Add --print-equal-lines option to headless, good for context when looking at output

Core/CmdLine.cpp

@@ -173,8 +173,8 @@ static const CommandLineParam g_autoParams[] = {
 	{POFF(appendConfig), CmdParamType::String, "appendconfig", '\0', "Merge config FILE into the current configuration"},
 	{POFF(root), CmdParamType::String, "root", 'r', "Mount root directory"},
 	{POFF(stateToLoad), CmdParamType::String, "state", '\0', "Load state from specified file"},
-	{POFF(compare), CmdParamType::Bool, "compare", 'c', "Enable comparison mode"},
-	{POFF(bench), CmdParamType::Bool, "bench", 'b', "Enable benchmark mode"},
+	{POFF(compare), CmdParamType::Bool, "compare", 'c', "Enable comparison mode", CmdLineMode::Headless},
+	{POFF(bench), CmdParamType::Bool, "bench", 'b', "Enable benchmark mode", CmdLineMode::Headless},
 	{POFF(oldAtrac), CmdParamType::Bool, "old-atrac", '\0', "Use old ATRAC decoder"},
 	{POFF(log), CmdParamType::String, "log", '\0', "Output log to FILE"},
 	{POFF(screenshotFilename), CmdParamType::String, "screenshot", '\0', "Take a screenshot and save to FILE"},
@@ -188,7 +188,7 @@ static const CommandLineParam g_autoParams[] = {
 	{POFF(breakAction), CmdParamType::Enum, "break", '\0', "Set the action for break exceptions", CmdLineMode::Both, g_ExceptionActionValues, ARRAY_SIZE(g_ExceptionActionValues)},
 	{POFF(logNativeCrashes), CmdParamType::Bool, "log-native-crashes", '\0', "Log a native stack trace (Windows only) on an otherwise-unhandled crash", CmdLineMode::Both},
 	{POFF(verbose), CmdParamType::Bool, "verbose", '\0', "Enable verbose output", CmdLineMode::Both},
-
+	{POFF(printEqualLines), CmdParamType::Bool, "print-equal-lines", '\0', "Print lines that are equal during comparison", CmdLineMode::Headless},
 	// TODO: At some point we should maybe simply expose all config settings to be set directly from the command line automatically?
 };
 

Core/CmdLine.h

@@ -91,6 +91,7 @@ struct CommandLineOptions {
 	std::optional<bool> bench;
 	std::optional<bool> verbose;
 	std::optional<double> timeout;
+	std::optional<bool> printEqualLines;
 
 	std::optional<std::string> screenshotFilename;
 	std::optional<std::string> screenshotFilenameSave;

headless/Compare.cpp

@@ -189,7 +189,7 @@ std::string GetTestName(const Path &bootFilename)
 	return ChopEnd(ChopFront(ChopFront(bootFilename.ToString(), "tests/"), "pspautotests/tests/"), ".prx");
 }
 
-bool CompareOutput(const Path &bootFilename, const std::string &output, bool verbose) {
+bool CompareOutput(const Path &bootFilename, const std::string &output, bool verbose, bool printEqualLines) {
 	Path expect_filename = bootFilename.GetFileExtension() == ".prx" ? bootFilename.WithReplacedExtension(".prx", ".expected") : bootFilename.WithExtraExtension(".expected");
 	std::unique_ptr<FileLoader> expect_loader(ConstructFileLoader(expect_filename));
 
@@ -203,8 +203,14 @@ bool CompareOutput(const Path &bootFilename, const std::string &output, bool ver
 
 		bool failed = false;
 		while (expected.HasLines()) {
-			if (expected.Compare(actual))
+			std::string value = expected.Peek(0);
+			if (expected.Compare(actual)) {  // note: Compare actually advances if equal. This is pretty ugly.
+				if (printEqualLines) {
+					printf("= %s\n", value.c_str());
+				}
+				// Lines were equal.
 				continue;
+			}
 
 			if (!failed) {
 				GitHubActionsPrint("error", "Incorrect output for %s", currentTestName.c_str());
@@ -274,8 +280,8 @@ bool CompareOutput(const Path &bootFilename, const std::string &output, bool ver
 	}
 }
 
-static inline double CompareChannel(int pix1, int pix2) {
-	double diff = pix1 - pix2;
+static inline float CompareChannel(int pix1, int pix2) {
+	float diff = pix1 - pix2;
 	return diff * diff;
 }
 
