1/* Define builtin-in macros for the C family front ends.
2   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 2, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING.  If not, write to the Free
18Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
1902110-1301, USA.  */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "tm.h"
25#include "tree.h"
26#include "version.h"
27#include "flags.h"
28#include "real.h"
29#include "c-common.h"
30#include "c-pragma.h"
31#include "output.h"
32#include "except.h"		/* For USING_SJLJ_EXCEPTIONS.  */
33#include "toplev.h"
34#include "tm_p.h"		/* Target prototypes.  */
35#include "target.h"
36
37#ifndef TARGET_OS_CPP_BUILTINS
38# define TARGET_OS_CPP_BUILTINS()
39#endif
40
41#ifndef TARGET_OBJFMT_CPP_BUILTINS
42# define TARGET_OBJFMT_CPP_BUILTINS()
43#endif
44
45#ifndef REGISTER_PREFIX
46#define REGISTER_PREFIX ""
47#endif
48
49/* Non-static as some targets don't use it.  */
50void builtin_define_std (const char *) ATTRIBUTE_UNUSED;
51static void builtin_define_with_value_n (const char *, const char *,
52					 size_t);
53static void builtin_define_with_int_value (const char *, HOST_WIDE_INT);
54static void builtin_define_with_hex_fp_value (const char *, tree,
55					      int, const char *,
56					      const char *,
57					      const char *);
58static void builtin_define_stdint_macros (void);
59static void builtin_define_type_max (const char *, tree, int);
60static void builtin_define_type_precision (const char *, tree);
61static void builtin_define_float_constants (const char *,
62					    const char *,
63					    const char *,
64					    tree);
65static void define__GNUC__ (void);
66
67/* Define NAME with value TYPE precision.  */
68static void
69builtin_define_type_precision (const char *name, tree type)
70{
71  builtin_define_with_int_value (name, TYPE_PRECISION (type));
72}
73
74/* Define the float.h constants for TYPE using NAME_PREFIX, FP_SUFFIX,
75   and FP_CAST. */
76static void
77builtin_define_float_constants (const char *name_prefix,
78		                const char *fp_suffix,
79				const char *fp_cast,
80				tree type)
81{
82  /* Used to convert radix-based values to base 10 values in several cases.
83
84     In the max_exp -> max_10_exp conversion for 128-bit IEEE, we need at
85     least 6 significant digits for correct results.  Using the fraction
86     formed by (log(2)*1e6)/(log(10)*1e6) overflows a 32-bit integer as an
87     intermediate; perhaps someone can find a better approximation, in the
88     mean time, I suspect using doubles won't harm the bootstrap here.  */
89
90  const double log10_2 = .30102999566398119521;
91  double log10_b;
92  const struct real_format *fmt;
93
94  char name[64], buf[128];
95  int dig, min_10_exp, max_10_exp;
96  int decimal_dig;
97
98  fmt = REAL_MODE_FORMAT (TYPE_MODE (type));
99  gcc_assert (fmt->b != 10);
100
101  /* The radix of the exponent representation.  */
102  if (type == float_type_node)
103    builtin_define_with_int_value ("__FLT_RADIX__", fmt->b);
104  log10_b = log10_2 * fmt->log2_b;
105
106  /* The number of radix digits, p, in the floating-point significand.  */
107  sprintf (name, "__%s_MANT_DIG__", name_prefix);
108  builtin_define_with_int_value (name, fmt->p);
109
110  /* The number of decimal digits, q, such that any floating-point number
111     with q decimal digits can be rounded into a floating-point number with
112     p radix b digits and back again without change to the q decimal digits,
113
114	p log10 b			if b is a power of 10
115	floor((p - 1) log10 b)		otherwise
116  */
117  dig = (fmt->p - 1) * log10_b;
118  sprintf (name, "__%s_DIG__", name_prefix);
119  builtin_define_with_int_value (name, dig);
120
121  /* The minimum negative int x such that b**(x-1) is a normalized float.  */
122  sprintf (name, "__%s_MIN_EXP__", name_prefix);
123  sprintf (buf, "(%d)", fmt->emin);
124  builtin_define_with_value (name, buf, 0);
125
126  /* The minimum negative int x such that 10**x is a normalized float,
127
128	  ceil (log10 (b ** (emin - 1)))
129	= ceil (log10 (b) * (emin - 1))
130
131     Recall that emin is negative, so the integer truncation calculates
132     the ceiling, not the floor, in this case.  */
133  min_10_exp = (fmt->emin - 1) * log10_b;
134  sprintf (name, "__%s_MIN_10_EXP__", name_prefix);
135  sprintf (buf, "(%d)", min_10_exp);
136  builtin_define_with_value (name, buf, 0);
137
138  /* The maximum int x such that b**(x-1) is a representable float.  */
139  sprintf (name, "__%s_MAX_EXP__", name_prefix);
140  builtin_define_with_int_value (name, fmt->emax);
141
142  /* The maximum int x such that 10**x is in the range of representable
143     finite floating-point numbers,
144
145	  floor (log10((1 - b**-p) * b**emax))
146	= floor (log10(1 - b**-p) + log10(b**emax))
147	= floor (log10(1 - b**-p) + log10(b)*emax)
148
149     The safest thing to do here is to just compute this number.  But since
150     we don't link cc1 with libm, we cannot.  We could implement log10 here
151     a series expansion, but that seems too much effort because:
152
153     Note that the first term, for all extant p, is a number exceedingly close
154     to zero, but slightly negative.  Note that the second term is an integer
155     scaling an irrational number, and that because of the floor we are only
156     interested in its integral portion.
