1 /* Define builtin-in macros for the C family front ends.
2 Copyright (C) 2002, 2003 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 2, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
23 #include "coretypes.h"
31 #include "except.h" /* For USING_SJLJ_EXCEPTIONS. */
33 #include "tm_p.h" /* Target prototypes. */
35 #ifndef REGISTER_PREFIX
36 #define REGISTER_PREFIX ""
39 static void builtin_define_std PARAMS ((const char *)) ATTRIBUTE_UNUSED;
40 static void builtin_define_with_value_n PARAMS ((const char *, const char *,
42 static void builtin_define_with_int_value PARAMS ((const char *,
44 static void builtin_define_with_hex_fp_value PARAMS ((const char *, tree,
47 static void builtin_define_type_max PARAMS ((const char *, tree, int));
48 static void builtin_define_type_precision PARAMS ((const char *, tree));
49 static void builtin_define_float_constants PARAMS ((const char *,
51 static void define__GNUC__ PARAMS ((void));
53 /* Define NAME with value TYPE precision. */
55 builtin_define_type_precision (name, type)
59 builtin_define_with_int_value (name, TYPE_PRECISION (type));
62 /* Define the float.h constants for TYPE using NAME_PREFIX and FP_SUFFIX. */
64 builtin_define_float_constants (name_prefix, fp_suffix, type)
65 const char *name_prefix;
66 const char *fp_suffix;
69 /* Used to convert radix-based values to base 10 values in several cases.
71 In the max_exp -> max_10_exp conversion for 128-bit IEEE, we need at
72 least 6 significant digits for correct results. Using the fraction
73 formed by (log(2)*1e6)/(log(10)*1e6) overflows a 32-bit integer as an
74 intermediate; perhaps someone can find a better approximation, in the
75 mean time, I suspect using doubles won't harm the bootstrap here. */
77 const double log10_2 = .30102999566398119521;
79 const struct real_format *fmt;
81 char name[64], buf[128];
82 int dig, min_10_exp, max_10_exp;
85 fmt = real_format_for_mode[TYPE_MODE (type) - QFmode];
87 /* The radix of the exponent representation. */
88 if (type == float_type_node)
89 builtin_define_with_int_value ("__FLT_RADIX__", fmt->b);
90 log10_b = log10_2 * fmt->log2_b;
92 /* The number of radix digits, p, in the floating-point significand. */
93 sprintf (name, "__%s_MANT_DIG__", name_prefix);
94 builtin_define_with_int_value (name, fmt->p);
96 /* The number of decimal digits, q, such that any floating-point number
97 with q decimal digits can be rounded into a floating-point number with
98 p radix b digits and back again without change to the q decimal digits,
100 p log10 b if b is a power of 10
101 floor((p - 1) log10 b) otherwise
103 dig = (fmt->p - 1) * log10_b;
104 sprintf (name, "__%s_DIG__", name_prefix);
105 builtin_define_with_int_value (name, dig);
107 /* The minimum negative int x such that b**(x-1) is a normalized float. */
108 sprintf (name, "__%s_MIN_EXP__", name_prefix);
109 sprintf (buf, "(%d)", fmt->emin);
110 builtin_define_with_value (name, buf, 0);
112 /* The minimum negative int x such that 10**x is a normalized float,
114 ceil (log10 (b ** (emin - 1)))
115 = ceil (log10 (b) * (emin - 1))
117 Recall that emin is negative, so the integer truncation calculates
118 the ceiling, not the floor, in this case. */
119 min_10_exp = (fmt->emin - 1) * log10_b;
120 sprintf (name, "__%s_MIN_10_EXP__", name_prefix);
121 sprintf (buf, "(%d)", min_10_exp);
122 builtin_define_with_value (name, buf, 0);
124 /* The maximum int x such that b**(x-1) is a representable float. */
125 sprintf (name, "__%s_MAX_EXP__", name_prefix);
126 builtin_define_with_int_value (name, fmt->emax);
128 /* The maximum int x such that 10**x is in the range of representable
129 finite floating-point numbers,
131 floor (log10((1 - b**-p) * b**emax))
132 = floor (log10(1 - b**-p) + log10(b**emax))
133 = floor (log10(1 - b**-p) + log10(b)*emax)
135 The safest thing to do here is to just compute this number. But since
136 we don't link cc1 with libm, we cannot. We could implement log10 here
137 a series expansion, but that seems too much effort because:
139 Note that the first term, for all extant p, is a number exceedingly close
140 to zero, but slightly negative. Note that the second term is an integer
141 scaling an irrational number, and that because of the floor we are only
142 interested in its integral portion.
