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
   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
  28 enum debug_info_type
  29 {
  30   NO_DEBUG,         /* Write no debug info.  */
  31   DBX_DEBUG,        /* Write BSD .stabs for DBX (using dbxout.c).  */
  32   SDB_DEBUG,        /* Write COFF for (old) SDB (using sdbout.c).  */
  33   DWARF2_DEBUG,     /* Write Dwarf v2 debug info (using dwarf2out.c).  */
  34   XCOFF_DEBUG,      /* Write IBM/Xcoff debug info (using dbxout.c).  */
  35   VMS_DEBUG,        /* Write VMS debug info (using vmsdbgout.c).  */
  36   VMS_AND_DWARF2_DEBUG /* Write VMS debug info (using vmsdbgout.c).
  37                           and DWARF v2 debug info (using dwarf2out.c).  */
  38 };
  39
  40 /* Specify which kind of debugging info to generate.  */
  41 extern enum debug_info_type write_symbols;
  42
  43 /* Names of debug_info_type, for error messages.  */
  44 extern const char *const debug_type_names[];
  45
  46 enum debug_info_level
  47 {
  48   DINFO_LEVEL_NONE,     /* Write no debugging info.  */
  49   DINFO_LEVEL_TERSE,    /* Write minimal info to support tracebacks only.  */
  50   DINFO_LEVEL_NORMAL,   /* Write info for all declarations (and line table).  */
  51   DINFO_LEVEL_VERBOSE   /* Write normal info plus #define/#undef info.  */
  52 };
  53
  54 /* Specify how much debugging info to generate.  */
  55 extern enum debug_info_level debug_info_level;
  56
  57 /* A major contribution to object and executable size is debug
  58    information size.  A major contribution to debug information
  59    size is struct descriptions replicated in several object files.
  60    The following function determines whether or not debug information
  61    should be generated for a given struct.  The indirect parameter
  62    indicates that the struct is being handled indirectly, via
  63    a pointer.  See opts.c for the implementation. */
  64
  65 enum debug_info_usage
  66 {
  67   DINFO_USAGE_DFN,      /* A struct definition. */
  68   DINFO_USAGE_DIR_USE,  /* A direct use, such as the type of a variable. */
  69   DINFO_USAGE_IND_USE,  /* An indirect use, such as through a pointer. */
  70   DINFO_USAGE_NUM_ENUMS /* The number of enumerators. */
  71 };
  72
  73 extern bool should_emit_struct_debug (tree type_decl, enum debug_info_usage);
  74 extern void set_struct_debug_option (const char *value);
  75
  76 /* Nonzero means use GNU-only extensions in the generated symbolic
  77    debugging information.  */
  78 extern bool use_gnu_debug_info_extensions;
  79
  80 /* Enumerate visibility settings.  This is deliberately ordered from most
  81    to least visibility.  */
  82 #ifndef SYMBOL_VISIBILITY_DEFINED
  83 #define SYMBOL_VISIBILITY_DEFINED
  84 enum symbol_visibility
  85 {
  86   VISIBILITY_DEFAULT,
  87   VISIBILITY_PROTECTED,
  88   VISIBILITY_HIDDEN,
  89   VISIBILITY_INTERNAL
  90 };
  91 #endif
  92
  93 /* The default visibility for all symbols (unless overridden).  */
  94 extern enum symbol_visibility default_visibility;
  95
  96 struct visibility_flags
  97 {
  98   unsigned inpragma : 1;        /* True when in #pragma GCC visibility.  */
  99   unsigned inlines_hidden : 1;  /* True when -finlineshidden in effect.  */
 100 };
 101
 102 /* Global visibility options.  */
 103 extern struct visibility_flags visibility_options;
 104
 105 /* Nonzero means do optimizations.  -opt.  */
 106
 107 extern int optimize;
 108
 109 /* Nonzero means optimize for size.  -Os.  */
 110
 111 extern int optimize_size;
 112
 113 /* Do print extra warnings (such as for uninitialized variables).
 114    -W/-Wextra.  */
 115
 116 extern bool extra_warnings;
 117
 118 /* Nonzero to warn about unused variables, functions et.al.  Use
 119    set_Wunused() to update the -Wunused-* flags that correspond to the
 120    -Wunused option.  */
 121
 122 extern void set_Wunused (int setting);
 123
 124 /* Used to set the level of -Wstrict-aliasing, when no level is specified.
 125    The external way to set the default level is to use
 126    -Wstrict-aliasing=level.
