gcc/flags.h

   1 /* Compilation switch flag definitions for GCC.
   2    Copyright (C) 1987, 1988, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002,
   3    2003, 2004, 2005, 2006, 2007, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef GCC_FLAGS_H
  23 #define GCC_FLAGS_H
  24
  25 #include "coretypes.h"
  26 #include "options.h"
  27 #include "real.h"
  28
  29 enum debug_info_type
  30 {
  31   NO_DEBUG,         /* Write no debug info.  */
  32   DBX_DEBUG,        /* Write BSD .stabs for DBX (using dbxout.c).  */
  33   SDB_DEBUG,        /* Write COFF for (old) SDB (using sdbout.c).  */
  34   DWARF2_DEBUG,     /* Write Dwarf v2 debug info (using dwarf2out.c).  */
  35   XCOFF_DEBUG,      /* Write IBM/Xcoff debug info (using dbxout.c).  */
  36   VMS_DEBUG,        /* Write VMS debug info (using vmsdbgout.c).  */
  37   VMS_AND_DWARF2_DEBUG /* Write VMS debug info (using vmsdbgout.c).
  38                           and DWARF v2 debug info (using dwarf2out.c).  */
  39 };
  40
  41 /* Specify which kind of debugging info to generate.  */
  42 extern enum debug_info_type write_symbols;
  43
  44 /* Names of debug_info_type, for error messages.  */
  45 extern const char *const debug_type_names[];
  46
  47 enum debug_info_level
  48 {
  49   DINFO_LEVEL_NONE,     /* Write no debugging info.  */
  50   DINFO_LEVEL_TERSE,    /* Write minimal info to support tracebacks only.  */
  51   DINFO_LEVEL_NORMAL,   /* Write info for all declarations (and line table).  */
  52   DINFO_LEVEL_VERBOSE   /* Write normal info plus #define/#undef info.  */
  53 };
  54
  55 /* Specify how much debugging info to generate.  */
  56 extern enum debug_info_level debug_info_level;
  57
  58 /* A major contribution to object and executable size is debug
  59    information size.  A major contribution to debug information
  60    size is struct descriptions replicated in several object files.
  61    The following function determines whether or not debug information
  62    should be generated for a given struct.  The indirect parameter
  63    indicates that the struct is being handled indirectly, via
  64    a pointer.  See opts.c for the implementation. */
  65
  66 enum debug_info_usage
  67 {
  68   DINFO_USAGE_DFN,      /* A struct definition. */
  69   DINFO_USAGE_DIR_USE,  /* A direct use, such as the type of a variable. */
  70   DINFO_USAGE_IND_USE,  /* An indirect use, such as through a pointer. */
  71   DINFO_USAGE_NUM_ENUMS /* The number of enumerators. */
  72 };
  73
  74 extern bool should_emit_struct_debug (tree type_decl, enum debug_info_usage);
  75 extern void set_struct_debug_option (const char *value);
  76
  77 /* Nonzero means use GNU-only extensions in the generated symbolic
  78    debugging information.  */
  79 extern bool use_gnu_debug_info_extensions;
  80
  81 /* Enumerate visibility settings.  This is deliberately ordered from most
  82    to least visibility.  */
  83 #ifndef SYMBOL_VISIBILITY_DEFINED
  84 #define SYMBOL_VISIBILITY_DEFINED
  85 enum symbol_visibility
  86 {
  87   VISIBILITY_DEFAULT,
  88   VISIBILITY_PROTECTED,
  89   VISIBILITY_HIDDEN,
  90   VISIBILITY_INTERNAL
  91 };
  92 #endif
  93
  94 /* The default visibility for all symbols (unless overridden).  */
  95 extern enum symbol_visibility default_visibility;
  96
  97 struct visibility_flags
  98 {
  99   unsigned inpragma : 1;        /* True when in #pragma GCC visibility.  */
 100   unsigned inlines_hidden : 1;  /* True when -finlineshidden in effect.  */
 101 };
 102
 103 /* Global visibility options.  */
 104 extern struct visibility_flags visibility_options;
 105
 106 /* Nonzero means do optimizations.  -opt.  */
 107
 108 extern int optimize;
 109
 110 /* Nonzero means optimize for size.  -Os.  */
 111
 112 extern int optimize_size;
 113
 114 /* True if this is the LTO front end (lto1).  This is used to disable
 115    gimple generation and lowering passes that are normally run on the
 116    output of a front end.  These passes must be bypassed for lto since
 117    they have already been done before the gimple was written.  */
 118
 119 extern bool in_lto_p;
 120
 121 /* Nonzero if we should write GIMPLE bytecode for link-time optimization.  */
 122
 123 extern int flag_generate_lto;
 124
 125 /* Used to set the level of -Wstrict-aliasing, when no level is specified.