157
158     In order for the first term to have any effect on the integral portion
159     of the second term, the second term has to be exceedingly close to an
160     integer itself (e.g. 123.000000000001 or something).  Getting a result
161     that close to an integer requires that the irrational multiplicand have
162     a long series of zeros in its expansion, which doesn't occur in the
163     first 20 digits or so of log10(b).
164
165     Hand-waving aside, crunching all of the sets of constants above by hand
166     does not yield a case for which the first term is significant, which
167     in the end is all that matters.  */
168  max_10_exp = fmt->emax * log10_b;
169  sprintf (name, "__%s_MAX_10_EXP__", name_prefix);
170  builtin_define_with_int_value (name, max_10_exp);
171
172  /* The number of decimal digits, n, such that any floating-point number
173     can be rounded to n decimal digits and back again without change to
174     the value.
175
176	p * log10(b)			if b is a power of 10
177	ceil(1 + p * log10(b))		otherwise
178
179     The only macro we care about is this number for the widest supported
180     floating type, but we want this value for rendering constants below.  */
181  {
182    double d_decimal_dig = 1 + fmt->p * log10_b;
183    decimal_dig = d_decimal_dig;
184    if (decimal_dig < d_decimal_dig)
185      decimal_dig++;
186  }
187  if (type == long_double_type_node)
188    builtin_define_with_int_value ("__DECIMAL_DIG__", decimal_dig);
189
190  /* Since, for the supported formats, B is always a power of 2, we
191     construct the following numbers directly as a hexadecimal
192     constants.  */
193
194  /* The maximum representable finite floating-point number,
195     (1 - b**-p) * b**emax  */
196  {
197    int i, n;
198    char *p;
199
200    strcpy (buf, "0x0.");
201    n = fmt->p * fmt->log2_b;
202    for (i = 0, p = buf + 4; i + 3 < n; i += 4)
203      *p++ = 'f';
204    if (i < n)
205      *p++ = "08ce"[n - i];
206    sprintf (p, "p%d", fmt->emax * fmt->log2_b);
207    if (fmt->pnan < fmt->p)
208      {
209	/* This is an IBM extended double format made up of two IEEE
210	   doubles.  The value of the long double is the sum of the
211	   values of the two parts.  The most significant part is
212	   required to be the value of the long double rounded to the
213	   nearest double.  Rounding means we need a slightly smaller
214	   value for LDBL_MAX.  */
215	buf[4 + fmt->pnan / 4] = "7bde"[fmt->pnan % 4];
216      }
217  }
218  sprintf (name, "__%s_MAX__", name_prefix);
219  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
220
221  /* The minimum normalized positive floating-point number,
222     b**(emin-1).  */
223  sprintf (name, "__%s_MIN__", name_prefix);
224  sprintf (buf, "0x1p%d", (fmt->emin - 1) * fmt->log2_b);
225  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
226
227  /* The difference between 1 and the least value greater than 1 that is
228     representable in the given floating point type, b**(1-p).  */
229  sprintf (name, "__%s_EPSILON__", name_prefix);
230  if (fmt->pnan < fmt->p)
231    /* This is an IBM extended double format, so 1.0 + any double is
232       representable precisely.  */
233      sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
234    else
235      sprintf (buf, "0x1p%d", (1 - fmt->p) * fmt->log2_b);
236  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
237
238  /* For C++ std::numeric_limits<T>::denorm_min.  The minimum denormalized
239     positive floating-point number, b**(emin-p).  Zero for formats that
240     don't support denormals.  */
241  sprintf (name, "__%s_DENORM_MIN__", name_prefix);
242  if (fmt->has_denorm)
243    {
244      sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
245      builtin_define_with_hex_fp_value (name, type, decimal_dig,
246					buf, fp_suffix, fp_cast);
247    }
248  else
249    {
