These changes are mostly inherited from previous iterations
of gnulib-printf-in-glib.

Here are explanations for some of them:
* g-gnulib.h is a minimal replacement for gnulib config.h
* gnulib_math.h is a processed copy of gnulib math.in.h
  We can't keep it named math.h, since we need to include
  both the system math.h and this header in some places.
* gnulib_math.h needs _GL_ATTRIBUTE_CONST, put it directly
  there instead of getting it from config.h
  Also, instead of copying _GL_FUNCDECL_RPL and _GL_WARN_ON_USE
  we simply include headers where these macros are defined.
* isnan source files get extra includes, in gnulib these
  were probably handled by makefiles and/or configure scripts
* glib has a test result named HAVE_LONG_LONG instead of HAVE_LONG_LONG_INT,
  so make the code use that
* One of the goals of using this gnulib implementation in glib is
  to have C99-compliant 3-digit exponent, therefore gnulib
  ifdefs that *disable* that behaviour are altered to keep it enabled.
  Another possible location for such a change is where %n use is
  being enabled or disabled. That, however, is not activated anyway,
  because this code is made not to use snprintf
* glib has G_MAXSIZE instead of SIZE_MAX, so use that
* The code is made to use glib alloca header
--- glib-82c3e92/glib/gnulib/asnprintf.c	2019-02-09 09:44:55.013866300 +0000
+++ glib-82c3e92/glib/gnulib/asnprintf.c	2019-02-09 10:08:46.444859600 +0000
@@ -16,6 +16,8 @@
 
 #include <config.h>
 
+#include "g-gnulib.h"
+
 /* Specification.  */
 #include "vasnprintf.h"
 
--- glib-82c3e92/glib/gnulib/isnand.c	2019-02-09 09:44:56.075691800 +0000
+++ glib-82c3e92/glib/gnulib/isnand.c	2019-02-09 10:09:35.443191100 +0000
@@ -16,4 +16,7 @@
 
 /* Written by Bruno Haible <bruno@clisp.org>, 2008.  */
 
+#include <config.h>
+#include "gnulib_math.h"
+#include "isnand-nolibm.h"
 #include "isnan.c"
--- glib-82c3e92/glib/gnulib/isnand-nolibm.h	2019-02-09 09:44:55.973651800 +0000
+++ glib-82c3e92/glib/gnulib/isnand-nolibm.h	2019-02-09 10:09:17.089604000 +0000
@@ -16,7 +16,7 @@
 
 #if HAVE_ISNAND_IN_LIBC
 /* Get declaration of isnan macro.  */
-# include <math.h>
+# include <gnulib_math.h>
 # if __GNUC__ >= 4
    /* GCC 4.0 and newer provides three built-ins for isnan.  */
 #  undef isnand
--- glib-82c3e92/glib/gnulib/isnanl.c	2019-02-09 09:44:56.285650400 +0000
+++ glib-82c3e92/glib/gnulib/isnanl.c	2019-02-09 10:10:00.060305200 +0000
@@ -17,4 +17,7 @@
 /* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
 
 #define USE_LONG_DOUBLE
+#include <config.h>
+#include "gnulib_math.h"
+#include "isnanl-nolibm.h"
 #include "isnan.c"
--- glib-82c3e92/glib/gnulib/isnanl-nolibm.h	2019-02-09 09:44:56.181628200 +0000
+++ glib-82c3e92/glib/gnulib/isnanl-nolibm.h	2019-02-09 10:09:45.731187400 +0000
@@ -16,7 +16,7 @@
 
 #if HAVE_ISNANL_IN_LIBC
 /* Get declaration of isnan macro or (older) isnanl function.  */
-# include <math.h>
+# include <gnulib_math.h>
 # if __GNUC__ >= 4
    /* GCC 4.0 and newer provides three built-ins for isnan.  */
 #  undef isnanl
--- glib-82c3e92/glib/gnulib/printf-args.c	2019-02-09 09:44:57.147081400 +0000
+++ glib-82c3e92/glib/gnulib/printf-args.c	2019-02-09 10:10:45.869597700 +0000
@@ -24,6 +24,8 @@
 # include <config.h>
 #endif
 
