1 files changed, 54 insertions, 0 deletions
diff --git a/gl/m4/limits-h.m4 b/gl/m4/limits-h.m4
new file mode 100644
index 0000000..6a5983e
--- /dev/null
+++ b/gl/m4/limits-h.m4
@@ -0,0 +1,54 @@
+dnl Check whether limits.h has needed features.
+
+dnl Copyright 2016-2023 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert.
+
+AC_DEFUN_ONCE([gl_LIMITS_H],
+[
+  gl_CHECK_NEXT_HEADERS([limits.h])
+
+  AC_CACHE_CHECK([whether limits.h has WORD_BIT, BOOL_WIDTH etc.],
+    [gl_cv_header_limits_width],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+             #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
+            #endif
+            #include <limits.h>
+            long long llm = LLONG_MAX;
+            int wb = WORD_BIT;
+            int ullw = ULLONG_WIDTH;
+            int bw = BOOL_WIDTH;
+            int bm = BOOL_MAX;
+            int mblm = MB_LEN_MAX;
+          ]])],
+       [gl_cv_header_limits_width=yes],
+       [gl_cv_header_limits_width=no])])
+  GL_GENERATE_LIMITS_H=true
+  AS_IF([test "$gl_cv_header_limits_width" = yes],
+    [AC_CACHE_CHECK([whether limits.h has SSIZE_MAX],
+       [gl_cv_header_limits_ssize_max],
+       [AC_COMPILE_IFELSE(
+          [AC_LANG_SOURCE(
+             [[#include <limits.h>
+               #ifndef SSIZE_MAX
+                 #error "SSIZE_MAX is not defined"
+               #endif
+             ]])],
+          [gl_cv_header_limits_ssize_max=yes],
+          [gl_cv_header_limits_ssize_max=no])])
+     if test "$gl_cv_header_limits_ssize_max" = yes; then
+       GL_GENERATE_LIMITS_H=false
+     fi])
+])
+
+dnl Unconditionally enables the replacement of <limits.h>.
+AC_DEFUN([gl_REPLACE_LIMITS_H],
+[
+  AC_REQUIRE([gl_LIMITS_H])
+  GL_GENERATE_LIMITS_H=true
+])