summaryrefslogtreecommitdiffstats
path: root/lib/strtod.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 16:58:41 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 16:58:41 +0000
commite1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe (patch)
treef5cc731bedcac0fb7fe14d952e4581e749f8bb87 /lib/strtod.c
parentInitial commit. (diff)
downloadcoreutils-e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe.tar.xz
coreutils-e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe.zip
Adding upstream version 9.4.upstream/9.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/strtod.c')
-rw-r--r--lib/strtod.c485
1 files changed, 485 insertions, 0 deletions
diff --git a/lib/strtod.c b/lib/strtod.c
new file mode 100644
index 0000000..63919f9
--- /dev/null
+++ b/lib/strtod.c
@@ -0,0 +1,485 @@
+/* Copyright (C) 1991-1992, 1997, 1999, 2003, 2006, 2008-2023 Free Software
+ Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation, either version 3 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#if ! defined USE_LONG_DOUBLE
+# include <config.h>
+#endif
+
+/* Specification. */
+#include <stdlib.h>
+
+#include <ctype.h> /* isspace() */
+#include <errno.h>
+#include <float.h> /* {DBL,LDBL}_{MIN,MAX} */
+#include <limits.h> /* LONG_{MIN,MAX} */
+#include <locale.h> /* localeconv() */
+#include <math.h> /* NAN */
+#include <stdio.h> /* sprintf() */
+#include <string.h> /* strdup() */
+#if HAVE_NL_LANGINFO
+# include <langinfo.h>
+#endif
+
+#include "c-ctype.h"
+
+#undef MIN
+#undef MAX
+#ifdef USE_LONG_DOUBLE
+# define STRTOD strtold
+# define LDEXP ldexpl
+# if defined __hpux && defined __hppa
+ /* We cannot call strtold on HP-UX/hppa, because its return type is a struct,
+ not a 'long double'. */
+# define HAVE_UNDERLYING_STRTOD 0
+# elif STRTOLD_HAS_UNDERFLOW_BUG
+ /* strtold would not set errno=ERANGE upon underflow. */
+# define HAVE_UNDERLYING_STRTOD 0
+# else
+# define HAVE_UNDERLYING_STRTOD HAVE_STRTOLD
+# endif
+# define DOUBLE long double
+# define MIN LDBL_MIN
+# define MAX LDBL_MAX
+# define L_(literal) literal##L
+#else
+# define STRTOD strtod
+# define LDEXP ldexp
+# define HAVE_UNDERLYING_STRTOD 1
+# define DOUBLE double
+# define MIN DBL_MIN
+# define MAX DBL_MAX
+# define L_(literal) literal
+#endif
+
+#if (defined USE_LONG_DOUBLE ? HAVE_LDEXPM_IN_LIBC : HAVE_LDEXP_IN_LIBC)
+# define USE_LDEXP 1
+#else
+# define USE_LDEXP 0
+#endif
+
+/* Return true if C is a space in the current locale, avoiding
+ problems with signed char and isspace. */
+static bool
+locale_isspace (char c)
+{
+ unsigned char uc = c;
+ return isspace (uc) != 0;
+}
+
+/* Determine the decimal-point character according to the current locale. */
+static char
+decimal_point_char (void)
+{
+ const char *point;
+ /* Determine it in a multithread-safe way. We know nl_langinfo is
+ multithread-safe on glibc systems and Mac OS X systems, but is not required
+ to be multithread-safe by POSIX. sprintf(), however, is multithread-safe.
