flags.h revision 50506 
1/* Compilation switch flag definitions for GNU CC.
2   Copyright (C) 1987, 88, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
3
4This file is part of GNU CC.
5
6GNU CC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU CC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU CC; see the file COPYING.  If not, write to
18the Free Software Foundation, 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21/* Name of the input .c file being compiled.  */
22extern char *main_input_filename;
23
24enum debug_info_type
25{
26  NO_DEBUG,	    /* Write no debug info.  */
27  DBX_DEBUG,	    /* Write BSD .stabs for DBX (using dbxout.c).  */
28  SDB_DEBUG,	    /* Write COFF for (old) SDB (using sdbout.c).  */
29  DWARF_DEBUG,	    /* Write Dwarf debug info (using dwarfout.c).  */
30  DWARF2_DEBUG,	    /* Write Dwarf v2 debug info (using dwarf2out.c).  */
31  XCOFF_DEBUG	    /* Write IBM/Xcoff debug info (using dbxout.c).  */
32};
33
34/* Specify which kind of debugging info to generate.  */
35extern enum debug_info_type write_symbols;
36
37enum debug_info_level
38{
39  DINFO_LEVEL_NONE,	/* Write no debugging info.  */
40  DINFO_LEVEL_TERSE,	/* Write minimal info to support tracebacks only.  */
41  DINFO_LEVEL_NORMAL,	/* Write info for all declarations (and line table). */
42  DINFO_LEVEL_VERBOSE	/* Write normal info plus #define/#undef info.  */
43};
44
45/* Specify how much debugging info to generate.  */
46extern enum debug_info_level debug_info_level;
47
48/* Nonzero means use GNU-only extensions in the generated symbolic
49   debugging information.  */
50extern int use_gnu_debug_info_extensions;
51
52/* Nonzero means do optimizations.  -opt.  */
53
54extern int optimize;
55
56/* Nonzero means optimize for size.  -Os.  */
57
58extern int optimize_size;
59
60/* Nonzero means do stupid register allocation.  -noreg.
61   Currently, this is 1 if `optimize' is 0.  */
62
63extern int obey_regdecls;
64
65/* Don't print functions as they are compiled and don't print
66   times taken by the various passes.  -quiet.  */
67
68extern int quiet_flag;
69
70/* Don't print warning messages.  -w.  */
71
72extern int inhibit_warnings;
73
74/* Do print extra warnings (such as for uninitialized variables).  -W.  */
75
76extern int extra_warnings;
77
78/* Nonzero to warn about unused local variables.  */
79
80extern int warn_unused;
81
82/* Nonzero means warn if inline function is too large.  */
83
84extern int warn_inline;
85
86/* Nonzero to warn about variables used before they are initialized.  */
87
88extern int warn_uninitialized;
89
90/* Zero if unknown pragmas are ignored
91   One if the compiler should warn about an unknown pragma not in
92   a system include file.
93   Greater than one if the compiler should warn for all unknown
94   pragmas.  */
95
96extern int warn_unknown_pragmas;
97
98/* Nonzero means warn about all declarations which shadow others.   */
99
100extern int warn_shadow;
101
102/* Warn if a switch on an enum fails to have a case for every enum value.  */
103
104extern int warn_switch;
105
106/* Nonzero means warn about function definitions that default the return type
107   or that use a null return and have a return-type other than void.  */
108
109extern int warn_return_type;
110
111/* Nonzero means warn about pointer casts that increase the required
112   alignment of the target type (and might therefore lead to a crash
113   due to a misaligned access).  */
114
115extern int warn_cast_align;
116
117/* Nonzero means warn that dbx info for template class methods isn't fully
118   supported yet.  */
119
120extern int warn_template_debugging;
121
122/* Nonzero means warn about any identifiers that match in the first N
123   characters.  The value N is in `id_clash_len'.  */
124
125extern int warn_id_clash;
126extern unsigned id_clash_len;
127
128/* Nonzero means warn about any objects definitions whose size is larger
129   than N bytes.  Also want about function definitions whose returned
130   values are larger than N bytes. The value N is in `larger_than_size'.  */
131
132extern int warn_larger_than;
133extern unsigned larger_than_size;
134
135/* Warn if a function returns an aggregate,
136   since there are often incompatible calling conventions for doing this.  */
137
138extern int warn_aggregate_return;
139
140/* Nonzero means that -Wformat accepts certain non-ANSI formats.  */
141
142extern int flag_format_extensions;
143
144/* Nonzero if generating code to do profiling.  */
145
146extern int profile_flag;
147
148/* Nonzero if generating code to do profiling on the basis of basic blocks.  */
149
150extern int profile_block_flag;
151
152/* Nonzero if generating code to profile program flow graph arcs. */
153
154extern int profile_arc_flag;
155
156/* Nonzero if generating info for gcov to calculate line test coverage. */
157
158extern int flag_test_coverage;
159
160/* Nonzero indicates that branch taken probabilities should be calculated. */
161
162extern int flag_branch_probabilities;
163
164/* Nonzero for -pedantic switch: warn about anything
165   that standard C forbids.  */
166
167extern int pedantic;
168
169/* Temporarily suppress certain warnings.
