From 067c9240c3ff5a4e1727ddba015c7b5b19fbae70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Mangano-Tarumi?= <fmang@mg0.fr>
Date: Sat, 1 Dec 2018 12:02:19 -0500
Subject: [PATCH] proces_options -> parse_options

The function is not supposed to have side effects anymore.
---
 src/cli.cc      |  7 +++---
 src/opustags.cc |  4 ++--
 src/opustags.h  | 61 +++++++++++++++++++++++--------------------------
 3 files changed, 34 insertions(+), 38 deletions(-)

diff --git a/src/cli.cc b/src/cli.cc
index ba201d1..e4e2972 100644
--- a/src/cli.cc
+++ b/src/cli.cc
@@ -52,8 +52,9 @@ static struct option getopt_options[] = {
 	{NULL, 0, 0, 0}
 };
 
-ot::status ot::process_options(int argc, char** argv, ot::options& opt)
+ot::status ot::parse_options(int argc, char** argv, ot::options& opt)
 {
+	opt = {};
 	if (argc == 1)
 		return {st::bad_arguments, "No arguments specified. Use -h for help."};
 
@@ -99,7 +100,7 @@ ot::status ot::process_options(int argc, char** argv, ot::options& opt)
 			break;
 		case 'S':
 			opt.set_all = true;
-			/* fall through */
+			break;
 		case 'D':
 			opt.delete_all = true;
 			break;
@@ -266,7 +267,7 @@ static bool same_file(const std::string& path_in, const std::string& path_out)
 	return false;
 }
 
-ot::status ot::run(ot::options& opt)
+ot::status ot::run(const ot::options& opt)
 {
 	if (opt.print_help) {
 		fputs(help_message, stdout);
diff --git a/src/opustags.cc b/src/opustags.cc
index 581326c..c00f3d4 100644
--- a/src/opustags.cc
+++ b/src/opustags.cc
@@ -14,9 +14,9 @@
  */
 int main(int argc, char** argv) {
 	ot::options opt;
-	ot::status rc = process_options(argc, argv, opt);
+	ot::status rc = ot::parse_options(argc, argv, opt);
 	if (rc == ot::st::ok)
-		rc = run(opt);
+		rc = ot::run(opt);
 
 	if (rc != ot::st::ok) {
 		if (!rc.message.empty())
diff --git a/src/opustags.h b/src/opustags.h
index 5f92eaa..b11a7e5 100644
--- a/src/opustags.h
+++ b/src/opustags.h
@@ -350,9 +350,16 @@ void delete_comments(opus_tags& tags, const char* field_name);
  */
 
 /**
- * Structured representation of the arguments to opustags.
+ * Structured representation of the command-line arguments to opustags. It must faithfully represent
+ * what the user asked for, with as little interpretation or deduction as possible.
  */
 struct options {
+	/**
+	 * When true, opustags prints a detailed help and exits. All the other options are ignored.
+	 *
+	 * Option: --help
+	 */
+	bool print_help = false;
 	/**
 	 * Path to the input file. It cannot be empty. The special "-" string means stdin.
 	 *
@@ -373,6 +380,12 @@ struct options {
 	 * Option: --in-place
 	 */
 	const char* inplace = nullptr;
+	/**
+	 * By default, opustags won't overwrite the output file if it already exists.
+	 *
+	 * Option: --overwrite
+	 */
+	bool overwrite = false;
 	/**
 	 * List of field names to delete. `{"ARTIST"}` will delete *all* the comments `ARTIST=*`. It
 	 * is currently case-sensitive. When #delete_all is true, it becomes meaningless.
@@ -386,6 +399,12 @@ struct options {
 	 * Option: --delete, --set
 	 */
 	std::vector<std::string> to_delete;
+	/**
+	 * Delete all the existing comments.
+	 *
+	 * Option: --delete-all
+	 */
+	bool delete_all = false;
 	/**
 	 * List of comments to add, in the current system encoding. For exemple `TITLE=a b c`. They
 	 * must be valid.
@@ -393,50 +412,26 @@ struct options {
 	 * Options: --add, --set, --set-all
 	 */
 	std::vector<std::string> to_add;
-	/**
-	 * Delete all the existing comments.
-	 *
-	 * Option: --delete-all
-	 */
-	bool delete_all = false;
 	/**
 	 * Replace the previous comments by the ones supplied by the user.
 	 *
-	 * Read a list of comments from stdin and populate #to_add. Implies #delete_all. Further
-	 * comments may be added with the --add option.
+	 * Read a list of comments from stdin and populate #to_add. Further comments may be added
+	 * with the --add option.
 	 *
 	 * Option: --set-all
 	 */
 	bool set_all = false;
-	/**
-	 * By default, opustags won't overwrite the output file if it already exists.
-	 *
-	 * Option: --overwrite
-	 */
-	bool overwrite = false;
-	/**
-	 * When true, opustags prints a detailed help and exits. All the other options are ignored.
-	 *
-	 * Option: --help
-	 */
-	bool print_help = false;
 };
 
 /**
- * Process the command-line arguments.
+ * Parse the command-line arguments. Does not perform I/O related validations, but checks the
+ * consistency of its arguments.
  *
- * This function does not perform I/O related validations, but checks the consistency of its
- * arguments.
+ * On error, the state of the options structure is unspecified.
  *
- * It returns one of :
- * - #ot::st::ok, meaning the process may continue normally.
- *   This happens when all the user wants is see the help or usage.
- * - #ot::st::bad_arguments, meaning the arguments were invalid and the process should exit with
- *   an error.
- *
- * Help messages are written on standard output, and error messages on standard error.
+ * \todo Return error messages in the status instead of writing them to stderr.
  */
-status process_options(int argc, char** argv, options& opt);
+status parse_options(int argc, char** argv, options& opt);
 
 /**
  * Print all the comments, separated by line breaks. Since a comment may
@@ -466,7 +461,7 @@ status process(ogg_reader& reader, ogg_writer* writer, const options &opt);
  * This is the main entry point to the opustags program, and pretty much the same as calling
  * opustags from the command-line.
  */
-status run(options& opt);
+status run(const options& opt);
 
 /** \} */