+#include "g-gnulib.h"
+
 /* Specification.  */
 #ifndef PRINTF_FETCHARGS
 # include "printf-args.h"
@@ -65,7 +67,7 @@
       case TYPE_ULONGINT:
         ap->a.a_ulongint = va_arg (args, unsigned long int);
         break;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
       case TYPE_LONGLONGINT:
         ap->a.a_longlongint = va_arg (args, long long int);
         break;
@@ -135,7 +137,7 @@
       case TYPE_COUNT_LONGINT_POINTER:
         ap->a.a_count_longint_pointer = va_arg (args, long int *);
         break;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
       case TYPE_COUNT_LONGLONGINT_POINTER:
         ap->a.a_count_longlongint_pointer = va_arg (args, long long int *);
         break;
--- glib-82c3e92/glib/gnulib/printf-args.h	2019-02-09 09:44:57.245167700 +0000
+++ glib-82c3e92/glib/gnulib/printf-args.h	2019-02-09 10:10:55.543592500 +0000
@@ -57,7 +57,7 @@
   TYPE_UINT,
   TYPE_LONGINT,
   TYPE_ULONGINT,
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
   TYPE_LONGLONGINT,
   TYPE_ULONGLONGINT,
 #endif
@@ -76,7 +76,7 @@
   TYPE_COUNT_SHORT_POINTER,
   TYPE_COUNT_INT_POINTER,
   TYPE_COUNT_LONGINT_POINTER
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
 , TYPE_COUNT_LONGLONGINT_POINTER
 #endif
 #if ENABLE_UNISTDIO
@@ -101,7 +101,7 @@
     unsigned int                a_uint;
     long int                    a_longint;
     unsigned long int           a_ulongint;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
     long long int               a_longlongint;
     unsigned long long int      a_ulonglongint;
 #endif
@@ -121,7 +121,7 @@
     short *                     a_count_short_pointer;
     int *                       a_count_int_pointer;
     long int *                  a_count_longint_pointer;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
     long long int *             a_count_longlongint_pointer;
 #endif
 #if ENABLE_UNISTDIO
--- glib-82c3e92/glib/gnulib/printf-frexp.c	2019-02-09 09:44:57.355099800 +0000
+++ glib-82c3e92/glib/gnulib/printf-frexp.c	2019-02-09 10:11:15.476905600 +0000
@@ -26,7 +26,7 @@
 #endif
 
 #include <float.h>
-#include <math.h>
+#include <gnulib_math.h>
 #ifdef USE_LONG_DOUBLE
 # include "fpucw.h"
 #endif
--- glib-82c3e92/glib/gnulib/printf-parse.c	2019-02-09 09:44:57.790835100 +0000
+++ glib-82c3e92/glib/gnulib/printf-parse.c	2019-02-09 10:11:32.783744500 +0000
@@ -31,6 +31,8 @@
 # include <config.h>
 #endif
 
+#include "g-gnulib.h"
+
 /* Specification.  */
 #ifndef PRINTF_PARSE
 # include "printf-parse.h"
@@ -447,7 +449,7 @@
               switch (c)
                 {
                 case 'd': case 'i':
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                   /* If 'long long' exists and is larger than 'long':  */
                   if (flags >= 16 || (flags & 4))
                     type = TYPE_LONGLONGINT;
@@ -465,7 +467,7 @@
                     type = TYPE_INT;
                   break;
                 case 'o': case 'u': case 'x': case 'X':
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                   /* If 'long long' exists and is larger than 'long':  */
                   if (flags >= 16 || (flags & 4))
                     type = TYPE_ULONGLONGINT;
@@ -525,7 +527,7 @@
                   type = TYPE_POINTER;
                   break;
                 case 'n':
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                   /* If 'long long' exists and is larger than 'long':  */
                   if (flags >= 16 || (flags & 4))
                     type = TYPE_COUNT_LONGLONGINT_POINTER;
--- glib-82c3e92/glib/gnulib/vasnprintf.c	2019-02-09 09:44:58.585342000 +0000
+++ glib-82c3e92/glib/gnulib/vasnprintf.c	2019-02-09 10:22:13.196848200 +0000
@@ -43,19 +43,21 @@
      DCHAR_IS_UINT16_T  Set to 1 if DCHAR_T is uint16_t.
      DCHAR_IS_UINT32_T  Set to 1 if DCHAR_T is uint32_t.  */
 
+#ifndef _WIN32
 /* Tell glibc's <stdio.h> to provide a prototype for snprintf().
    This must come before <config.h> because <config.h> may include
    <features.h>, and once <features.h> has been included, it's too late.  */
 #ifndef _GNU_SOURCE
 # define _GNU_SOURCE    1
 #endif
+#endif
 
 #ifndef VASNPRINTF
 # include <config.h>
 #endif
-#ifndef IN_LIBINTL
-# include <alloca.h>
-#endif
+#include "glib/galloca.h"
+
+#include "g-gnulib.h"
 
