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 2, 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 COPYING.  If not, write to the Free
  20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, USA.  */
  22
  23 #ifndef GCC_FLAGS_H
  24 #define GCC_FLAGS_H
  25
  26 #include "coretypes.h"
  27 #include "options.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 /* Do print extra warnings (such as for uninitialized variables).
 115    -W/-Wextra.  */
 116
 117 extern bool extra_warnings;
 118
 119 /* Nonzero to warn about unused variables, functions et.al.  Use
 120    set_Wunused() to update the -Wunused-* flags that correspond to the
 121    -Wunused option.  */
 122
 123 extern void set_Wunused (int setting);
 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 constructs which might not be strict
 142    aliasing safe.  */
 143
 144 extern int warn_strict_aliasing;
 145
 146 /* Nonzero means warn about optimizations which rely on undefined
 147    signed overflow.  */
 148
 149 extern int warn_strict_overflow;
 150
 151 /* Temporarily suppress certain warnings.
 152    This is set while reading code from a system header file.  */
 153
 154 extern int in_system_header;
 155
 156 /* Nonzero for -dp: annotate the assembly with a comment describing the
 157    pattern and alternative used.  */
 158
 159 extern int flag_print_asm_name;
 160 \f
 161 /* Now the symbols that are set with `-f' switches.  */
 162
 163 /* Nonzero means `char' should be signed.  */
 164
 165 extern int flag_signed_char;
 166
 167 /* Nonzero means give an enum type only as many bytes as it needs.  A value
 168    of 2 means it has not yet been initialized.  */
 169
 170 extern int flag_short_enums;
 171
 172 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
 173
 174 extern int flag_pcc_struct_return;
 175
 176 /* 0 means straightforward implementation of complex divide acceptable.
 177    1 means wide ranges of inputs must work for complex divide.
 178    2 means C99-like requirements for complex multiply and divide.  */
 179
 180 extern int flag_complex_method;
 181
 182 /* Nonzero means that we don't want inlining by virtue of -fno-inline,
 183    not just because the tree inliner turned us off.  */
 184
 185 extern int flag_really_no_inline;
 186
 187 /* Nonzero if we are only using compiler to check syntax errors.  */
 188
 189 extern int rtl_dump_and_exit;
 190
 191 /* Nonzero means we should save auxiliary info into a .X file.  */
 192
 193 extern int flag_gen_aux_info;
 194
 195 /* Nonzero means suppress output of instruction numbers and line number
 196    notes in debugging dumps.  */
 197
 198 extern int flag_dump_unnumbered;
 199
 200 /* Nonzero means change certain warnings into errors.
 201    Usually these are warnings about failure to conform to some standard.  */
 202
 203 extern int flag_pedantic_errors;
 204
 205 /* Nonzero if we are compiling code for a shared library, zero for
 206    executable.  */
 207
 208 extern int flag_shlib;
 209
 210 /* -dA causes debug information to be produced in
 211    the generated assembly code (to make it more readable).  This option
 212    is generally only of use to those who actually need to read the
 213    generated assembly code (perhaps while debugging the compiler itself).
 214    Currently, this switch is only used by dwarfout.c; however, it is intended
 215    to be a catchall for printing debug information in the assembler file.  */
 216
 217 extern int flag_debug_asm;
 218
 219 /* Generate code for GNU or NeXT Objective-C runtime environment.  */
 220
 221 extern int flag_next_runtime;
 222
 223 extern int flag_dump_rtl_in_asm;
 224 \f
 225 /* Other basic status info about current function.  */
 226
 227 /* Nonzero means current function must be given a frame pointer.
 228    Set in stmt.c if anything is allocated on the stack there.
 229    Set in reload1.c if anything is allocated on the stack there.  */
 230
 231 extern int frame_pointer_needed;
 232
 233 /* Nonzero if subexpressions must be evaluated from left-to-right.  */
 234 extern int flag_evaluation_order;
 235
 236 /* Value of the -G xx switch, and whether it was passed or not.  */
 237 extern unsigned HOST_WIDE_INT g_switch_value;
 238 extern bool g_switch_set;
 239
 240 /* Values of the -falign-* flags: how much to align labels in code.
 241    0 means `use default', 1 means `don't align'.
