flags.h revision 258206 
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
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 2, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING.  If not, write to the Free
20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2102110-1301, USA.  */
22
23#ifndef GCC_FLAGS_H
24#define GCC_FLAGS_H
25
26#include "coretypes.h"
27#include "options.h"
28
29enum 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.  */
42extern enum debug_info_type write_symbols;
43
44/* Names of debug_info_type, for error messages.  */
45extern const char *const debug_type_names[];
46
47enum 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.  */
56extern 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
66enum 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
74extern bool should_emit_struct_debug (tree type_decl, enum debug_info_usage);
75extern void set_struct_debug_option (const char *value);
76
77/* Nonzero means use GNU-only extensions in the generated symbolic
78   debugging information.  */
79extern 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
85enum 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).  */
95extern enum symbol_visibility default_visibility;
96
97struct 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.  */
104extern struct visibility_flags visibility_options;
105
106/* Nonzero means do optimizations.  -opt.  */
107
108extern int optimize;
109
110/* Nonzero means optimize for size.  -Os.  */
111
112extern int optimize_size;
113
114/* Do print extra warnings (such as for uninitialized variables).
115   -W/-Wextra.  */
116
117extern 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
123extern void set_Wunused (int setting);
124
125/* Nonzero means warn about any objects definitions whose size is larger
126   than N bytes.  Also want about function definitions whose returned
127   values are larger than N bytes. The value N is in `larger_than_size'.  */
128
129extern bool warn_larger_than;
130extern HOST_WIDE_INT larger_than_size;
131
132/* Nonzero means warn about constructs which might not be strict
133   aliasing safe.  */
134
135extern int warn_strict_aliasing;
136
137/* Nonzero means warn about optimizations which rely on undefined
138   signed overflow.  */
139
140extern int warn_strict_overflow;
141
142/* Temporarily suppress certain warnings.
143   This is set while reading code from a system header file.  */
144
145extern int in_system_header;
146
147/* Nonzero for -dp: annotate the assembly with a comment describing the
148   pattern and alternative used.  */
149
150extern int flag_print_asm_name;
151
152/* Now the symbols that are set with `-f' switches.  */
153
154/* Nonzero means `char' should be signed.  */
155
156extern 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
161extern int flag_short_enums;
162
163/* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
164
165extern 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
171extern int flag_complex_method;
172
173/* Nonzero means that we don't want inlining by virtue of -fno-inline,
174   not just because the tree inliner turned us off.  */
175
176extern int flag_really_no_inline;
177
178/* Nonzero if we are only using compiler to check syntax errors.  */
179
180extern int rtl_dump_and_exit;
181
182/* Nonzero means we should save auxiliary info into a .X file.  */
183
184extern int flag_gen_aux_info;
185
186/* Nonzero means suppress output of instruction numbers and line number
187   notes in debugging dumps.  */
188
189extern int flag_dump_unnumbered;
190
191/* Nonzero means change certain warnings into errors.
192   Usually these are warnings about failure to conform to some standard.  */
193
194extern int flag_pedantic_errors;
195
196/* Nonzero if we are compiling code for a shared library, zero for
197   executable.  */
198
199extern int flag_shlib;
200
201/* -dA causes debug information to be produced in
202   the generated assembly code (to make it more readable).  This option
203   is generally only of use to those who actually need to read the
204   generated assembly code (perhaps while debugging the compiler itself).
205   Currently, this switch is only used by dwarfout.c; however, it is intended
206   to be a catchall for printing debug information in the assembler file.  */
207
208extern int flag_debug_asm;
209
210/* Generate code for GNU or NeXT Objective-C runtime environment.  */
211
212extern int flag_next_runtime;
213
214extern int flag_dump_rtl_in_asm;
215
216/* If one, renumber instruction UIDs to reduce the number of
217   unused UIDs if there are a lot of instructions.  If greater than
218   one, unconditionally renumber instruction UIDs.  */
219extern int flag_renumber_insns;
220
221/* Other basic status info about current function.  */
222
223/* Nonzero means current function must be given a frame pointer.
224   Set in stmt.c if anything is allocated on the stack there.
225   Set in reload1.c if anything is allocated on the stack there.  */
226
227extern int frame_pointer_needed;
228
229/* Nonzero if subexpressions must be evaluated from left-to-right.  */
230extern int flag_evaluation_order;
231
232/* Value of the -G xx switch, and whether it was passed or not.  */
233extern unsigned HOST_WIDE_INT g_switch_value;
234extern bool g_switch_set;
235
236/* Values of the -falign-* flags: how much to align labels in code.
237   0 means `use default', 1 means `don't align'.