+ localeconv() is rarely multithread-safe. */
+#if HAVE_NL_LANGINFO && (__GLIBC__ || defined __UCLIBC__ || (defined __APPLE__ && defined __MACH__))
+ point = nl_langinfo (RADIXCHAR);
+#elif 1
+ char pointbuf[5];
+ sprintf (pointbuf, "%#.0f", 1.0);
+ point = &pointbuf[1];
+#else
+ point = localeconv () -> decimal_point;
+#endif
+ /* The decimal point is always a single byte: either '.' or ','. */
+ return (point[0] != '\0' ? point[0] : '.');
+}
+
+#if !USE_LDEXP
+ #undef LDEXP
+ #define LDEXP dummy_ldexp
+ /* A dummy definition that will never be invoked. */
+ static DOUBLE LDEXP (_GL_UNUSED DOUBLE x, _GL_UNUSED int exponent)
+ {
+ abort ();
+ return L_(0.0);
+ }
+#endif
+
+/* Return X * BASE**EXPONENT. Return an extreme value and set errno
+ to ERANGE if underflow or overflow occurs. */
+static DOUBLE
+scale_radix_exp (DOUBLE x, int radix, long int exponent)
+{
+ /* If RADIX == 10, this code is neither precise nor fast; it is
+ merely a straightforward and relatively portable approximation.
+ If N == 2, this code is precise on a radix-2 implementation,
+ albeit perhaps not fast if ldexp is not in libc. */
+
+ long int e = exponent;
+
+ if (USE_LDEXP && radix == 2)
+ return LDEXP (x, e < INT_MIN ? INT_MIN : INT_MAX < e ? INT_MAX : e);
+ else
+ {
+ DOUBLE r = x;
+
+ if (r != 0)
+ {
+ if (e < 0)
+ {
+ while (e++ != 0)
+ {
+ r /= radix;
+ if (r == 0 && x != 0)
+ {
+ errno = ERANGE;
+ break;
+ }
+ }
+ }
+ else
+ {
+ while (e-- != 0)
+ {
+ if (r < -MAX / radix)
+ {
+ errno = ERANGE;
+ return -HUGE_VAL;
+ }
+ else if (MAX / radix < r)
+ {
+ errno = ERANGE;
+ return HUGE_VAL;
+ }
+ else
+ r *= radix;
+ }
+ }
+ }
+
+ return r;
+ }
+}
+
+/* Parse a number at NPTR; this is a bit like strtol (NPTR, ENDPTR)
+ except there are no leading spaces or signs or "0x", and ENDPTR is
+ nonnull. The number uses a base BASE (either 10 or 16) fraction, a
+ radix RADIX (either 10 or 2) exponent, and exponent character
+ EXPCHAR. BASE is RADIX**RADIX_MULTIPLIER. */
+static DOUBLE
+parse_number (const char *nptr,
+ int base, int radix, int radix_multiplier, char radixchar,
+ char expchar,
+ char **endptr)
+{
+ const char *s = nptr;
+ const char *digits_start;
+ const char *digits_end;
+ const char *radixchar_ptr;
+ long int exponent;
+ DOUBLE num;
+
+ /* First, determine the start and end of the digit sequence. */
+ digits_start = s;
+ radixchar_ptr = NULL;
+ for (;; ++s)
+ {
+ if (base == 16 ? c_isxdigit (*s) : c_isdigit (*s))
+ ;
+ else if (radixchar_ptr == NULL && *s == radixchar)
+ {
+ /* Record that we have found the decimal point. */
+ radixchar_ptr = s;
+ }
+ else
+ /* Any other character terminates the digit sequence. */
+ break;
+ }
+ digits_end = s;
+ /* Now radixchar_ptr == NULL or
+ digits_start <= radixchar_ptr < digits_end. */
+
+ if (false)
+ { /* Unoptimized. */
+ exponent =
+ (radixchar_ptr != NULL
+ ? - (long int) (digits_end - radixchar_ptr - 1)
+ : 0);
+ }
+ else
+ { /* Remove trailing zero digits. This reduces rounding errors for
+ inputs such as 1.0000000000 or 10000000000e-10. */
+ while (digits_end > digits_start)
+ {
+ if (digits_end - 1 == radixchar_ptr || *(digits_end - 1) == '0')
+ digits_end--;
+ else
+ break;
+ }
+ exponent =
