[ovs-dev] [PATCH] stdio: New module, initially to provide working [v]snprintf() on Windows.
Saurabh Shah
ssaurabh at vmware.com
Mon Dec 23 22:00:35 UTC 2013
Looks good to me. Thanks for creating the patch & adding unit test.
From: Ben Pfaff <blp at nicira.com<mailto:blp at nicira.com>>
Date: Monday, December 23, 2013 12:52 PM
To: "dev at openvswitch.org<mailto:dev at openvswitch.org>" <dev at openvswitch.org<mailto:dev at openvswitch.org>>
Cc: Ben Pfaff <blp at nicira.com<mailto:blp at nicira.com>>, Saurabh Shah <ssaurabh at vmware.com<mailto:ssaurabh at vmware.com>>
Subject: [PATCH] stdio: New module, initially to provide working [v]snprintf() on Windows.
This should transparently define snprintf() and vsnprintf() wrappers for
use on Windows.
CC: Saurabh Shah <ssaurabh at vmware.com<mailto:ssaurabh at vmware.com>>
Signed-off-by: Ben Pfaff <blp at nicira.com<mailto:blp at nicira.com>>
---
configure.ac | 4 ++--
lib/automake.mk | 5 ++++-
lib/stdio.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
lib/stdio.h.in | 43 +++++++++++++++++++++++++++++++++++++++++++
tests/library.at | 4 ++++
tests/test-util.c | 18 ++++++++++++++++++
6 files changed, 119 insertions(+), 3 deletions(-)
create mode 100644 lib/stdio.c
create mode 100644 lib/stdio.h.in
diff --git a/configure.ac b/configure.ac
index 8ddc1f9..dd13fef 100644
--- a/configure.ac
+++ b/configure.ac
@@ -91,8 +91,8 @@ OVS_CHECK_ATOMIC_ALWAYS_LOCK_FREE(8)
OVS_CHECK_POSIX_AIO
OVS_CHECK_PTHREAD_SET_NAME
-OVS_CHECK_INCLUDE_NEXT([string.h])
-AC_CONFIG_FILES([lib/string.h])
+OVS_CHECK_INCLUDE_NEXT([stdio.h string.h])
+AC_CONFIG_FILES([lib/stdio.h lib/string.h])
OVS_ENABLE_OPTION([-Wall])
OVS_ENABLE_OPTION([-Wextra])
diff --git a/lib/automake.mk b/lib/automake.mk
index 5eece1c..ac6ff4a 100644
--- a/lib/automake.mk
+++ b/lib/automake.mk
@@ -196,6 +196,7 @@ lib_libopenvswitch_la_SOURCES = \
lib/stream-unix.c \
lib/stream.c \
lib/stream.h \
+ lib/stdio.c \
lib/string.c \
lib/svec.c \
lib/svec.h \
@@ -234,7 +235,9 @@ lib_libopenvswitch_la_SOURCES = \
lib/vswitch-idl.h \
lib/vtep-idl.c \
lib/vtep-idl.h
-EXTRA_DIST += lib/string.h.in
+EXTRA_DIST += \
+ lib/stdio.h.in \
+ lib/string.h.in
nodist_lib_libopenvswitch_la_SOURCES = \
lib/dirs.c
diff --git a/lib/stdio.c b/lib/stdio.c
new file mode 100644
index 0000000..49a5078
--- /dev/null
+++ b/lib/stdio.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2013 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * https://urldefense.proofpoint.com/v1/url?u=http://www.apache.org/licenses/LICENSE-2.0&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=pEkjsHfytvHEWufeZPpgqSOJMdMjuZPbesVsNhCUc0E%3D%0A&m=H8lj6jOEoXzv4McfmlSY9kuHTSI9B8Vs62Ca%2B0h40AM%3D%0A&s=64ba0a530a096f7102e7018896864cac04b51d2076865b7f8110987aef75f1cd
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+
+#ifdef _WIN32
+#undef snprintf
+#undef vsnprintf
+
+int
+ovs_snprintf(char *s, size_t n, const char *format, ... )
+{
+ va_list args;