170   This is set while reading code from a system header file.  */
171
172extern int in_system_header;
173
174/* Nonzero for -dp: annotate the assembly with a comment describing the
175   pattern and alternative used.  */
176
177extern int flag_print_asm_name;
178
179/* Now the symbols that are set with `-f' switches.  */
180
181/* Nonzero means `char' should be signed.  */
182
183extern int flag_signed_char;
184
185/* Nonzero means give an enum type only as many bytes as it needs.  */
186
187extern int flag_short_enums;
188
189/* Nonzero for -fcaller-saves: allocate values in regs that need to
190   be saved across function calls, if that produces overall better code.
191   Optional now, so people can test it.  */
192
193extern int flag_caller_saves;
194
195/* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
196
197extern int flag_pcc_struct_return;
198
199/* Nonzero for -fforce-mem: load memory value into a register
200   before arithmetic on it.  This makes better cse but slower compilation.  */
201
202extern int flag_force_mem;
203
204/* Nonzero for -fforce-addr: load memory address into a register before
205   reference to memory.  This makes better cse but slower compilation.  */
206
207extern int flag_force_addr;
208
209/* Nonzero for -fdefer-pop: don't pop args after each function call;
210   instead save them up to pop many calls' args with one insns.  */
211
212extern int flag_defer_pop;
213
214/* Nonzero for -ffloat-store: don't allocate floats and doubles
215   in extended-precision registers.  */
216
217extern int flag_float_store;
218
219/* Nonzero enables strength-reduction in loop.c.  */
220
221extern int flag_strength_reduce;
222
223/* Nonzero enables loop unrolling in unroll.c.  Only loops for which the
224   number of iterations can be calculated at compile-time (UNROLL_COMPLETELY,
225   UNROLL_MODULO) or at run-time (preconditioned to be UNROLL_MODULO) are
226   unrolled.  */
227
228extern int flag_unroll_loops;
229
230/* Nonzero enables loop unrolling in unroll.c.  All loops are unrolled.
231   This is generally not a win.  */
232
233extern int flag_unroll_all_loops;
234
235/* Nonzero forces all invariant computations in loops to be moved
236   outside the loop. */
237
238extern int flag_move_all_movables;
239
240/* Nonzero forces all general induction variables in loops to be
241   strength reduced. */
242
243extern int flag_reduce_all_givs;
244
245/* Nonzero for -fcse-follow-jumps:
246   have cse follow jumps to do a more extensive job.  */
247
248extern int flag_cse_follow_jumps;
249
250/* Nonzero for -fcse-skip-blocks:
251   have cse follow a branch around a block.  */
252
253extern int flag_cse_skip_blocks;
254
255/* Nonzero for -fexpensive-optimizations:
256   perform miscellaneous relatively-expensive optimizations.  */
257extern int flag_expensive_optimizations;
258
259/* Nonzero for -fwritable-strings:
260   store string constants in data segment and don't uniquize them.  */
261
262extern int flag_writable_strings;
263
264/* Nonzero means don't put addresses of constant functions in registers.
