1/* Define builtin-in macros for the C family front ends.
2   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007
3   Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to the Free
19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2002110-1301, USA.  */
21
22#include "config.h"
23#include "system.h"
24#include "coretypes.h"
25#include "tm.h"
26#include "tree.h"
27#include "version.h"
28#include "flags.h"
29#include "real.h"
30#include "c-common.h"
31#include "c-pragma.h"
32#include "output.h"
33#include "except.h"		/* For USING_SJLJ_EXCEPTIONS.  */
34#include "toplev.h"
35#include "tm_p.h"		/* Target prototypes.  */
36#include "target.h"
37
38#ifndef TARGET_OS_CPP_BUILTINS
39# define TARGET_OS_CPP_BUILTINS()
40#endif
41
42#ifndef TARGET_OBJFMT_CPP_BUILTINS
43# define TARGET_OBJFMT_CPP_BUILTINS()
44#endif
45
46#ifndef REGISTER_PREFIX
47#define REGISTER_PREFIX ""
48#endif
49
50/* Non-static as some targets don't use it.  */
51void builtin_define_std (const char *) ATTRIBUTE_UNUSED;
52static void builtin_define_with_value_n (const char *, const char *,
53					 size_t);
54static void builtin_define_with_int_value (const char *, HOST_WIDE_INT);
55static void builtin_define_with_hex_fp_value (const char *, tree,
56					      int, const char *,
57					      const char *,
58					      const char *);
59static void builtin_define_stdint_macros (void);
60static void builtin_define_type_max (const char *, tree, int);
61static void builtin_define_type_precision (const char *, tree);
62static void builtin_define_float_constants (const char *,
63					    const char *,
64					    const char *,
65					    tree);
66static void define__GNUC__ (void);
67
68/* Define NAME with value TYPE precision.  */
69static void
70builtin_define_type_precision (const char *name, tree type)
71{
72  builtin_define_with_int_value (name, TYPE_PRECISION (type));
73}
74
75/* Define the float.h constants for TYPE using NAME_PREFIX, FP_SUFFIX,
76   and FP_CAST. */
77static void
78builtin_define_float_constants (const char *name_prefix,
79		                const char *fp_suffix,
80				const char *fp_cast,
81				tree type)
82{
83  /* Used to convert radix-based values to base 10 values in several cases.
84
85     In the max_exp -> max_10_exp conversion for 128-bit IEEE, we need at
86     least 6 significant digits for correct results.  Using the fraction
87     formed by (log(2)*1e6)/(log(10)*1e6) overflows a 32-bit integer as an
88     intermediate; perhaps someone can find a better approximation, in the
89     mean time, I suspect using doubles won't harm the bootstrap here.  */
90
91  const double log10_2 = .30102999566398119521;
92  double log10_b;
93  const struct real_format *fmt;
94
95  char name[64], buf[128];
96  int dig, min_10_exp, max_10_exp;
97  int decimal_dig;
98
99  fmt = REAL_MODE_FORMAT (TYPE_MODE (type));
100  gcc_assert (fmt->b != 10);
101
102  /* The radix of the exponent representation.  */
103  if (type == float_type_node)
104    builtin_define_with_int_value ("__FLT_RADIX__", fmt->b);
105  log10_b = log10_2 * fmt->log2_b;
106
107  /* The number of radix digits, p, in the floating-point significand.  */
108  sprintf (name, "__%s_MANT_DIG__", name_prefix);
109  builtin_define_with_int_value (name, fmt->p);
110
111  /* The number of decimal digits, q, such that any floating-point number
112     with q decimal digits can be rounded into a floating-point number with
113     p radix b digits and back again without change to the q decimal digits,
114
115	p log10 b			if b is a power of 10
116	floor((p - 1) log10 b)		otherwise
117  */
118  dig = (fmt->p - 1) * log10_b;
119  sprintf (name, "__%s_DIG__", name_prefix);
120  builtin_define_with_int_value (name, dig);
121
122  /* The minimum negative int x such that b**(x-1) is a normalized float.  */
123  sprintf (name, "__%s_MIN_EXP__", name_prefix);
124  sprintf (buf, "(%d)", fmt->emin);
125  builtin_define_with_value (name, buf, 0);
126
127  /* The minimum negative int x such that 10**x is a normalized float,
128
129	  ceil (log10 (b ** (emin - 1)))
130	= ceil (log10 (b) * (emin - 1))
131
132     Recall that emin is negative, so the integer truncation calculates
133     the ceiling, not the floor, in this case.  */
134  min_10_exp = (fmt->emin - 1) * log10_b;
135  sprintf (name, "__%s_MIN_10_EXP__", name_prefix);
136  sprintf (buf, "(%d)", min_10_exp);
