* gcc.dg/const-elim-1.c: Remove xfail for xtensa-*-*.
[official-gcc.git] / gcc / target.h
blobf141f04095f4bde8ad777b28c16b6eee33ac2f17
1 /* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 2, or (at your option) any
7 later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 In other words, you are welcome to use, share and improve this program.
19 You are forbidden to forbid anyone else to use, share and improve
20 what you give them. Help stamp out software-hoarding! */
22 /* This file contains a data structure that describes a GCC target.
23 At present it is incomplete, but in future it should grow to
24 contain most or all target machine and target O/S specific
25 information.
27 This structure has its initializer declared in target-def.h in the
28 form of large macro TARGET_INITIALIZER that expands to many smaller
29 macros.
31 The smaller macros each initialize one component of the structure,
32 and each has a default. Each target should have a file that
33 includes target.h and target-def.h, and overrides any inappropriate
34 defaults by undefining the relevant macro and defining a suitable
35 replacement. That file should then contain the definition of
36 "targetm" like so:
38 struct gcc_target targetm = TARGET_INITIALIZER;
40 Doing things this way allows us to bring together everything that
41 defines a GCC target. By supplying a default that is appropriate
42 to most targets, we can easily add new items without needing to
43 edit dozens of target configuration files. It should also allow us
44 to gradually reduce the amount of conditional compilation that is
45 scattered throughout GCC. */
47 #ifndef GCC_TARGET_H
48 #define GCC_TARGET_H
50 #include "tm.h"
51 #include "insn-modes.h"
53 struct stdarg_info;
55 struct gcc_target
57 /* Functions that output assembler for the target. */
58 struct asm_out
60 /* Opening and closing parentheses for asm expression grouping. */
61 const char *open_paren, *close_paren;
63 /* Assembler instructions for creating various kinds of integer object. */
64 const char *byte_op;
65 struct asm_int_op
67 const char *hi;
68 const char *si;
69 const char *di;
70 const char *ti;
71 } aligned_op, unaligned_op;
73 /* Try to output the assembler code for an integer object whose
74 value is given by X. SIZE is the size of the object in bytes and
75 ALIGNED_P indicates whether it is aligned. Return true if
76 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
77 and UNALIGNED_OP are NULL. */
78 bool (* integer) (rtx x, unsigned int size, int aligned_p);
80 /* Output code that will globalize a label. */
81 void (* globalize_label) (FILE *, const char *);
83 /* Output code that will emit a label for unwind info, if this
84 target requires such labels. Second argument is the decl the
85 unwind info is associated with, third is a boolean: true if
86 this is for exception handling, fourth is a boolean: true if
87 this is only a placeholder for an omitted FDE. */
88 void (* unwind_label) (FILE *, tree, int, int);
90 /* Emit any directives required to unwind this instruction. */
91 void (* unwind_emit) (FILE *, rtx);
93 /* Output an internal label. */
94 void (* internal_label) (FILE *, const char *, unsigned long);
96 /* Emit an assembler directive to set visibility for the symbol
97 associated with the tree decl. */
98 void (* visibility) (tree, int);
100 /* Output the assembler code for entry to a function. */
101 void (* function_prologue) (FILE *, HOST_WIDE_INT);
103 /* Output the assembler code for end of prologue. */
104 void (* function_end_prologue) (FILE *);
106 /* Output the assembler code for start of epilogue. */
107 void (* function_begin_epilogue) (FILE *);
109 /* Output the assembler code for function exit. */
110 void (* function_epilogue) (FILE *, HOST_WIDE_INT);
112 /* Tell assembler to change to section NAME with attributes FLAGS.
