Use Windows CRT string functions in some places.

Copy wsutil/wsprintf.h from change 16537. Update it to use functions
appropriate to Visual C++ >= 2015, < 2015, and everything else. Add
notes about specific API issues.

Update epan/expert.c to use ws_snprintf, since the VS profiler shows it
as a minor hot spot. This reduces load time for a large-ish capture from
~14s to ~12s here.

Migrate a previous column-utils change.

Change-Id: Id4064b7c06c35fd447b63c73f731afee181df4f9
Reviewed-on: https://code.wireshark.org/review/16483
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: João Valverde <j@v6e.pt>

2 files changed, 102 insertions, 1 deletions

diff --git a/wsutil/Makefile.am b/wsutil/Makefile.am
index 95c57d2582..2cedf9ddbb 100644
--- a/wsutil/Makefile.am
+++ b/wsutil/Makefile.am
@@ -89,7 +89,8 @@ libwsutil_nonrepl_INCLUDES = \
 	utf8_entities.h		\
 	ws_cpuid.h		\
 	ws_mempbrk.h		\
-	ws_mempbrk_int.h
+	ws_mempbrk_int.h	\
+	ws_printf.h
 
 # Header files for functions in libwsutil's ABI on this platform.
 libwsutil_abi_INCLUDES = \
diff --git a/wsutil/ws_printf.h b/wsutil/ws_printf.h
new file mode 100644
index 0000000000..1ee3bf69e6
--- /dev/null
+++ b/wsutil/ws_printf.h
@@ -0,0 +1,100 @@
+/*
+ * Wrappers for printf like functions.
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 2007 Gerald Combs
+ *
+ * This program 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __WS_PRINTF_H__
+#define __WS_PRINTF_H__
+
+/*
+ * GLib's string utility routines are slow on windows, likely due to calling
+ * g_printf_string_upper_bound. Using ws_snprintf and ws_vsnprintf in hot
+ * code paths can speed up program execution. Otherwise you're probably safe
+ * sticking with g_snprintf and g_vsnprintf.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#ifdef _WIN32
+#include <strsafe.h>
+
+#if _MSC_VER < 1900
+#include <stdarg.h>
+
+/*
+ * vsnprintf_s's return value isn't compatible with C99 vsnprintf. We don't
+ * return anything in order to avoid confusion.
+ */
+
+static __inline void
+ws_vsnprintf(char *buffer, size_t size_of_buffer, const char *format, va_list argptr) {
+    /* We could alternatively use StringCchVPrintfA */
+    vsnprintf_s(buffer, size_of_buffer, _TRUNCATE, format, argptr);
+}
+
+#else /* _MSC_VER uses UCRT */
+
+/* The UCRT versions of snprintf and vsnprintf conform to C99 */
+
+static __inline void
+ws_vsnprintf(char *buffer, size_t size_of_buffer, const char *format, va_list argptr)
+{
+    vsnprintf(buffer, size_of_buffer, format, argptr);
+}
+
+#endif /* _MSC_VER */
+
+#else /* _WIN32 */
+
+#include <glib.h>
+
+/*
+ * Use g_vsnprintf. On Linux and macOS these should be a thin wrapper around
+ * vsprintf.
+ */
+
+static inline void
+ws_vsnprintf(char *buffer, size_t size_of_buffer, const char *format, va_list argptr)
+{
+    g_vsnprintf(buffer, (gulong) size_of_buffer, format, argptr);
+}
+
+#endif /* _WIN32 */
+
+#ifdef _WIN32
+static __inline void
+#else
+static inline void
+#endif
+ws_snprintf(char *buffer, size_t size_of_buffer, const char * format, ...) {
+    va_list argptr;
+
+    va_start(argptr, format);
+    ws_vsnprintf(buffer, size_of_buffer, format, argptr);
+    va_end(argptr);
+}
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __WS_PRINTF_H__ */