238   For each variable, there is an _log variant which is the power
239   of two not less than the variable, for .align output.  */
240
241extern int align_loops_log;
242extern int align_loops_max_skip;
243extern int align_jumps_log;
244extern int align_jumps_max_skip;
245extern int align_labels_log;
246extern int align_labels_max_skip;
247extern int align_functions_log;
248
249/* Like align_functions_log above, but used by front-ends to force the
250   minimum function alignment.  Zero means no alignment is forced.  */
251extern int force_align_functions_log;
252
253/* Nonzero if we dump in VCG format, not plain text.  */
254extern int dump_for_graph;
255
256/* Selection of the graph form.  */
257enum graph_dump_types
258{
259  no_graph = 0,
260  vcg
261};
262extern enum graph_dump_types graph_dump_format;
263
264/* Nonzero means to collect statistics which might be expensive
265   and to print them when we are done.  */
266extern int flag_detailed_statistics;
267
268/* Nonzero means that we defer emitting functions until they are actually
269   used.  */
270extern int flag_remove_unreachable_functions;
271
272/* Nonzero if we should track variables.  */
273extern int flag_var_tracking;
274
275/* True if flag_speculative_prefetching was set by user.  Used to suppress
276   warning message in case flag was set by -fprofile-{generate,use}.  */
277extern bool flag_speculative_prefetching_set;
278
279/* A string that's used when a random name is required.  NULL means
280   to make it really random.  */
281
282extern const char *flag_random_seed;
283
284/* Returns TRUE if generated code should match ABI version N or
285   greater is in use.  */
286
287#define abi_version_at_least(N) \
288  (flag_abi_version == 0 || flag_abi_version >= (N))
289
290/* True if the given mode has a NaN representation and the treatment of
291   NaN operands is important.  Certain optimizations, such as folding
292   x * 0 into 0, are not correct for NaN operands, and are normally
293   disabled for modes with NaNs.  The user can ask for them to be
294   done anyway using the -funsafe-math-optimizations switch.  */
295#define HONOR_NANS(MODE) \
296  (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
297
298/* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
299#define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
300
301/* As for HONOR_NANS, but true if the mode can represent infinity and
302   the treatment of infinite values is important.  */
303#define HONOR_INFINITIES(MODE) \
304  (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
305
306/* Like HONOR_NANS, but true if the given mode distinguishes between
307   positive and negative zero, and the sign of zero is important.  */
308#define HONOR_SIGNED_ZEROS(MODE) \
309  (MODE_HAS_SIGNED_ZEROS (MODE) && !flag_unsafe_math_optimizations)
310
311/* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
312   and the rounding mode is important.  */
313#define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
314  (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
315
316/* True if overflow wraps around for the given integral type.  That
317   is, TYPE_MAX + 1 == TYPE_MIN.  */
318#define TYPE_OVERFLOW_WRAPS(TYPE) \
319  (TYPE_UNSIGNED (TYPE) || flag_wrapv)
320
321/* True if overflow is undefined for the given integral type.  We may
322   optimize on the assumption that values in the type never overflow.
323
324   IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
325   must issue a warning based on warn_strict_overflow.  In some cases
326   it will be appropriate to issue the warning immediately, and in
327   other cases it will be appropriate to simply set a flag and let the
328   caller decide whether a warning is appropriate or not.  */
329#define TYPE_OVERFLOW_UNDEFINED(TYPE) \
330  (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
331
332/* True if overflow for the given integral type should issue a
333   trap.  */
334#define TYPE_OVERFLOW_TRAPS(TYPE) \
335  (!TYPE_UNSIGNED (TYPE) && flag_trapv)
336
337/* Names for the different levels of -Wstrict-overflow=N.  The numeric
338   values here correspond to N.  */
339
340enum warn_strict_overflow_code
341{
342  /* Overflow warning that should be issued with -Wall: a questionable
343     construct that is easy to avoid even when using macros.  Example:
344     folding (x + CONSTANT > x) to 1.  */
345  WARN_STRICT_OVERFLOW_ALL = 1,
346  /* Overflow warning about folding a comparison to a constant because
347     of undefined signed overflow, other than cases covered by
348     WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
349     (this is false when x == INT_MIN).  */
350  WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
351  /* Overflow warning about changes to comparisons other than folding
352     them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
353  WARN_STRICT_OVERFLOW_COMPARISON = 3,
354  /* Overflow warnings not covered by the above cases.  Example:
355     folding ((x * 10) / 5) to (x * 2).  */
356  WARN_STRICT_OVERFLOW_MISC = 4,
357  /* Overflow warnings about reducing magnitude of constants in
358     comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
359  WARN_STRICT_OVERFLOW_MAGNITUDE = 5
360};
361
362/* Whether to emit an overflow warning whose code is C.  */
363#define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
364
365#endif /* ! GCC_FLAGS_H */
366