wat2wasm: Always write output to a file (#682)

This involves deriving the output filename from the input
filename when none is otherwise specified.

Also split out filename handling utilities and add unittests
for them.

1 files changed, 51 insertions, 0 deletions

diff --git a/src/filenames.h b/src/filenames.h
new file mode 100644
index 00000000..87529aa2
--- /dev/null
+++ b/src/filenames.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2016 WebAssembly Community Group participants
+ *
+ * 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.
+ */
+
+#ifndef WABT_FILENAMES_H_
+#define WABT_FILENAMES_H_
+
+#include "src/common.h"
+
+namespace wabt {
+
+extern const char* kWasmExtension;
+extern const char* kWatExtension;
+
+// Return only the file extension, e.g.:
+//
+// "foo.txt", => ".txt"
+// "foo" => ""
+// "/foo/bar/foo.wasm" => ".wasm"
+string_view GetExtension(string_view filename);
+
+// Strip extension, e.g.:
+//
+// "foo", => "foo"
+// "foo.bar" => "foo"
+// "/path/to/foo.bar" => "/path/to/foo"
+// "\\path\\to\\foo.bar" => "\\path\\to\\foo"
+string_view StripExtension(string_view s);
+
+// Strip everything up to and including the last slash, e.g.:
+//
+// "/foo/bar/baz", => "baz"
+// "/usr/local/include/stdio.h", => "stdio.h"
+// "foo.bar", => "foo.bar"
+string_view GetBasename(string_view filename);
+
+}  // namespace wabt
+
+#endif /* WABT_FILENAMES_H_ */