 /* Specification.  */
 #ifndef VASNPRINTF
@@ -90,29 +92,29 @@
 #include "verify.h"
 
 #if (NEED_PRINTF_DOUBLE || NEED_PRINTF_LONG_DOUBLE) && !defined IN_LIBINTL
-# include <math.h>
+# include <gnulib_math.h>
 # include "float+.h"
 #endif
 
 #if (NEED_PRINTF_DOUBLE || NEED_PRINTF_INFINITE_DOUBLE) && !defined IN_LIBINTL
-# include <math.h>
+# include <gnulib_math.h>
 # include "isnand-nolibm.h"
 #endif
 
 #if (NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_INFINITE_LONG_DOUBLE) && !defined IN_LIBINTL
-# include <math.h>
+# include <gnulib_math.h>
 # include "isnanl-nolibm.h"
 # include "fpucw.h"
 #endif
 
 #if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_DOUBLE) && !defined IN_LIBINTL
-# include <math.h>
+# include <gnulib_math.h>
 # include "isnand-nolibm.h"
 # include "printf-frexp.h"
 #endif
 
 #if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_LONG_DOUBLE) && !defined IN_LIBINTL
-# include <math.h>
+# include <gnulib_math.h>
 # include "isnanl-nolibm.h"
 # include "printf-frexpl.h"
 # include "fpucw.h"
@@ -1553,7 +1555,7 @@
   switch (conversion)
     {
     case 'd': case 'i': case 'u':
-# if HAVE_LONG_LONG_INT
+# if HAVE_LONG_LONG
       if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
         tmp_length =
           (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
@@ -1583,7 +1585,7 @@
       break;
 
     case 'o':
-# if HAVE_LONG_LONG_INT
+# if HAVE_LONG_LONG
       if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
         tmp_length =
           (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
@@ -1611,7 +1613,7 @@
       break;
 
     case 'x': case 'X':
-# if HAVE_LONG_LONG_INT
+# if HAVE_LONG_LONG
       if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
         tmp_length =
           (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
@@ -1939,7 +1941,7 @@
                   case TYPE_COUNT_LONGINT_POINTER:
                     *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
                     break;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                   case TYPE_COUNT_LONGLONGINT_POINTER:
                     *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
                     break;
@@ -4245,7 +4247,7 @@
                                   static const wchar_t decimal_format[] =
                                     /* Produce the same number of exponent digits
                                        as the native printf implementation.  */
-#    if defined _WIN32 && ! defined __CYGWIN__
+#    if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                                     { '%', '+', '.', '3', 'd', '\0' };
 #    else
                                     { '%', '+', '.', '2', 'd', '\0' };
@@ -4259,7 +4261,7 @@
                                   static const char decimal_format[] =
                                     /* Produce the same number of exponent digits
                                        as the native printf implementation.  */
-#    if defined _WIN32 && ! defined __CYGWIN__
+#    if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                                     "%+.3d";
 #    else
                                     "%+.2d";
@@ -4438,7 +4440,7 @@
                                           static const wchar_t decimal_format[] =
                                             /* Produce the same number of exponent digits
                                                as the native printf implementation.  */
-#    if defined _WIN32 && ! defined __CYGWIN__
+#    if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                                             { '%', '+', '.', '3', 'd', '\0' };
 #    else
                                             { '%', '+', '.', '2', 'd', '\0' };
@@ -4452,7 +4454,7 @@
                                           static const char decimal_format[] =
                                             /* Produce the same number of exponent digits
                                                as the native printf implementation.  */
-#    if defined _WIN32 && ! defined __CYGWIN__
+#    if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                                             "%+.3d";
 #    else
                                             "%+.2d";
@@ -4510,7 +4512,7 @@
                                 *p++ = '+';
                                 /* Produce the same number of exponent digits as
                                    the native printf implementation.  */
-#   if defined _WIN32 && ! defined __CYGWIN__
+#   if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                                 *p++ = '0';
 #   endif
                                 *p++ = '0';
@@ -4835,10 +4837,10 @@
 
                 switch (type)
                   {
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                   case TYPE_LONGLONGINT:
                   case TYPE_ULONGLONGINT:
-# if defined _WIN32 && ! defined __CYGWIN__
+# if (defined _WIN32 && FALSE) && ! defined __CYGWIN__
                     *fbp++ = 'I';
                     *fbp++ = '6';
                     *fbp++ = '4';
@@ -5063,7 +5065,7 @@
                           SNPRINTF_BUF (arg);
                         }
                         break;
-#if HAVE_LONG_LONG_INT
+#if HAVE_LONG_LONG
                       case TYPE_LONGLONGINT:
                         {
                           long long int arg = a.arg[dp->arg_index].a.a_longlongint;
--- glib-82c3e92/glib/gnulib/xsize.h	2019-02-09 09:44:59.231076600 +0000
+++ glib-82c3e92/glib/gnulib/xsize.h	2019-02-09 10:21:28.789553900 +0000
@@ -18,10 +18,12 @@
 #ifndef _XSIZE_H
 #define _XSIZE_H
 