 126    The external way to set the default level is to use
 127    -Wstrict-aliasing=level.
 128    ONOFF is assumed to take value 1 when -Wstrict-aliasing is specified,
 129    and 0 otherwise.  After calling this function, wstrict_aliasing will be
 130    set to the default value of -Wstrict_aliasing=level.  */
 131
 132 extern void set_Wstrict_aliasing (int onoff);
 133
 134 /* Nonzero means warn about any objects definitions whose size is larger
 135    than N bytes.  Also want about function definitions whose returned
 136    values are larger than N bytes. The value N is in `larger_than_size'.  */
 137
 138 extern bool warn_larger_than;
 139 extern HOST_WIDE_INT larger_than_size;
 140
 141 /* Nonzero means warn about any function whose frame size is larger
 142    than N bytes. */
 143
 144 extern bool warn_frame_larger_than;
 145 extern HOST_WIDE_INT frame_larger_than_size;
 146
 147 /* Nonzero for -dp: annotate the assembly with a comment describing the
 148    pattern and alternative used.  */
 149
 150 extern int flag_print_asm_name;
 151 \f
 152 /* Now the symbols that are set with `-f' switches.  */
 153
 154 /* Nonzero means `char' should be signed.  */
 155
 156 extern int flag_signed_char;
 157
 158 /* Nonzero means give an enum type only as many bytes as it needs.  A value
 159    of 2 means it has not yet been initialized.  */
 160
 161 extern int flag_short_enums;
 162
 163 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 164
 165 extern int flag_pcc_struct_return;
 166
 167 /* 0 means straightforward implementation of complex divide acceptable.
 168    1 means wide ranges of inputs must work for complex divide.
 169    2 means C99-like requirements for complex multiply and divide.  */
 170
 171 extern int flag_complex_method;
 172
 173 /* Nonzero if we are only using compiler to check syntax errors.  */
 174
 175 extern int rtl_dump_and_exit;
 176
 177 /* Nonzero means we should save auxiliary info into a .X file.  */
 178
 179 extern int flag_gen_aux_info;
 180
 181 /* Nonzero means suppress output of instruction numbers and line number
 182    notes in debugging dumps.  */
 183
 184 extern int flag_dump_unnumbered;
 185
 186 /* Nonzero means change certain warnings into errors.
 187    Usually these are warnings about failure to conform to some standard.  */
 188
 189 extern int flag_pedantic_errors;
 190
 191 /* Nonzero means make permerror produce warnings instead of errors.  */
 192
 193 extern int flag_permissive;
 194
 195 /* Nonzero if we are compiling code for a shared library, zero for
 196    executable.  */
 197
 198 extern int flag_shlib;
 199
 200 /* -dA causes debug information to be produced in
 201    the generated assembly code (to make it more readable).  This option
 202    is generally only of use to those who actually need to read the
 203    generated assembly code (perhaps while debugging the compiler itself).