+ (radixchar_ptr != NULL
+ ? (digits_end > radixchar_ptr
+ ? - (long int) (digits_end - radixchar_ptr - 1)
+ : (long int) (radixchar_ptr - digits_end))
+ : (long int) (s - digits_end));
+ }
+
+ /* Then, convert the digit sequence to a number. */
+ {
+ const char *dp;
+ num = 0;
+ for (dp = digits_start; dp < digits_end; dp++)
+ if (dp != radixchar_ptr)
+ {
+ int digit;
+
+ /* Make sure that multiplication by BASE will not overflow. */
+ if (!(num <= MAX / base))
+ {
+ /* The value of the digit and all subsequent digits don't matter,
+ since we have already gotten as many digits as can be
+ represented in a 'DOUBLE'. This doesn't necessarily mean that
+ the result will overflow: The exponent may reduce it to within
+ range. */
+ exponent +=
+ (digits_end - dp)
+ - (radixchar_ptr >= dp && radixchar_ptr < digits_end ? 1 : 0);
+ break;
+ }
+
+ /* Eat the next digit. */
+ if (c_isdigit (*dp))
+ digit = *dp - '0';
+ else if (base == 16 && c_isxdigit (*dp))
+ digit = c_tolower (*dp) - ('a' - 10);
+ else
+ abort ();
+ num = num * base + digit;
+ }
+ }
+
+ exponent = exponent * radix_multiplier;
+
+ /* Finally, parse the exponent. */
+ if (c_tolower (*s) == expchar && ! locale_isspace (s[1]))
+ {
+ /* Add any given exponent to the implicit one. */
+ int saved_errno = errno;
+ char *end;
+ long int value = strtol (s + 1, &end, 10);
+ errno = saved_errno;
+
+ if (s + 1 != end)
+ {
+ /* Skip past the exponent, and add in the implicit exponent,
+ resulting in an extreme value on overflow. */
+ s = end;
+ exponent =
+ (exponent < 0
+ ? (value < LONG_MIN - exponent ? LONG_MIN : exponent + value)
+ : (LONG_MAX - exponent < value ? LONG_MAX : exponent + value));
+ }
+ }
+
+ *endptr = (char *) s;
+ return scale_radix_exp (num, radix, exponent);
+}
+
+/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
+ ICC 10.0 has a bug when optimizing the expression -zero.
+ The expression -MIN * MIN does not work when cross-compiling
+ to PowerPC on Mac OS X 10.5. */
+static DOUBLE
+minus_zero (void)
+{
+#if defined __hpux || defined __sgi || defined __ICC
+ return -MIN * MIN;
+#else
+ return -0.0;
+#endif
+}
+
+/* Convert NPTR to a DOUBLE. If ENDPTR is not NULL, a pointer to the
+ character after the last one used in the number is put in *ENDPTR. */
+DOUBLE
+STRTOD (const char *nptr, char **endptr)
+#if HAVE_UNDERLYING_STRTOD
+# ifdef USE_LONG_DOUBLE
+# undef strtold
+# else
+# undef strtod
+# endif
+#else
+# undef STRTOD
+# define STRTOD(NPTR,ENDPTR) \
+ parse_number (NPTR, 10, 10, 1, radixchar, 'e', ENDPTR)
+#endif
+/* From here on, STRTOD refers to the underlying implementation. It needs
+ to handle only finite unsigned decimal numbers with non-null ENDPTR. */
+{
+ char radixchar;
+ bool negative = false;
+
+ /* The number so far. */
+ DOUBLE num;
+
+ const char *s = nptr;
+ const char *end;
+ char *endbuf;
+ int saved_errno = errno;
+
+ radixchar = decimal_point_char ();
+
+ /* Eat whitespace. */
+ while (locale_isspace (*s))
+ ++s;
+
+ /* Get the sign. */
+ negative = *s == '-';
+ if (*s == '-' || *s == '+')
+ ++s;
+
+ num = STRTOD (s, &endbuf);
+ end = endbuf;
+
+ if (c_isdigit (s[*s == radixchar]))
+ {
+ /* If a hex float was converted incorrectly, do it ourselves.
