xref: /openbsd/gnu/gcc/gcc/flags.h (revision 17c8d4a9)
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 "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 /* Nonzero means use GNU-only extensions in the generated symbolic
58    debugging information.  */
59 extern 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
65 enum 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).  */
75 extern enum symbol_visibility default_visibility;
76 
77 struct 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.  */
84 extern struct visibility_flags visibility_options;
85 
86 /* Nonzero means do optimizations.  -opt.  */
87 
88 extern int optimize;
89 
90 /* Nonzero means optimize for size.  -Os.  */
91 
92 extern int optimize_size;
93 
94 /* Do print extra warnings (such as for uninitialized variables).
95    -W/-Wextra.  */
96 
97 extern 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 
103 extern 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 
109 extern bool warn_larger_than;
110 extern HOST_WIDE_INT larger_than_size;
111 
112 /* Nonzero means warn about any function whose stack usage is larger
113    than N bytes.  The value N is in `stack_larger_than_size'.  */
114 
115 extern int warn_stack_larger_than;
116 extern HOST_WIDE_INT stack_larger_than_size;
117 
118 /* Nonzero means warn about constructs which might not be strict
119    aliasing safe.  */
120 
121 extern int warn_strict_aliasing;
122 
123 /* Nonzero means warn about optimizations which rely on undefined
124    signed overflow.  */
125 
126 extern int warn_strict_overflow;
127 
128 /* Temporarily suppress certain warnings.
129    This is set while reading code from a system header file.  */
130 
131 extern int in_system_header;
132 
133 /* Nonzero for -dp: annotate the assembly with a comment describing the
134    pattern and alternative used.  */
135 
136 extern int flag_print_asm_name;
137 
138 /* Now the symbols that are set with `-f' switches.  */
139 
140 /* Nonzero means `char' should be signed.  */
141 
142 extern int flag_signed_char;
143 
144 /* Nonzero means give an enum type only as many bytes as it needs.  A value
145    of 2 means it has not yet been initialized.  */
146 
147 extern int flag_short_enums;
148 
149 /* Nonzero for -fpcc-struct-return: return values the same way PCC does.  */
150 
151 extern int flag_pcc_struct_return;
152 
153 /* 0 means straightforward implementation of complex divide acceptable.
154    1 means wide ranges of inputs must work for complex divide.
155    2 means C99-like requirements for complex multiply and divide.  */
156 
157 extern int flag_complex_method;
158 
159 /* Nonzero means that we don't want inlining by virtue of -fno-inline,
160    not just because the tree inliner turned us off.  */
161 
162 extern int flag_really_no_inline;
163 
164 /* Nonzero if we are only using compiler to check syntax errors.  */
165 
166 extern int rtl_dump_and_exit;
167 
168 /* Nonzero means we should save auxiliary info into a .X file.  */
169 
170 extern int flag_gen_aux_info;
171 
172 /* Nonzero means suppress output of instruction numbers and line number
173    notes in debugging dumps.  */
174 
175 extern int flag_dump_unnumbered;
176 
177 /* Nonzero means change certain warnings into errors.
178    Usually these are warnings about failure to conform to some standard.  */
179 
180 extern int flag_pedantic_errors;
181 
182 /* Nonzero if we are compiling code for a shared library, zero for
183    executable.  */
184 
185 extern int flag_shlib;
186 
187 /* -dA causes debug information to be produced in
188    the generated assembly code (to make it more readable).  This option
189    is generally only of use to those who actually need to read the
190    generated assembly code (perhaps while debugging the compiler itself).
191    Currently, this switch is only used by dwarfout.c; however, it is intended
192    to be a catchall for printing debug information in the assembler file.  */
193 
194 extern int flag_debug_asm;
195 
196 /* Generate code for GNU or NeXT Objective-C runtime environment.  */
197 
198 extern int flag_next_runtime;
199 
200 extern int flag_dump_rtl_in_asm;
201 
202 /* If one, renumber instruction UIDs to reduce the number of
203    unused UIDs if there are a lot of instructions.  If greater than
204    one, unconditionally renumber instruction UIDs.  */
205 extern int flag_renumber_insns;
206 
207 /* Other basic status info about current function.  */
208 
209 /* Nonzero means current function must be given a frame pointer.
210    Set in stmt.c if anything is allocated on the stack there.
211    Set in reload1.c if anything is allocated on the stack there.  */
212 
213 extern int frame_pointer_needed;
214 
215 /* Nonzero if subexpressions must be evaluated from left-to-right.  */
216 extern int flag_evaluation_order;
217 
218 /* Value of the -G xx switch, and whether it was passed or not.  */
219 extern unsigned HOST_WIDE_INT g_switch_value;
220 extern bool g_switch_set;
221 
222 /* Values of the -falign-* flags: how much to align labels in code.
223    0 means `use default', 1 means `don't align'.
