Builds: Add a fallback-c89.c for pre-C99 compilers

Some supported compilers lack some C99 math functions that are beginning
to be used in the code, so this adds a fallback implementation for them,
namely round() and lrint(), where the fallbacks are used if they are not
found during configure.

For Visual Studio builds, config.h.win32.in is updated to reflect the
situation on various Visual Studio versions as Visual Studio builds
do not use autotools.

8 files changed, 68 insertions, 3 deletions

diff --git a/config.h.win32.in b/config.h.win32.in
index 9a8640b5b..1aaa149f0 100644
--- a/config.h.win32.in
+++ b/config.h.win32.in
@@ -41,12 +41,22 @@
 /*#define HAVE_INTTYPES_H*/
 #endif
 
+/* Define to 1 if lrint() is available */
+#if !defined (_MSC_VER) || (_MSC_VER >= 1800)
+#define HAVE_LRINT 1
+#endif
+
 /* Define to 1 if you have the <memory.h> header file. */
 #define HAVE_MEMORY_H 1
 
 /* Define to 1 is libjpeg supports progressive JPEG */
 #define HAVE_PROGRESSIVE_JPEG 1
 
+/* Define to 1 if round() is available */
+#if !defined (_MSC_VER) || (_MSC_VER >= 1800)
+#define HAVE_ROUND 1
+#endif
+
 /* Define to 1 if sigsetjmp is available */
 /*#undef HAVE_SIGSETJMP*/
 
diff --git a/configure.ac b/configure.ac
index 491a9b5bf..5bab06144 100644
--- a/configure.ac
+++ b/configure.ac
@@ -424,6 +424,9 @@ AC_CHECK_FUNCS(setrlimit)
 saved_cflags="$CFLAGS"
 saved_ldflags="$LDFLAGS"
 
+AC_CHECK_LIB(m,round,)
+AC_CHECK_LIB(m,lrint,)
+AC_CHECK_FUNCS(round lrint)
 
 # Checks for header files.
 AC_HEADER_STDC
diff --git a/gdk-pixbuf/Makefile.am b/gdk-pixbuf/Makefile.am
index a3189857b..691cb78a0 100644
--- a/gdk-pixbuf/Makefile.am
+++ b/gdk-pixbuf/Makefile.am
@@ -595,7 +595,8 @@ EXTRA_DIST =					\
 	gdk-pixbuf-enum-types.c.template	\
 	gdk-pixbuf-enum-types.h.template	\
 	gen-color-table.pl			\
-	gdiplus.def
+	gdiplus.def				\
+	fallback-c89.c
 
 # ---------- MSVC Items ------------------
 
diff --git a/gdk-pixbuf/fallback-c89.c b/gdk-pixbuf/fallback-c89.c
new file mode 100755
index 000000000..f2078ff16
--- /dev/null
+++ b/gdk-pixbuf/fallback-c89.c
@@ -0,0 +1,49 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2011 Chun-wei Fan <fanc999@yahoo.com.tw>
+ *
+ * Author: Chun-wei Fan <fanc999@yahoo.com.tw>
+ *
+ * This library 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 2 of the License, or (at your option) any later version.
+ *
+ * This library 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 library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <math.h>
+ 
+/* Workaround for round() for non-GCC/non-C99 compilers */
+#ifndef HAVE_ROUND
+static inline double
+round (double x)
+{
+  if (x >= 0)
+    return floor (x + 0.5);
+  else
+    return ceil (x - 0.5);
+}
+#endif
+
+/* Workaround for lrint() for non-GCC/non-C99 compilers */
+#ifndef HAVE_LRINT
+static inline long
+lrint (double x)
+{
+  if (ceil (x + 0.5) == floor (x + 0.5))
+    {
+      if (x < 1 && x > -1)
+        return 0;
+
+      return (int) ceil (x) % 2 == 0 ? ceil (x) : floor (x);
+    }
+  else
+    return x >= 0 ? floor (x + 0.5) : ceil (x - 0.5);
+}
+#endif
\ No newline at end of file
diff --git a/gdk-pixbuf/io-jpeg.c b/gdk-pixbuf/io-jpeg.c
index 96f993f40..92ec36b47 100644
--- a/gdk-pixbuf/io-jpeg.c
+++ b/gdk-pixbuf/io-jpeg.c
@@ -35,6 +35,7 @@
 #include <math.h>
 
 #include "gdk-pixbuf-private.h"
+#include "fallback-c89.c"
 
 #ifndef HAVE_SIGSETJMP
 #define sigjmp_buf jmp_buf
diff --git a/gdk-pixbuf/io-png.c b/gdk-pixbuf/io-png.c
index a9fc1f6bf..759e78a1f 100644
--- a/gdk-pixbuf/io-png.c
+++ b/gdk-pixbuf/io-png.c
@@ -28,8 +28,7 @@
 #include <png.h>
 #include <math.h>
 #include "gdk-pixbuf-private.h"
-
-
+#include "fallback-c89.c"
 
 static gboolean
 setup_png_transformations(png_structp png_read_ptr, png_infop png_info_ptr,
diff --git a/gdk-pixbuf/io-tiff.c b/gdk-pixbuf/io-tiff.c
index 62f25313a..4d10ef094 100644
--- a/gdk-pixbuf/io-tiff.c
+++ b/gdk-pixbuf/io-tiff.c
@@ -36,6 +36,7 @@
 #include <tiffio.h>
 #include <errno.h>
 #include "gdk-pixbuf-private.h"
+#include "fallback-c89.c"
 
 #ifdef G_OS_WIN32
 #include <fcntl.h>
diff --git a/gdk-pixbuf/pixops/pixops.c b/gdk-pixbuf/pixops/pixops.c
index dc1b46152..f91f0e339 100644
--- a/gdk-pixbuf/pixops/pixops.c
+++ b/gdk-pixbuf/pixops/pixops.c
@@ -21,6 +21,7 @@
 #include <math.h>
 #include <glib.h>
 
+#include "../fallback-c89.c"
 #include "pixops.h"
 #include "pixops-internal.h"