Headless: refuse a run that can't honour an explicit --disable-hle

When the firmware module a --disable-hle bit asks for is neither installed nor
on the disc, that library silently runs our HLE instead. For the emulator that
is the right thing; for a test tool it means the run measures something other
than what was asked for and says so only as one INFO line, which is easy to
grep past and easy to never see. It cost a round of wrong results here, where
the memory stick headless defaults to (beside the exe, not the app's) had no
firmware, so a comparison against the real mpeg.prx was quietly a comparison
against the HLE it was supposed to be measured against.

g_unavailableDisableFlags already records exactly which flags fell back, so it
just needed an accessor. Headless now names each one, prints the flash0:/kd and
memory stick it looked in, and fails the run.

Only an explicit --disable-hle binds. sceMpeg and sceMp4 are LLE by default, and
falling back is the correct and expected behaviour wherever no firmware is
installed - making that fatal would fail every run on such a machine.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

headless/Headless.cpp

@@ -55,6 +55,7 @@
 #include "Core/Core.h"
 #include "Core/CoreTiming.h"
 #include "Core/EmuThread.h"
+#include "Core/HLE/HLE.h"
 #include "Core/MIPS/MIPSTables.h"
 #include "Core/System.h"
 #include "Core/Util/PSARUnpack.h"
@@ -83,6 +84,9 @@ static bool g_screenshotSaved = false;
 static double g_maxScreenshotError = 0.0;
 static bool g_screenshotFailed = false;
 static std::string g_debugOutputBuffer;
+// Set when a run was asked for a configuration that couldn't be honoured. That isn't a test result,
+// so it fails the process whether or not this run was comparing anything.
+static bool g_configRefused = false;
 static bool g_writeFailureScreenshot = true;
 static bool g_writeDebugOutput = true;
 // Whether the emulated program's stdout/stderr are forwarded to ours. On by default - just running
@@ -325,6 +329,10 @@ struct AutoTestOptions {
 	bool verbose;
 	bool bench;
 	bool printEqualLines;
+	// What --disable-hle asked for, or 0 if it was not passed. Only an explicit request binds:
+	// sceMpeg and sceMp4 run the firmware module by default now and fall back to the HLE wherever
+	// none is installed, which must not fail every run on such a machine.
+	int requiredDisableHLE;
 };
 
 static bool RunAutoTest(GraphicsContext *graphicsContext, CoreParameter &coreParameter, const AutoTestOptions &opt) {
@@ -364,6 +372,29 @@ static bool RunAutoTest(GraphicsContext *graphicsContext, CoreParameter &corePar
 		return false;
 	}
 
+	// Running a different configuration than the one asked for measures the wrong thing without
+	// saying so, which is worse in a test tool than not running at all.
+	const int missingHLE = (int)HLEGetUnavailableDisableFlags() & opt.requiredDisableHLE;
+	if (missingHLE) {
+		for (int i = 0; i < (int)DisableHLEFlags::Count; i++) {
+			if (!(missingHLE & (1 << i))) {
+				continue;
+			}
+			const HLEModuleMeta *meta = GetHLEModuleMetaByFlag((DisableHLEFlags)(1 << i));
+			fprintf(stderr, "--disable-hle asked for %s, but no firmware module for it is installed "
+				"or on the disc - our HLE would run instead.\n", meta ? meta->modname : "an unknown module");
+		}
+		// Nearly always because headless defaulted the memory stick to one beside the exe rather than
+		// the app's, so the firmware installed through the app isn't the firmware it looked at.
+		fprintf(stderr, "Looked in %s (memory stick %s).\n",
+			(g_Config.nandRootDirectory / "flash0" / "kd").c_str(), g_Config.memStickDirectory.c_str());
+		GitHubActionsPrint("error", "Requested --disable-hle unavailable for %s", currentTestName.c_str());
+		g_configRefused = true;
+		// Booted, so it has to come down the same way a finished run does.
+		PSP_Shutdown(true);
+		return false;
+	}
+
 	System_Notify(SystemNotification::BOOT_DONE);
 
 	PSP_UpdateDebugStats((DebugOverlay)g_Config.iDebugOverlay == DebugOverlay::DEBUG_STATS || g_Config.bLogFrameDrops);
@@ -607,6 +638,10 @@ int RunTests(GraphicsContext *graphicsContext, CoreParameter &coreParameter, con
 		}
 	}
 
+	if (g_configRefused) {
+		return 1;
+	}
+
 	return 0;
 }
 
@@ -668,6 +703,7 @@ int main(int argc, const char* argv[]) {
 	testOptions.verbose = cmdLineOptions.verbose.value_or(false);
 	testOptions.printEqualLines = cmdLineOptions.printEqualLines.value_or(false);
 	testOptions.maxScreenshotError = cmdLineOptions.maxScreenshotError.value_or(0.0);
+	testOptions.requiredDisableHLE = cmdLineOptions.disableHLE.value_or(0);
 
 	bool fullLog = cmdLineOptions.enableLogging.value_or(false);
 	const char *stateToLoad = cmdLineOptions.stateToLoad.has_value() ? cmdLineOptions.stateToLoad.value().c_str() : nullptr;