113 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
114 which this section is associated. */
115 void (* named_section) (const char *name, unsigned int flags, tree decl);
117 /* Switch to the section that holds the exception table. */
118 void (* exception_section) (void);
120 /* Switch to the section that holds the exception frames. */
121 void (* eh_frame_section) (void);
123 /* Select and switch to a section for EXP. It may be a DECL or a
124 constant. RELOC is nonzero if runtime relocations must be applied;
125 bit 1 will be set if the runtime relocations require non-local
126 name resolution. ALIGN is the required alignment of the data. */
127 void (* select_section) (tree, int, unsigned HOST_WIDE_INT);
129 /* Select and switch to a section for X with MODE. ALIGN is
130 the desired alignment of the data. */
131 void (* select_rtx_section) (enum machine_mode, rtx,
132 unsigned HOST_WIDE_INT);
134 /* Select a unique section name for DECL. RELOC is the same as
135 for SELECT_SECTION. */
136 void (* unique_section) (tree, int);
138 /* Tell assembler to switch to the readonly data section associated
139 with function DECL. */
140 void (* function_rodata_section) (tree);
142 /* Output a constructor for a symbol with a given priority. */
143 void (* constructor) (rtx, int);
145 /* Output a destructor for a symbol with a given priority. */
146 void (* destructor) (rtx, int);
148 /* Output the assembler code for a thunk function. THUNK_DECL is the
149 declaration for the thunk function itself, FUNCTION is the decl for
150 the target function. DELTA is an immediate constant offset to be
151 added to THIS. If VCALL_OFFSET is nonzero, the word at
152 *(*this + vcall_offset) should be added to THIS. */
153 void (* output_mi_thunk) (FILE *file, tree thunk_decl,
154 HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
155 tree function_decl);
157 /* Determine whether output_mi_thunk would succeed. */
158 /* ??? Ideally, this hook would not exist, and success or failure
159 would be returned from output_mi_thunk directly. But there's
160 too much undo-able setup involved in invoking output_mi_thunk.
161 Could be fixed by making output_mi_thunk emit rtl instead of
162 text to the output file. */
163 bool (* can_output_mi_thunk) (tree thunk_decl, HOST_WIDE_INT delta,
164 HOST_WIDE_INT vcall_offset,
165 tree function_decl);
167 /* Output any boilerplate text needed at the beginning of a
168 translation unit. */
169 void (*file_start) (void);
171 /* Output any boilerplate text needed at the end of a
172 translation unit. */
173 void (*file_end) (void);
175 /* Output an assembler pseudo-op to declare a library function name
176 external. */
177 void (*external_libcall) (rtx);
179 /* Output an assembler directive to mark decl live. This instructs
180 linker to not dead code strip this symbol. */
181 void (*mark_decl_preserved) (const char *);
183 } asm_out;
185 /* Functions relating to instruction scheduling. */
186 struct sched
188 /* Given the current cost, COST, of an insn, INSN, calculate and
189 return a new cost based on its relationship to DEP_INSN through
190 the dependence LINK. The default is to make no adjustment. */
191 int (* adjust_cost) (rtx insn, rtx link, rtx def_insn, int cost);
193 /* Adjust the priority of an insn as you see fit. Returns the new
194 priority. */
195 int (* adjust_priority) (rtx, int);
197 /* Function which returns the maximum number of insns that can be
198 scheduled in the same machine cycle. This must be constant
199 over an entire compilation. The default is 1. */
200 int (* issue_rate) (void);
202 /* Calculate how much this insn affects how many more insns we
203 can emit this cycle. Default is they all cost the same. */
204 int (* variable_issue) (FILE *, int, rtx, int);
206 /* Initialize machine-dependent scheduling code. */
207 void (* md_init) (FILE *, int, int);
209 /* Finalize machine-dependent scheduling code. */
210 void (* md_finish) (FILE *, int);
212 /* Initialize machine-dependent function while scheduling code. */
213 void (* md_init_global) (FILE *, int, int);
215 /* Finalize machine-dependent function wide scheduling code. */
216 void (* md_finish_global) (FILE *, int);
218 /* Reorder insns in a machine-dependent fashion, in two different
219 places. Default does nothing. */
220 int (* reorder) (FILE *, int, rtx *, int *, int);
221 int (* reorder2) (FILE *, int, rtx *, int *, int);
223 /* The following member value is a pointer to a function called
224 after evaluation forward dependencies of insns in chain given
225 by two parameter values (head and tail correspondingly). */
226 void (* dependencies_evaluation_hook) (rtx, rtx);
228 /* The values of the following four members are pointers to
229 functions used to simplify the automaton descriptions.
