's the user's fault; otherwise, the compiler's fault. */
86 extern void output_operand_lossage (const char *, ...) ATTRIBUTE_PRINTF_1;
88 /* Output a string of assembler code, substituting insn operands.
89 Defined in final.cc. */
90 extern void output_asm_insn (const char *, rtx *);
92 /* Compute a worst-case reference address of a branch so that it
93 can be safely used in the presence of aligned labels.
94 Defined in final.cc. */
95 extern int insn_current_reference_address (rtx_insn *);
97 /* Find the alignment associated with a CODE_LABEL.
98 Defined in final.cc. */
99 extern align_flags label_to_alignment (rtx);
101 /* Output a LABEL_REF, or a bare CODE_LABEL, as an assembler symbol. */
102 extern void output_asm_label (rtx);
104 /* Marks SYMBOL_REFs in x as referenced through use of assemble_external. */
105 extern void mark_symbol_refs_as_used (rtx);
107 /* Print a memory reference operand for address X with access mode MODE
108 using machine-dependent assembler syntax. */
109 extern void output_address (machine_mode, rtx);
111 /* Print an integer constant expression in assembler syntax.
112 Addition and subtraction are the only arithmetic
113 that may appear in these expressions. */
114 extern void output_addr_const (FILE *, rtx);
116 /* Output a string of assembler code, substituting numbers, strings
117 and fixed syntactic prefixes. */
118 #if GCC_VERSION >= 3004
119 #define ATTRIBUTE_ASM_FPRINTF(m, n) __attribute__ ((__format__ (__asm_fprintf__, m, n))) ATTRIBUTE_NONNULL(m)
121 #define ATTRIBUTE_ASM_FPRINTF(m, n) ATTRIBUTE_NONNULL(m)
124 extern void fprint_whex (FILE *, unsigned HOST_WIDE_INT);
125 extern void fprint_ul (FILE *, unsigned long);
126 extern int sprint_ul (char *, unsigned long);
128 extern void asm_fprintf (FILE *file, const char *p, ...)
129 ATTRIBUTE_ASM_FPRINTF(2, 3);
131 /* Return nonzero if this function has no function calls. */
132 extern int leaf_function_p (void);
134 /* Return 1 if branch is a forward branch.
135 Uses insn_shuid array, so it works only in the final pass. May be used by
136 output templates to add branch prediction hints, for example. */
137 extern int final_forward_branch_p (rtx_insn *);
139 /* Return 1 if this function uses only the registers that can be
140 safely renumbered. */
141 extern int only_leaf_regs_used (void);
143 /* Scan IN_RTX and its subexpressions, and renumber all regs into those
144 available in leaf functions. */
145 extern void leaf_renumber_regs_insn (rtx);
147 /* Locate the proper template for the given insn-code. */
148 extern const char *get_insn_template (int, rtx_insn *);
150 /* Functions in varasm.cc. */
152 /* Emit any pending weak declarations. */
153 extern void weak_finish (void);
155 /* Decode an `asm' spec for a declaration as a register name.
156 Return the register number, or -1 if nothing specified,
157 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
158 or -3 if ASMSPEC is `cc' and is not recognized,
159 or -4 if ASMSPEC is `memory' and is not recognized.
160 Accept an exact spelling or a decimal number.
161 Prefixes such as % are optional. */
162 extern int decode_reg_name (const char *);
164 /* Similar to decode_reg_name, but takes an extra parameter that is a
165 pointer to the number of (internal) registers described by the
167 extern int decode_reg_name_and_count (const char *, int *);
169 extern void do_assemble_alias (tree, tree);
170 extern void do_assemble_symver (tree, tree);
172 extern void default_assemble_visibility (tree, int);
174 /* Output a string of literal assembler code
175 for an `asm' keyword used between functions. */
176 extern void assemble_asm (tree);
178 /* Get the function's name from a decl, as described by its RTL. */
179 extern const char *get_fnname_from_decl (tree);
181 /* Output assembler code for the constant pool of a function and associated
182 with defining the name of the function. DECL describes the function.
183 NAME is the function's name. For the constant pool, we use the current
184 constant pool data. */
185 extern void assemble_start_function (tree, const char *);
187 /* Output assembler code associated with defining the size of the
188 function. DECL describes the function. NAME is the function's name. */
189 extern void assemble_end_function (tree, const char *);
191 /* Assemble everything that is needed for a variable or function declaration.