137  builtin_define_with_value (name, buf, 0);
138
139  /* The maximum int x such that b**(x-1) is a representable float.  */
140  sprintf (name, "__%s_MAX_EXP__", name_prefix);
141  builtin_define_with_int_value (name, fmt->emax);
142
143  /* The maximum int x such that 10**x is in the range of representable
144     finite floating-point numbers,
145
146	  floor (log10((1 - b**-p) * b**emax))
147	= floor (log10(1 - b**-p) + log10(b**emax))
148	= floor (log10(1 - b**-p) + log10(b)*emax)
149
150     The safest thing to do here is to just compute this number.  But since
151     we don't link cc1 with libm, we cannot.  We could implement log10 here
152     a series expansion, but that seems too much effort because:
153
154     Note that the first term, for all extant p, is a number exceedingly close
155     to zero, but slightly negative.  Note that the second term is an integer
156     scaling an irrational number, and that because of the floor we are only
157     interested in its integral portion.
158
159     In order for the first term to have any effect on the integral portion
160     of the second term, the second term has to be exceedingly close to an
161     integer itself (e.g. 123.000000000001 or something).  Getting a result
162     that close to an integer requires that the irrational multiplicand have
163     a long series of zeros in its expansion, which doesn't occur in the
164     first 20 digits or so of log10(b).
165
166     Hand-waving aside, crunching all of the sets of constants above by hand
167     does not yield a case for which the first term is significant, which
168     in the end is all that matters.  */
169  max_10_exp = fmt->emax * log10_b;
170  sprintf (name, "__%s_MAX_10_EXP__", name_prefix);
171  builtin_define_with_int_value (name, max_10_exp);
172
173  /* The number of decimal digits, n, such that any floating-point number
174     can be rounded to n decimal digits and back again without change to
175     the value.
176
177	p * log10(b)			if b is a power of 10
178	ceil(1 + p * log10(b))		otherwise
179
180     The only macro we care about is this number for the widest supported
181     floating type, but we want this value for rendering constants below.  */
182  {
183    double d_decimal_dig = 1 + fmt->p * log10_b;
184    decimal_dig = d_decimal_dig;
185    if (decimal_dig < d_decimal_dig)
186      decimal_dig++;
187  }
188  if (type == long_double_type_node)
189    builtin_define_with_int_value ("__DECIMAL_DIG__", decimal_dig);
190
191  /* Since, for the supported formats, B is always a power of 2, we
192     construct the following numbers directly as a hexadecimal
193     constants.  */
194
195  /* The maximum representable finite floating-point number,
196     (1 - b**-p) * b**emax  */
197  {
198    int i, n;
199    char *p;
200
201    strcpy (buf, "0x0.");
202    n = fmt->p * fmt->log2_b;
203    for (i = 0, p = buf + 4; i + 3 < n; i += 4)
204      *p++ = 'f';
205    if (i < n)
206      *p++ = "08ce"[n - i];
207    sprintf (p, "p%d", fmt->emax * fmt->log2_b);
208    if (fmt->pnan < fmt->p)
209      {
210	/* This is an IBM extended double format made up of two IEEE
211	   doubles.  The value of the long double is the sum of the
212	   values of the two parts.  The most significant part is
213	   required to be the value of the long double rounded to the
214	   nearest double.  Rounding means we need a slightly smaller
215	   value for LDBL_MAX.  */
216	buf[4 + fmt->pnan / 4] = "7bde"[fmt->pnan % 4];
217      }
218  }
219  sprintf (name, "__%s_MAX__", name_prefix);
220  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
221
222  /* The minimum normalized positive floating-point number,
223     b**(emin-1).  */
224  sprintf (name, "__%s_MIN__", name_prefix);
225  sprintf (buf, "0x1p%d", (fmt->emin - 1) * fmt->log2_b);
226  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
227
228  /* The difference between 1 and the least value greater than 1 that is
229     representable in the given floating point type, b**(1-p).  */
230  sprintf (name, "__%s_EPSILON__", name_prefix);
231  if (fmt->pnan < fmt->p)
232    /* This is an IBM extended double format, so 1.0 + any double is
233       representable precisely.  */
234      sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
235    else
236      sprintf (buf, "0x1p%d", (1 - fmt->p) * fmt->log2_b);
237  builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