230 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
231 returning insns which are used to change the pipeline hazard
232 recognizer state when the new simulated processor cycle
233 correspondingly starts and finishes. The function defined by
234 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
235 to initialize the corresponding insns. The default values of
236 the members result in not changing the automaton state when
237 the new simulated processor cycle correspondingly starts and
238 finishes. */
239 void (* init_dfa_pre_cycle_insn) (void);
240 rtx (* dfa_pre_cycle_insn) (void);
241 void (* init_dfa_post_cycle_insn) (void);
242 rtx (* dfa_post_cycle_insn) (void);
244 /* The following member value is a pointer to a function returning value
245 which defines how many insns in queue `ready' will we try for
246 multi-pass scheduling. If the member value is nonzero and the
247 function returns positive value, the DFA based scheduler will make
248 multi-pass scheduling for the first cycle. In other words, we will
249 try to choose ready insn which permits to start maximum number of
250 insns on the same cycle. */
251 int (* first_cycle_multipass_dfa_lookahead) (void);
253 /* The following member value is pointer to a function controlling
254 what insns from the ready insn queue will be considered for the
255 multipass insn scheduling. If the hook returns zero for insn
256 passed as the parameter, the insn will be not chosen to be
257 issued. */
258 int (* first_cycle_multipass_dfa_lookahead_guard) (rtx);
260 /* The following member value is pointer to a function called by
261 the insn scheduler before issuing insn passed as the third
262 parameter on given cycle. If the hook returns nonzero, the
263 insn is not issued on given processors cycle. Instead of that,
264 the processor cycle is advanced. If the value passed through
265 the last parameter is zero, the insn ready queue is not sorted
266 on the new cycle start as usually. The first parameter passes
267 file for debugging output. The second one passes the scheduler
268 verbose level of the debugging output. The forth and the fifth
269 parameter values are correspondingly processor cycle on which
270 the previous insn has been issued and the current processor
271 cycle. */
272 int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *);
274 /* The following member value is a pointer to a function called
275 by the insn scheduler. It should return true if there exists a
276 dependence which is considered costly by the target, between
277 the insn passed as the first parameter, and the insn passed as
278 the second parameter. The third parameter is the INSN_DEPEND
279 link that represents the dependence between the two insns. The
280 fourth argument is the cost of the dependence as estimated by
281 the scheduler. The last argument is the distance in cycles
282 between the already scheduled insn (first parameter) and the
283 the second insn (second parameter). */
284 bool (* is_costly_dependence) (rtx, rtx, rtx, int, int);
285 } sched;
287 /* Functions relating to vectorization. */
288 struct vectorize
290 /* The following member value is a pointer to a function called
291 by the vectorizer, and return the decl of the target builtin
292 function. */
293 tree (* builtin_mask_for_load) (void);
294 } vectorize;
296 /* The initial value of target_flags. */
297 int default_target_flags;
299 /* Handle target switch CODE (an OPT_* value). ARG is the argument
300 passed to the switch; it is NULL if no argument was. VALUE is the
301 value of ARG if CODE specifies a UInteger option, otherwise it is
302 1 if the positive form of the switch was used and 0 if the negative
303 form was. Return true if the switch was valid. */
304 bool (* handle_option) (size_t code, const char *arg, int value);
306 /* Return machine mode for filter value. */
307 enum machine_mode (* eh_return_filter_mode) (void);
309 /* Given two decls, merge their attributes and return the result. */
310 tree (* merge_decl_attributes) (tree, tree);
312 /* Given two types, merge their attributes and return the result. */
313 tree (* merge_type_attributes) (tree, tree);
315 /* Table of machine attributes and functions to handle them.
