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 /* Used to set the level of -Wstrict-aliasing, when no level is specified.
 115    The external way to set the default level is to use
 116    -Wstrict-aliasing=level.
 117    ONOFF is assumed to take value 1 when -Wstrict-aliasing is specified,
 118    and 0 otherwise.  After calling this function, wstrict_aliasing will be
 119    set to the default value of -Wstrict_aliasing=level.  */
 120
 121 extern void set_Wstrict_aliasing (int onoff);
 122
 123 /* Nonzero means warn about any objects definitions whose size is larger
 124    than N bytes.  Also want about function definitions whose returned
 125    values are larger than N bytes. The value N is in `larger_than_size'.  */
 126
 127 extern bool warn_larger_than;
 128 extern HOST_WIDE_INT larger_than_size;
 129
 130 /* Nonzero means warn about any function whose frame size is larger
 131    than N bytes. */
 132
 133 extern bool warn_frame_larger_than;
 134 extern HOST_WIDE_INT frame_larger_than_size;
 135
 136 /* Nonzero for -dp: annotate the assembly with a comment describing the
 137    pattern and alternative used.  */
 138
 139 extern int flag_print_asm_name;
 140 \f
 141 /* Now the symbols that are set with `-f' switches.  */
 142
 143 /* Nonzero means `char' should be signed.  */
 144
 145 extern int flag_signed_char;
 146
 147 /* Nonzero means give an enum type only as many bytes as it needs.  A value
 148    of 2 means it has not yet been initialized.  */
 149
 150 extern int flag_short_enums;
 151
 152 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 153
 154 extern int flag_pcc_struct_return;
 155
 156 /* 0 means straightforward implementation of complex divide acceptable.
 157    1 means wide ranges of inputs must work for complex divide.
 158    2 means C99-like requirements for complex multiply and divide.  */
 159
 160 extern int flag_complex_method;
 161
 162 /* Nonzero if we are only using compiler to check syntax errors.  */
 163
 164 extern int rtl_dump_and_exit;
 165
 166 /* Nonzero means we should save auxiliary info into a .X file.  */
 167
 168 extern int flag_gen_aux_info;
 169
 170 /* Nonzero means suppress output of instruction numbers and line number
 171    notes in debugging dumps.  */
 172
 173 extern int flag_dump_unnumbered;
 174
 175 /* Nonzero means change certain warnings into errors.
 176    Usually these are warnings about failure to conform to some standard.  */
 177
 178 extern int flag_pedantic_errors;
 179
 180 /* Nonzero means make permerror produce warnings instead of errors.  */
 181
 182 extern int flag_permissive;
 183
 184 /* Nonzero if we are compiling code for a shared library, zero for
 185    executable.  */
 186
 187 extern int flag_shlib;
 188
 189 /* -dA causes debug information to be produced in
 190    the generated assembly code (to make it more readable).  This option
 191    is generally only of use to those who actually need to read the
 192    generated assembly code (perhaps while debugging the compiler itself).
 193    Currently, this switch is only used by dwarfout.c; however, it is intended
 194    to be a catchall for printing debug information in the assembler file.  */
 195
 196 extern int flag_debug_asm;
 197
 198 /* Generate code for GNU or NeXT Objective-C runtime environment.  */
 199
 200 extern int flag_next_runtime;
 201
 202 extern int flag_dump_rtl_in_asm;
 203
 204 /* The algorithm used for the integrated register allocator (IRA).  */
 205 enum ira_algorithm
 206 {
 207   IRA_ALGORITHM_CB,
 208   IRA_ALGORITHM_PRIORITY
 209 };
 210
 211 extern enum ira_algorithm flag_ira_algorithm;
 212
 213 /* The regions used for the integrated register allocator (IRA).  */
 214 enum ira_region
 215 {
 216   IRA_REGION_ONE,
 217   IRA_REGION_ALL,
 218   IRA_REGION_MIXED
 219 };
 220
 221 extern enum ira_region flag_ira_region;
 222
 223 extern unsigned int flag_ira_verbose;
 224
 225 /* The options for excess precision.  */
 226 enum excess_precision
 227 {
 228   EXCESS_PRECISION_DEFAULT,
 229   EXCESS_PRECISION_FAST,
 230   EXCESS_PRECISION_STANDARD
 231 };
 232
 233 /* The excess precision specified on the command line, or defaulted by
 234    the front end.  */
 235 extern enum excess_precision flag_excess_precision_cmdline;
 236
 237 /* The excess precision currently in effect.  */
 238 extern enum excess_precision flag_excess_precision;
 239
 240 \f
 241 /* Other basic status info about current function.  */
 242
 243 /* Nonzero if subexpressions must be evaluated from left-to-right.  */
 244 extern int flag_evaluation_order;
 245
 246 /* Value of the -G xx switch, and whether it was passed or not.  */
 247 extern unsigned HOST_WIDE_INT g_switch_value;
 248 extern bool g_switch_set;
 249
 250 /* Same for selective scheduling.  */
 251 extern bool sel_sched_switch_set;
 252
 253 /* Whether to run the warn_unused_result attribute pass.  */
 254 extern bool flag_warn_unused_result;
 255
 256 /* Values of the -falign-* flags: how much to align labels in code.
 257    0 means `use default', 1 means `don't align'.