238
239  /* For C++ std::numeric_limits<T>::denorm_min.  The minimum denormalized
240     positive floating-point number, b**(emin-p).  Zero for formats that
241     don't support denormals.  */
242  sprintf (name, "__%s_DENORM_MIN__", name_prefix);
243  if (fmt->has_denorm)
244    {
245      sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
246      builtin_define_with_hex_fp_value (name, type, decimal_dig,
247					buf, fp_suffix, fp_cast);
248    }
249  else
250    {
251      sprintf (buf, "0.0%s", fp_suffix);
252      builtin_define_with_value (name, buf, 0);
253    }
254
255  sprintf (name, "__%s_HAS_DENORM__", name_prefix);
256  builtin_define_with_value (name, fmt->has_denorm ? "1" : "0", 0);
257
258  /* For C++ std::numeric_limits<T>::has_infinity.  */
259  sprintf (name, "__%s_HAS_INFINITY__", name_prefix);
260  builtin_define_with_int_value (name,
261				 MODE_HAS_INFINITIES (TYPE_MODE (type)));
262  /* For C++ std::numeric_limits<T>::has_quiet_NaN.  We do not have a
263     predicate to distinguish a target that has both quiet and
264     signalling NaNs from a target that has only quiet NaNs or only
265     signalling NaNs, so we assume that a target that has any kind of
266     NaN has quiet NaNs.  */
267  sprintf (name, "__%s_HAS_QUIET_NAN__", name_prefix);
268  builtin_define_with_int_value (name, MODE_HAS_NANS (TYPE_MODE (type)));
269}
270
271/* Define __DECx__ constants for TYPE using NAME_PREFIX and SUFFIX. */
272static void
273builtin_define_decimal_float_constants (const char *name_prefix,
274					const char *suffix,
275					tree type)
276{
277  const struct real_format *fmt;
278  char name[64], buf[128], *p;
279  int digits;
280
281  fmt = REAL_MODE_FORMAT (TYPE_MODE (type));
282
283  /* The number of radix digits, p, in the significand.  */
284  sprintf (name, "__%s_MANT_DIG__", name_prefix);
285  builtin_define_with_int_value (name, fmt->p);
286
287  /* The minimum negative int x such that b**(x-1) is a normalized float.  */
288  sprintf (name, "__%s_MIN_EXP__", name_prefix);
289  sprintf (buf, "(%d)", fmt->emin);
290  builtin_define_with_value (name, buf, 0);
291
292  /* The maximum int x such that b**(x-1) is a representable float.  */
293  sprintf (name, "__%s_MAX_EXP__", name_prefix);
294  builtin_define_with_int_value (name, fmt->emax);
295
296  /* Compute the minimum representable value.  */
297  sprintf (name, "__%s_MIN__", name_prefix);
298  sprintf (buf, "1E%d%s", fmt->emin, suffix);
299  builtin_define_with_value (name, buf, 0);
300
301  /* Compute the maximum representable value.  */
302  sprintf (name, "__%s_MAX__", name_prefix);
303  p = buf;
304  for (digits = fmt->p; digits; digits--)
305    {
306      *p++ = '9';
307      if (digits == fmt->p)
308	*p++ = '.';
309    }
310  *p = 0;
311  /* fmt->p plus 1, to account for the decimal point.  */
312  sprintf (&buf[fmt->p + 1], "E%d%s", fmt->emax, suffix);
313  builtin_define_with_value (name, buf, 0);
314
315  /* Compute epsilon (the difference between 1 and least value greater
316     than 1 representable).  */
317  sprintf (name, "__%s_EPSILON__", name_prefix);
318  sprintf (buf, "1E-%d%s", fmt->p - 1, suffix);
319  builtin_define_with_value (name, buf, 0);
320
321  /* Minimum denormalized postive decimal value.  */
322  sprintf (name, "__%s_DEN__", name_prefix);
323  p = buf;
324  for (digits = fmt->p; digits > 1; digits--)
325    {
326      *p++ = '0';
327      if (digits == fmt->p)
328	*p++ = '.';
329    }
330  *p = 0;
331  sprintf (&buf[fmt->p], "1E%d%s", fmt->emin, suffix);
332  builtin_define_with_value (name, buf, 0);
333}
334
335/* Define __GNUC__, __GNUC_MINOR__ and __GNUC_PATCHLEVEL__.  */
336static void
337define__GNUC__ (void)
338{
339  /* The format of the version string, enforced below, is
340     ([^0-9]*-)?[0-9]+[.][0-9]+([.][0-9]+)?([- ].*)?  */
341  const char *q, *v = version_string;
342
343  while (*v && !ISDIGIT (*v))
344    v++;
345  gcc_assert (*v && (v <= version_string || v[-1] == '-'));
346
347  q = v;
348  while (ISDIGIT (*v))
349    v++;
350  builtin_define_with_value_n ("__GNUC__", q, v - q);
351  if (c_dialect_cxx ())
352    builtin_define_with_value_n ("__GNUG__", q, v - q);
353
354  gcc_assert (*v == '.' && ISDIGIT (v[1]));
355
356  q = ++v;
357  while (ISDIGIT (*v))
358    v++;
359  builtin_define_with_value_n ("__GNUC_MINOR__", q, v - q);
360
361  if (*v == '.')
