flags.h revision 169699 
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 "options.h"
27
28enum 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.  */
41extern enum debug_info_type write_symbols;
42
43/* Names of debug_info_type, for error messages.  */
44extern const char *const debug_type_names[];
45
46enum 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.  */
55extern enum debug_info_level debug_info_level;
56
57/* Nonzero means use GNU-only extensions in the generated symbolic
58   debugging information.  */
59extern bool use_gnu_debug_info_extensions;
60
61/* Enumerate visibility settings.  This is deliberately ordered from most
62   to least visibility.  */
63#ifndef SYMBOL_VISIBILITY_DEFINED
64#define SYMBOL_VISIBILITY_DEFINED
65enum symbol_visibility
66{
67  VISIBILITY_DEFAULT,
68  VISIBILITY_PROTECTED,
69  VISIBILITY_HIDDEN,
70  VISIBILITY_INTERNAL
71};
72#endif
73
74/* The default visibility for all symbols (unless overridden).  */
75extern enum symbol_visibility default_visibility;
76
77struct visibility_flags
78{
79  unsigned inpragma : 1;	/* True when in #pragma GCC visibility.  */
80  unsigned inlines_hidden : 1;	/* True when -finlineshidden in effect.  */
81};
82
83/* Global visibility options.  */
84extern struct visibility_flags visibility_options;
85
86/* Nonzero means do optimizations.  -opt.  */
87
88extern int optimize;
89
90/* Nonzero means optimize for size.  -Os.  */
91
92extern int optimize_size;
93
94/* Do print extra warnings (such as for uninitialized variables).
95   -W/-Wextra.  */
96
97extern bool extra_warnings;
98
99/* Nonzero to warn about unused variables, functions et.al.  Use
100   set_Wunused() to update the -Wunused-* flags that correspond to the
101   -Wunused option.  */
102
103extern void set_Wunused (int setting);
104
105/* Nonzero means warn about any objects definitions whose size is larger
106   than N bytes.  Also want about function definitions whose returned
107   values are larger than N bytes. The value N is in `larger_than_size'.  */
108
109extern bool warn_larger_than;
110extern HOST_WIDE_INT larger_than_size;
111
112/* Nonzero means warn about constructs which might not be strict
113   aliasing safe.  */
114
115extern int warn_strict_aliasing;
116
117/* Nonzero means warn about optimizations which rely on undefined
118   signed overflow.  */
119
120extern int warn_strict_overflow;
121
122/* Temporarily suppress certain warnings.
123   This is set while reading code from a system header file.  */
124
125extern int in_system_header;
126
127/* Nonzero for -dp: annotate the assembly with a comment describing the
128   pattern and alternative used.  */
129
130extern int flag_print_asm_name;
131
132/* Now the symbols that are set with `-f' switches.  */
133
134/* Nonzero means `char' should be signed.  */
135
136extern int flag_signed_char;
137
138/* Nonzero means give an enum type only as many bytes as it needs.  A value
139   of 2 means it has not yet been initialized.  */
140
141extern int flag_short_enums;
142
143/* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
144
145extern int flag_pcc_struct_return;
146
147/* 0 means straightforward implementation of complex divide acceptable.
148   1 means wide ranges of inputs must work for complex divide.
149   2 means C99-like requirements for complex multiply and divide.  */
150
151extern int flag_complex_method;
152
153/* Nonzero means that we don't want inlining by virtue of -fno-inline,
154   not just because the tree inliner turned us off.  */
155
156extern int flag_really_no_inline;
157
158/* Nonzero if we are only using compiler to check syntax errors.  */
159
160extern int rtl_dump_and_exit;
161
162/* Nonzero means we should save auxiliary info into a .X file.  */
163
164extern int flag_gen_aux_info;
165
166/* Nonzero means suppress output of instruction numbers and line number
167   notes in debugging dumps.  */
168
169extern int flag_dump_unnumbered;
170
171/* Nonzero means change certain warnings into errors.
172   Usually these are warnings about failure to conform to some standard.  */
173
174extern int flag_pedantic_errors;
175
176/* Nonzero if we are compiling code for a shared library, zero for
177   executable.  */
178
179extern int flag_shlib;
180
181/* -dA causes debug information to be produced in
182   the generated assembly code (to make it more readable).  This option
183   is generally only of use to those who actually need to read the
184   generated assembly code (perhaps while debugging the compiler itself).
185   Currently, this switch is only used by dwarfout.c; however, it is intended
186   to be a catchall for printing debug information in the assembler file.  */
187
188extern int flag_debug_asm;
189
190/* Generate code for GNU or NeXT Objective-C runtime environment.  */
191
192extern int flag_next_runtime;
193
194extern int flag_dump_rtl_in_asm;
195
196/* If one, renumber instruction UIDs to reduce the number of
197   unused UIDs if there are a lot of instructions.  If greater than
198   one, unconditionally renumber instruction UIDs.  */
199extern int flag_renumber_insns;
200
201/* Other basic status info about current function.  */
202
203/* Nonzero means current function must be given a frame pointer.