144 In order for the first term to have any effect on the integral portion
145 of the second term, the second term has to be exceedingly close to an
146 integer itself (e.g. 123.000000000001 or something). Getting a result
147 that close to an integer requires that the irrational multiplicand have
148 a long series of zeros in its expansion, which doesn't occur in the
149 first 20 digits or so of log10(b).
151 Hand-waving aside, crunching all of the sets of constants above by hand
152 does not yield a case for which the first term is significant, which
153 in the end is all that matters. */
154 max_10_exp = fmt->emax * log10_b;
155 sprintf (name, "__%s_MAX_10_EXP__", name_prefix);
156 builtin_define_with_int_value (name, max_10_exp);
158 /* The number of decimal digits, n, such that any floating-point number
159 can be rounded to n decimal digits and back again without change to
162 p * log10(b) if b is a power of 10
163 ceil(1 + p * log10(b)) otherwise
165 The only macro we care about is this number for the widest supported
166 floating type, but we want this value for rendering constants below. */
168 double d_decimal_dig = 1 + fmt->p * log10_b;
169 decimal_dig = d_decimal_dig;
170 if (decimal_dig < d_decimal_dig)
173 if (type == long_double_type_node)
174 builtin_define_with_int_value ("__DECIMAL_DIG__", decimal_dig);
176 /* Since, for the supported formats, B is always a power of 2, we
177 construct the following numbers directly as a hexadecimal
180 /* The maximum representable finite floating-point number,
181 (1 - b**-p) * b**emax */
186 strcpy (buf, "0x0.");
187 n = fmt->p * fmt->log2_b;
188 for (i = 0, p = buf + 4; i + 3 < n; i += 4)
191 *p++ = "08ce"[n - i];
192 sprintf (p, "p%d", fmt->emax * fmt->log2_b);
194 sprintf (name, "__%s_MAX__", name_prefix);
195 builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
197 /* The minimum normalized positive floating-point number,
199 sprintf (name, "__%s_MIN__", name_prefix);
200 sprintf (buf, "0x1p%d", (fmt->emin - 1) * fmt->log2_b);
201 builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
203 /* The difference between 1 and the least value greater than 1 that is
204 representable in the given floating point type, b**(1-p). */
205 sprintf (name, "__%s_EPSILON__", name_prefix);
206 sprintf (buf, "0x1p%d", (1 - fmt->p) * fmt->log2_b);
207 builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
209 /* For C++ std::numeric_limits<T>::denorm_min. The minimum denormalized
210 positive floating-point number, b**(emin-p). Zero for formats that
211 don't support denormals. */
212 sprintf (name, "__%s_DENORM_MIN__", name_prefix);
215 sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
216 builtin_define_with_hex_fp_value (name, type, decimal_dig,
221 sprintf (buf, "0.0%s", fp_suffix);
222 builtin_define_with_value (name, buf, 0);
225 /* For C++ std::numeric_limits<T>::has_infinity. */
226 sprintf (name, "__%s_HAS_INFINITY__", name_prefix);
227 builtin_define_with_int_value (name,
228 MODE_HAS_INFINITIES (TYPE_MODE (type)));
229 /* For C++ std::numeric_limits<T>::has_quiet_NaN. We do not have a
230 predicate to distinguish a target that has both quiet and
231 signalling NaNs from a target that has only quiet NaNs or only
232 signalling NaNs, so we assume that a target that has any kind of
233 NaN has quiet NaNs. */
234 sprintf (name, "__%s_HAS_QUIET_NAN__", name_prefix);
235 builtin_define_with_int_value (name, MODE_HAS_NANS (TYPE_MODE (type)));
238 /* Define __GNUC__, __GNUC_MINOR__ and __GNUC_PATCHLEVEL__. */
242 /* The format of the version string, enforced below, is
243 ([^0-9]*-)?[0-9]+[.][0-9]+([.][0-9]+)?([- ].*)? */
244 const char *q, *v = version_string;
246 while (*v && ! ISDIGIT (*v))
248 if (!*v || (v > version_string && v[-1] != '-'))
254 builtin_define_with_value_n ("__GNUC__", q, v - q);
255 if (c_language == clk_cplusplus)
256 builtin_define_with_value_n ("__GNUG__", q, v - q);