192 Not used for automatic variables, and not used for function definitions.
193 Should not be called for variables of incomplete structure type.
195 TOP_LEVEL is nonzero if this variable has file scope.
196 AT_END is nonzero if this is the special handling, at end of compilation,
197 to define things that have had only tentative definitions.
198 DONT_OUTPUT_DATA if nonzero means don't actually output the
199 initial value (that will be done by the caller). */
200 extern void assemble_variable (tree, int, int, int);
202 /* Assemble everything that is needed for a variable declaration that has
203 no definition in the current translation unit. */
204 extern void assemble_undefined_decl (tree);
206 /* Compute the alignment of variable specified by DECL.
207 DONT_OUTPUT_DATA is from assemble_variable. */
208 extern void align_variable (tree decl, bool dont_output_data);
210 /* Queue for outputting something to declare an external symbol to the
211 assembler. (Most assemblers don't need this, so we normally output
212 nothing.) Do nothing if DECL is not external. */
213 extern void assemble_external (tree);
215 /* Assemble code to leave SIZE bytes of zeros. */
216 extern void assemble_zeros (unsigned HOST_WIDE_INT);
218 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
219 extern void assemble_align (unsigned int);
221 /* Assemble a string constant with the specified C string as contents. */
222 extern void assemble_string (const char *, int);
224 /* Similar, for calling a library function FUN. */
225 extern void assemble_external_libcall (rtx);
227 /* Assemble a label named NAME. */
228 extern void assemble_label (FILE *, const char *);
230 /* Output to FILE (an assembly file) a reference to NAME. If NAME
231 starts with a *, the rest of NAME is output verbatim. Otherwise
232 NAME is transformed in a target-specific way (usually by the
233 addition of an underscore). */
234 extern void assemble_name_raw (FILE *, const char *);
236 /* Return NAME that should actually be emitted, looking through
237 transparent aliases. If NAME refers to an entity that is also
238 represented as a tree (like a function or variable), mark the entity
240 extern const char *assemble_name_resolve (const char *);
242 /* Like assemble_name_raw, but should be used when NAME might refer to
243 an entity that is also represented as a tree (like a function or
244 variable). If NAME does refer to such an entity, that entity will
245 be marked as referenced. */
246 extern void assemble_name (FILE *, const char *);
248 /* Return the assembler directive for creating a given kind of integer
249 object. SIZE is the number of bytes in the object and ALIGNED_P
250 indicates whether it is known to be aligned. Return NULL if the
251 assembly dialect has no such directive.
253 The returned string should be printed at the start of a new line and
254 be followed immediately by the object's initial value. */
255 extern const char *integer_asm_op (int, int);
257 /* Use directive OP to assemble an integer object X. Print OP at the
258 start of the line, followed immediately by the value of X. */
259 extern void assemble_integer_with_op (const char *, rtx);
261 /* The default implementation of the asm_out.integer target hook. */
262 extern bool default_assemble_integer (rtx, unsigned int, int);
264 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
265 the alignment of the integer in bits. Return 1 if we were able to output
266 the constant, otherwise 0. If FORCE is nonzero the constant must
268 extern bool assemble_integer (rtx, unsigned, unsigned, int);
270 /* Return section for TEXT_SECITON_NAME if DECL or DECL_SECTION_NAME (DECL)
272 extern section *get_named_text_section (tree, const char *, const char *);
274 /* An interface to assemble_integer for the common case in which a value is
275 fully aligned and must be printed. VALUE is the value of the integer
276 object and SIZE is the number of bytes it contains. */
277 #define assemble_aligned_integer(SIZE, VALUE) \
278 assemble_integer (VALUE, SIZE, (SIZE) * BITS_PER_UNIT, 1)
280 /* Assemble the floating-point constant D into an object of size MODE. ALIGN
281 is the alignment of the constant in bits. If REVERSE is true, D is output
282 in reverse storage order. */
283 extern void assemble_real (REAL_VALUE_TYPE, scalar_float_mode, unsigned,
286 /* Write the address of the entity given by SYMBOL to SEC. */
287 extern void assemble_addr_to_section (rtx, section *);
289 /* Return TRUE if and only if the constant pool has no entries. Note
290 that even entries we might end up choosing not to emit are counted
291 here, so there is the potential for missed optimizations. */
292 extern bool constant_pool_empty_p (void);
294 extern rtx_insn *peephole (rtx_insn *);
296 extern void output_shared_constant_pool (void);
298 extern void output_object_blocks (void);
300 extern void output_quoted_string (FILE *, const char *);
302 /* When outputting delayed branch sequences, this rtx holds the
303 sequence being output. It is null when no delayed branch
304 sequence is being output, so it can be used as a test in the
307 This variable is defined in final.cc. */
308 extern rtx_sequence *final_sequence;
310 /* File in which assembler code is being written. */
313 extern FILE *asm_out_file;
316 /* The first global object in the file. */
317 extern const char *first_global_object_name;
319 /* The first weak object in the file. */
320 extern const char *weak_global_object_name;
322 /* Nonnull if the insn currently being emitted was a COND_EXEC pattern. */
323 extern rtx current_insn_predicate;
325 /* Last insn processed by final_scan_insn. */
326 extern rtx_insn *current_output_insn;
328 /* Nonzero while outputting an `asm' with operands.