250      sprintf (buf, "0.0%s", fp_suffix);
251      builtin_define_with_value (name, buf, 0);
252    }
253
254  sprintf (name, "__%s_HAS_DENORM__", name_prefix);
255  builtin_define_with_value (name, fmt->has_denorm ? "1" : "0", 0);
256
257  /* For C++ std::numeric_limits<T>::has_infinity.  */
258  sprintf (name, "__%s_HAS_INFINITY__", name_prefix);
259  builtin_define_with_int_value (name,
260				 MODE_HAS_INFINITIES (TYPE_MODE (type)));
261  /* For C++ std::numeric_limits<T>::has_quiet_NaN.  We do not have a
262     predicate to distinguish a target that has both quiet and
263     signalling NaNs from a target that has only quiet NaNs or only
264     signalling NaNs, so we assume that a target that has any kind of
265     NaN has quiet NaNs.  */
266  sprintf (name, "__%s_HAS_QUIET_NAN__", name_prefix);
267  builtin_define_with_int_value (name, MODE_HAS_NANS (TYPE_MODE (type)));
268}
269
270/* Define __DECx__ constants for TYPE using NAME_PREFIX and SUFFIX. */
271static void
272builtin_define_decimal_float_constants (const char *name_prefix,
273					const char *suffix,
274					tree type)
275{
276  const struct real_format *fmt;
277  char name[64], buf[128], *p;
278  int digits;
279
280  fmt = REAL_MODE_FORMAT (TYPE_MODE (type));
281
282  /* The number of radix digits, p, in the significand.  */
283  sprintf (name, "__%s_MANT_DIG__", name_prefix);
284  builtin_define_with_int_value (name, fmt->p);
285
286  /* The minimum negative int x such that b**(x-1) is a normalized float.  */
287  sprintf (name, "__%s_MIN_EXP__", name_prefix);
288  sprintf (buf, "(%d)", fmt->emin);
289  builtin_define_with_value (name, buf, 0);
290
291  /* The maximum int x such that b**(x-1) is a representable float.  */
292  sprintf (name, "__%s_MAX_EXP__", name_prefix);
293  builtin_define_with_int_value (name, fmt->emax);
294
295  /* Compute the minimum representable value.  */
296  sprintf (name, "__%s_MIN__", name_prefix);
297  sprintf (buf, "1E%d%s", fmt->emin, suffix);
298  builtin_define_with_value (name, buf, 0);
299
300  /* Compute the maximum representable value.  */
301  sprintf (name, "__%s_MAX__", name_prefix);
302  p = buf;
303  for (digits = fmt->p; digits; digits--)
304    {
305      *p++ = '9';
306      if (digits == fmt->p)
307	*p++ = '.';
308    }
309  *p = 0;
310  /* fmt->p plus 1, to account for the decimal point.  */
311  sprintf (&buf[fmt->p + 1], "E%d%s", fmt->emax, suffix);
312  builtin_define_with_value (name, buf, 0);
313
314  /* Compute epsilon (the difference between 1 and least value greater
315     than 1 representable).  */
316  sprintf (name, "__%s_EPSILON__", name_prefix);
317  sprintf (buf, "1E-%d%s", fmt->p - 1, suffix);
318  builtin_define_with_value (name, buf, 0);
319
320  /* Minimum denormalized postive decimal value.  */
321  sprintf (name, "__%s_DEN__", name_prefix);
322  p = buf;
323  for (digits = fmt->p; digits > 1; digits--)
324    {
325      *p++ = '0';
326      if (digits == fmt->p)
327	*p++ = '.';
328    }
329  *p = 0;
330  sprintf (&buf[fmt->p], "1E%d%s", fmt->emin, suffix);
331  builtin_define_with_value (name, buf, 0);
332}
333
334/* Define __GNUC__, __GNUC_MINOR__ and __GNUC_PATCHLEVEL__.  */
335static void
336define__GNUC__ (void)
337{
338  /* The format of the version string, enforced below, is
339     ([^0-9]*-)?[0-9]+[.][0-9]+([.][0-9]+)?([- ].*)?  */
340  const char *q, *v = version_string;
341
342  while (*v && !ISDIGIT (*v))
343    v++;
344  gcc_assert (*v && (v <= version_string || v[-1] == '-'));
345
346  q = v;
347  while (ISDIGIT (*v))
348    v++;
349  builtin_define_with_value_n ("__GNUC__", q, v - q);
350  if (c_dialect_cxx ())
351    builtin_define_with_value_n ("__GNUG__", q, v - q);
352
353  gcc_assert (*v == '.' && ISDIGIT (v[1]));
354
355  q = ++v;
356  while (ISDIGIT (*v))
357    v++;
358  builtin_define_with_value_n ("__GNUC_MINOR__", q, v - q);
359
360  if (*v == '.')
