gcc/flags.h

   1 /* Compilation switch flag definitions for GNU CC.
   2    Copyright (C) 1987, 88, 94, 95, 96, 1997 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Name of the input .c file being compiled.  */
  22 extern char *main_input_filename;
  23
  24 enum 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.  */
  35 extern enum debug_info_type write_symbols;
  36
  37 enum 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.  */
  46 extern enum debug_info_level debug_info_level;
  47
  48 /* Nonzero means use GNU-only extensions in the generated symbolic
  49    debugging information.  */
  50 extern int use_gnu_debug_info_extensions;
  51
  52 /* Nonzero means do optimizations.  -opt.  */
  53
  54 extern int optimize;
  55
  56 /* Nonzero means do stupid register allocation.  -noreg.
  57    Currently, this is 1 if `optimize' is 0.  */
  58
  59 extern int obey_regdecls;
  60
  61 /* Don't print functions as they are compiled and don't print
  62    times taken by the various passes.  -quiet.  */
  63
  64 extern int quiet_flag;
  65
  66 /* Don't print warning messages.  -w.  */
  67
  68 extern int inhibit_warnings;
  69
  70 /* Do print extra warnings (such as for uninitialized variables).  -W.  */
  71
  72 extern int extra_warnings;
  73
  74 /* Nonzero to warn about unused local variables.  */
  75
  76 extern int warn_unused;
  77
  78 /* Nonzero means warn if inline function is too large.  */
  79
  80 extern int warn_inline;
  81
  82 /* Nonzero to warn about variables used before they are initialized.  */
  83
  84 extern int warn_uninitialized;
  85
  86 /* Zero if unknown pragmas are ignored
  87    One if the compiler should warn about an unknown pragma not in
  88    a system include file.
  89    Greater than one if the compiler should warn for all unknown
  90    pragmas.  */
  91
  92 extern int warn_unknown_pragmas;
  93
  94 /* Nonzero means warn about all declarations which shadow others.   */
  95
  96 extern int warn_shadow;
  97
  98 /* Warn if a switch on an enum fails to have a case for every enum value.  */
  99
 100 extern int warn_switch;
 101
 102 /* Nonzero means warn about function definitions that default the return type
 103    or that use a null return and have a return-type other than void.  */
 104
 105 extern int warn_return_type;
 106
 107 /* Nonzero means warn about pointer casts that increase the required
 108    alignment of the target type (and might therefore lead to a crash
 109    due to a misaligned access).  */
 110
 111 extern int warn_cast_align;
 112
 113 /* Nonzero means warn that dbx info for template class methods isn't fully
 114    supported yet.  */
 115
 116 extern int warn_template_debugging;
 117
 118 /* Nonzero means warn about any identifiers that match in the first N
 119    characters.  The value N is in `id_clash_len'.  */
 120
 121 extern int warn_id_clash;
 122 extern unsigned id_clash_len;
 123
 124 /* Nonzero means warn about any objects definitions whose size is larger
 125    than N bytes.  Also want about function definitions whose returned
 126    values are larger than N bytes. The value N is in `larger_than_size'.  */
 127
 128 extern int warn_larger_than;
 129 extern unsigned larger_than_size;
 130
 131 /* Warn if a function returns an aggregate,
 132    since there are often incompatible calling conventions for doing this.  */
 133
 134 extern int warn_aggregate_return;
 135
 136 /* Nonzero if generating code to do profiling.  */
 137
 138 extern int profile_flag;
 139
 140 /* Nonzero if generating code to do profiling on the basis of basic blocks.  */
 141
 142 extern int profile_block_flag;
 143
 144 /* Nonzero if generating code to profile program flow graph arcs. */
 145
 146 extern int profile_arc_flag;
 147
 148 /* Nonzero if generating info for gcov to calculate line test coverage. */
 149
 150 extern int flag_test_coverage;
 151
 152 /* Nonzero indicates that branch taken probabilities should be calculated. */
 153
 154 extern int flag_branch_probabilities;
 155
 156 /* Nonzero for -pedantic switch: warn about anything
 157    that standard C forbids.  */
 158
 159 extern int pedantic;
 160
 161 /* Temporarily suppress certain warnings.
