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