329 This means that inconsistencies are the user's fault, so don't die.
330 The precise value is the insn being output, to pass to error_for_asm. */
331 extern const rtx_insn *this_is_asm_operands;
333 /* Carry information from ASM_DECLARE_OBJECT_NAME
334 to ASM_FINISH_DECLARE_OBJECT. */
335 extern int size_directive_output;
336 extern tree last_assemble_variable_decl;
338 extern bool first_function_block_is_cold;
340 /* Decide whether DECL needs to be in a writable section.
341 RELOC is the same as for SELECT_SECTION. */
342 extern bool decl_readonly_section (const_tree, int);
344 /* This can be used to compute RELOC for the function above, when
345 given a constant expression. */
346 extern int compute_reloc_for_constant (tree);
348 /* This can be used to compute RELOC for get_variable_section. */
349 extern int compute_reloc_for_var (tree);
351 /* User label prefix in effect for this compilation. */
352 extern const char *user_label_prefix;
354 /* Default target function prologue and epilogue assembler output. */
355 extern void default_function_pro_epilogue (FILE *);
357 /* Default target function switched text sections. */
358 extern void default_function_switched_text_sections (FILE *, tree, bool);
360 /* Default target hook that outputs nothing to a stream. */
361 extern void no_asm_to_stream (FILE *);
363 /* Flags controlling properties of a section. */
366 /* This SECTION_STYLE is used for unnamed sections that we can switch
367 to using a special assembler directive. */
370 SECTION_ENTSIZE = (1UL << 8) - 1, /* entity size in section */
371 SECTION_CODE = 1UL << 8, /* contains code */
372 SECTION_WRITE = 1UL << 9, /* data is writable */
374 SECTION_DEBUG = 1UL << 10, /* contains debug data */
375 SECTION_LINKONCE = 1UL << 11, /* is linkonce */
376 SECTION_SMALL = 1UL << 12, /* contains "small data" */
377 SECTION_BSS = 1UL << 13, /* contains zeros only */
378 SECTION_MERGE = 1UL << 14, /* contains mergeable data */
379 SECTION_STRINGS = 1UL << 15, /* contains zero terminated strings
380 without embedded zeros */
381 SECTION_OVERRIDE = 1UL << 16, /* allow override of default flags */
382 SECTION_TLS = 1UL << 17, /* contains thread-local storage */
383 SECTION_NOTYPE = 1UL << 18, /* don't output @progbits */
384 SECTION_DECLARED = 1UL << 19, /* section has been used */
386 /* This SECTION_STYLE is used for named sections that we can switch
387 to using a general section directive. */
388 SECTION_NAMED = 1UL << 20,
390 /* This SECTION_STYLE is used for sections that we cannot switch to at
391 all. The choice of section is implied by the directive that we use
392 to declare the object. */
393 SECTION_NOSWITCH = 1UL << 21,
395 /* bits used for SECTION_STYLE */
396 SECTION_STYLE_MASK = SECTION_NAMED | SECTION_NOSWITCH,
398 SECTION_COMMON = 1UL << 22, /* contains common data */
399 SECTION_RELRO = 1UL << 23, /* data is readonly after
400 relocation processing */
401 SECTION_EXCLUDE = 1UL << 24, /* discarded by the linker */
402 SECTION_RETAIN = 1UL << 25, /* retained by the linker. */
403 SECTION_LINK_ORDER = 1UL << 26, /* section needs link-order. */
405 /* NB: The maximum SECTION_MACH_DEP is (1UL << 28) since AVR needs 4 bits
406 in SECTION_MACH_DEP. */
407 SECTION_MACH_DEP = 1UL << 27,
409 /* subsequent bits reserved for target */
412 /* A helper function for default_elf_select_section and
413 default_elf_unique_section. Categorizes the DECL. */
415 enum section_category
420 SECCAT_RODATA_MERGE_STR,
421 SECCAT_RODATA_MERGE_STR_INIT,
422 SECCAT_RODATA_MERGE_CONST,
427 /* To optimize loading of shared programs, define following subsections
429 _REL Contains data that has relocations, so they get grouped
430 together and dynamic linker will visit fewer pages in memory.