204   Set in stmt.c if anything is allocated on the stack there.
205   Set in reload1.c if anything is allocated on the stack there.  */
206
207extern int frame_pointer_needed;
208
209/* Nonzero if subexpressions must be evaluated from left-to-right.  */
210extern int flag_evaluation_order;
211
212/* Value of the -G xx switch, and whether it was passed or not.  */
213extern unsigned HOST_WIDE_INT g_switch_value;
214extern bool g_switch_set;
215
216/* Values of the -falign-* flags: how much to align labels in code.
217   0 means `use default', 1 means `don't align'.
218   For each variable, there is an _log variant which is the power
219   of two not less than the variable, for .align output.  */
220
221extern int align_loops_log;
222extern int align_loops_max_skip;
223extern int align_jumps_log;
224extern int align_jumps_max_skip;
225extern int align_labels_log;
226extern int align_labels_max_skip;
227extern int align_functions_log;
228
229/* Like align_functions_log above, but used by front-ends to force the
230   minimum function alignment.  Zero means no alignment is forced.  */
231extern int force_align_functions_log;
232
233/* Nonzero if we dump in VCG format, not plain text.  */
234extern int dump_for_graph;
235
236/* Selection of the graph form.  */
237enum graph_dump_types
238{
239  no_graph = 0,
240  vcg
241};
242extern enum graph_dump_types graph_dump_format;
243
244/* Nonzero means to collect statistics which might be expensive
245   and to print them when we are done.  */
246extern int flag_detailed_statistics;
247
248/* Nonzero means that we defer emitting functions until they are actually
249   used.  */
250extern int flag_remove_unreachable_functions;
251
252/* Nonzero if we should track variables.  */
253extern int flag_var_tracking;
254
255/* True if flag_speculative_prefetching was set by user.  Used to suppress
256   warning message in case flag was set by -fprofile-{generate,use}.  */
257extern bool flag_speculative_prefetching_set;
258
259/* A string that's used when a random name is required.  NULL means
260   to make it really random.  */
261
262extern const char *flag_random_seed;
263
264/* Returns TRUE if generated code should match ABI version N or
265   greater is in use.  */
266
267#define abi_version_at_least(N) \
268  (flag_abi_version == 0 || flag_abi_version >= (N))
269
270/* True if the given mode has a NaN representation and the treatment of
271   NaN operands is important.  Certain optimizations, such as folding
272   x * 0 into 0, are not correct for NaN operands, and are normally
273   disabled for modes with NaNs.  The user can ask for them to be
274   done anyway using the -funsafe-math-optimizations switch.  */
275#define HONOR_NANS(MODE) \
276  (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
277
278/* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
279#define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
280
281/* As for HONOR_NANS, but true if the mode can represent infinity and
282   the treatment of infinite values is important.  */
283#define HONOR_INFINITIES(MODE) \
284  (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
285
286/* Like HONOR_NANS, but true if the given mode distinguishes between
287   positive and negative zero, and the sign of zero is important.  */
288#define HONOR_SIGNED_ZEROS(MODE) \
289  (MODE_HAS_SIGNED_ZEROS (MODE) && !flag_unsafe_math_optimizations)
290
291/* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
292   and the rounding mode is important.  */
293#define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
294  (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
295
296/* True if overflow wraps around for the given integral type.  That
297   is, TYPE_MAX + 1 == TYPE_MIN.  */
298#define TYPE_OVERFLOW_WRAPS(TYPE) \
299  (TYPE_UNSIGNED (TYPE) || flag_wrapv)
300
301/* True if overflow is undefined for the given integral type.  We may
302   optimize on the assumption that values in the type never overflow.
303
304   IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
305   must issue a warning based on warn_strict_overflow.  In some cases
306   it will be appropriate to issue the warning immediately, and in
307   other cases it will be appropriate to simply set a flag and let the
308   caller decide whether a warning is appropriate or not.  */
309#define TYPE_OVERFLOW_UNDEFINED(TYPE) \
310  (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
311
312/* True if overflow for the given integral type should issue a
313   trap.  */
314#define TYPE_OVERFLOW_TRAPS(TYPE) \
315  (!TYPE_UNSIGNED (TYPE) && flag_trapv)
316
317/* Names for the different levels of -Wstrict-overflow=N.  The numeric
318   values here correspond to N.  */
319
320enum warn_strict_overflow_code
321{
322  /* Overflow warning that should be issued with -Wall: a questionable
323     construct that is easy to avoid even when using macros.  Example:
324     folding (x + CONSTANT > x) to 1.  */
325  WARN_STRICT_OVERFLOW_ALL = 1,
326  /* Overflow warning about folding a comparison to a constant because
327     of undefined signed overflow, other than cases covered by
328     WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
329     (this is false when x == INT_MIN).  */
330  WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
331  /* Overflow warning about changes to comparisons other than folding
332     them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
333  WARN_STRICT_OVERFLOW_COMPARISON = 3,
334  /* Overflow warnings not covered by the above cases.  Example:
335     folding ((x * 10) / 5) to (x * 2).  */
336  WARN_STRICT_OVERFLOW_MISC = 4,
337  /* Overflow warnings about reducing magnitude of constants in
338     comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
339  WARN_STRICT_OVERFLOW_MAGNITUDE = 5
340};
341
342/* Whether to emit an overflow warning whose code is C.  */
343#define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
344
345#endif /* ! GCC_FLAGS_H */
346