316 Ignored if NULL. */
317 const struct attribute_spec *attribute_table;
319 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
320 one if they are compatible and two if they are nearly compatible
321 (which causes a warning to be generated). */
322 int (* comp_type_attributes) (tree type1, tree type2);
324 /* Assign default attributes to the newly defined TYPE. */
325 void (* set_default_type_attributes) (tree type);
327 /* Insert attributes on the newly created DECL. */
328 void (* insert_attributes) (tree decl, tree *attributes);
330 /* Return true if FNDECL (which has at least one machine attribute)
331 can be inlined despite its machine attributes, false otherwise. */
332 bool (* function_attribute_inlinable_p) (tree fndecl);
334 /* Return true if bitfields in RECORD_TYPE should follow the
335 Microsoft Visual C++ bitfield layout rules. */
336 bool (* ms_bitfield_layout_p) (tree record_type);
338 /* Return true if anonymous bitfields affect structure alignment. */
339 bool (* align_anon_bitfield) (void);
341 /* Set up target-specific built-in functions. */
342 void (* init_builtins) (void);
344 /* Expand a target-specific builtin. */
345 rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget,
346 enum machine_mode mode, int ignore);
348 /* Select a replacement for a target-specific builtin. This is done
349 *before* regular type checking, and so allows the target to implement
350 a crude form of function overloading. The result is a complete
351 expression that implements the operation. */
352 tree (*resolve_overloaded_builtin) (tree decl, tree params);
354 /* Fold a target-specific builtin. */
355 tree (* fold_builtin) (tree fndecl, tree arglist, bool ignore);
357 /* For a vendor-specific fundamental TYPE, return a pointer to
358 a statically-allocated string containing the C++ mangling for
359 TYPE. In all other cases, return NULL. */
360 const char * (* mangle_fundamental_type) (tree type);
362 /* Make any adjustments to libfunc names needed for this target. */
363 void (* init_libfuncs) (void);
365 /* Given a decl, a section name, and whether the decl initializer
366 has relocs, choose attributes for the section. */
367 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
368 unsigned int (* section_type_flags) (tree, const char *, int);
370 /* True if new jumps cannot be created, to replace existing ones or
371 not, at the current point in the compilation. */
372 bool (* cannot_modify_jumps_p) (void);
374 /* Return a register class for which branch target register
375 optimizations should be applied. */
376 int (* branch_target_register_class) (void);
378 /* Return true if branch target register optimizations should include
379 callee-saved registers that are not already live during the current
380 function. AFTER_PE_GEN is true if prologues and epilogues have
381 already been generated. */
382 bool (* branch_target_register_callee_saved) (bool after_pe_gen);
384 /* True if the constant X cannot be placed in the constant pool. */
385 bool (* cannot_force_const_mem) (rtx);
387 /* True if the insn X cannot be duplicated. */
388 bool (* cannot_copy_insn_p) (rtx);
390 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
391 rtx (* delegitimize_address) (rtx);
393 /* True if it is OK to do sibling call optimization for the specified
394 call expression EXP. DECL will be the called function, or NULL if
395 this is an indirect call. */
396 bool (*function_ok_for_sibcall) (tree decl, tree exp);
398 /* True if EXP should be placed in a "small data" section. */
399 bool (* in_small_data_p) (tree);
401 /* True if EXP names an object for which name resolution must resolve
402 to the current module. */
403 bool (* binds_local_p) (tree);
405 /* Do something target-specific to record properties of the DECL into
406 the associated SYMBOL_REF. */
407 void (* encode_section_info) (tree, rtx, int);
409 /* Undo the effects of encode_section_info on the symbol string. */
410 const char * (* strip_name_encoding) (const char *);
412 /* If shift optabs for MODE are known to always truncate the shift count,
413 return the mask that they apply. Return 0 otherwise. */
414 unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
416 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
417 bool (* valid_pointer_mode) (enum machine_mode mode);
419 /* True if MODE is valid for the target. By "valid", we mean able to
420 be manipulated in non-trivial ways. In particular, this means all
421 the arithmetic is supported. */
422 bool (* scalar_mode_supported_p) (enum machine_mode mode);
424 /* Similarly for vector modes. "Supported" here is less strict. At
425 least some operations are supported; need to check optabs or builtins
426 for further details. */
427 bool (* vector_mode_supported_p) (enum machine_mode mode);
429 /* True if a vector is opaque. */
430 bool (* vector_opaque_p) (tree);
432 /* Compute a (partial) cost for rtx X. Return true if the complete
433 cost has been computed, and false if subexpressions should be
434 scanned. In either case, *TOTAL contains the cost result. */
435 /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
436 not necessarily defined at this point. */
437 bool (* rtx_costs) (rtx x, int code, int outer_code, int *total);