 162    This is set while reading code from a system header file.  */
 163
 164 extern int in_system_header;
 165
 166 /* Nonzero for -dp: annotate the assembly with a comment describing the
 167    pattern and alternative used.  */
 168
 169 extern int flag_print_asm_name;
 170 \f
 171 /* Now the symbols that are set with `-f' switches.  */
 172
 173 /* Nonzero means `char' should be signed.  */
 174
 175 extern int flag_signed_char;
 176
 177 /* Nonzero means give an enum type only as many bytes as it needs.  */
 178
 179 extern int flag_short_enums;
 180
 181 /* Nonzero for -fcaller-saves: allocate values in regs that need to
 182    be saved across function calls, if that produces overall better code.
 183    Optional now, so people can test it.  */
 184
 185 extern int flag_caller_saves;
 186
 187 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 188
 189 extern int flag_pcc_struct_return;
 190
 191 /* Nonzero for -fforce-mem: load memory value into a register
 192    before arithmetic on it.  This makes better cse but slower compilation.  */
 193
 194 extern int flag_force_mem;
 195
 196 /* Nonzero for -fforce-addr: load memory address into a register before
 197    reference to memory.  This makes better cse but slower compilation.  */
 198
 199 extern int flag_force_addr;
 200
 201 /* Nonzero for -fdefer-pop: don't pop args after each function call;
 202    instead save them up to pop many calls' args with one insns.  */
 203
 204 extern int flag_defer_pop;
 205
 206 /* Nonzero for -ffloat-store: don't allocate floats and doubles
 207    in extended-precision registers.  */
 208
 209 extern int flag_float_store;
 210
 211 /* Nonzero enables strength-reduction in loop.c.  */
 212
 213 extern int flag_strength_reduce;
 214
 215 /* Nonzero enables loop unrolling in unroll.c.  Only loops for which the
 216    number of iterations can be calculated at compile-time (UNROLL_COMPLETELY,
 217    UNROLL_MODULO) or at run-time (preconditioned to be UNROLL_MODULO) are
 218    unrolled.  */
 219
 220 extern int flag_unroll_loops;
 221
 222 /* Nonzero enables loop unrolling in unroll.c.  All loops are unrolled.
 223    This is generally not a win.  */
 224
 225 extern int flag_unroll_all_loops;
 226
 227 /* Nonzero forces all invariant computations in loops to be moved
 228    outside the loop. */
 229
 230 extern int flag_move_all_movables;
 231
 232 /* Nonzero forces all general induction variables in loops to be
 233    strength reduced. */
 234
 235 extern int flag_reduce_all_givs;
 236
 237 /* Nonzero for -fcse-follow-jumps:
 238    have cse follow jumps to do a more extensive job.  */
 239
 240 extern int flag_cse_follow_jumps;
 241
 242 /* Nonzero for -fcse-skip-blocks:
 243    have cse follow a branch around a block.  */
 244
 245 extern int flag_cse_skip_blocks;
 246
 247 /* Nonzero for -fexpensive-optimizations:
 248    perform miscellaneous relatively-expensive optimizations.  */
 249 extern int flag_expensive_optimizations;
 250
 251 /* Nonzero for -fwritable-strings:
 252    store string constants in data segment and don't uniquize them.  */
 253
 254 extern int flag_writable_strings;
 255
 256 /* Nonzero means don't put addresses of constant functions in registers.