362    {
363      gcc_assert (ISDIGIT (v[1]));
364      q = ++v;
365      while (ISDIGIT (*v))
366	v++;
367      builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", q, v - q);
368    }
369  else
370    builtin_define_with_value_n ("__GNUC_PATCHLEVEL__", "0", 1);
371
372  gcc_assert (!*v || *v == ' ' || *v == '-');
373}
374
375/* Define macros used by <stdint.h>.  Currently only defines limits
376   for intmax_t, used by the testsuite.  */
377static void
378builtin_define_stdint_macros (void)
379{
380  int intmax_long;
381  if (intmax_type_node == long_long_integer_type_node)
382    intmax_long = 2;
383  else if (intmax_type_node == long_integer_type_node)
384    intmax_long = 1;
385  else if (intmax_type_node == integer_type_node)
386    intmax_long = 0;
387  else
388    gcc_unreachable ();
389  builtin_define_type_max ("__INTMAX_MAX__", intmax_type_node, intmax_long);
390}
391
392/* Hook that registers front end and target-specific built-ins.  */
393void
394c_cpp_builtins (cpp_reader *pfile)
395{
396  /* -undef turns off target-specific built-ins.  */
397  if (flag_undef)
398    return;
399
400  define__GNUC__ ();
401
402  /* For stddef.h.  They require macros defined in c-common.c.  */
403  c_stddef_cpp_builtins ();
404
405  if (c_dialect_cxx ())
406    {
407      if (flag_weak && SUPPORTS_ONE_ONLY)
408	cpp_define (pfile, "__GXX_WEAK__=1");
409      else
410	cpp_define (pfile, "__GXX_WEAK__=0");
411      if (warn_deprecated)
412	cpp_define (pfile, "__DEPRECATED");
413    }
414  /* Note that we define this for C as well, so that we know if
415     __attribute__((cleanup)) will interface with EH.  */
416  if (flag_exceptions)
417    cpp_define (pfile, "__EXCEPTIONS");
418
419  /* Represents the C++ ABI version, always defined so it can be used while
420     preprocessing C and assembler.  */
421  if (flag_abi_version == 0)
422    /* Use a very large value so that:
423
424	 #if __GXX_ABI_VERSION >= <value for version X>
425
426       will work whether the user explicitly says "-fabi-version=x" or
427       "-fabi-version=0".  Do not use INT_MAX because that will be
428       different from system to system.  */
429    builtin_define_with_int_value ("__GXX_ABI_VERSION", 999999);
430  else if (flag_abi_version == 1)
431    /* Due to a historical accident, this version had the value
432       "102".  */
433    builtin_define_with_int_value ("__GXX_ABI_VERSION", 102);
434  else
435    /* Newer versions have values 1002, 1003, ....  */
436    builtin_define_with_int_value ("__GXX_ABI_VERSION",
437				   1000 + flag_abi_version);
438
439  /* libgcc needs to know this.  */
440  if (USING_SJLJ_EXCEPTIONS)
441    cpp_define (pfile, "__USING_SJLJ_EXCEPTIONS__");
442
443  /* limits.h needs to know these.  */
444  builtin_define_type_max ("__SCHAR_MAX__", signed_char_type_node, 0);
445  builtin_define_type_max ("__SHRT_MAX__", short_integer_type_node, 0);
446  builtin_define_type_max ("__INT_MAX__", integer_type_node, 0);
447  builtin_define_type_max ("__LONG_MAX__", long_integer_type_node, 1);
448  builtin_define_type_max ("__LONG_LONG_MAX__", long_long_integer_type_node, 2);
449  builtin_define_type_max ("__WCHAR_MAX__", wchar_type_node, 0);
450
451  builtin_define_type_precision ("__CHAR_BIT__", char_type_node);
452
453  /* stdint.h (eventually) and the testsuite need to know these.  */
454  builtin_define_stdint_macros ();
455
456  /* float.h needs to know these.  */
457