+ int len;
+
+ va_start(args, format);
+ len = ovs_vsnprintf(s, n, format, args);
+ va_end(args);
+
+ return len;
+}
+
+int
+ovs_vsnprintf(char *s, size_t n, const char *format, va_list args)
+{
+ int needed = _vscprintf(format, args);
+ if (s && n) {
+ vsnprintf(s, n, format, args);
+ s[n - 1] = '\0';
+ }
+ return needed;
+}
+#endif /* _WIN32 */
diff --git a/lib/stdio.h.in b/lib/stdio.h.in
new file mode 100644
index 0000000..3bf1f03
--- /dev/null
+++ b/lib/stdio.h.in
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2013 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * https://urldefense.proofpoint.com/v1/url?u=http://www.apache.org/licenses/LICENSE-2.0&k=oIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=pEkjsHfytvHEWufeZPpgqSOJMdMjuZPbesVsNhCUc0E%3D%0A&m=H8lj6jOEoXzv4McfmlSY9kuHTSI9B8Vs62Ca%2B0h40AM%3D%0A&s=64ba0a530a096f7102e7018896864cac04b51d2076865b7f8110987aef75f1cd
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#@INCLUDE_NEXT@ @NEXT_STDIO_H@
+
+#if !defined STDIO_H_WRAPPER
+#define STDIO_H_WRAPPER 1
+
+#ifdef _WIN32
+
+#include <stdarg.h>
+#include <stddef.h>
+
+/* Windows libc has defective snprintf() and vsnprintf():
+ *
+ * - They return -1 if the output won't fit.
+ *
+ * - They don't null-terminate the output if it won't fit.
+ *
+ * We need working versions so here we define substitutes. */
+#undef snprintf
+#define snprintf ovs_snprintf
+int ovs_snprintf(char *, size_t, const char *, ...);
+
+#undef vsnprintf
+#define vsnprintf ovs_vsnprintf
+int ovs_vsnprintf(char *, size_t, const char *, va_list);
+#endif /* _WIN32 */
+
+#endif /* stdio.h wrapper */
diff --git a/tests/library.at b/tests/library.at
index 57cdd6c..b0ccd40 100644
--- a/tests/library.at
+++ b/tests/library.at
@@ -181,3 +181,7 @@ AT_CHECK([sed 's/.*: //
])
AT_CLEANUP
+
+AT_SETUP([snprintf])
+AT_CHECK([test-util snprintf])
+AT_CLEANUP
diff --git a/tests/test-util.c b/tests/test-util.c
index 9152562..363abb1 100644
--- a/tests/test-util.c
+++ b/tests/test-util.c
@@ -1013,6 +1013,23 @@ test_ovs_scan(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
ovs_assert(sscanf("0x12-3]xyz", "%[^-a-f]", str));
ovs_assert(!strcmp(str, "0x12"));
}
+
+static void
+test_snprintf(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
+{
+ char s[16];
+
+ ovs_assert(snprintf(s, 4, "abcde") == 5);
+ ovs_assert(!strcmp(s, "abc"));
+
+ ovs_assert(snprintf(s, 5, "abcde") == 5);
+ ovs_assert(!strcmp(s, "abcd"));
+
+ ovs_assert(snprintf(s, 6, "abcde") == 5);
+ ovs_assert(!strcmp(s, "abcde"));
+
+ ovs_assert(snprintf(NULL, 0, "abcde") == 5);
+}
?
static const struct command commands[] = {
{"ctz", 0, 0, test_ctz},
@@ -1028,6 +1045,7 @@ static const struct command commands[] = {
{"follow-symlinks", 1, INT_MAX, test_follow_symlinks},
{"assert", 0, 0, test_assert},
{"ovs_scan", 0, 0, test_ovs_scan},
+ {"snprintf", 0, 0, test_snprintf},
{NULL, 0, 0, NULL},
};
--
1.7.10.4
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