t/helper: add an empty test-tool program

This will become an umbrella program that absorbs most [1] t/helper
programs in. By having a single executable binary we reduce disk usage
(libgit.a is replicated by every t/helper program) and shorten link
time a bit.

Running "make --jobs=1; du -sh t/helper" with ccache fully populated,
it takes 27 seconds and 277MB at the beginning of this series, 17
seconds and 42MB at the end.

[1] There are a couple programs that will not become part of
    test-tool: test-line-buffer and test-svn-fe have extra
    dependencies and test-fake-ssh's program name has to be a single
    word for some ssh tests.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 31 insertions, 0 deletions

diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
new file mode 100644
index 0000000000..da1dd6621c
--- /dev/null
+++ b/t/helper/test-tool.c
@@ -0,0 +1,27 @@
+#include "git-compat-util.h"
+#include "test-tool.h"
+
+struct test_cmd {
+	const char *name;
+	int (*fn)(int argc, const char **argv);
+};
+
+static struct test_cmd cmds[] = {
+};
+
+int cmd_main(int argc, const char **argv)
+{
+	int i;
+
+	if (argc < 2)
+		die("I need a test name!");
+
+	for (i = 0; i < ARRAY_SIZE(cmds); i++) {
+		if (!strcmp(cmds[i].name, argv[1])) {
+			argv++;
+			argc--;
+			return cmds[i].fn(argc, argv);
+		}
+	}
+	die("There is no test named '%s'", argv[1]);
+}
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
new file mode 100644
index 0000000000..6ce57ae0cc
--- /dev/null
+++ b/t/helper/test-tool.h
@@ -0,0 +1,4 @@
+#ifndef __TEST_TOOL_H__
+#define __TEST_TOOL_H__
+
+#endif