224    For each variable, there is an _log variant which is the power
225    of two not less than the variable, for .align output.  */
226 
227 extern int align_loops_log;
228 extern int align_loops_max_skip;
229 extern int align_jumps_log;
230 extern int align_jumps_max_skip;
231 extern int align_labels_log;
232 extern int align_labels_max_skip;
233 extern int align_functions_log;
234 
235 /* Like align_functions_log above, but used by front-ends to force the
236    minimum function alignment.  Zero means no alignment is forced.  */
237 extern int force_align_functions_log;
238 
239 /* Nonzero if we dump in VCG format, not plain text.  */
240 extern int dump_for_graph;
241 
242 /* Selection of the graph form.  */
243 enum graph_dump_types
244 {
245   no_graph = 0,
246   vcg
247 };
248 extern enum graph_dump_types graph_dump_format;
249 
250 /* Nonzero means to collect statistics which might be expensive
251    and to print them when we are done.  */
252 extern int flag_detailed_statistics;
253 
254 /* Nonzero means that we defer emitting functions until they are actually
255    used.  */
256 extern int flag_remove_unreachable_functions;
257 
258 /* Nonzero if we should track variables.  */
259 extern int flag_var_tracking;
260 
261 /* True if flag_speculative_prefetching was set by user.  Used to suppress
262    warning message in case flag was set by -fprofile-{generate,use}.  */
263 extern bool flag_speculative_prefetching_set;
264 
265 /* A string that's used when a random name is required.  NULL means
266    to make it really random.  */
267 
268 extern const char *flag_random_seed;
269 
270 /* Returns TRUE if generated code should match ABI version N or
271    greater is in use.  */
272 
273 #define abi_version_at_least(N) \
274   (flag_abi_version == 0 || flag_abi_version >= (N))
275 
276 /* True if the given mode has a NaN representation and the treatment of
277    NaN operands is important.  Certain optimizations, such as folding
278    x * 0 into 0, are not correct for NaN operands, and are normally
279    disabled for modes with NaNs.  The user can ask for them to be
280    done anyway using the -funsafe-math-optimizations switch.  */
281 #define HONOR_NANS(MODE) \
282   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
283 
284 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
285 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
286 
287 /* As for HONOR_NANS, but true if the mode can represent infinity and
288    the treatment of infinite values is important.  */
289 #define HONOR_INFINITIES(MODE) \
290   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
291 
292 /* Like HONOR_NANS, but true if the given mode distinguishes between
293    positive and negative zero, and the sign of zero is important.  */
294 #define HONOR_SIGNED_ZEROS(MODE) \
295   (MODE_HAS_SIGNED_ZEROS (MODE) && !flag_unsafe_math_optimizations)
296 
297 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
298    and the rounding mode is important.  */
299 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
300   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
301 
302 /* True if overflow wraps around for the given integral type.  That
303    is, TYPE_MAX + 1 == TYPE_MIN.  */
304 #define TYPE_OVERFLOW_WRAPS(TYPE) \
305   (TYPE_UNSIGNED (TYPE) || flag_wrapv)
306 
307 /* True if overflow is undefined for the given integral type.  We may
308    optimize on the assumption that values in the type never overflow.
309 
310    IMPORTANT NOTE: Any optimization based on TYPE_OVERFLOW_UNDEFINED
311    must issue a warning based on warn_strict_overflow.  In some cases
312    it will be appropriate to issue the warning immediately, and in
313    other cases it will be appropriate to simply set a flag and let the
314    caller decide whether a warning is appropriate or not.  */
315 #define TYPE_OVERFLOW_UNDEFINED(TYPE) \
316   (!TYPE_UNSIGNED (TYPE) && !flag_wrapv && !flag_trapv && flag_strict_overflow)
317 
318 /* True if overflow for the given integral type should issue a
319    trap.  */
320 #define TYPE_OVERFLOW_TRAPS(TYPE) \
321   (!TYPE_UNSIGNED (TYPE) && flag_trapv)
322 
323 /* Names for the different levels of -Wstrict-overflow=N.  The numeric
324    values here correspond to N.  */
325 
326 enum warn_strict_overflow_code
327 {
328   /* Overflow warning that should be issued with -Wall: a questionable
329      construct that is easy to avoid even when using macros.  Example:
330      folding (x + CONSTANT > x) to 1.  */
331   WARN_STRICT_OVERFLOW_ALL = 1,
332   /* Overflow warning about folding a comparison to a constant because
333      of undefined signed overflow, other than cases covered by
334      WARN_STRICT_OVERFLOW_ALL.  Example: folding (abs (x) >= 0) to 1
335      (this is false when x == INT_MIN).  */
336   WARN_STRICT_OVERFLOW_CONDITIONAL = 2,
337   /* Overflow warning about changes to comparisons other than folding
338      them to a constant.  Example: folding (x + 1 > 1) to (x > 0).  */
339   WARN_STRICT_OVERFLOW_COMPARISON = 3,
340   /* Overflow warnings not covered by the above cases.  Example:
341      folding ((x * 10) / 5) to (x * 2).  */
342   WARN_STRICT_OVERFLOW_MISC = 4,
343   /* Overflow warnings about reducing magnitude of constants in
344      comparison.  Example: folding (x + 2 > y) to (x + 1 >= y).  */
345   WARN_STRICT_OVERFLOW_MAGNITUDE = 5
346 };
347 
348 /* Whether to emit an overflow warning whose code is C.  */
349 #define issue_strict_overflow_warning(c) (warn_strict_overflow >= (int) (c))
350 
351 #endif /* ! GCC_FLAGS_H */
352