361    {
362      gcc_assert (ISDIGIT (v[1]));
363      q = ++v;
364      while (ISDIGIT (*v))
365	v++;
366      builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", q, v - q);
367    }
368  else
369    builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", "0", 1);
370
371  gcc_assert (!*v || *v == ' ' || *v == '-');
372}
373
374/* Define macros used by <stdint.h>.  Currently only defines limits
375   for intmax_t, used by the testsuite.  */
376static void
377builtin_define_stdint_macros (void)
378{
379  int intmax_long;
380  if (intmax_type_node == long_long_integer_type_node)
381    intmax_long = 2;
382  else if (intmax_type_node == long_integer_type_node)
383    intmax_long = 1;
384  else if (intmax_type_node == integer_type_node)
385    intmax_long = 0;
386  else
387    gcc_unreachable ();
388  builtin_define_type_max ("__INTMAX_MAX__", intmax_type_node, intmax_long);
389}
390
391/* Hook that registers front end and target-specific built-ins.  */
392void
393c_cpp_builtins (cpp_reader *pfile)
394{
395  /* -undef turns off target-specific built-ins.  */
396  if (flag_undef)
397    return;
398
399  define__GNUC__ ();
400
401  /* For stddef.h.  They require macros defined in c-common.c.  */
402  c_stddef_cpp_builtins ();
403
404  if (c_dialect_cxx ())
405    {
406      if (flag_weak && SUPPORTS_ONE_ONLY)
407	cpp_define (pfile, "__GXX_WEAK__=1");
408      else
409	cpp_define (pfile, "__GXX_WEAK__=0");
410      if (warn_deprecated)
411	cpp_define (pfile, "__DEPRECATED");
412    }
413  /* Note that we define this for C as well, so that we know if
414     __attribute__((cleanup)) will interface with EH.  */
415  if (flag_exceptions)
416    cpp_define (pfile, "__EXCEPTIONS");
417
418  /* Represents the C++ ABI version, always defined so it can be used while
419     preprocessing C and assembler.  */
420  if (flag_abi_version == 0)
421    /* Use a very large value so that:
422
423	 #if __GXX_ABI_VERSION >= <value for version X>
424
425       will work whether the user explicitly says "-fabi-version=x" or
426       "-fabi-version=0".  Do not use INT_MAX because that will be
427       different from system to system.  */
428    builtin_define_with_int_value ("__GXX_ABI_VERSION", 999999);
429  else if (flag_abi_version == 1)
430    /* Due to a historical accident, this version had the value
431       "102".  */
432    builtin_define_with_int_value ("__GXX_ABI_VERSION", 102);
433  else
434    /* Newer versions have values 1002, 1003, ....  */
435    builtin_define_with_int_value ("__GXX_ABI_VERSION",
436				   1000 + flag_abi_version);
437
438  /* libgcc needs to know this.  */
439  if (USING_SJLJ_EXCEPTIONS)
440    cpp_define (pfile, "__USING_SJLJ_EXCEPTIONS__");
441
442  /* limits.h needs to know these.  */
443  builtin_define_type_max ("__SCHAR_MAX__", signed_char_type_node, 0);
444  builtin_define_type_max ("__SHRT_MAX__", short_integer_type_node, 0);
445  builtin_define_type_max ("__INT_MAX__", integer_type_node, 0);
446  builtin_define_type_max ("__LONG_MAX__", long_integer_type_node, 1);
447  builtin_define_type_max ("__LONG_LONG_MAX__", long_long_integer_type_node, 2);
448  builtin_define_type_max ("__WCHAR_MAX__", wchar_type_node, 0);
449
450  builtin_define_type_precision ("__CHAR_BIT__", char_type_node);
451
452  /* stdint.h (eventually) and the testsuite need to know these.  */
453  builtin_define_stdint_macros ();
454
455  /* float.h needs to know these.  */
456
457  builtin_define_with_int_value ("__FLT_EVAL_METHOD__",
