eal/windows: hide asprintf shim

Make asprintf(3) implementation for Windows private to EAL, so that it's
hidden from external consumers. It is not exposed to internal consumers
either, because they don't need asprintf() and also because callers from
other modules would have no reliable way to free allocated memory.

Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Acked-by: Khoa To <khot@microsoft.com>
Acked-by: Nick Connolly <nick.connolly@mayadata.io>
Acked-by: Ranjit Menon <ranjit.menon@intel.com>

lib/librte_eal/common/eal_private.h

@@ -716,4 +716,15 @@ void __rte_thread_init(unsigned int lcore_id, rte_cpuset_t *cpuset);
  */
 void __rte_thread_uninit(void);
 
+/**
+ * asprintf(3) replacement for Windows.
+ */
+#ifdef RTE_EXEC_ENV_WINDOWS
+__rte_format_printf(2, 3)
+int eal_asprintf(char **buffer, const char *format, ...);
+
+#define asprintf(buffer, format, ...) \
+		eal_asprintf(buffer, format, ##__VA_ARGS__)
+#endif
+
 #endif /* _EAL_PRIVATE_H_ */

lib/librte_eal/windows/eal.c

@@ -2,6 +2,8 @@
  * Copyright(c) 2019 Intel Corporation
  */
 
+#include <stdarg.h>
+
 #include <fcntl.h>
 #include <io.h>
 #include <share.h>
@@ -416,6 +418,34 @@ rte_eal_init(int argc, char **argv)
 	return fctret;
 }
 
+/* Don't use MinGW asprintf() to have identical code with all toolchains. */
+int
+eal_asprintf(char **buffer, const char *format, ...)
+{
+	int size, ret;
+	va_list arg;
+
+	va_start(arg, format);
+	size = vsnprintf(NULL, 0, format, arg);
+	va_end(arg);
+	if (size < 0)
+		return -1;
+	size++;
+
+	*buffer = malloc(size);
+	if (*buffer == NULL)
+		return -1;
+
+	va_start(arg, format);
+	ret = vsnprintf(*buffer, size, format, arg);
+	va_end(arg);
+	if (ret != size - 1) {
+		free(*buffer);
+		return -1;
+	}
+	return ret;
+}
+
 int
 rte_vfio_container_dma_map(__rte_unused int container_fd,
 			__rte_unused uint64_t vaddr,

lib/librte_eal/windows/include/rte_os.h

@@ -10,7 +10,6 @@
  * which is not supported natively or named differently in Windows.
  */
 
-#include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -71,34 +70,6 @@ extern "C" {
 typedef long long ssize_t;
 
 #ifndef RTE_TOOLCHAIN_GCC
-
-static inline int
-asprintf(char **buffer, const char *format, ...)
-{
-	int size, ret;
-	va_list arg;
-
-	va_start(arg, format);
-	size = vsnprintf(NULL, 0, format, arg);
-	va_end(arg);
-	if (size < 0)
-		return -1;
-	size++;
-
-	*buffer = (char *)malloc(size);
-	if (*buffer == NULL)
-		return -1;
-
-	va_start(arg, format);
-	ret = vsnprintf(*buffer, size, format, arg);
-	va_end(arg);
-	if (ret != size - 1) {
-		free(*buffer);
-		return -1;
-	}
-	return ret;
-}
-
 static inline const char *
 eal_strerror(int code)
 {
@@ -111,7 +82,6 @@ eal_strerror(int code)
 #ifndef strerror
 #define strerror eal_strerror
 #endif
-
 #endif /* RTE_TOOLCHAIN_GCC */
 
 #ifdef __cplusplus