265   Used for compiling the Unix kernel, where strange substitutions are
266   done on the assembly output.  */
267
268extern int flag_no_function_cse;
269
270/* Nonzero for -fomit-frame-pointer:
271   don't make a frame pointer in simple functions that don't require one.  */
272
273extern int flag_omit_frame_pointer;
274
275/* Nonzero to inhibit use of define_optimization peephole opts.  */
276
277extern int flag_no_peephole;
278
279/* Nonzero means all references through pointers are volatile.  */
280
281extern int flag_volatile;
282
283/* Nonzero means treat all global and extern variables as global.  */
284
285extern int flag_volatile_global;
286
287/* Nonzero allows GCC to violate some IEEE or ANSI rules regarding math
288   operations in the interest of optimization.  For example it allows
289   GCC to assume arguments to sqrt are nonnegative numbers, allowing
290   faster code for sqrt to be generated. */
291
292extern int flag_fast_math;
293
294/* Nonzero means to run loop optimizations twice.  */
295
296extern int flag_rerun_loop_opt;
297
298/* Nonzero means to assume that a structure or an array reference at
299   a varying address cannot alias a scalar at a fixed address. */
300
301extern int flag_structure_noalias;
302
303/* Nonzero means make functions that look like good inline candidates
304   go inline.  */
305
306extern int flag_inline_functions;
307
308/* Nonzero for -fkeep-inline-functions: even if we make a function
309   go inline everywhere, keep its definition around for debugging
310   purposes.  */
311
312extern int flag_keep_inline_functions;
313
314/* Nonzero means that functions declared `inline' will be treated
315   as `static'.  Prevents generation of zillions of copies of unused
316   static inline functions; instead, `inlines' are written out
317   only when actually used.  Used in conjunction with -g.  Also
318   does the right thing with #pragma interface.  */
319
320extern int flag_no_inline;
321
322/* Nonzero if we are only using compiler to check syntax errors.  */
323
324extern int flag_syntax_only;
325
326/* Nonzero means we should save auxiliary info into a .X file.  */
327
328extern int flag_gen_aux_info;
329
330/* Nonzero means make the text shared if supported.  */
331
332extern int flag_shared_data;
333
334/* flag_schedule_insns means schedule insns within basic blocks (before
335   local_alloc).
336   flag_schedule_insns_after_reload means schedule insns after
337   global_alloc.  */
338
339extern int flag_schedule_insns;
340extern int flag_schedule_insns_after_reload;
341
342#ifdef HAIFA
343/* The following flags have effect only for scheduling before register
344   allocation:
345
346   flag_schedule_interblock means schedule insns accross basic blocks.
347   flag_schedule_speculative means allow speculative motion of non-load insns.
348   flag_schedule_speculative_load means allow speculative motion of some
349   load insns.
350   flag_schedule_speculative_load_dangerous allows speculative motion of more
351   load insns.  */
352
353extern int flag_schedule_interblock;
354extern int flag_schedule_speculative;
355extern int flag_schedule_speculative_load;
356extern int flag_schedule_speculative_load_dangerous;
357
358/* flag_on_branch_count_reg means try to replace add-1,compare,branch tupple
359   by a cheaper branch, on a count register. */
360extern int flag_branch_on_count_reg;
361#endif  /* HAIFA */
362
363
364/* Nonzero means put things in delayed-branch slots if supported. */
365
366extern int flag_delayed_branch;
367
368/* Nonzero means pretend it is OK to examine bits of target floats,
369   even if that isn't true.  The resulting code will have incorrect constants,
370   but the same series of instructions that the native compiler would make.  */
371
372extern int flag_pretend_float;
373
374/* Nonzero means change certain warnings into errors.
375   Usually these are warnings about failure to conform to some standard.  */
376
377extern int flag_pedantic_errors;
378
379/* Nonzero means generate position-independent code.