458  builtin_define_with_int_value ("__FLT_EVAL_METHOD__",
459				 TARGET_FLT_EVAL_METHOD);
460
461  /* And decfloat.h needs this.  */
462  builtin_define_with_int_value ("__DEC_EVAL_METHOD__",
463                                 TARGET_DEC_EVAL_METHOD);
464
465  builtin_define_float_constants ("FLT", "F", "%s", float_type_node);
466  /* Cast the double precision constants when single precision constants are
467     specified. The correct result is computed by the compiler when using
468     macros that include a cast. This has the side-effect of making the value
469     unusable in const expressions. */
470  if (flag_single_precision_constant)
471    builtin_define_float_constants ("DBL", "L", "((double)%s)", double_type_node);
472  else
473    builtin_define_float_constants ("DBL", "", "%s", double_type_node);
474  builtin_define_float_constants ("LDBL", "L", "%s", long_double_type_node);
475
476  /* For decfloat.h.  */
477  builtin_define_decimal_float_constants ("DEC32", "DF", dfloat32_type_node);
478  builtin_define_decimal_float_constants ("DEC64", "DD", dfloat64_type_node);
479  builtin_define_decimal_float_constants ("DEC128", "DL", dfloat128_type_node);
480
481  /* For use in assembly language.  */
482  builtin_define_with_value ("__REGISTER_PREFIX__", REGISTER_PREFIX, 0);
483  builtin_define_with_value ("__USER_LABEL_PREFIX__", user_label_prefix, 0);
484
485  /* Misc.  */
486  builtin_define_with_value ("__VERSION__", version_string, 1);
487
488  if (flag_gnu89_inline)
489    cpp_define (pfile, "__GNUC_GNU_INLINE__");
490  else
491    cpp_define (pfile, "__GNUC_STDC_INLINE__");
492
493  /* Definitions for LP64 model.  */
494  if (TYPE_PRECISION (long_integer_type_node) == 64
495      && POINTER_SIZE == 64
496      && TYPE_PRECISION (integer_type_node) == 32)
497    {
498      cpp_define (pfile, "_LP64");
499      cpp_define (pfile, "__LP64__");
500    }
501
502  /* Other target-independent built-ins determined by command-line
503     options.  */
504  if (optimize_size)
505    cpp_define (pfile, "__OPTIMIZE_SIZE__");
506  if (optimize)
507    cpp_define (pfile, "__OPTIMIZE__");
508
509  if (fast_math_flags_set_p ())
510    cpp_define (pfile, "__FAST_MATH__");
511  if (flag_really_no_inline)
512    cpp_define (pfile, "__NO_INLINE__");
513  if (flag_signaling_nans)
514    cpp_define (pfile, "__SUPPORT_SNAN__");
515  if (flag_finite_math_only)
516    cpp_define (pfile, "__FINITE_MATH_ONLY__=1");
517  else
518    cpp_define (pfile, "__FINITE_MATH_ONLY__=0");
519  if (flag_pic)
520    {
521      builtin_define_with_int_value ("__pic__", flag_pic);
522      builtin_define_with_int_value ("__PIC__", flag_pic);
523    }
524
525  if (flag_iso)
526    cpp_define (pfile, "__STRICT_ANSI__");
527
528  if (!flag_signed_char)
529    cpp_define (pfile, "__CHAR_UNSIGNED__");
530
531  if (c_dialect_cxx () && TYPE_UNSIGNED (wchar_type_node))
532    cpp_define (pfile, "__WCHAR_UNSIGNED__");
533
534  /* Make the choice of ObjC runtime visible to source code.  */
535  if (c_dialect_objc () && flag_next_runtime)
536    cpp_define (pfile, "__NEXT_RUNTIME__");
537
538  /* Show the availability of some target pragmas.  */
539  if (flag_mudflap || targetm.handle_pragma_redefine_extname)
540    cpp_define (pfile, "__PRAGMA_REDEFINE_EXTNAME");
541
542  if (targetm.handle_pragma_extern_prefix)
543    cpp_define (pfile, "__PRAGMA_EXTERN_PREFIX");
544
545  /* Make the choice of the stack protector runtime visible to source code.