+#include <glib.h>
+
 /* Get size_t.  */
 #include <stddef.h>
 
-/* Get SIZE_MAX.  */
+/* Get G_MAXSIZE.  */
 #include <limits.h>
 #if HAVE_STDINT_H
 # include <stdint.h>
@@ -42,8 +44,8 @@
    returns a piece of memory that is way too small, and the program then
    crashes while attempting to fill the memory.
    To avoid this, the functions and macros in this file check for overflow.
-   The convention is that SIZE_MAX represents overflow.
-   malloc (SIZE_MAX) is not guaranteed to fail -- think of a malloc
+   The convention is that G_MAXSIZE represents overflow.
+   malloc (G_MAXSIZE) is not guaranteed to fail -- think of a malloc
    implementation that uses mmap --, it's recommended to use size_overflow_p()
    or size_in_bounds_p() before invoking malloc().
    The example thus becomes:
@@ -53,7 +55,7 @@
 
 /* Convert an arbitrary value >= 0 to type size_t.  */
 #define xcast_size_t(N) \
-  ((N) <= SIZE_MAX ? (size_t) (N) : SIZE_MAX)
+  ((N) <= G_MAXSIZE ? (size_t) (N) : G_MAXSIZE)
 
 /* Sum of two sizes, with overflow check.  */
 XSIZE_INLINE size_t
@@ -63,7 +65,7 @@
 xsum (size_t size1, size_t size2)
 {
   size_t sum = size1 + size2;
-  return (sum >= size1 ? sum : SIZE_MAX);
+  return (sum >= size1 ? sum : G_MAXSIZE);
 }
 
 /* Sum of three sizes, with overflow check.  */
@@ -94,23 +96,23 @@
 xmax (size_t size1, size_t size2)
 {
   /* No explicit check is needed here, because for any n:
-     max (SIZE_MAX, n) == SIZE_MAX and max (n, SIZE_MAX) == SIZE_MAX.  */
+     max (G_MAXSIZE, n) == G_MAXSIZE and max (n, G_MAXSIZE) == G_MAXSIZE.  */
   return (size1 >= size2 ? size1 : size2);
 }
 
 /* Multiplication of a count with an element size, with overflow check.
    The count must be >= 0 and the element size must be > 0.
    This is a macro, not a function, so that it works correctly even
-   when N is of a wider type and N > SIZE_MAX.  */
+   when N is of a wider type and N > G_MAXSIZE.  */
 #define xtimes(N, ELSIZE) \
-  ((N) <= SIZE_MAX / (ELSIZE) ? (size_t) (N) * (ELSIZE) : SIZE_MAX)
+  ((N) <= G_MAXSIZE / (ELSIZE) ? (size_t) (N) * (ELSIZE) : G_MAXSIZE)
 
 /* Check for overflow.  */
 #define size_overflow_p(SIZE) \
-  ((SIZE) == SIZE_MAX)
+  ((SIZE) == G_MAXSIZE)
 /* Check against overflow.  */
 #define size_in_bounds_p(SIZE) \
-  ((SIZE) != SIZE_MAX)
+  ((SIZE) != G_MAXSIZE)
 
 _GL_INLINE_HEADER_END
 
--- a/glib/gnulib/gnulib_math.h.in
+++ b/glib/gnulib/gnulib_math.h.in
@@ -25,6 +25,13 @@
 /* The include_next requires a split double-inclusion guard.  */
 #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_MATH_H@
 
+/* The __const__ attribute was added in gcc 2.95.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST /* empty */
+#endif
+
 #ifndef _@GUARD_PREFIX@_MATH_H
 #define _@GUARD_PREFIX@_MATH_H
 
@@ -41,9 +48,9 @@ _GL_INLINE_HEADER_BEGIN
 # define _GL_MATH_INLINE _GL_INLINE
 #endif
 
-/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+#include "c++defs.h"
 
-/* The definition of _GL_ARG_NONNULL is copied here.  */
+#include "arg-nonnull.h"
 
 /* The definition of _GL_WARN_ON_USE is copied here.  */