gcc/flags.h

   1 /* Compilation switch flag definitions for GNU CC.
   2    Copyright (C) 1987, 88, 94, 95, 96, 97, 1998 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 optimize for size.  -Os.  */
  57
  58 extern int optimize_size;
  59
  60 /* Nonzero means do stupid register allocation.  -noreg.
  61    Currently, this is 1 if `optimize' is 0.  */
  62
  63 extern 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
  68 extern int quiet_flag;
  69
  70 /* Don't print warning messages.  -w.  */
  71
  72 extern int inhibit_warnings;
  73
  74 /* Do print extra warnings (such as for uninitialized variables).  -W.  */
  75
  76 extern int extra_warnings;
  77
  78 /* Nonzero to warn about unused local variables.  */
  79
  80 extern int warn_unused;
  81
  82 /* Nonzero means warn if inline function is too large.  */
  83
  84 extern int warn_inline;
  85
  86 /* Nonzero to warn about variables used before they are initialized.  */
  87
  88 extern 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
  96 extern int warn_unknown_pragmas;
  97
  98 /* Nonzero means warn about all declarations which shadow others.   */
  99
 100 extern int warn_shadow;
 101
 102 /* Warn if a switch on an enum fails to have a case for every enum value.  */
 103
 104 extern 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
 109 extern 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
 115 extern int warn_cast_align;
 116
 117 /* Nonzero means warn that dbx info for template class methods isn't fully
 118    supported yet.  */
 119
 120 extern 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
 125 extern int warn_id_clash;
 126 extern 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
 132 extern int warn_larger_than;
 133 extern 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
 138 extern int warn_aggregate_return;
 139
 140 /* Nonzero if generating code to do profiling.  */
 141
 142 extern int profile_flag;
 143
 144 /* Nonzero if generating code to do profiling on the basis of basic blocks.  */
 145
 146 extern int profile_block_flag;
 147
 148 /* Nonzero if generating code to profile program flow graph arcs. */
 149
 150 extern int profile_arc_flag;
 151
 152 /* Nonzero if generating info for gcov to calculate line test coverage. */
 153
 154 extern int flag_test_coverage;
 155
 156 /* Nonzero indicates that branch taken probabilities should be calculated. */
 157
 158 extern int flag_branch_probabilities;
 159
 160 /* Nonzero for -pedantic switch: warn about anything
 161    that standard C forbids.  */
 162
 163 extern int pedantic;
 164
 165 /* Temporarily suppress certain warnings.
 166    This is set while reading code from a system header file.  */
 167
 168 extern int in_system_header;
 169
 170 /* Nonzero for -dp: annotate the assembly with a comment describing the
 171    pattern and alternative used.  */
 172
 173 extern int flag_print_asm_name;
 174 \f
 175 /* Now the symbols that are set with `-f' switches.  */
 176
 177 /* Nonzero means `char' should be signed.  */
 178
 179 extern int flag_signed_char;
 180
 181 /* Nonzero means give an enum type only as many bytes as it needs.  */
 182
 183 extern int flag_short_enums;
 184
 185 /* Nonzero for -fcaller-saves: allocate values in regs that need to
 186    be saved across function calls, if that produces overall better code.
 187    Optional now, so people can test it.  */
 188
 189 extern int flag_caller_saves;
 190
 191 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 192
 193 extern int flag_pcc_struct_return;
 194
 195 /* Nonzero for -fforce-mem: load memory value into a register
 196    before arithmetic on it.  This makes better cse but slower compilation.  */
 197
 198 extern int flag_force_mem;
 199
 200 /* Nonzero for -fforce-addr: load memory address into a register before
 201    reference to memory.  This makes better cse but slower compilation.  */
 202
 203 extern int flag_force_addr;
 204
 205 /* Nonzero for -fdefer-pop: don't pop args after each function call;
 206    instead save them up to pop many calls' args with one insns.  */
 207
 208 extern int flag_defer_pop;
 209
 210 /* Nonzero for -ffloat-store: don't allocate floats and doubles
 211    in extended-precision registers.  */
 212
 213 extern int flag_float_store;
 214
 215 /* Nonzero enables strength-reduction in loop.c.  */
 216
 217 extern int flag_strength_reduce;
 218
 219 /* Nonzero enables loop unrolling in unroll.c.  Only loops for which the
 220    number of iterations can be calculated at compile-time (UNROLL_COMPLETELY,
 221    UNROLL_MODULO) or at run-time (preconditioned to be UNROLL_MODULO) are
 222    unrolled.  */
 223
 224 extern int flag_unroll_loops;
 225
 226 /* Nonzero enables loop unrolling in unroll.c.  All loops are unrolled.
