[ovs-dev] [PATCH] stdio: New module, initially to provide working [v]snprintf() on Windows.
Gurucharan Shetty
shettyg at nicira.com
Mon Dec 23 22:18:56 UTC 2013
On Mon, Dec 23, 2013 at 12:52 PM, Ben Pfaff <blp at nicira.com> wrote:
> This should transparently define snprintf() and vsnprintf() wrappers for
> use on Windows.
>
> CC: Saurabh Shah <ssaurabh at vmware.com>
> Signed-off-by: Ben Pfaff <blp at nicira.com>
Needs a .gitignore entry for lib/stdio,h
> ---
> 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:
> + *
> + * http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * 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:
> + *
> + * http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * 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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