431 _RO Contains data that is otherwise read-only. This is useful
432 with prelinking as most relocations won't be dynamically
433 linked and thus stay read only.
434 _LOCAL Marks data containing relocations only to local objects.
435 These relocations will get fully resolved by prelinking. */
437 SECCAT_DATA_REL_LOCAL,
439 SECCAT_DATA_REL_RO_LOCAL,
449 /* Information that is provided by all instances of the section type. */
450 struct GTY(()) section_common {
451 /* The set of SECTION_* flags that apply to this section. */
455 /* Information about a SECTION_NAMED section. */
456 struct GTY(()) named_section {
457 struct section_common common;
459 /* The name of the section. */
462 /* If nonnull, the VAR_DECL or FUNCTION_DECL with which the
463 section is associated. */
467 /* A callback that writes the assembly code for switching to an unnamed
468 section. The argument provides callback-specific data. */
469 typedef void (*unnamed_section_callback) (const char *);
471 /* Information about a SECTION_UNNAMED section. */
472 struct GTY(()) unnamed_section {
473 struct section_common common;
475 /* The callback used to switch to the section, and the data that
476 should be passed to the callback. */
477 unnamed_section_callback GTY ((callback)) callback;
480 /* The next entry in the chain of unnamed sections. */
484 /* A callback that writes the assembly code for a decl in a
485 SECTION_NOSWITCH section. DECL is the decl that should be assembled
486 and NAME is the name of its SYMBOL_REF. SIZE is the size of the decl
487 in bytes and ROUNDED is that size rounded up to the next
488 BIGGEST_ALIGNMENT / BITS_PER_UNIT boundary.
490 Return true if the callback used DECL_ALIGN to set the object's
491 alignment. A false return value implies that we are relying
492 on the rounded size to align the decl. */
493 typedef bool (*noswitch_section_callback) (tree decl, const char *name,
494 unsigned HOST_WIDE_INT size,
495 unsigned HOST_WIDE_INT rounded);
497 /* Information about a SECTION_NOSWITCH section. */
498 struct GTY(()) noswitch_section {
499 struct section_common common;
501 /* The callback used to assemble decls in this section. */
502 noswitch_section_callback GTY ((callback)) callback;
505 /* Information about a section, which may be named or unnamed. */
506 union GTY ((desc ("SECTION_STYLE (&(%h))"), for_user)) section {
507 struct section_common GTY ((skip)) common;
508 struct named_section GTY ((tag ("SECTION_NAMED"))) named;
509 struct unnamed_section GTY ((tag ("SECTION_UNNAMED"))) unnamed;
510 struct noswitch_section GTY ((tag ("SECTION_NOSWITCH"))) noswitch;
513 /* Return the style of section SECT. */
514 #define SECTION_STYLE(SECT) ((SECT)->common.flags & SECTION_STYLE_MASK)
518 /* Special well-known sections. */
519 extern GTY(()) section *text_section;
520 extern GTY(()) section *data_section;
521 extern GTY(()) section *readonly_data_section;
522 extern GTY(()) section *sdata_section;
523 extern GTY(()) section *ctors_section;
524 extern GTY(()) section *dtors_section;
525 extern GTY(()) section *bss_section;
526 extern GTY(()) section *sbss_section;
527 extern GTY(()) section *exception_section;
528 extern GTY(()) section *eh_frame_section;
529 extern GTY(()) section *tls_comm_section;
530 extern GTY(()) section *comm_section;
531 extern GTY(()) section *lcomm_section;
532 extern GTY(()) section *bss_noswitch_section;
534 extern GTY(()) section *in_section;
535 extern GTY(()) bool in_cold_section_p;
537 extern section *get_unnamed_section (unsigned int, void (*) (const char *),
539 extern section *get_section (const char *, unsigned int, tree,
540 bool not_existing = false);
541 extern section *get_named_section (tree, const char *, int);
542 extern section *get_variable_section (tree, bool);
543 extern void place_block_symbol (rtx);
544 extern rtx get_section_anchor (struct object_block *, HOST_WIDE_INT,
546 extern section *mergeable_constant_section (machine_mode,
547 unsigned HOST_WIDE_INT,
549 extern section *function_section (tree);