 127    ONOFF is assumed to take value 1 when -Wstrict-aliasing is specified,
 128    and 0 otherwise.  After calling this function, wstrict_aliasing will be
 129    set to the default value of -Wstrict_aliasing=level.  */
 130
 131 extern void set_Wstrict_aliasing (int onoff);
 132
 133 /* Nonzero means warn about any objects definitions whose size is larger
 134    than N bytes.  Also want about function definitions whose returned
 135    values are larger than N bytes. The value N is in `larger_than_size'.  */
 136
 137 extern bool warn_larger_than;
 138 extern HOST_WIDE_INT larger_than_size;
 139
 140 /* Nonzero means warn about constructs which might not be strict
 141    aliasing safe.  */
 142
 143 extern int warn_strict_aliasing;
 144
 145 /* Nonzero means warn about optimizations which rely on undefined
 146    signed overflow.  */
 147
 148 extern int warn_strict_overflow;
 149
 150 /* Temporarily suppress certain warnings.
 151    This is set while reading code from a system header file.  */
 152
 153 extern int in_system_header;
 154
 155 /* Nonzero for -dp: annotate the assembly with a comment describing the
 156    pattern and alternative used.  */
 157
 158 extern int flag_print_asm_name;
 159 \f
 160 /* Now the symbols that are set with `-f' switches.  */
 161
 162 /* Nonzero means `char' should be signed.  */
 163
 164 extern int flag_signed_char;
 165
 166 /* Nonzero means give an enum type only as many bytes as it needs.  A value
 167    of 2 means it has not yet been initialized.  */
 168
 169 extern int flag_short_enums;
 170
 171 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 172
 173 extern int flag_pcc_struct_return;
 174
 175 /* 0 means straightforward implementation of complex divide acceptable.
 176    1 means wide ranges of inputs must work for complex divide.
 177    2 means C99-like requirements for complex multiply and divide.  */
 178
 179 extern int flag_complex_method;
 180
 181 /* Nonzero means that we don't want inlining by virtue of -fno-inline,
 182    not just because the tree inliner turned us off.  */
 183
 184 extern int flag_really_no_inline;
 185
 186 /* Nonzero if we are only using compiler to check syntax errors.  */
 187
 188 extern int rtl_dump_and_exit;
 189
 190 /* Nonzero means we should save auxiliary info into a .X file.  */
 191
 192 extern int flag_gen_aux_info;
 193
 194 /* Nonzero means suppress output of instruction numbers and line number
 195    notes in debugging dumps.  */
 196
 197 extern int flag_dump_unnumbered;
 198
 199 /* Nonzero means change certain warnings into errors.
 200    Usually these are warnings about failure to conform to some standard.  */
 201
 202 extern int flag_pedantic_errors;
 203
 204 /* Nonzero if we are compiling code for a shared library, zero for
 205    executable.  */
 206
 207 extern int flag_shlib;
 208
 209 /* -dA causes debug information to be produced in
 210    the generated assembly code (to make it more readable).  This option
 211    is generally only of use to those who actually need to read the
 212    generated assembly code (perhaps while debugging the compiler itself).
 213    Currently, this switch is only used by dwarfout.c; however, it is intended
 214    to be a catchall for printing debug information in the assembler file.  */
 215
 216 extern int flag_debug_asm;
 217
 218 /* Generate code for GNU or NeXT Objective-C runtime environment.  */
 219
 220 extern int flag_next_runtime;
 221
 222 extern int flag_dump_rtl_in_asm;
 223 \f
 224 /* Other basic status info about current function.  */
 225
 226 /* Nonzero means current function must be given a frame pointer.
 227    Set in stmt.c if anything is allocated on the stack there.
 228    Set in reload1.c if anything is allocated on the stack there.  */
 229
 230 extern int frame_pointer_needed;
 231
 232 /* Nonzero if subexpressions must be evaluated from left-to-right.  */
 233 extern int flag_evaluation_order;
 234
 235 /* Value of the -G xx switch, and whether it was passed or not.  */
 236 extern unsigned HOST_WIDE_INT g_switch_value;
 237 extern bool g_switch_set;
 238
 239 /* Values of the -falign-* flags: how much to align labels in code.
 240    0 means `use default', 1 means `don't align'.