 204    Currently, this switch is only used by dwarfout.c; however, it is intended
 205    to be a catchall for printing debug information in the assembler file.  */
 206
 207 extern int flag_debug_asm;
 208
 209 /* Generate code for GNU or NeXT Objective-C runtime environment.  */
 210
 211 extern int flag_next_runtime;
 212
 213 extern int flag_dump_rtl_in_asm;
 214
 215 /* The algorithm used for the integrated register allocator (IRA).  */
 216 enum ira_algorithm
 217 {
 218   IRA_ALGORITHM_CB,
 219   IRA_ALGORITHM_PRIORITY
 220 };
 221
 222 extern enum ira_algorithm flag_ira_algorithm;
 223
 224 /* The regions used for the integrated register allocator (IRA).  */
 225 enum ira_region
 226 {
 227   IRA_REGION_ONE,
 228   IRA_REGION_ALL,
 229   IRA_REGION_MIXED
 230 };
 231
 232 extern enum ira_region flag_ira_region;
 233
 234 extern unsigned int flag_ira_verbose;
 235
 236 /* The options for excess precision.  */
 237 enum excess_precision
 238 {
 239   EXCESS_PRECISION_DEFAULT,
 240   EXCESS_PRECISION_FAST,
 241   EXCESS_PRECISION_STANDARD
 242 };
 243
 244 /* The excess precision specified on the command line, or defaulted by
 245    the front end.  */
 246 extern enum excess_precision flag_excess_precision_cmdline;
 247
 248 /* The excess precision currently in effect.  */
 249 extern enum excess_precision flag_excess_precision;
 250
 251 \f
 252 /* Other basic status info about current function.  */
 253
 254 /* Nonzero if subexpressions must be evaluated from left-to-right.  */
 255 extern int flag_evaluation_order;
 256
 257 /* Value of the -G xx switch, and whether it was passed or not.  */
 258 extern unsigned HOST_WIDE_INT g_switch_value;
 259 extern bool g_switch_set;
 260
 261 /* Same for selective scheduling.  */
 262 extern bool sel_sched_switch_set;
 263
 264 /* Whether to run the warn_unused_result attribute pass.  */
 265 extern bool flag_warn_unused_result;
 266
 267 /* Values of the -falign-* flags: how much to align labels in code.
 268    0 means `use default', 1 means `don't align'.
 269    For each variable, there is an _log variant which is the power
 270    of two not less than the variable, for .align output.  */
 271
 272 extern int align_loops_log;
 273 extern int align_loops_max_skip;
 274 extern int align_jumps_log;
 275 extern int align_jumps_max_skip;
 276 extern int align_labels_log;
 277 extern int align_labels_max_skip;
 278 extern int align_functions_log;
 279
 280 /* Nonzero if we dump in VCG format, not plain text.  */
 281 extern int dump_for_graph;
 282
 283 /* Selection of the graph form.  */
 284 enum graph_dump_types
 285 {
 286   no_graph = 0,
 287   vcg
 288 };
 289 extern enum graph_dump_types graph_dump_format;
 290
 291 /* Nonzero means to collect statistics which might be expensive
 292    and to print them when we are done.  */
 293 extern int flag_detailed_statistics;
 294
 295 /* Nonzero means that we defer emitting functions until they are actually
 296    used.  */
 297 extern int flag_remove_unreachable_functions;
 298
 299 /* Nonzero if we should track variables.  */
 300 extern int flag_var_tracking;
 301
 302 /* True if flag_speculative_prefetching was set by user.  Used to suppress
 303    warning message in case flag was set by -fprofile-{generate,use}.  */
 304 extern bool flag_speculative_prefetching_set;
 305
 306 /* Type of stack check.  */
 307 enum stack_check_type
 308 {
 309   /* Do not check the stack.  */
 310   NO_STACK_CHECK = 0,
 311
 312   /* Check the stack generically, i.e. assume no specific support
 313      from the target configuration files.  */
 314   GENERIC_STACK_CHECK,
 315
 316   /* Check the stack and rely on the target configuration files to
 317      check the static frame of functions, i.e. use the generic
 318      mechanism only for dynamic stack allocations.  */
 319   STATIC_BUILTIN_STACK_CHECK,
 320
 321   /* Check the stack and entirely rely on the target configuration
 322      files, i.e. do not use the generic mechanism at all.  */
 323   FULL_BUILTIN_STACK_CHECK
 324 };
 325 extern enum stack_check_type flag_stack_check;
 326
 327 /* Returns TRUE if generated code should match ABI version N or