546     The macro names and values here were chosen for compatibility with an
547     earlier implementation, i.e. ProPolice.  */
548  if (flag_stack_protect == 2)
549    cpp_define (pfile, "__SSP_ALL__=2");
550  else if (flag_stack_protect == 1)
551    cpp_define (pfile, "__SSP__=1");
552
553  if (flag_openmp)
554    cpp_define (pfile, "_OPENMP=200505");
555
556  /* A straightforward target hook doesn't work, because of problems
557     linking that hook's body when part of non-C front ends.  */
558# define preprocessing_asm_p() (cpp_get_options (pfile)->lang == CLK_ASM)
559# define preprocessing_trad_p() (cpp_get_options (pfile)->traditional)
560# define builtin_define(TXT) cpp_define (pfile, TXT)
561# define builtin_assert(TXT) cpp_assert (pfile, TXT)
562  TARGET_CPU_CPP_BUILTINS ();
563  TARGET_OS_CPP_BUILTINS ();
564  TARGET_OBJFMT_CPP_BUILTINS ();
565
566  /* Support the __declspec keyword by turning them into attributes.
567     Note that the current way we do this may result in a collision
568     with predefined attributes later on.  This can be solved by using
569     one attribute, say __declspec__, and passing args to it.  The
570     problem with that approach is that args are not accumulated: each
571     new appearance would clobber any existing args.  */
572  if (TARGET_DECLSPEC)
573    builtin_define ("__declspec(x)=__attribute__((x))");
574}
575
576/* Pass an object-like macro.  If it doesn't lie in the user's
577   namespace, defines it unconditionally.  Otherwise define a version
578   with two leading underscores, and another version with two leading
579   and trailing underscores, and define the original only if an ISO
580   standard was not nominated.
581
582   e.g. passing "unix" defines "__unix", "__unix__" and possibly
583   "unix".  Passing "_mips" defines "__mips", "__mips__" and possibly
584   "_mips".  */
585void
586builtin_define_std (const char *macro)
587{
588  size_t len = strlen (macro);
589  char *buff = (char *) alloca (len + 5);
590  char *p = buff + 2;
591  char *q = p + len;
592
593  /* prepend __ (or maybe just _) if in user's namespace.  */
594  memcpy (p, macro, len + 1);
595  if (!( *p == '_' && (p[1] == '_' || ISUPPER (p[1]))))
596    {
597      if (*p != '_')
598	*--p = '_';
599      if (p[1] != '_')
600	*--p = '_';
601    }
602  cpp_define (parse_in, p);
603
604  /* If it was in user's namespace...  */
605  if (p != buff + 2)
606    {
607      /* Define the macro with leading and following __.  */
608      if (q[-1] != '_')
609	*q++ = '_';
610      if (q[-2] != '_')
611	*q++ = '_';
612      *q = '\0';
613      cpp_define (parse_in, p);
614
615      /* Finally, define the original macro if permitted.  */
616      if (!flag_iso)
617	cpp_define (parse_in, macro);
618    }
619}
620
621/* Pass an object-like macro and a value to define it to.  The third
622   parameter says whether or not to turn the value into a string
623   constant.  */
624void
625builtin_define_with_value (const char *macro, const char *expansion, int is_str)
626{
627  char *buf;
628  size_t mlen = strlen (macro);
629  size_t elen = strlen (expansion);
630  size_t extra = 2;  /* space for an = and a NUL */
631
632  if (is_str)
633    extra += 2;  /* space for two quote marks */
634
635  buf = (char *) alloca (mlen + elen + extra);
636  if (is_str)
637    sprintf (buf, "%s=\"%s\"", macro, expansion);
638  else
639    sprintf (buf, "%s=%s", macro, expansion);
640
641  cpp_define (parse_in, buf);
642}
643
644/* Pass an object-like macro and a value to define it to.  The third
645   parameter is the length of the expansion.  */
646static void
647builtin_define_with_value_n (const char *macro, const char *expansion, size_t elen)