@@ -284,7 +290,6 @@ static inline double ComparePixel(u32 pix1, u32 pix2) {
 	double r = CompareChannel(pix1 & 0xFF, pix2 & 0xFF);
 	double g = CompareChannel((pix1 >> 8) & 0xFF, (pix2 >> 8) & 0xFF);
 	double b = CompareChannel((pix1 >> 16) & 0xFF, (pix2 >> 16) & 0xFF);
-
 	return r + g + b;
 }
 

headless/Compare.h

@@ -30,7 +30,7 @@ Path ExpectedFromFilename(const Path &bootFilename);
 Path ExpectedScreenshotFromFilename(const Path &bootFilename);
 std::string GetTestName(const Path &bootFilename);
 
-bool CompareOutput(const Path &bootFilename, const std::string &output, bool verbose);
+bool CompareOutput(const Path &bootFilename, const std::string &output, bool verbose, bool printEqualLines);
 std::vector<u32> TranslateDebugBufferToCompare(const GPUDebugBuffer *buffer, u32 stride, u32 h);
 
 class ScreenshotComparer {

headless/Headless.cpp

@@ -251,6 +251,7 @@ struct AutoTestOptions {
 	bool compare;
 	bool verbose;
 	bool bench;
+	bool printEqualLines;
 };
 
 static bool RunAutoTest(HeadlessHost *headlessHost, CoreParameter &coreParameter, const AutoTestOptions &opt) {
@@ -355,7 +356,7 @@ static bool RunAutoTest(HeadlessHost *headlessHost, CoreParameter &coreParameter
 	}
 
 	if (opt.compare && passed) {
-		passed = CompareOutput(coreParameter.fileToStart, output, opt.verbose);
+		passed = CompareOutput(coreParameter.fileToStart, output, opt.verbose, opt.printEqualLines);
 	}
 
 	return passed;
@@ -453,6 +454,7 @@ int main(int argc, const char* argv[]) {
 	testOptions.bench = cmdLineOptions.bench.value_or(false);
 	testOptions.timeout = cmdLineOptions.timeout.value_or(std::numeric_limits<double>::infinity());
 	testOptions.verbose = cmdLineOptions.verbose.value_or(false);
+	testOptions.printEqualLines = cmdLineOptions.printEqualLines.value_or(false);
 
 	bool fullLog = false;
 	const char *stateToLoad = 0;
@@ -724,8 +726,7 @@ int main(int argc, const char* argv[]) {
 
 	if (testOptions.compare) {
 		printf("%d tests passed, %d tests failed, %d tests missing.\n", (int)passedTests.size(), (int)failedTests.size(), (int)missingTests.size());
-		if (!failedTests.empty())
-		{
+		if (!failedTests.empty()) {
 			printf("Failed tests:\n");
 			for (size_t i = 0; i < failedTests.size(); ++i) {
 				printf("  %s\n", failedTests[i].c_str());

headless/README.md

@@ -1,6 +1,6 @@
 # PPSSPPHeadless
 
-Non-interactive, headless build of PPSSPP. It boots a PSP executable, PRX, or GE frame dump (`.ppdmp`) without a GUI, outputs emulated debug text to the console, optionally captures and compares screenshots, and exits.
+Non-interactive, headless build of PPSSPP. It boots a PSP executable, PRX, or GE frame dump (`.ppdmp`) without a GUI, outputs emulated debug text to the console, optionally captures and compares text output or screenshots, and exits.
 
 Primarily intended for:
 - Automated regression testing (via [pspautotests](https://github.com/hrydgard/pspautotests/))
@@ -120,7 +120,8 @@ When the MSE exceeds `--max-mse`, the following files are saved in the working d
 The `--compare` flag also compares emulated debug output (`printf` / `sceIoWrite` to the emulator channel) against a `.expected` text file:
 
 - For `.prx` files: same path with `.expected` extension.
-- The comparison is line-based with a diff algorithm that highlights insertions/deletions.
+- The comparison is line-based with a diff algorithm that highlights mismatches and insertions/deletions, although the support for the
+  latter is limited, it's not a full-on diff.
 
 If only a screenshot reference exists and no `.expected` file, the test passes as long as there is no unexpected text output.
 
@@ -157,13 +158,14 @@ Example workflow step:
 
 The following configuration is hardcoded for headless mode (config file is never saved):
 
+(For actual up-to-date hardcoded config, see the headless.cpp file).
+
 | Setting              | Value      | Notes                                    |
 |----------------------|------------|------------------------------------------|
 | Internal resolution  | 1× (480×272) | Fixed.                                 |
 | Hardware transform   | Enabled    |                                          |
 | Vertex decoder JIT   | Enabled    |                                          |
 | Software renderer JIT| Enabled    |                                          |
-| Skip GPU readback    | No skip    | Full readback for accurate screenshots.  |
 | Ignore bad mem access| Enabled    |                                          |
 | Firmware version     | 6.60       |                                          |
 | PSP model            | Slim       |                                          |