380   This is not fully implemented yet.  */
381
382extern int flag_pic;
383
384/* Nonzero means generate extra code for exception handling and enable
385   exception handling.  */
386
387extern int flag_exceptions;
388
389/* Nonzero means use the new model for exception handling. Replaces
390   -DNEW_EH_MODEL as a compile option. */
391
392extern int flag_new_exceptions;
393
394/* Nonzero means don't place uninitialized global data in common storage
395   by default.  */
396
397extern int flag_no_common;
398
399/* -finhibit-size-directive inhibits output of .size for ELF.
400   This is used only for compiling crtstuff.c,
401   and it may be extended to other effects
402   needed for crtstuff.c on other systems.  */
403extern int flag_inhibit_size_directive;
404
405/* Nonzero means place each function into its own section on those platforms
406   which support arbitrary section names and unlimited numbers of sections.  */
407
408extern int flag_function_sections;
409
410/* -fverbose-asm causes extra commentary information to be produced in
411   the generated assembly code (to make it more readable).  This option
412   is generally only of use to those who actually need to read the
413   generated assembly code (perhaps while debugging the compiler itself).
414   -fno-verbose-asm, the default, causes the extra information
415   to not be added and is useful when comparing two assembler files.  */
416
417extern int flag_verbose_asm;
418
419/* -dA causes debug information to be produced in
420   the generated assembly code (to make it more readable).  This option
421   is generally only of use to those who actually need to read the
422   generated assembly code (perhaps while debugging the compiler itself).
423   Currently, this switch is only used by dwarfout.c; however, it is intended
424   to be a catchall for printing debug information in the assembler file.  */
425
426extern int flag_debug_asm;
427
428/* -fgnu-linker specifies use of the GNU linker for initializations.
429   -fno-gnu-linker says that collect will be used.  */
430extern int flag_gnu_linker;
431
432/* Tag all structures with __attribute__(packed) */
433extern int flag_pack_struct;
434
435/* This flag is only tested if alias checking is enabled.
436   0 if pointer arguments may alias each other.  True in C.
437   1 if pointer arguments may not alias each other but may alias
438   global variables.
439   2 if pointer arguments may not alias each other and may not
440   alias global variables.  True in Fortran.
441   The value is ignored if flag_alias_check is 0.  */
442extern int flag_argument_noalias;
443
444/* Nonzero if we should do (language-dependent) alias analysis.
445   Typically, this analysis will assume that expressions of certain
446   types do not alias expressions of certain other types.  Only used
447   if alias analysis (in general) is enabled.  */
448extern int flag_strict_aliasing;
449
450/* Emit code to check for stack overflow; also may cause large objects
451   to be allocated dynamically.  */
452extern int flag_stack_check;
453
454/* Do the full regmove optimization pass.  */
455extern int flag_regmove;
456
457/* Other basic status info about current function.  */
458
459/* Nonzero means current function must be given a frame pointer.
460   Set in stmt.c if anything is allocated on the stack there.
461   Set in reload1.c if anything is allocated on the stack there.  */
462
463extern int frame_pointer_needed;
464
465/* Set nonzero if jump_optimize finds that control falls through
466   at the end of the function.  */
467
468extern int can_reach_end;
469
470/* Nonzero if function being compiled receives nonlocal gotos
471   from nested functions.  */
472
473extern int current_function_has_nonlocal_label;
474
475/* Nonzero if function being compiled has nonlocal gotos to parent
476   function.  */
477
478extern int current_function_has_nonlocal_goto;
479
480/* Nonzero if this function has a computed goto.
481
482   It is computed during find_basic_blocks or during stupid life
483   analysis.  */
484
485extern int current_function_has_computed_jump;
486
487/* Nonzero if GCC must add code to check memory access (used by Checker).  */
488
489extern int flag_check_memory_usage;
490
491/* Nonzero if GCC must prefix function names (used with
492   flag_check_memory_usage).  */
493
494extern int flag_prefix_function_name;
495/* Nonzero if the current function is a thunk, so we should try to cut
496   corners where we can.  */
497extern int current_function_is_thunk;
498
499/* Value of the -G xx switch, and whether it was passed or not.  */
500extern int g_switch_value;
501extern int g_switch_set;
502