 258    For each variable, there is an _log variant which is the power
 259    of two not less than the variable, for .align output.  */
 260
 261 extern int align_loops_log;
 262 extern int align_loops_max_skip;
 263 extern int align_jumps_log;
 264 extern int align_jumps_max_skip;
 265 extern int align_labels_log;
 266 extern int align_labels_max_skip;
 267 extern int align_functions_log;
 268
 269 /* Nonzero if we dump in VCG format, not plain text.  */
 270 extern int dump_for_graph;
 271
 272 /* Selection of the graph form.  */
 273 enum graph_dump_types
 274 {
 275   no_graph = 0,
 276   vcg
 277 };
 278 extern enum graph_dump_types graph_dump_format;
 279
 280 /* Nonzero means to collect statistics which might be expensive
 281    and to print them when we are done.  */
 282 extern int flag_detailed_statistics;
 283
 284 /* Nonzero means that we defer emitting functions until they are actually
 285    used.  */
 286 extern int flag_remove_unreachable_functions;
 287
 288 /* Nonzero if we should track variables.  */
 289 extern int flag_var_tracking;
 290
 291 /* True if flag_speculative_prefetching was set by user.  Used to suppress
 292    warning message in case flag was set by -fprofile-{generate,use}.  */
 293 extern bool flag_speculative_prefetching_set;
 294
 295 /* Type of stack check.  */
 296 enum stack_check_type
 297 {
 298   /* Do not check the stack.  */
 299   NO_STACK_CHECK = 0,
 300
 301   /* Check the stack generically, i.e. assume no specific support
 302      from the target configuration files.  */
 303   GENERIC_STACK_CHECK,
 304
 305   /* Check the stack and rely on the target configuration files to
 306      check the static frame of functions, i.e. use the generic
 307      mechanism only for dynamic stack allocations.  */
 308   STATIC_BUILTIN_STACK_CHECK,
 309
 310   /* Check the stack and entirely rely on the target configuration
 311      files, i.e. do not use the generic mechanism at all.  */
 312   FULL_BUILTIN_STACK_CHECK
 313 };
 314 extern enum stack_check_type flag_stack_check;
 315
 316 /* Returns TRUE if generated code should match ABI version N or
 317    greater is in use.  */
 318
 319 #define abi_version_at_least(N) \
 320   (flag_abi_version == 0 || flag_abi_version >= (N))
 321
 322 /* Return whether the function should be excluded from
 323    instrumentation.  */
 324 extern bool flag_instrument_functions_exclude_p (tree fndecl);
 325
 326 /* True if the given mode has a NaN representation and the treatment of
 327    NaN operands is important.  Certain optimizations, such as folding
 328    x * 0 into 0, are not correct for NaN operands, and are normally
 329    disabled for modes with NaNs.  The user can ask for them to be
 330    done anyway using the -funsafe-math-optimizations switch.  */
 331 #define HONOR_NANS(MODE) \
 332   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
 333
 334 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 335 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
 336
 337 /* As for HONOR_NANS, but true if the mode can represent infinity and
 338    the treatment of infinite values is important.  */
 339 #define HONOR_INFINITIES(MODE) \
 340   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
 341
 342 /* Like HONOR_NANS, but true if the given mode distinguishes between
 343    positive and negative zero, and the sign of zero is important.  */
 344 #define HONOR_SIGNED_ZEROS(MODE) \
 345   (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros)
 346
 347 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 348    and the rounding mode is important.  */
 349 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
 350   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
 351
 352 /* True if overflow wraps around for the given integral type.  That
 353    is, TYPE_MAX + 1 == TYPE_MIN.  */
 354 #define TYPE_OVERFLOW_WRAPS(TYPE) \
 355   (TYPE_UNSIGNED (TYPE) || flag_wrapv)
 356
 357 /* True if overflow is undefined for the given integral type.  We may
 358    optimize on the assumption that values in the type never overflow.
 359
 360    IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
 361    must issue a warning based on warn_strict_overflow.  In some cases
 362    it will be appropriate to issue the warning immediately, and in
 363    other cases it will be appropriate to simply set a flag and let the
 364    caller decide whether a warning is appropriate or not.  */
 365 #define TYPE_OVERFLOW_UNDEFINED(TYPE) \
 366   (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
 367
 368 /* True if overflow for the given integral type should issue a
 369    trap.  */
 370 #define TYPE_OVERFLOW_TRAPS(TYPE) \
 371   (!TYPE_UNSIGNED (TYPE) && flag_trapv)
 372
 373 /* True if pointer types have undefined overflow.  */
 374 #define POINTER_TYPE_OVERFLOW_UNDEFINED (flag_strict_overflow)
 375
 376 /* Names for the different levels of -Wstrict-overflow=N.  The numeric
 377    values here correspond to N.  */
 378
 379 enum warn_strict_overflow_code
 380 {
 381   /* Overflow warning that should be issued with -Wall: a questionable
 382      construct that is easy to avoid even when using macros.  Example:
 383      folding (x + CONSTANT > x) to 1.  */
 384   WARN_STRICT_OVERFLOW_ALL = 1,
 385   /* Overflow warning about folding a comparison to a constant because
 386      of undefined signed overflow, other than cases covered by
 387      WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
 388      (this is false when x == INT_MIN).  */
 389   WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
 390   /* Overflow warning about changes to comparisons other than folding
 391      them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
 392   WARN_STRICT_OVERFLOW_COMPARISON = 3,
 393   /* Overflow warnings not covered by the above cases.  Example:
 394      folding ((x * 10) / 5) to (x * 2).  */
 395   WARN_STRICT_OVERFLOW_MISC = 4,
 396   /* Overflow warnings about reducing magnitude of constants in
 397      comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
 398   WARN_STRICT_OVERFLOW_MAGNITUDE = 5
 399 };
 400
 401 /* Whether to emit an overflow warning whose code is C.  */
 402 #define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
 403
 404 #endif /* ! GCC_FLAGS_H */