 257    Used for compiling the Unix kernel, where strange substitutions are
 258    done on the assembly output.  */
 259
 260 extern int flag_no_function_cse;
 261
 262 /* Nonzero for -fomit-frame-pointer:
 263    don't make a frame pointer in simple functions that don't require one.  */
 264
 265 extern int flag_omit_frame_pointer;
 266
 267 /* Nonzero to inhibit use of define_optimization peephole opts.  */
 268
 269 extern int flag_no_peephole;
 270
 271 /* Nonzero means all references through pointers are volatile.  */
 272
 273 extern int flag_volatile;
 274
 275 /* Nonzero means treat all global and extern variables as global.  */
 276
 277 extern int flag_volatile_global;
 278
 279 /* Nonzero allows GCC to violate some IEEE or ANSI rules regarding math
 280    operations in the interest of optimization.  For example it allows
 281    GCC to assume arguments to sqrt are nonnegative numbers, allowing
 282    faster code for sqrt to be generated. */
 283
 284 extern int flag_fast_math;
 285
 286 /* Nonzero means to run loop optimizations twice.  */
 287
 288 extern int flag_rerun_loop_opt;
 289
 290 /* Nonzero means make functions that look like good inline candidates
 291    go inline.  */
 292
 293 extern int flag_inline_functions;
 294
 295 /* Nonzero for -fkeep-inline-functions: even if we make a function
 296    go inline everywhere, keep its definition around for debugging
 297    purposes.  */
 298
 299 extern int flag_keep_inline_functions;
 300
 301 /* Nonzero means that functions declared `inline' will be treated
 302    as `static'.  Prevents generation of zillions of copies of unused
 303    static inline functions; instead, `inlines' are written out
 304    only when actually used.  Used in conjunction with -g.  Also
 305    does the right thing with #pragma interface.  */
 306
 307 extern int flag_no_inline;
 308
 309 /* Nonzero if we are only using compiler to check syntax errors.  */
 310
 311 extern int flag_syntax_only;
 312
 313 /* Nonzero means we should save auxiliary info into a .X file.  */
 314
 315 extern int flag_gen_aux_info;
 316
 317 /* Nonzero means make the text shared if supported.  */
 318
 319 extern int flag_shared_data;
 320
 321 /* flag_schedule_insns means schedule insns within basic blocks (before
 322    local_alloc).
 323    flag_schedule_insns_after_reload means schedule insns after
 324    global_alloc.  */
 325
 326 extern int flag_schedule_insns;
 327 extern int flag_schedule_insns_after_reload;
 328
 329 #ifdef HAIFA
 330 /* The following flags have effect only for scheduling before register
 331    allocation:
 332
 333    flag_schedule_interblock means schedule insns accross basic blocks.
 334    flag_schedule_speculative means allow speculative motion of non-load insns.
 335    flag_schedule_speculative_load means allow speculative motion of some
 336    load insns.
 337    flag_schedule_speculative_load_dangerous allows speculative motion of more
 338    load insns.
 339    flag_schedule_reverse_before_reload means try to reverse original order
 340    of insns (S).
 341    flag_schedule_reverse_after_reload means try to reverse original order
 342    of insns (R).  */
 343
 344 extern int flag_schedule_interblock;
 345 extern int flag_schedule_speculative;
 346 extern int flag_schedule_speculative_load;
 347 extern int flag_schedule_speculative_load_dangerous;
 348 extern int flag_schedule_reverse_before_reload;
 349 extern int flag_schedule_reverse_after_reload;
 350
 351 /* flag_on_branch_count_reg means try to replace add-1,compare,branch tupple
 352    by a cheaper branch, on a count register. */
 353 extern int flag_branch_on_count_reg;
 354 #endif  /* HAIFA */
 355
 356
 357 /* Nonzero means put things in delayed-branch slots if supported. */
 358
 359 extern int flag_delayed_branch;
 360
 361 /* Nonzero means pretend it is OK to examine bits of target floats,
 362    even if that isn't true.  The resulting code will have incorrect constants,
 363    but the same series of instructions that the native compiler would make.  */
 364
 365 extern int flag_pretend_float;
 366
 367 /* Nonzero means change certain warnings into errors.