439 /* Compute the cost of X, used as an address. Never called with
440 invalid addresses. */
441 int (* address_cost) (rtx x);
443 /* Given a register, this hook should return a parallel of registers
444 to represent where to find the register pieces. Define this hook
445 if the register and its mode are represented in Dwarf in
446 non-contiguous locations, or if the register should be
447 represented in more than one register in Dwarf. Otherwise, this
448 hook should return NULL_RTX. */
449 rtx (* dwarf_register_span) (rtx);
451 /* Fetch the fixed register(s) which hold condition codes, for
452 targets where it makes sense to look for duplicate assignments to
453 the condition codes. This should return true if there is such a
454 register, false otherwise. The arguments should be set to the
455 fixed register numbers. Up to two condition code registers are
456 supported. If there is only one for this target, the int pointed
457 at by the second argument should be set to -1. */
458 bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
460 /* If two condition code modes are compatible, return a condition
461 code mode which is compatible with both, such that a comparison
462 done in the returned mode will work for both of the original
463 modes. If the condition code modes are not compatible, return
464 VOIDmode. */
465 enum machine_mode (* cc_modes_compatible) (enum machine_mode,
466 enum machine_mode);
468 /* Do machine-dependent code transformations. Called just before
469 delayed-branch scheduling. */
470 void (* machine_dependent_reorg) (void);
472 /* Create the __builtin_va_list type. */
473 tree (* build_builtin_va_list) (void);
475 /* Gimplifies a VA_ARG_EXPR. */
476 tree (* gimplify_va_arg_expr) (tree valist, tree type, tree *pre_p,
477 tree *post_p);
479 /* Validity-checking routines for PCH files, target-specific.
480 get_pch_validity returns a pointer to the data to be stored,
481 and stores the size in its argument. pch_valid_p gets the same
482 information back and returns NULL if the PCH is valid,
483 or an error message if not.
485 void * (* get_pch_validity) (size_t *);
486 const char * (* pch_valid_p) (const void *, size_t);
488 /* True if the compiler should give an enum type only as many
489 bytes as it takes to represent the range of possible values of
490 that type. */
491 bool (* default_short_enums) (void);
493 /* This target hook returns an rtx that is used to store the address
494 of the current frame into the built-in setjmp buffer. */
495 rtx (* builtin_setjmp_frame_value) (void);
497 /* This target hook should add STRING_CST trees for any hard regs
498 the port wishes to automatically clobber for an asm. */
499 tree (* md_asm_clobbers) (tree, tree, tree);
501 /* This target hook allows the backend to specify a calling convention
502 in the debug information. This function actually returns an
503 enum dwarf_calling_convention, but because of forward declarations
504 and not wanting to include dwarf2.h everywhere target.h is included
505 the function is being declared as an int. */
506 int (* dwarf_calling_convention) (tree);
508 /* This target hook allows the backend to emit frame-related insns that
509 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
510 engine will invoke it on insns of the form
511 (set (reg) (unspec [...] UNSPEC_INDEX))
513 (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
514 to let the backend emit the call frame instructions. */
515 void (* dwarf_handle_frame_unspec) (const char *, rtx, int);
517 /* Perform architecture specific checking of statements gimplified
518 from VA_ARG_EXPR. LHS is left hand side of MODIFY_EXPR, RHS
519 is right hand side. Returns true if the statements doesn't need
520 to be checked for va_list references. */
521 bool (*stdarg_optimize_hook) (struct stdarg_info *ai, tree lhs, tree rhs);
523 /* Functions relating to calls - argument passing, returns, etc. */
524 struct calls {
525 bool (*promote_function_args) (tree fntype);
526 bool (*promote_function_return) (tree fntype);
527 bool (*promote_prototypes) (tree fntype);
528 rtx (*struct_value_rtx) (tree fndecl, int incoming);
529 bool (*return_in_memory) (tree type, tree fndecl);
530 bool (*return_in_msb) (tree type);
532 /* Return true if a parameter must be passed by reference. TYPE may
533 be null if this is a libcall. CA may be null if this query is
534 from __builtin_va_arg. */
535 bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
536 tree type, bool named_arg);
538 rtx (*expand_builtin_saveregs) (void);
539 /* Returns pretend_argument_size. */
540 void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
541 tree type, int *pretend_arg_size,
542 int second_time);
543 bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
544 /* Returns true if we should use
545 targetm.calls.setup_incoming_varargs() and/or
546 targetm.calls.strict_argument_naming(). */
547 bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
549 /* Given a complex type T, return true if a parameter of type T
550 should be passed as two scalars. */
551 bool (* split_complex_arg) (tree type);
553 /* Return true if type T, mode MODE, may not be passed in registers,
554 but must be passed on the stack. */
555 /* ??? This predicate should be applied strictly after pass-by-reference.