 241    For each variable, there is an _log variant which is the power
 242    of two not less than the variable, for .align output.  */
 243
 244 extern int align_loops_log;
 245 extern int align_loops_max_skip;
 246 extern int align_jumps_log;
 247 extern int align_jumps_max_skip;
 248 extern int align_labels_log;
 249 extern int align_labels_max_skip;
 250 extern int align_functions_log;
 251
 252 /* Nonzero if we dump in VCG format, not plain text.  */
 253 extern int dump_for_graph;
 254
 255 /* Selection of the graph form.  */
 256 enum graph_dump_types
 257 {
 258   no_graph = 0,
 259   vcg
 260 };
 261 extern enum graph_dump_types graph_dump_format;
 262
 263 /* Nonzero means to collect statistics which might be expensive
 264    and to print them when we are done.  */
 265 extern int flag_detailed_statistics;
 266
 267 /* Nonzero means that we defer emitting functions until they are actually
 268    used.  */
 269 extern int flag_remove_unreachable_functions;
 270
 271 /* Nonzero if we should track variables.  */
 272 extern int flag_var_tracking;
 273
 274 /* True if flag_speculative_prefetching was set by user.  Used to suppress
 275    warning message in case flag was set by -fprofile-{generate,use}.  */
 276 extern bool flag_speculative_prefetching_set;
 277
 278 /* Returns TRUE if generated code should match ABI version N or
 279    greater is in use.  */
 280
 281 #define abi_version_at_least(N) \
 282   (flag_abi_version == 0 || flag_abi_version >= (N))
 283
 284 /* Return whether the function should be excluded from
 285    instrumentation.  */
 286 extern bool flag_instrument_functions_exclude_p (tree fndecl);
 287
 288 /* True if the given mode has a NaN representation and the treatment of
 289    NaN operands is important.  Certain optimizations, such as folding
 290    x * 0 into 0, are not correct for NaN operands, and are normally
 291    disabled for modes with NaNs.  The user can ask for them to be
 292    done anyway using the -funsafe-math-optimizations switch.  */
 293 #define HONOR_NANS(MODE) \
 294   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
 295
 296 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 297 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
 298
 299 /* As for HONOR_NANS, but true if the mode can represent infinity and
 300    the treatment of infinite values is important.  */
 301 #define HONOR_INFINITIES(MODE) \
 302   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
 303
 304 /* Like HONOR_NANS, but true if the given mode distinguishes between
 305    positive and negative zero, and the sign of zero is important.  */
 306 #define HONOR_SIGNED_ZEROS(MODE) \
 307   (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros)
 308
 309 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 310    and the rounding mode is important.  */
 311 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
 312   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
 313
 314 /* True if overflow wraps around for the given integral type.  That
 315    is, TYPE_MAX + 1 == TYPE_MIN.  */
 316 #define TYPE_OVERFLOW_WRAPS(TYPE) \
 317   (TYPE_UNSIGNED (TYPE) || flag_wrapv)
 318
 319 /* True if overflow is undefined for the given integral type.  We may
 320    optimize on the assumption that values in the type never overflow.
 321
 322    IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
 323    must issue a warning based on warn_strict_overflow.  In some cases
 324    it will be appropriate to issue the warning immediately, and in
 325    other cases it will be appropriate to simply set a flag and let the
 326    caller decide whether a warning is appropriate or not.  */
 327 #define TYPE_OVERFLOW_UNDEFINED(TYPE) \
 328   (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
 329
 330 /* True if overflow for the given integral type should issue a
 331    trap.  */
 332 #define TYPE_OVERFLOW_TRAPS(TYPE) \
 333   (!TYPE_UNSIGNED (TYPE) && flag_trapv)
 334
 335 /* Names for the different levels of -Wstrict-overflow=N.  The numeric
 336    values here correspond to N.  */
 337
 338 enum warn_strict_overflow_code
 339 {
 340   /* Overflow warning that should be issued with -Wall: a questionable
 341      construct that is easy to avoid even when using macros.  Example:
 342      folding (x + CONSTANT > x) to 1.  */
 343   WARN_STRICT_OVERFLOW_ALL = 1,
 344   /* Overflow warning about folding a comparison to a constant because
 345      of undefined signed overflow, other than cases covered by
 346      WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
 347      (this is false when x == INT_MIN).  */
 348   WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
 349   /* Overflow warning about changes to comparisons other than folding
 350      them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
 351   WARN_STRICT_OVERFLOW_COMPARISON = 3,
 352   /* Overflow warnings not covered by the above cases.  Example:
 353      folding ((x * 10) / 5) to (x * 2).  */
 354   WARN_STRICT_OVERFLOW_MISC = 4,
 355   /* Overflow warnings about reducing magnitude of constants in
 356      comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
 357   WARN_STRICT_OVERFLOW_MAGNITUDE = 5
 358 };
 359
 360 /* Whether to emit an overflow warning whose code is C.  */
 361 #define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
 362
 363 #endif /* ! GCC_FLAGS_H */