 242    For each variable, there is an _log variant which is the power
 243    of two not less than the variable, for .align output.  */
 244
 245 extern int align_loops_log;
 246 extern int align_loops_max_skip;
 247 extern int align_jumps_log;
 248 extern int align_jumps_max_skip;
 249 extern int align_labels_log;
 250 extern int align_labels_max_skip;
 251 extern int align_functions_log;
 252
 253 /* Like align_functions_log above, but used by front-ends to force the
 254    minimum function alignment.  Zero means no alignment is forced.  */
 255 extern int force_align_functions_log;
 256
 257 /* Nonzero if we dump in VCG format, not plain text.  */
 258 extern int dump_for_graph;
 259
 260 /* Selection of the graph form.  */
 261 enum graph_dump_types
 262 {
 263   no_graph = 0,
 264   vcg
 265 };
 266 extern enum graph_dump_types graph_dump_format;
 267
 268 /* Nonzero means to collect statistics which might be expensive
 269    and to print them when we are done.  */
 270 extern int flag_detailed_statistics;
 271
 272 /* Nonzero means that we defer emitting functions until they are actually
 273    used.  */
 274 extern int flag_remove_unreachable_functions;
 275
 276 /* Nonzero if we should track variables.  */
 277 extern int flag_var_tracking;
 278
 279 /* True if flag_speculative_prefetching was set by user.  Used to suppress
 280    warning message in case flag was set by -fprofile-{generate,use}.  */
 281 extern bool flag_speculative_prefetching_set;
 282
 283 /* Returns TRUE if generated code should match ABI version N or
 284    greater is in use.  */
 285
 286 #define abi_version_at_least(N) \
 287   (flag_abi_version == 0 || flag_abi_version >= (N))
 288
 289 /* True if the given mode has a NaN representation and the treatment of
 290    NaN operands is important.  Certain optimizations, such as folding
 291    x * 0 into 0, are not correct for NaN operands, and are normally
 292    disabled for modes with NaNs.  The user can ask for them to be
 293    done anyway using the -funsafe-math-optimizations switch.  */
 294 #define HONOR_NANS(MODE) \
 295   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
 296
 297 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 298 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
 299
 300 /* As for HONOR_NANS, but true if the mode can represent infinity and
 301    the treatment of infinite values is important.  */
 302 #define HONOR_INFINITIES(MODE) \
 303   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
 304
 305 /* Like HONOR_NANS, but true if the given mode distinguishes between
 306    positive and negative zero, and the sign of zero is important.  */
 307 #define HONOR_SIGNED_ZEROS(MODE) \
 308   (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros)
 309
 310 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 311    and the rounding mode is important.  */
 312 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
 313   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
 314
 315 /* True if overflow wraps around for the given integral type.  That
 316    is, TYPE_MAX + 1 == TYPE_MIN.  */
 317 #define TYPE_OVERFLOW_WRAPS(TYPE) \
 318   (TYPE_UNSIGNED (TYPE) || flag_wrapv)
 319
 320 /* True if overflow is undefined for the given integral type.  We may
 321    optimize on the assumption that values in the type never overflow.
 322
 323    IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
 324    must issue a warning based on warn_strict_overflow.  In some cases
 325    it will be appropriate to issue the warning immediately, and in
 326    other cases it will be appropriate to simply set a flag and let the
 327    caller decide whether a warning is appropriate or not.  */
 328 #define TYPE_OVERFLOW_UNDEFINED(TYPE) \
 329   (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
 330
 331 /* True if overflow for the given integral type should issue a
 332    trap.  */
 333 #define TYPE_OVERFLOW_TRAPS(TYPE) \
 334   (!TYPE_UNSIGNED (TYPE) && flag_trapv)
 335
 336 /* Names for the different levels of -Wstrict-overflow=N.  The numeric
 337    values here correspond to N.  */
 338
 339 enum warn_strict_overflow_code
 340 {
 341   /* Overflow warning that should be issued with -Wall: a questionable
 342      construct that is easy to avoid even when using macros.  Example:
 343      folding (x + CONSTANT > x) to 1.  */
 344   WARN_STRICT_OVERFLOW_ALL = 1,
 345   /* Overflow warning about folding a comparison to a constant because
 346      of undefined signed overflow, other than cases covered by
 347      WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
 348      (this is false when x == INT_MIN).  */
 349   WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
 350   /* Overflow warning about changes to comparisons other than folding
 351      them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
 352   WARN_STRICT_OVERFLOW_COMPARISON = 3,
 353   /* Overflow warnings not covered by the above cases.  Example:
 354      folding ((x * 10) / 5) to (x * 2).  */
 355   WARN_STRICT_OVERFLOW_MISC = 4,
 356   /* Overflow warnings about reducing magnitude of constants in
 357      comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
 358   WARN_STRICT_OVERFLOW_MAGNITUDE = 5
 359 };
 360
 361 /* Whether to emit an overflow warning whose code is C.  */
 362 #define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
 363
 364 #endif /* ! GCC_FLAGS_H */