556 Need audit to verify that this is the case. */
557 bool (* must_pass_in_stack) (enum machine_mode mode, tree t);
559 /* Return true if type TYPE, mode MODE, which is passed by reference,
560 should have the object copy generated by the callee rather than
561 the caller. It is never called for TYPE requiring constructors. */
562 bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
563 tree type, bool named);
565 /* Return zero for arguments passed entirely on the stack or entirely
566 in registers. If passed in both, return the number of bytes passed
567 in registers; the balance is therefore passed on the stack. */
568 int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
569 tree type, bool named);
571 /* Return the diagnostic message string if function without a prototype
572 is not allowed for this 'val' argument; NULL otherwise. */
573 const char *(*invalid_arg_for_unprototyped_fn) (tree typelist,
574 tree funcdecl, tree val);
575 } calls;
577 /* Functions specific to the C++ frontend. */
578 struct cxx {
579 /* Return the integer type used for guard variables. */
580 tree (*guard_type) (void);
581 /* Return true if only the low bit of the guard should be tested. */
582 bool (*guard_mask_bit) (void);
583 /* Returns the size of the array cookie for an array of type. */
584 tree (*get_cookie_size) (tree);
585 /* Returns true if the element size should be stored in the
586 array cookie. */
587 bool (*cookie_has_size) (void);
588 /* Allows backends to perform additional processing when
589 deciding if a class should be exported or imported. */
590 int (*import_export_class) (tree, int);
591 /* Returns true if constructors and destructors return "this". */
592 bool (*cdtor_returns_this) (void);
593 /* Returns true if the key method for a class can be an inline
594 function, so long as it is not declared inline in the class
595 itself. Returning true is the behavior required by the Itanium
596 C++ ABI. */
597 bool (*key_method_may_be_inline) (void);
598 /* DECL is a virtual table, virtual table table, typeinfo object,
599 or other similar implicit class data object that will be
600 emitted with external linkage in this translation unit. No ELF
601 visibility has been explicitly specified. If the target needs
602 to specify a visibility other than that of the containing class,
603 use this hook to set DECL_VISIBILITY and
604 DECL_VISIBILITY_SPECIFIED. */
605 void (*determine_class_data_visibility) (tree decl);
606 /* Returns true (the default) if virtual tables and other
607 similar implicit class data objects are always COMDAT if they
608 have external linkage. If this hook returns false, then
609 class data for classes whose virtual table will be emitted in
610 only one translation unit will not be COMDAT. */
611 bool (*class_data_always_comdat) (void);
612 /* Returns true if __aeabi_atexit should be used to register static
613 destructors. */
614 bool (*use_aeabi_atexit) (void);
615 } cxx;
617 /* Leave the boolean fields at the end. */
619 /* True if arbitrary sections are supported. */
620 bool have_named_sections;
622 /* True if "native" constructors and destructors are supported,
623 false if we're using collect2 for the job. */
624 bool have_ctors_dtors;
626 /* True if thread-local storage is supported. */
627 bool have_tls;
629 /* True if a small readonly data section is supported. */
630 bool have_srodata_section;
632 /* True if EH frame info sections should be zero-terminated. */
633 bool terminate_dw2_eh_frame_info;
635 /* True if #NO_APP should be emitted at the beginning of
636 assembly output. */
637 bool file_start_app_off;
639 /* True if output_file_directive should be called for main_input_filename
640 at the beginning of assembly output. */
641 bool file_start_file_directive;
643 /* True if #pragma redefine_extname is to be supported. */
644 bool handle_pragma_redefine_extname;
646 /* True if #pragma extern_prefix is to be supported. */
647 bool handle_pragma_extern_prefix;
649 /* True if the target is allowed to reorder memory accesses unless
650 synchronization is explicitly requested. */
651 bool relaxed_ordering;
653 /* Leave the boolean fields at the end. */
656 extern struct gcc_target targetm;
658 #endif /* GCC_TARGET_H */