 227    This is generally not a win.  */
 228
 229 extern int flag_unroll_all_loops;
 230
 231 /* Nonzero forces all invariant computations in loops to be moved
 232    outside the loop. */
 233
 234 extern int flag_move_all_movables;
 235
 236 /* Nonzero forces all general induction variables in loops to be
 237    strength reduced. */
 238
 239 extern int flag_reduce_all_givs;
 240
 241 /* Nonzero for -fcse-follow-jumps:
 242    have cse follow jumps to do a more extensive job.  */
 243
 244 extern int flag_cse_follow_jumps;
 245
 246 /* Nonzero for -fcse-skip-blocks:
 247    have cse follow a branch around a block.  */
 248
 249 extern int flag_cse_skip_blocks;
 250
 251 /* Nonzero for -fexpensive-optimizations:
 252    perform miscellaneous relatively-expensive optimizations.  */
 253 extern int flag_expensive_optimizations;
 254
 255 /* Nonzero for -fwritable-strings:
 256    store string constants in data segment and don't uniquize them.  */
 257
 258 extern int flag_writable_strings;
 259
 260 /* Nonzero means don't put addresses of constant functions in registers.
 261    Used for compiling the Unix kernel, where strange substitutions are
 262    done on the assembly output.  */
 263
 264 extern int flag_no_function_cse;
 265
 266 /* Nonzero for -fomit-frame-pointer:
 267    don't make a frame pointer in simple functions that don't require one.  */
 268
 269 extern int flag_omit_frame_pointer;
 270
 271 /* Nonzero to inhibit use of define_optimization peephole opts.  */
 272
 273 extern int flag_no_peephole;
 274
 275 /* Nonzero means all references through pointers are volatile.  */
 276
 277 extern int flag_volatile;
 278
 279 /* Nonzero means treat all global and extern variables as global.  */
 280
 281 extern int flag_volatile_global;
 282
 283 /* Nonzero allows GCC to violate some IEEE or ANSI rules regarding math
 284    operations in the interest of optimization.  For example it allows
 285    GCC to assume arguments to sqrt are nonnegative numbers, allowing
 286    faster code for sqrt to be generated. */
 287
 288 extern int flag_fast_math;
 289
 290 /* Nonzero means to run loop optimizations twice.  */
 291
 292 extern int flag_rerun_loop_opt;
 293
 294 /* Nonzero means make functions that look like good inline candidates
 295    go inline.  */
 296
 297 extern int flag_inline_functions;
 298
 299 /* Nonzero for -fkeep-inline-functions: even if we make a function
 300    go inline everywhere, keep its definition around for debugging
 301    purposes.  */
 302
 303 extern int flag_keep_inline_functions;
 304
 305 /* Nonzero means that functions declared `inline' will be treated
 306    as `static'.  Prevents generation of zillions of copies of unused
 307    static inline functions; instead, `inlines' are written out
 308    only when actually used.  Used in conjunction with -g.  Also
 309    does the right thing with #pragma interface.  */
 310
 311 extern int flag_no_inline;
 312
 313 /* Nonzero if we are only using compiler to check syntax errors.  */
 314
 315 extern int flag_syntax_only;
 316
 317 /* Nonzero means we should save auxiliary info into a .X file.  */
 318
 319 extern int flag_gen_aux_info;
 320
 321 /* Nonzero means make the text shared if supported.  */
 322
 323 extern int flag_shared_data;
 324
 325 /* flag_schedule_insns means schedule insns within basic blocks (before
 326    local_alloc).
 327    flag_schedule_insns_after_reload means schedule insns after
 328    global_alloc.  */
 329
 330 extern int flag_schedule_insns;
 331 extern int flag_schedule_insns_after_reload;
 332
 333 #ifdef HAIFA
 334 /* The following flags have effect only for scheduling before register
 335    allocation:
 336
 337    flag_schedule_interblock means schedule insns accross basic blocks.
 338    flag_schedule_speculative means allow speculative motion of non-load insns.
 339    flag_schedule_speculative_load means allow speculative motion of some
 340    load insns.
 341    flag_schedule_speculative_load_dangerous allows speculative motion of more
 342    load insns.  */
 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
 349 /* flag_on_branch_count_reg means try to replace add-1,compare,branch tupple
 350    by a cheaper branch, on a count register. */
 351 extern int flag_branch_on_count_reg;
 352 #endif  /* HAIFA */
 353
 354
 355 /* Nonzero means put things in delayed-branch slots if supported. */
 356
 357 extern int flag_delayed_branch;
 358
 359 /* Nonzero means pretend it is OK to examine bits of target floats,
 360    even if that isn't true.  The resulting code will have incorrect constants,
 361    but the same series of instructions that the native compiler would make.  */
 362
 363 extern int flag_pretend_float;
 364
 365 /* Nonzero means change certain warnings into errors.
 366    Usually these are warnings about failure to conform to some standard.  */
 367
 368 extern int flag_pedantic_errors;
 369
 370 /* Nonzero means generate position-independent code.