458				 TARGET_FLT_EVAL_METHOD);
459
460  /* And decfloat.h needs this.  */
461  builtin_define_with_int_value ("__DEC_EVAL_METHOD__",
462                                 TARGET_DEC_EVAL_METHOD);
463
464  builtin_define_float_constants ("FLT", "F", "%s", float_type_node);
465  /* Cast the double precision constants when single precision constants are
466     specified. The correct result is computed by the compiler when using
467     macros that include a cast. This has the side-effect of making the value
468     unusable in const expressions. */
469  if (flag_single_precision_constant)
470    builtin_define_float_constants ("DBL", "L", "((double)%s)", double_type_node);
471  else
472    builtin_define_float_constants ("DBL", "", "%s", double_type_node);
473  builtin_define_float_constants ("LDBL", "L", "%s", long_double_type_node);
474
475  /* For decfloat.h.  */
476  builtin_define_decimal_float_constants ("DEC32", "DF", dfloat32_type_node);
477  builtin_define_decimal_float_constants ("DEC64", "DD", dfloat64_type_node);
478  builtin_define_decimal_float_constants ("DEC128", "DL", dfloat128_type_node);
479
480  /* For use in assembly language.  */
481  builtin_define_with_value ("__REGISTER_PREFIX__", REGISTER_PREFIX, 0);
482  builtin_define_with_value ("__USER_LABEL_PREFIX__", user_label_prefix, 0);
483
484  /* Misc.  */
485  builtin_define_with_value ("__VERSION__", version_string, 1);
486
487  cpp_define (pfile, "__GNUC_GNU_INLINE__");
488
489  /* Definitions for LP64 model.  */
490  if (TYPE_PRECISION (long_integer_type_node) == 64
491      && POINTER_SIZE == 64
492      && TYPE_PRECISION (integer_type_node) == 32)
493    {
494      cpp_define (pfile, "_LP64");
495      cpp_define (pfile, "__LP64__");
496    }
497
498  /* Other target-independent built-ins determined by command-line
499     options.  */
500  if (optimize_size)
501    cpp_define (pfile, "__OPTIMIZE_SIZE__");
502  if (optimize)
503    cpp_define (pfile, "__OPTIMIZE__");
504
505  if (fast_math_flags_set_p ())
506    cpp_define (pfile, "__FAST_MATH__");
507  if (flag_really_no_inline)
508    cpp_define (pfile, "__NO_INLINE__");
509  if (flag_signaling_nans)
510    cpp_define (pfile, "__SUPPORT_SNAN__");
511  if (flag_finite_math_only)
512    cpp_define (pfile, "__FINITE_MATH_ONLY__=1");
513  else
514    cpp_define (pfile, "__FINITE_MATH_ONLY__=0");
515  if (flag_pic)
516    {
517      builtin_define_with_int_value ("__pic__", flag_pic);
518      builtin_define_with_int_value ("__PIC__", flag_pic);
519    }
520  if (flag_pie)
521    {
522      builtin_define_with_int_value ("__pie__", flag_pie);
523      builtin_define_with_int_value ("__PIE__", flag_pie);
524    }
525
526  if (flag_iso)
527    cpp_define (pfile, "__STRICT_ANSI__");
528
529  if (!flag_signed_char)
530    cpp_define (pfile, "__CHAR_UNSIGNED__");
531
532  if (c_dialect_cxx () && TYPE_UNSIGNED (wchar_type_node))
533    cpp_define (pfile, "__WCHAR_UNSIGNED__");
534
535  /* Make the choice of ObjC runtime visible to source code.  */
536  if (c_dialect_objc () && flag_next_runtime)
537    cpp_define (pfile, "__NEXT_RUNTIME__");
538
539  /* Show the availability of some target pragmas.  */
540  if (flag_mudflap || targetm.handle_pragma_redefine_extname)
541    cpp_define (pfile, "__PRAGMA_REDEFINE_EXTNAME");
542
543  if (targetm.handle_pragma_extern_prefix)
544    cpp_define (pfile, "__PRAGMA_EXTERN_PREFIX");
545
546  /* Make the choice of the stack protector runtime visible to source code.