258 if (*v != '.' || !ISDIGIT (v[1]))
263 builtin_define_with_value_n ("__GNUC_MINOR__", q, v - q);
272 builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", q, v - q);
275 builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", "0", 1);
277 if (*v && *v != ' ' && *v != '-')
281 /* Hook that registers front end and target-specific built-ins. */
283 cb_register_builtins (pfile)
286 /* -undef turns off target-specific built-ins. */
292 /* For stddef.h. They require macros defined in c-common.c. */
293 c_stddef_cpp_builtins ();
295 if (c_language == clk_cplusplus)
297 if (SUPPORTS_ONE_ONLY)
298 cpp_define (pfile, "__GXX_WEAK__=1");
300 cpp_define (pfile, "__GXX_WEAK__=0");
302 cpp_define (pfile, "__EXCEPTIONS");
304 cpp_define (pfile, "__DEPRECATED");
307 /* represents the C++ ABI version, always defined so it can be used while
308 preprocessing C and assembler. */
309 cpp_define (pfile, "__GXX_ABI_VERSION=102");
311 /* libgcc needs to know this. */
312 if (USING_SJLJ_EXCEPTIONS)
313 cpp_define (pfile, "__USING_SJLJ_EXCEPTIONS__");
315 /* limits.h needs to know these. */
316 builtin_define_type_max ("__SCHAR_MAX__", signed_char_type_node, 0);
317 builtin_define_type_max ("__SHRT_MAX__", short_integer_type_node, 0);
318 builtin_define_type_max ("__INT_MAX__", integer_type_node, 0);
319 builtin_define_type_max ("__LONG_MAX__", long_integer_type_node, 1);
320 builtin_define_type_max ("__LONG_LONG_MAX__", long_long_integer_type_node, 2);
321 builtin_define_type_max ("__WCHAR_MAX__", wchar_type_node, 0);
323 builtin_define_type_precision ("__CHAR_BIT__", char_type_node);
325 /* float.h needs to know these. */
327 builtin_define_with_int_value ("__FLT_EVAL_METHOD__",
328 TARGET_FLT_EVAL_METHOD);
330 builtin_define_float_constants ("FLT", "F", float_type_node);
331 builtin_define_float_constants ("DBL", "", double_type_node);
332 builtin_define_float_constants ("LDBL", "L", long_double_type_node);
334 /* For use in assembly language. */
335 builtin_define_with_value ("__REGISTER_PREFIX__", REGISTER_PREFIX, 0);
336 builtin_define_with_value ("__USER_LABEL_PREFIX__", user_label_prefix, 0);
339 builtin_define_with_value ("__VERSION__", version_string, 1);
341 /* Other target-independent built-ins determined by command-line
344 cpp_define (pfile, "__OPTIMIZE_SIZE__");
346 cpp_define (pfile, "__OPTIMIZE__");
349 cpp_define (pfile, "__STDC_HOSTED__=1");
351 cpp_define (pfile, "__STDC_HOSTED__=0");
353 if (fast_math_flags_set_p ())
354 cpp_define (pfile, "__FAST_MATH__");
355 if (flag_really_no_inline)
356 cpp_define (pfile, "__NO_INLINE__");
357 if (flag_signaling_nans)
358 cpp_define (pfile, "__SUPPORT_SNAN__");
359 if (flag_finite_math_only)
360 cpp_define (pfile, "__FINITE_MATH_ONLY__=1");
362 cpp_define (pfile, "__FINITE_MATH_ONLY__=0");
365 cpp_define (pfile, "__STRICT_ANSI__");
367 if (!flag_signed_char)
368 cpp_define (pfile, "__CHAR_UNSIGNED__");
370 if (c_language == clk_cplusplus && TREE_UNSIGNED (wchar_type_node))
371 cpp_define (pfile, "__WCHAR_UNSIGNED__");
373 /* Make the choice of ObjC runtime visible to source code. */
374 if (flag_objc && flag_next_runtime)
375 cpp_define (pfile, "__NEXT_RUNTIME__");
377 /* A straightforward target hook doesn't work, because of problems
378 linking that hook's body when part of non-C front ends. */
379 # define preprocessing_asm_p() (cpp_get_options (pfile)->lang == CLK_ASM)
380 # define preprocessing_trad_p() (cpp_get_options (pfile)->traditional)
381 # define builtin_define(TXT) cpp_define (pfile, TXT)
382 # define builtin_assert(TXT) cpp_assert (pfile, TXT)
383 TARGET_CPU_CPP_BUILTINS ();
384 TARGET_OS_CPP_BUILTINS ();
387 /* Pass an object-like macro. If it doesn't lie in the user's
388 namespace, defines it unconditionally. Otherwise define a version
389 with two leading underscores, and another version with two leading
390 and trailing underscores, and define the original only if an ISO
391 standard was not nominated.