 371    This is not fully implemented yet.  */
 372
 373 extern int flag_pic;
 374
 375 /* Nonzero means generate extra code for exception handling and enable
 376    exception handling.  */
 377
 378 extern int flag_exceptions;
 379
 380 /* Nonzero means use the new model for exception handling. Replaces
 381    -DNEW_EH_MODEL as a compile option. */
 382
 383 extern int flag_new_exceptions;
 384
 385 /* Nonzero means don't place uninitialized global data in common storage
 386    by default.  */
 387
 388 extern int flag_no_common;
 389
 390 /* -finhibit-size-directive inhibits output of .size for ELF.
 391    This is used only for compiling crtstuff.c,
 392    and it may be extended to other effects
 393    needed for crtstuff.c on other systems.  */
 394 extern int flag_inhibit_size_directive;
 395
 396 /* Nonzero means place each function into its own section on those platforms
 397    which support arbitrary section names and unlimited numbers of sections.  */
 398
 399 extern int flag_function_sections;
 400
 401 /* ... and similar for data.  */
 402
 403 extern int flag_data_sections;
 404
 405 /* -fverbose-asm causes extra commentary information to be produced in
 406    the generated assembly code (to make it more readable).  This option
 407    is generally only of use to those who actually need to read the
 408    generated assembly code (perhaps while debugging the compiler itself).
 409    -fno-verbose-asm, the default, causes the extra information
 410    to not be added and is useful when comparing two assembler files.  */
 411
 412 extern int flag_verbose_asm;
 413
 414 /* -dA causes debug information to be produced in
 415    the generated assembly code (to make it more readable).  This option
 416    is generally only of use to those who actually need to read the
 417    generated assembly code (perhaps while debugging the compiler itself).
 418    Currently, this switch is only used by dwarfout.c; however, it is intended
 419    to be a catchall for printing debug information in the assembler file.  */
 420
 421 extern int flag_debug_asm;
 422
 423 /* -fgnu-linker specifies use of the GNU linker for initializations.
 424    -fno-gnu-linker says that collect will be used.  */
 425 extern int flag_gnu_linker;
 426
 427 /* Tag all structures with __attribute__(packed) */
 428 extern int flag_pack_struct;
 429
 430 /* This flag is only tested if alias checking is enabled.
 431    0 if pointer arguments may alias each other.  True in C.
 432    1 if pointer arguments may not alias each other but may alias
 433    global variables.
 434    2 if pointer arguments may not alias each other and may not
 435    alias global variables.  True in Fortran.
 436    The value is ignored if flag_alias_check is 0.  */
 437 extern int flag_argument_noalias;
 438
 439 /* Nonzero if we should do (language-dependent) alias analysis.
 440    Typically, this analysis will assume that expressions of certain
 441    types do not alias expressions of certain other types.  Only used
 442    if alias analysis (in general) is enabled.  */
 443 extern int flag_strict_aliasing;
 444
 445 /* Emit code to check for stack overflow; also may cause large objects
 446    to be allocated dynamically.  */
 447 extern int flag_stack_check;
 448
 449 /* Do the full regmove optimization pass.  */
 450 extern int flag_regmove;
 451
 452 /* Instrument functions with calls at entry and exit, for profiling.  */
 453 extern int flag_instrument_function_entry_exit;
 454 \f
 455 /* Other basic status info about current function.  */
 456
 457 /* Nonzero means current function must be given a frame pointer.
 458    Set in stmt.c if anything is allocated on the stack there.
 459    Set in reload1.c if anything is allocated on the stack there.  */
 460
 461 extern int frame_pointer_needed;
 462
 463 /* Set nonzero if jump_optimize finds that control falls through
 464    at the end of the function.  */
 465
 466 extern int can_reach_end;
 467
 468 /* Nonzero if function being compiled receives nonlocal gotos
 469    from nested functions.  */
 470
 471 extern int current_function_has_nonlocal_label;
 472
 473 /* Nonzero if function being compiled has nonlocal gotos to parent
 474    function.  */
 475
 476 extern int current_function_has_nonlocal_goto;
 477
 478 /* Nonzero if this function has a computed goto.
 479
 480    It is computed during find_basic_blocks or during stupid life
 481    analysis.  */
 482
 483 extern int current_function_has_computed_jump;
 484
 485 /* Nonzero if GCC must add code to check memory access (used by Checker).  */
 486
 487 extern int flag_check_memory_usage;
 488
 489 /* Nonzero if GCC must prefix function names (used with
 490    flag_check_memory_usage).  */
 491
 492 extern int flag_prefix_function_name;
 493 /* Nonzero if the current function is a thunk, so we should try to cut
 494    corners where we can.  */
 495 extern int current_function_is_thunk;
 496
 497 /* Value of the -G xx switch, and whether it was passed or not.  */
 498 extern int g_switch_value;
 499 extern int g_switch_set;