547     The macro names and values here were chosen for compatibility with an
548     earlier implementation, i.e. ProPolice.  */
549  if (flag_stack_protect == 3)
550    cpp_define (pfile, "__SSP_STRONG__=3");
551  else if (flag_stack_protect == 2)
552    cpp_define (pfile, "__SSP_ALL__=2");
553  else if (flag_stack_protect == 1)
554    cpp_define (pfile, "__SSP__=1");
555
556  if (flag_openmp)
557    cpp_define (pfile, "_OPENMP=200505");
558
559  /* A straightforward target hook doesn't work, because of problems
560     linking that hook's body when part of non-C front ends.  */
561# define preprocessing_asm_p() (cpp_get_options (pfile)->lang == CLK_ASM)
562# define preprocessing_trad_p() (cpp_get_options (pfile)->traditional)
563# define builtin_define(TXT) cpp_define (pfile, TXT)
564# define builtin_assert(TXT) cpp_assert (pfile, TXT)
565  TARGET_CPU_CPP_BUILTINS ();
566  TARGET_OS_CPP_BUILTINS ();
567  TARGET_OBJFMT_CPP_BUILTINS ();
568
569  /* Support the __declspec keyword by turning them into attributes.
570     Note that the current way we do this may result in a collision
571     with predefined attributes later on.  This can be solved by using
572     one attribute, say __declspec__, and passing args to it.  The
573     problem with that approach is that args are not accumulated: each
574     new appearance would clobber any existing args.  */
575  if (TARGET_DECLSPEC)
576    builtin_define ("__declspec(x)=__attribute__((x))");
577}
578
579/* Pass an object-like macro.  If it doesn't lie in the user's
580   namespace, defines it unconditionally.  Otherwise define a version
581   with two leading underscores, and another version with two leading
582   and trailing underscores, and define the original only if an ISO
583   standard was not nominated.
584
585   e.g. passing "unix" defines "__unix", "__unix__" and possibly
586   "unix".  Passing "_mips" defines "__mips", "__mips__" and possibly
587   "_mips".  */
588void
589builtin_define_std (const char *macro)
590{
591  size_t len = strlen (macro);
592  char *buff = (char *) alloca (len + 5);
593  char *p = buff + 2;
594  char *q = p + len;
595
596  /* prepend __ (or maybe just _) if in user's namespace.  */
597  memcpy (p, macro, len + 1);
598  if (!( *p == '_' && (p[1] == '_' || ISUPPER (p[1]))))
599    {
600      if (*p != '_')
601	*--p = '_';
602      if (p[1] != '_')
603	*--p = '_';
604    }
605  cpp_define (parse_in, p);
606
607  /* If it was in user's namespace...  */
608  if (p != buff + 2)
609    {
610      /* Define the macro with leading and following __.  */
611      if (q[-1] != '_')
612	*q++ = '_';
613      if (q[-2] != '_')
614	*q++ = '_';
615      *q = '\0';
616      cpp_define (parse_in, p);
617
618      /* Finally, define the original macro if permitted.  */
619      if (!flag_iso)
620	cpp_define (parse_in, macro);
621    }
622}
623
624/* Pass an object-like macro and a value to define it to.  The third
625   parameter says whether or not to turn the value into a string
626   constant.  */
627void
628builtin_define_with_value (const char *macro, const char *expansion, int is_str)
629{
630  char *buf;
631  size_t mlen = strlen (macro);
632  size_t elen = strlen (expansion);
633  size_t extra = 2;  /* space for an = and a NUL */
634
635  if (is_str)
636    extra += 2;  /* space for two quote marks */
637
638  buf = (char *) alloca (mlen + elen + extra);
639  if (is_str)
640    sprintf (buf, "%s=\"%s\"", macro, expansion);
641  else
642    sprintf (buf, "%s=%s", macro, expansion);
643
644  cpp_define (parse_in, buf);
645}
646
647/* Pass an object-like macro and a value to define it to.  The third
648   parameter is the length of the expansion.  */
649static void
