[dpdk-stable] [PATCH] eal/windows: use bundled getopt with MinGW

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

Clang builds use getopt.c in librte_eal while MinGW provides
implementation as part of the toolchain. Statically linking librte_eal
to an application that depends on getopt results in undefined reference
errors with MinGW. There are no such errors with Clang, because with
Clang librte_eal actually defines getopt functions.

Use getopt.c in EAL with Clang and MinGW to get identical behavior.
Adjust code for MinGW. Incidentally, this removes a bug when free() is
called on uninitialized memory.

Fixes: 5e373e456e6 ("eal/windows: add getopt implementation")
Cc: stable@dpdk.org

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Reported-by: Khoa To <khot@microsoft.com>
Reported-by: Tal Shnaiderman <talshn@nvidia.com>
---

This patch probably supesedes http://patchwork.dpdk.org/patch/78574/.

 lib/librte_eal/meson.build      | 3 ---
 lib/librte_eal/windows/getopt.c | 9 ++++-----
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/lib/librte_eal/meson.build b/lib/librte_eal/meson.build
index 8d492897d..7d6222e78 100644
--- a/lib/librte_eal/meson.build
+++ b/lib/librte_eal/meson.build
@@ -25,6 +25,3 @@ endif
 if cc.has_function('getentropy', prefix : '#include <unistd.h>')
 	cflags += '-DRTE_LIBEAL_USE_GETENTROPY'
 endif
-if cc.has_header('getopt.h')
-	cflags += ['-DHAVE_GETOPT_H', '-DHAVE_GETOPT', '-DHAVE_GETOPT_LONG']
-endif
diff --git a/lib/librte_eal/windows/getopt.c b/lib/librte_eal/windows/getopt.c
index a08f7c109..a1f51c6c2 100644
--- a/lib/librte_eal/windows/getopt.c
+++ b/lib/librte_eal/windows/getopt.c
@@ -242,7 +242,6 @@ getopt_internal(int nargc, char **nargv, const char *options,
 	char *oli;				/* option letter list index */
 	int optchar, short_too;
 	static int posixly_correct = -1;
-	char *buf;
 	size_t len;
 	int optreset = 0;
 
@@ -253,16 +252,16 @@ getopt_internal(int nargc, char **nargv, const char *options,
 	 * Disable GNU extensions if POSIXLY_CORRECT is set or options
 	 * string begins with a '+'.
 	 */
-	if (posixly_correct == -1)
-		posixly_correct = _dupenv_s(&buf, &len, "POSIXLY_CORRECT");
+	if (posixly_correct == -1) {
+		errno_t err = _wgetenv_s(&len, NULL, 0, L"POSIXLY_CORRECT");
+		posixly_correct = (err == 0) && (len > 0);
+	}
 	if (!posixly_correct || *options == '+')
 		flags &= ~FLAG_PERMUTE;
 	else if (*options == '-')
 		flags |= FLAG_ALLARGS;
 	if (*options == '+' || *options == '-')
 		options++;
-	if (!posixly_correct)
-		free(buf);
 	/*
 	 * reset if requested
 	 */
-- 
2.25.4