648{
649  char *buf;
650  size_t mlen = strlen (macro);
651
652  /* Space for an = and a NUL.  */
653  buf = (char *) alloca (mlen + elen + 2);
654  memcpy (buf, macro, mlen);
655  buf[mlen] = '=';
656  memcpy (buf + mlen + 1, expansion, elen);
657  buf[mlen + elen + 1] = '\0';
658
659  cpp_define (parse_in, buf);
660}
661
662/* Pass an object-like macro and an integer value to define it to.  */
663static void
664builtin_define_with_int_value (const char *macro, HOST_WIDE_INT value)
665{
666  char *buf;
667  size_t mlen = strlen (macro);
668  size_t vlen = 18;
669  size_t extra = 2; /* space for = and NUL.  */
670
671  buf = (char *) alloca (mlen + vlen + extra);
672  memcpy (buf, macro, mlen);
673  buf[mlen] = '=';
674  sprintf (buf + mlen + 1, HOST_WIDE_INT_PRINT_DEC, value);
675
676  cpp_define (parse_in, buf);
677}
678
679/* Pass an object-like macro a hexadecimal floating-point value.  */
680static void
681builtin_define_with_hex_fp_value (const char *macro,
682				  tree type ATTRIBUTE_UNUSED, int digits,
683				  const char *hex_str,
684				  const char *fp_suffix,
685				  const char *fp_cast)
686{
687  REAL_VALUE_TYPE real;
688  char dec_str[64], buf1[256], buf2[256];
689
690  /* Hex values are really cool and convenient, except that they're
691     not supported in strict ISO C90 mode.  First, the "p-" sequence
692     is not valid as part of a preprocessor number.  Second, we get a
693     pedwarn from the preprocessor, which has no context, so we can't
694     suppress the warning with __extension__.
695
696     So instead what we do is construct the number in hex (because
697     it's easy to get the exact correct value), parse it as a real,
698     then print it back out as decimal.  */
699
700  real_from_string (&real, hex_str);
701  real_to_decimal (dec_str, &real, sizeof (dec_str), digits, 0);
702
703  /* Assemble the macro in the following fashion
704     macro = fp_cast [dec_str fp_suffix] */
705  sprintf (buf1, "%s%s", dec_str, fp_suffix);
706  sprintf (buf2, fp_cast, buf1);
707  sprintf (buf1, "%s=%s", macro, buf2);
708
709  cpp_define (parse_in, buf1);
710}
711
712/* Define MAX for TYPE based on the precision of the type.  IS_LONG is
713   1 for type "long" and 2 for "long long".  We have to handle
714   unsigned types, since wchar_t might be unsigned.  */
715
716static void
717builtin_define_type_max (const char *macro, tree type, int is_long)
718{
719  static const char *const values[]
720    = { "127", "255",
721	"32767", "65535",
722	"2147483647", "4294967295",
723	"9223372036854775807", "18446744073709551615",
724	"170141183460469231731687303715884105727",
725	"340282366920938463463374607431768211455" };
726  static const char *const suffixes[] = { "", "U", "L", "UL", "LL", "ULL" };
727
728  const char *value, *suffix;
729  char *buf;
730  size_t idx;
731
732  /* Pre-rendering the values mean we don't have to futz with printing a
733     multi-word decimal value.  There are also a very limited number of
734     precisions that we support, so it's really a waste of time.  */
735  switch (TYPE_PRECISION (type))
736    {
737    case 8:	idx = 0; break;
738    case 16:	idx = 2; break;
739    case 32:	idx = 4; break;
740    case 64:	idx = 6; break;
741    case 128:	idx = 8; break;
742    default:    gcc_unreachable ();
743    }
744
745  value = values[idx + TYPE_UNSIGNED (type)];
746  suffix = suffixes[is_long * 2 + TYPE_UNSIGNED (type)];
747
748  buf = (char *) alloca (strlen (macro) + 1 + strlen (value)
749                         + strlen (suffix) + 1);
750  sprintf (buf, "%s=%s%s", macro, value, suffix);
751
752  cpp_define (parse_in, buf);
753}
754