Put the main() and wmain() routines for CLI programs into a separate file.

That means that code is only in one place, rather than having copies of
it in each of those programs.

CLI programs that, on Windows, should get UTF-8 arguments rather than
arguments in the local code page should:

	include the top-level cli_main.h header;

	define the main function as real_main();

	be built with the top-level cli_main.c file.

On UN*X, cli_main.c has a main() program, and just passes the arguments
on to real_main().

On Windows, cli_main.c has a wmain() function that converts the UTF-16
arguments it's handed to UTF-8 arguments, using WideCharToMultiByte() so
that it doesn't use any functions other than those provided by the
system, and then calls real_main() with the argument count and UTF-8
arguments.

Change-Id: I8b11f01dbc5c63fce599d1bef9ad96cd92c3c01e
Reviewed-on: https://code.wireshark.org/review/31017
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 73 insertions, 0 deletions

diff --git a/cli_main.c b/cli_main.c
new file mode 100644
index 0000000000..ee5f67e93c
--- /dev/null
+++ b/cli_main.c
@@ -0,0 +1,73 @@
+/*
+ * Compile and link this with all CLI programs where the main routine
+ * should get UTF-8 arguments on Windows.  In those programs, declare
+ * the main program as real_main() rather than main().
+ *
+ * This is used in software licensed under the GPLv2, and its license MUST
+ * be compatible with that license.
+ *
+ * This is used in software licensed under the Apache 2.0 license, and its
+ * license MUST be compatible with that license.
+ *
+ * For that purpose, we use the MIT (X11) license.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "cli_main.h"
+
+#ifdef _WIN32
+#include <stdlib.h>
+#include <stdio.h>
+#include <windows.h>
+
+int
+wmain(int argc, wchar_t *wc_argv[])
+{
+	char **argv;
+	int i;
+
+	argv = (char **)malloc((argc + 1) * sizeof(char *));
+	if (argv == NULL) {
+		fprintf(stderr, "Out of memory for converted argument list\n");
+		return 2;
+	}
+	for (i = 0; i < argc; i++) {
+		/*
+		 * XXX = use WC_ERR_INVALID_CHARS rather than 0, and fail if
+		 * the argument isn't valid UTF-16?
+		 */
+		int width;
+		char *utf8_string;
+
+		width = WideCharToMultiByte(CP_UTF8, 0, wc_argv[i], -1, NULL, 0,
+		    NULL, NULL);
+		if (width == 0) {
+			fprintf(stderr, "WideCharToMultiByte failed: %d\n",
+			    width);
+			return 2;
+		}
+		utf8_string = malloc(width);
+		if (utf8_string == NULL) {
+			fprintf(stderr,
+			    "Out of memory for converted argument list\n");
+			return 2;
+		}
+		if (WideCharToMultiByte(CP_UTF8, 0, wc_argv[i], -1, utf8_string,
+		    width, NULL, NULL) == 0) {
+			fprintf(stderr, "WideCharToMultiByte failed: %d\n",
+			    width);
+			return 2;
+		}
+		argv[i] = utf8_string;
+	}
+	argv[i] = NULL;
+	return real_main(argc, argv);
+}
+#else /* _WIN32 */
+int
+main(int argc, char *argv[])
+{
+	return real_main(argc, argv);
+}
+#endif