550 extern section *unlikely_text_section (void);
551 extern section *current_function_section (void);
552 extern void switch_to_other_text_partition (void);
554 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
555 not) section for PRIORITY. */
556 extern section *get_cdtor_priority_section (int, bool);
558 extern bool unlikely_text_section_p (section *);
559 extern void switch_to_section (section *, tree = nullptr);
560 extern void output_section_asm_op (const char *);
562 extern void record_tm_clone_pair (tree, tree);
563 extern void finish_tm_clone_pairs (void);
564 extern tree get_tm_clone_pair (tree);
566 extern void default_asm_output_source_filename (FILE *, const char *);
567 extern void output_file_directive (FILE *, const char *);
569 extern unsigned int default_section_type_flags (tree, const char *, int);
571 extern bool have_global_bss_p (void);
572 extern bool bss_initializer_p (const_tree, bool = false);
574 extern void default_no_named_section (const char *, unsigned int, tree);
575 extern void default_elf_asm_named_section (const char *, unsigned int, tree);
576 extern enum section_category categorize_decl_for_section (const_tree, int);
577 extern void default_coff_asm_named_section (const char *, unsigned int, tree);
578 extern void default_pe_asm_named_section (const char *, unsigned int, tree);
580 extern void default_named_section_asm_out_destructor (rtx, int);
581 extern void default_dtor_section_asm_out_destructor (rtx, int);
582 extern void default_named_section_asm_out_constructor (rtx, int);
583 extern void default_ctor_section_asm_out_constructor (rtx, int);
585 extern section *default_select_section (tree, int, unsigned HOST_WIDE_INT);
586 extern section *default_elf_select_section (tree, int, unsigned HOST_WIDE_INT);
587 extern void default_unique_section (tree, int);
588 extern section *default_function_rodata_section (tree, bool);
589 extern section *default_no_function_rodata_section (tree, bool);
590 extern section *default_clone_table_section (void);
591 extern section *default_select_rtx_section (machine_mode, rtx,
592 unsigned HOST_WIDE_INT);
593 extern section *default_elf_select_rtx_section (machine_mode, rtx,
594 unsigned HOST_WIDE_INT);
595 extern void default_encode_section_info (tree, rtx, int);
596 extern const char *default_strip_name_encoding (const char *);
597 extern void default_asm_output_anchor (rtx);
598 extern bool default_use_anchors_for_symbol_p (const_rtx);
599 extern bool default_binds_local_p (const_tree);
600 extern bool default_binds_local_p_1 (const_tree, int);
601 extern bool default_binds_local_p_2 (const_tree);
602 extern bool default_binds_local_p_3 (const_tree, bool, bool, bool, bool);
603 extern void default_globalize_label (FILE *, const char *);
604 extern void default_globalize_decl_name (FILE *, tree);
605 extern void default_emit_unwind_label (FILE *, tree, int, int);
606 extern void default_emit_except_table_label (FILE *);
607 extern void default_generate_internal_label (char *, const char *,
609 extern void default_internal_label (FILE *, const char *, unsigned long);
610 extern void default_asm_declare_constant_name (FILE *, const char *,
611 const_tree, HOST_WIDE_INT);
612 extern void default_file_start (void);
613 extern void file_end_indicate_exec_stack (void);
614 extern void file_end_indicate_split_stack (void);
616 extern void default_elf_asm_output_external (FILE *file, tree,
618 extern void default_elf_asm_output_limited_string (FILE *, const char *);
619 extern void default_elf_asm_output_ascii (FILE *, const char *, unsigned int);
620 extern void default_elf_internal_label (FILE *, const char *, unsigned long);
622 extern void default_elf_init_array_asm_out_constructor (rtx, int);
623 extern void default_elf_fini_array_asm_out_destructor (rtx, int);
624 extern int maybe_assemble_visibility (tree);
626 extern int default_address_cost (rtx, machine_mode, addr_space_t, bool);
629 extern void output_stack_usage (void);
631 #endif /* ! GCC_OUTPUT_H */