 328    greater is in use.  */
 329
 330 #define abi_version_at_least(N) \
 331   (flag_abi_version == 0 || flag_abi_version >= (N))
 332
 333 /* Return whether the function should be excluded from
 334    instrumentation.  */
 335 extern bool flag_instrument_functions_exclude_p (tree fndecl);
 336
 337 /* True if the given mode has a NaN representation and the treatment of
 338    NaN operands is important.  Certain optimizations, such as folding
 339    x * 0 into 0, are not correct for NaN operands, and are normally
 340    disabled for modes with NaNs.  The user can ask for them to be
 341    done anyway using the -funsafe-math-optimizations switch.  */
 342 #define HONOR_NANS(MODE) \
 343   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
 344
 345 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 346 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
 347
 348 /* As for HONOR_NANS, but true if the mode can represent infinity and
 349    the treatment of infinite values is important.  */
 350 #define HONOR_INFINITIES(MODE) \
 351   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
 352
 353 /* Like HONOR_NANS, but true if the given mode distinguishes between
 354    positive and negative zero, and the sign of zero is important.  */
 355 #define HONOR_SIGNED_ZEROS(MODE) \
 356   (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros)
 357
 358 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 359    and the rounding mode is important.  */
 360 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
 361   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
 362
 363 /* True if overflow wraps around for the given integral type.  That
 364    is, TYPE_MAX + 1 == TYPE_MIN.  */
 365 #define TYPE_OVERFLOW_WRAPS(TYPE) \
 366   (TYPE_UNSIGNED (TYPE) || flag_wrapv)
 367
 368 /* True if overflow is undefined for the given integral type.  We may
 369    optimize on the assumption that values in the type never overflow.
 370
 371    IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
 372    must issue a warning based on warn_strict_overflow.  In some cases
 373    it will be appropriate to issue the warning immediately, and in
 374    other cases it will be appropriate to simply set a flag and let the
 375    caller decide whether a warning is appropriate or not.  */
 376 #define TYPE_OVERFLOW_UNDEFINED(TYPE) \
 377   (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
 378
 379 /* True if overflow for the given integral type should issue a
 380    trap.  */
 381 #define TYPE_OVERFLOW_TRAPS(TYPE) \
 382   (!TYPE_UNSIGNED (TYPE) && flag_trapv)
 383
 384 /* True if pointer types have undefined overflow.  */
 385 #define POINTER_TYPE_OVERFLOW_UNDEFINED (flag_strict_overflow)
 386
 387 /* Names for the different levels of -Wstrict-overflow=N.  The numeric
 388    values here correspond to N.  */
 389
 390 enum warn_strict_overflow_code
 391 {
 392   /* Overflow warning that should be issued with -Wall: a questionable
 393      construct that is easy to avoid even when using macros.  Example:
 394      folding (x + CONSTANT > x) to 1.  */
 395   WARN_STRICT_OVERFLOW_ALL = 1,
 396   /* Overflow warning about folding a comparison to a constant because
 397      of undefined signed overflow, other than cases covered by
 398      WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
 399      (this is false when x == INT_MIN).  */
 400   WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
 401   /* Overflow warning about changes to comparisons other than folding
 402      them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
 403   WARN_STRICT_OVERFLOW_COMPARISON = 3,
 404   /* Overflow warnings not covered by the above cases.  Example:
 405      folding ((x * 10) / 5) to (x * 2).  */
 406   WARN_STRICT_OVERFLOW_MISC = 4,
 407   /* Overflow warnings about reducing magnitude of constants in
 408      comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
 409   WARN_STRICT_OVERFLOW_MAGNITUDE = 5
 410 };
 411
 412 /* Whether to emit an overflow warning whose code is C.  */
 413 #define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
 414
 415 #endif /* ! GCC_FLAGS_H */