Call the new command line parser from all backends

Core/CmdLine.cpp

@@ -2,7 +2,59 @@
 #include "Core/CmdLine.h"
 #include "Common/StringUtils.h"
 
-void CommandLineOptions::Parse(int argc, const char *argv[]) {
+static int printUsage(int argc, const char *argv[]) {
+	// NOTE: by convention, --help outputs to stdout,
+	// not to stderr, since it is intended output in this
+	// case (usage printed under different circumstances,
+	// say in response to error during parsing commandline,
+	// may go to stderr).
+	FILE *dst = stdout;
+
+	const char *progname = argc > 0 ? argv[0] : "ppsspp";
+	// NOTE: wording largely taken from
+	// https://www.ppsspp.org/docs/reference/command-line/
+	fprintf(dst, "PPSSPP - a PSP emulator (SDL build)\n");
+	fprintf(dst, "Usage: %s [options] [FILE]\n\n", progname);
+	fprintf(dst, "Launches FILE (e.g. ISO image) if present.\n");
+	fprintf(dst, "Options (some of these are specific to SDL backend):\n");
+	fprintf(dst, "  -h, --help            show this message and exit\n");
+	fprintf(dst, "  --version             show version information and exit\n");
+
+	fprintf(dst, "  -d                    set the log level to debug\n");
+	fprintf(dst, "  -v                    set the log level to verbose\n");
+	fprintf(dst, "  --loglevel=INTEGER    set the log level to specified value\n");
+	fprintf(dst, "  --log=FILE            output log to FILE\n");
+	fprintf(dst, "  --state=FILE          load state from FILE\n");
+
+	fprintf(dst, "  -i                    use the interpreter\n");
+	fprintf(dst, "  -r                    use IR interpreter\n");
+	fprintf(dst, "  -j                    use JIT\n");
+	fprintf(dst, "  -J                    use IR JIT\n");
+
+	fprintf(dst, "  --fullscreen          force full screen mode, ignoring saved configuration\n");
+	fprintf(dst, "  --windowed            force windowed mode, ignoring saved configuration\n");
+	fprintf(dst, "  --xres PIXELS         set X resolution\n");
+	fprintf(dst, "  --yres PIXELS         set Y resolution\n");
+	fprintf(dst, "  --dpi  FACTOR         set DPI\n");
+	fprintf(dst, "  --scale FACTOR        set scale\n");
+	fprintf(dst, "  --ipad                set resolution to 1024x768\n");
+	fprintf(dst, "  --portrait            portrait mode\n");
+	fprintf(dst, "  --graphics=BACKEND    use a different gpu backend\n");
+	fprintf(dst, "                        options: gles, software, etc. (also opengl3.1, etc.)\n");
+
+	fprintf(dst, "  --pause-menu-exit     change \"Exit to menu\" in pause menu to \"Exit\"\n");
+	fprintf(dst, "  --escape-exit         escape key exits the application\n");
+	fprintf(dst, "  --gamesettings        go directly to settings\n");
+	fprintf(dst, "  --touchscreentest     go directly to the touchscreentest screen\n");
+	fprintf(dst, "  --appendconfig=FILE   merge config FILE into the current configuration\n");
+
+	return 0;
+}
+
+// Logging should be done with plain printf here.
+// Error reporting is done with fprintf(stderr, ....).
+// Actually might want to reconsider given Android...
+CommandLineParseResult CommandLineOptions::Parse(int argc, const char *argv[]) {
 	constexpr std::string_view gpuBackendStr = "--graphics=";
 	constexpr std::string_view configOption = "--config=";
 	constexpr std::string_view controlsOption = "--controlconfig=";
@@ -12,10 +64,18 @@ void CommandLineOptions::Parse(int argc, const char *argv[]) {
 #endif
 
 	// The rest is handled in NativeInit().
-	for (size_t i = 1; i < argc; ++i) {
+	// NOTE: We don't increment i here, as we'll sometimes handle options that read the next argument.
+	for (size_t i = 1; i < argc; ) {
 		const size_t len = strlen(argv[i]);
-		if (argv[i][0] != '-' || len < 2) {
-			continue;
+
+		if (len > 0 && argv[i][0] != '-') {
+			// This is a filename to boot.
+			if (!bootFilename.has_value()) {
+				bootFilename = std::string(argv[i]);
+			} else {
+				// Already have a filename.
+				fprintf(stderr, "Warning: Ignoring extra boot filename '%s'.\n", argv[i]);
+			}
 		}
 
 		// single char commands, like -l, -s, -d
@@ -31,19 +91,36 @@ void CommandLineOptions::Parse(int argc, const char *argv[]) {
 			case 'd':
 				debugLogLevel = true;
 				break;
+			case 'h':
+				printUsage(argc, argv);
+				return CommandLineParseResult::Exit;
+			case 'v':
+				printf("%s\n", PPSSPP_GIT_VERSION);
+				return CommandLineParseResult::Exit;
 			}
 		}
 
+#if defined(__APPLE__)
+		// On Apple system debugged executable may get -NSDocumentRevisionsDebugMode YES in argv.
+		if (equals(argv[i], "-NSDocumentRevisionsDebugMode")) {
+			// Ignore
+		}
+#endif
 		// Simple bool commands
 
 		// NOTE: We need to parse --fullscreen early, before we create the window.
-		if (equals(argv[i], "--fullscreen")) {
+		if (equals(argv[i], "--help")) {
+			printUsage(argc, argv);
+			return CommandLineParseResult::Exit;
+		} else if (equals(argv[i], "--version")) {
+			printf("%s\n", PPSSPP_GIT_VERSION);
+			return CommandLineParseResult::Exit;
+		} else if (equals(argv[i], "--fullscreen")) {
 			fullscreen = true;
 		} else if (equals(argv[i], "--windowed")) {
 			fullscreen = false;
-		}
 		// Commands with parameters. TODO: Should support both space and equals, like --config=foo.ini and --config foo.ini
-		if (startsWith(argv[i], gpuBackendStr)) {
+		} else if (startsWith(argv[i], gpuBackendStr)) {
 			const std::string_view restOfOption = argv[i] + gpuBackendStr.size();
 			// Force software rendering off, as picking gles implies HW acceleration.
 			// We could add more options for software such as "software-gles",
@@ -66,8 +143,14 @@ void CommandLineOptions::Parse(int argc, const char *argv[]) {
 			configFilename = std::string(argv[i] + configOption.size());
 		} else if (startsWith(argv[i], controlsOption)) {
 			controlsConfigFilename = std::string(argv[i] + controlsOption.size());
+		} else {
+			// Report unknown argument later once this is complete.
 		}
+
+		// To the next argument.
+		i++;
 	}
+	return CommandLineParseResult::Continue;
 }
 
 void CommandLineOptions::ApplyToConfig() const {