1 files changed, 141 insertions, 0 deletions
diff --git a/include/typemax.h b/include/typemax.h
new file mode 100644
index 0000000..e3b98f4
--- /dev/null
+++ b/include/typemax.h
@@ -0,0 +1,141 @@
+/* typemax.h -- encapsulate max values for long, long long, etc. */
+
+/* Copyright (C) 2001-2021 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * NOTE:  This should be included after config.h, limits.h, stdint.h, and
+ *	  inttypes.h
+ */
+
+#ifndef _SH_TYPEMAX_H
+#define _SH_TYPEMAX_H
+
+#ifndef CHAR_BIT
+#  define CHAR_BIT 8
+#endif
+
+/* Nonzero if the integer type T is signed.  */
+#ifndef TYPE_SIGNED
+#  define TYPE_SIGNED(t)	(! ((t) 0 < (t) -1))
+#endif
+
+#ifndef TYPE_SIGNED_MAGNITUDE
+#  define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
+#endif
+
+#ifndef TYPE_WIDTH
+#  define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT)
+#endif
+
+#ifndef TYPE_MINIMUM
+#  define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t))
+#endif
+
+#ifndef TYPE_MAXIMUM
+#  define TYPE_MAXIMUM(t)  \
+  ((t) (! TYPE_SIGNED (t) \
+        ? (t) -1 \
+        : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1)))
+#endif
+
+#ifdef HAVE_LONG_LONG_INT
+#  ifndef LLONG_MAX
+#    define LLONG_MAX   TYPE_MAXIMUM(long long int)
+#    define LLONG_MIN	TYPE_MINIMUM(long long int)
+#  endif
+#  ifndef ULLONG_MAX
+#    define ULLONG_MAX  TYPE_MAXIMUM(unsigned long long int)
+#  endif
+#endif
+
+#ifndef ULONG_MAX
+#  define ULONG_MAX	((unsigned long) ~(unsigned long) 0)
+#endif
+
+#ifndef LONG_MAX
+#  define LONG_MAX	((long int) (ULONG_MAX >> 1))
+#  define LONG_MIN	((long int) (-LONG_MAX - 1L))
+#endif
+
+#ifndef INT_MAX		/* ouch */
+#  define INT_MAX	TYPE_MAXIMUM(int)
+#  define INT_MIN	TYPE_MINIMUM(int)
+#  define UINT_MAX	((unsigned int) ~(unsigned int)0)
+#endif
+
+#ifndef SHRT_MAX
+#  define SHRT_MAX	TYPE_MAXIMUM(short)
+#  define SHRT_MIN	TYPE_MINIMUM(short)
+#  define USHRT_MAX	((unsigned short) ~(unsigned short)0)
+#endif
+
+#ifndef UCHAR_MAX
+#  define UCHAR_MAX	255
+#endif
+
+/* workaround for gcc bug in versions < 2.7 */
+#if defined (HAVE_LONG_LONG_INT) && __GNUC__ == 2 && __GNUC_MINOR__ < 7
+static const unsigned long long int maxquad = ULLONG_MAX;
+#  undef ULLONG_MAX
+#  define ULLONG_MAX maxquad
+#endif
+
+#if !defined (INTMAX_MAX) || !defined (INTMAX_MIN)
+
+#if SIZEOF_INTMAX_T == SIZEOF_LONG_LONG
+#  define INTMAX_MAX	LLONG_MAX
+#  define INTMAX_MIN	LLONG_MIN
+#elif SIZEOF_INTMAX_T == SIZEOF_LONG
+#  define INTMAX_MAX	LONG_MAX
+#  define INTMAX_MIN	LONG_MIN
+#else
+#  define INTMAX_MAX	INT_MAX
+#  define INTMAX_MIN	INT_MIN
+#endif
+
+#endif
+
+#ifndef SSIZE_MAX
+#  define SSIZE_MAX	INT_MAX
+#endif
+
+#ifndef SIZE_MAX
+#  define SIZE_MAX	((size_t) ~(size_t)0)
+#endif
+
+#ifndef sh_imaxabs
+#  define sh_imaxabs(x)	(((x) >= 0) ? (x) : -(x))
+#endif
+
+/* Handle signed arithmetic overflow and underflow.  Have to do it this way
+   to avoid compilers optimizing out simpler overflow checks. */
+
+/* Make sure that a+b does not exceed MAXV or is smaller than MINV (if b < 0).
+   Assumes that b > 0 if a > 0 and b < 0 if a < 0 */
+#define ADDOVERFLOW(a,b,minv,maxv) \
+	((((a) > 0) && ((b) > ((maxv) - (a)))) || \
+	 (((a) < 0) && ((b) < ((minv) - (a)))))
+
+/* Make sure that a-b is not smaller than MINV or exceeds MAXV (if b < 0).
+   Assumes that b > 0 if a > 0 and b < 0 if a < 0 */
+#define SUBOVERFLOW(a,b,minv,maxv) \
+	((((b) > 0) && ((a) < ((minv) + (b)))) || \
+	 (((b) < 0) && ((a) > ((maxv) + (b)))))
+
+#endif /* _SH_TYPEMAX_H */