 368    Usually these are warnings about failure to conform to some standard.  */
 369
 370 extern int flag_pedantic_errors;
 371
 372 /* Nonzero means generate position-independent code.
 373    This is not fully implemented yet.  */
 374
 375 extern int flag_pic;
 376
 377 /* Nonzero means generate extra code for exception handling and enable
 378    exception handling.  */
 379
 380 extern int flag_exceptions;
 381
 382 /* Nonzero means don't place uninitialized global data in common storage
 383    by default.  */
 384
 385 extern int flag_no_common;
 386
 387 /* -finhibit-size-directive inhibits output of .size for ELF.
 388    This is used only for compiling crtstuff.c,
 389    and it may be extended to other effects
 390    needed for crtstuff.c on other systems.  */
 391 extern int flag_inhibit_size_directive;
 392
 393 /* Nonzero means place each function into its own section on those platforms
 394    which support arbitrary section names and unlimited numbers of sections.  */
 395
 396 extern int flag_function_sections;
 397
 398 /* -fverbose-asm causes extra commentary information to be produced in
 399    the generated assembly code (to make it more readable).  This option
 400    is generally only of use to those who actually need to read the
 401    generated assembly code (perhaps while debugging the compiler itself).
 402    -fverbose-asm is the default.  -fno-verbose-asm causes the extra information
 403    to not be added and is useful when comparing two assembler files.  */
 404
 405 extern int flag_verbose_asm;
 406
 407 /* -dA causes debug information to be produced in
 408    the generated assembly code (to make it more readable).  This option
 409    is generally only of use to those who actually need to read the
 410    generated assembly code (perhaps while debugging the compiler itself).
 411    Currently, this switch is only used by dwarfout.c; however, it is intended
 412    to be a catchall for printing debug information in the assembler file.  */
 413
 414 extern int flag_debug_asm;
 415
 416 /* -fgnu-linker specifies use of the GNU linker for initializations.
 417    -fno-gnu-linker says that collect will be used.  */
 418 extern int flag_gnu_linker;
 419
 420 /* Tag all structures with __attribute__(packed) */
 421 extern int flag_pack_struct;
 422
 423 /* This flag is only tested if alias checking is enabled.
 424    0 if pointer arguments may alias each other.  True in C.
 425    1 if pointer arguments may not alias each other but may alias
 426    global variables.
 427    2 if pointer arguments may not alias each other and may not
 428    alias global variables.  True in Fortran.
 429    The value is ignored if flag_alias_check is 0.  */
 430 extern int flag_argument_noalias;
 431
 432 /* Emit code to check for stack overflow; also may cause large objects
 433    to be allocated dynamically.  */
 434 extern int flag_stack_check;
 435 \f
 436 /* Other basic status info about current function.  */
 437
 438 /* Nonzero means current function must be given a frame pointer.
 439    Set in stmt.c if anything is allocated on the stack there.
 440    Set in reload1.c if anything is allocated on the stack there.  */
 441
 442 extern int frame_pointer_needed;
 443
 444 /* Set nonzero if jump_optimize finds that control falls through
 445    at the end of the function.  */
 446
 447 extern int can_reach_end;
 448
 449 /* Nonzero if function being compiled receives nonlocal gotos
 450    from nested functions.  */
 451
 452 extern int current_function_has_nonlocal_label;
 453
 454 /* Nonzero if function being compiled has nonlocal gotos to parent
 455    function.  */
 456
 457 extern int current_function_has_nonlocal_goto;
 458
 459 /* Nonzero if GCC must add code to check memory access (used by Checker).  */
 460
 461 extern int flag_check_memory_usage;
 462
 463 /* Nonzero if GCC must prefix function names (used with
 464    flag_check_memory_usage).  */
 465
 466 extern int flag_prefix_function_name;
 467 /* Nonzero if the current function is a thunk, so we should try to cut
 468    corners where we can.  */
 469 extern int current_function_is_thunk;