+ If the string starts with "0x" but does not contain digits,
+ consume the "0" ourselves. If a hex float is followed by a
+ 'p' but no exponent, then adjust the end pointer. */
+ if (*s == '0' && c_tolower (s[1]) == 'x')
+ {
+ if (! c_isxdigit (s[2 + (s[2] == radixchar)]))
+ {
+ end = s + 1;
+
+ /* strtod() on z/OS returns ERANGE for "0x". */
+ errno = saved_errno;
+ }
+ else if (end <= s + 2)
+ {
+ num = parse_number (s + 2, 16, 2, 4, radixchar, 'p', &endbuf);
+ end = endbuf;
+ }
+ else
+ {
+ const char *p = s + 2;
+ while (p < end && c_tolower (*p) != 'p')
+ p++;
+ if (p < end && ! c_isdigit (p[1 + (p[1] == '-' || p[1] == '+')]))
+ {
+ char *dup = strdup (s);
+ errno = saved_errno;
+ if (!dup)
+ {
+ /* Not really our day, is it. Rounding errors are
+ better than outright failure. */
+ num =
+ parse_number (s + 2, 16, 2, 4, radixchar, 'p', &endbuf);
+ }
+ else
+ {
+ dup[p - s] = '\0';
+ num = STRTOD (dup, &endbuf);
+ saved_errno = errno;
+ free (dup);
+ errno = saved_errno;
+ }
+ end = p;
+ }
+ }
+ }
+ else
+ {
+ /* If "1e 1" was misparsed as 10.0 instead of 1.0, re-do the
+ underlying STRTOD on a copy of the original string
+ truncated to avoid the bug. */
+ const char *e = s + 1;
+ while (e < end && c_tolower (*e) != 'e')
+ e++;
+ if (e < end && ! c_isdigit (e[1 + (e[1] == '-' || e[1] == '+')]))
+ {
+ char *dup = strdup (s);
+ errno = saved_errno;
+ if (!dup)
+ {
+ /* Not really our day, is it. Rounding errors are
+ better than outright failure. */
+ num = parse_number (s, 10, 10, 1, radixchar, 'e', &endbuf);
+ }
+ else
+ {
+ dup[e - s] = '\0';
+ num = STRTOD (dup, &endbuf);
+ saved_errno = errno;
+ free (dup);
+ errno = saved_errno;
+ }
+ end = e;
+ }
+ }
+
+ s = end;
+ }
+
+ /* Check for infinities and NaNs. */
+ else if (c_tolower (*s) == 'i'
+ && c_tolower (s[1]) == 'n'
+ && c_tolower (s[2]) == 'f')
+ {
+ s += 3;
+ if (c_tolower (*s) == 'i'
+ && c_tolower (s[1]) == 'n'
+ && c_tolower (s[2]) == 'i'
+ && c_tolower (s[3]) == 't'
+ && c_tolower (s[4]) == 'y')
+ s += 5;
+ num = HUGE_VAL;
+ errno = saved_errno;
+ }
+ else if (c_tolower (*s) == 'n'
+ && c_tolower (s[1]) == 'a'
+ && c_tolower (s[2]) == 'n')
+ {
+ s += 3;
+ if (*s == '(')
+ {
+ const char *p = s + 1;
+ while (c_isalnum (*p))
+ p++;
+ if (*p == ')')
+ s = p + 1;
+ }
+
+ /* If the underlying implementation misparsed the NaN, assume
+ its result is incorrect, and return a NaN. Normally it's
+ better to use the underlying implementation's result, since a
+ nice implementation populates the bits of the NaN according
+ to interpreting n-char-sequence as a hexadecimal number. */
+ if (s != end || num == num)
+ num = NAN;
+ errno = saved_errno;
+ }
+ else
+ {
+ /* No conversion could be performed. */
+ errno = EINVAL;
+ s = nptr;
+ }
+
+ if (endptr != NULL)
+ *endptr = (char *) s;
+ /* Special case -0.0, since at least ICC miscompiles negation. We
+ can't use copysign(), as that drags in -lm on some platforms. */
+ if (!num && negative)
+ return minus_zero ();
+ return negative ? -num : num;
+}