650builtin_define_with_value_n (const char *macro, const char *expansion, size_t elen)
651{
652  char *buf;
653  size_t mlen = strlen (macro);
654
655  /* Space for an = and a NUL.  */
656  buf = (char *) alloca (mlen + elen + 2);
657  memcpy (buf, macro, mlen);
658  buf[mlen] = '=';
659  memcpy (buf + mlen + 1, expansion, elen);
660  buf[mlen + elen + 1] = '\0';
661
662  cpp_define (parse_in, buf);
663}
664
665/* Pass an object-like macro and an integer value to define it to.  */
666static void
667builtin_define_with_int_value (const char *macro, HOST_WIDE_INT value)
668{
669  char *buf;
670  size_t mlen = strlen (macro);
671  size_t vlen = 18;
672  size_t extra = 2; /* space for = and NUL.  */
673
674  buf = (char *) alloca (mlen + vlen + extra);
675  memcpy (buf, macro, mlen);
676  buf[mlen] = '=';
677  sprintf (buf + mlen + 1, HOST_WIDE_INT_PRINT_DEC, value);
678
679  cpp_define (parse_in, buf);
680}
681
682/* Pass an object-like macro a hexadecimal floating-point value.  */
683static void
684builtin_define_with_hex_fp_value (const char *macro,
685				  tree type ATTRIBUTE_UNUSED, int digits,
686				  const char *hex_str,
687				  const char *fp_suffix,
688				  const char *fp_cast)
689{
690  REAL_VALUE_TYPE real;
691  char dec_str[64], buf1[256], buf2[256];
692
693  /* Hex values are really cool and convenient, except that they're
694     not supported in strict ISO C90 mode.  First, the "p-" sequence
695     is not valid as part of a preprocessor number.  Second, we get a
696     pedwarn from the preprocessor, which has no context, so we can't
697     suppress the warning with __extension__.
698
699     So instead what we do is construct the number in hex (because
700     it's easy to get the exact correct value), parse it as a real,
701     then print it back out as decimal.  */
702
703  real_from_string (&real, hex_str);
704  real_to_decimal (dec_str, &real, sizeof (dec_str), digits, 0);
705
706  /* Assemble the macro in the following fashion
707     macro = fp_cast [dec_str fp_suffix] */
708  sprintf (buf1, "%s%s", dec_str, fp_suffix);
709  sprintf (buf2, fp_cast, buf1);
710  sprintf (buf1, "%s=%s", macro, buf2);
711
712  cpp_define (parse_in, buf1);
713}
714
715/* Define MAX for TYPE based on the precision of the type.  IS_LONG is
716   1 for type "long" and 2 for "long long".  We have to handle
717   unsigned types, since wchar_t might be unsigned.  */
718
719static void
720builtin_define_type_max (const char *macro, tree type, int is_long)
721{
722  static const char *const values[]
723    = { "127", "255",
724	"32767", "65535",
725	"2147483647", "4294967295",
726	"9223372036854775807", "18446744073709551615",
727	"170141183460469231731687303715884105727",
728	"340282366920938463463374607431768211455" };
729  static const char *const suffixes[] = { "", "U", "L", "UL", "LL", "ULL" };
730
731  const char *value, *suffix;
732  char *buf;
733  size_t idx;
734
735  /* Pre-rendering the values mean we don't have to futz with printing a
736     multi-word decimal value.  There are also a very limited number of
737     precisions that we support, so it's really a waste of time.  */
738  switch (TYPE_PRECISION (type))
739    {
740    case 8:	idx = 0; break;
741    case 16:	idx = 2; break;
742    case 32:	idx = 4; break;
743    case 64:	idx = 6; break;
744    case 128:	idx = 8; break;
745    default:    gcc_unreachable ();
746    }
747
748  value = values[idx + TYPE_UNSIGNED (type)];
749  suffix = suffixes[is_long * 2 + TYPE_UNSIGNED (type)];
750
751  buf = (char *) alloca (strlen (macro) + 1 + strlen (value)
752                         + strlen (suffix) + 1);
753  sprintf (buf, "%s=%s%s", macro, value, suffix);
754
755  cpp_define (parse_in, buf);
756}
757