393 e.g. passing "unix" defines "__unix", "__unix__" and possibly
394 "unix". Passing "_mips" defines "__mips", "__mips__" and possibly
397 builtin_define_std (macro)
400 size_t len = strlen (macro);
401 char *buff = alloca (len + 5);
405 /* prepend __ (or maybe just _) if in user's namespace. */
406 memcpy (p, macro, len + 1);
407 if (!( *p == '_' && (p[1] == '_' || ISUPPER (p[1]))))
414 cpp_define (parse_in, p);
416 /* If it was in user's namespace... */
419 /* Define the macro with leading and following __. */
425 cpp_define (parse_in, p);
427 /* Finally, define the original macro if permitted. */
429 cpp_define (parse_in, macro);
433 /* Pass an object-like macro and a value to define it to. The third
434 parameter says whether or not to turn the value into a string
437 builtin_define_with_value (macro, expansion, is_str)
439 const char *expansion;
443 size_t mlen = strlen (macro);
444 size_t elen = strlen (expansion);
445 size_t extra = 2; /* space for an = and a NUL */
448 extra += 2; /* space for two quote marks */
450 buf = alloca (mlen + elen + extra);
452 sprintf (buf, "%s=\"%s\"", macro, expansion);
454 sprintf (buf, "%s=%s", macro, expansion);
456 cpp_define (parse_in, buf);
459 /* Pass an object-like macro and a value to define it to. The third
460 parameter is the length of the expansion. */
462 builtin_define_with_value_n (macro, expansion, elen)
464 const char *expansion;
468 size_t mlen = strlen (macro);
470 /* Space for an = and a NUL. */
471 buf = alloca (mlen + elen + 2);
472 memcpy (buf, macro, mlen);
474 memcpy (buf + mlen + 1, expansion, elen);
475 buf[mlen + elen + 1] = '\0';
477 cpp_define (parse_in, buf);
480 /* Pass an object-like macro and an integer value to define it to. */
482 builtin_define_with_int_value (macro, value)
487 size_t mlen = strlen (macro);
489 size_t extra = 2; /* space for = and NUL. */
491 buf = alloca (mlen + vlen + extra);
492 memcpy (buf, macro, mlen);
494 sprintf (buf + mlen + 1, HOST_WIDE_INT_PRINT_DEC, value);
496 cpp_define (parse_in, buf);
499 /* Pass an object-like macro a hexadecimal floating-point value. */
501 builtin_define_with_hex_fp_value (macro, type, digits, hex_str, fp_suffix)
503 tree type ATTRIBUTE_UNUSED;
506 const char *fp_suffix;
508 REAL_VALUE_TYPE real;
509 char dec_str[64], buf[256];
511 /* Hex values are really cool and convenient, except that they're
512 not supported in strict ISO C90 mode. First, the "p-" sequence
513 is not valid as part of a preprocessor number. Second, we get a
514 pedwarn from the preprocessor, which has no context, so we can't
515 suppress the warning with __extension__.
517 So instead what we do is construct the number in hex (because
518 it's easy to get the exact correct value), parse it as a real,
519 then print it back out as decimal. */
521 real_from_string (&real, hex_str);
522 real_to_decimal (dec_str, &real, sizeof (dec_str), digits, 0);
524 sprintf (buf, "%s=%s%s", macro, dec_str, fp_suffix);
525 cpp_define (parse_in, buf);
528 /* Define MAX for TYPE based on the precision of the type. IS_LONG is
529 1 for type "long" and 2 for "long long". We have to handle
530 unsigned types, since wchar_t might be unsigned. */
533 builtin_define_type_max (macro, type, is_long)
538 static const char *const values[]
541 "2147483647", "4294967295",
542 "9223372036854775807", "18446744073709551615",
543 "170141183460469231731687303715884105727",
544 "340282366920938463463374607431768211455" };
545 static const char *const suffixes[] = { "", "U", "L", "UL", "LL", "ULL" };
547 const char *value, *suffix;
551 /* Pre-rendering the values mean we don't have to futz with printing a
552 multi-word decimal value. There are also a very limited number of
553 precisions that we support, so it's really a waste of time. */
554 switch (TYPE_PRECISION (type))
556 case 8: idx = 0; break;
557 case 16: idx = 2; break;
558 case 32: idx = 4; break;
559 case 64: idx = 6; break;
560 case 128: idx = 8; break;
564 value = values[idx + TREE_UNSIGNED (type)];
565 suffix = suffixes[is_long * 2 + TREE_UNSIGNED (type)];
567 buf = alloca (strlen (macro) + 1 + strlen (value) + strlen (suffix) + 1);
568 sprintf (buf, "%s=%s%s", macro, value, suffix);
570 cpp_define (parse_in, buf);