Add VM native module loader regression coverage

CMakeLists.txt

@@ -2073,4 +2073,12 @@ if(BUILD_UNIT_TESTS)
 	target_include_directories(unit_macros PRIVATE ${CMAKE_SOURCE_DIR}/src)
 	add_test(NAME unit_macros COMMAND unit_macros)
 	set_tests_properties(unit_macros PROPERTIES LABELS "unit;validation")
+
+	add_executable(unit_vm_native_loader
+		tests/unit/test_vm_native_loader.c
+		src/qcommon/vm_native_loader.c
+	)
+	target_include_directories(unit_vm_native_loader PRIVATE ${CMAKE_SOURCE_DIR}/src)
+	add_test(NAME unit_vm_native_loader COMMAND unit_vm_native_loader)
+	set_tests_properties(unit_vm_native_loader PROPERTIES LABELS "unit;validation")
 endif()

src/qcommon/vm.c

@@ -35,6 +35,7 @@ and one exported function: Perform
 */
 
 #include "vm_local.h"
+#include "vm_native_loader.h"
 
 opcode_info_t ops[ OP_MAX ] =
 {
@@ -1720,25 +1721,20 @@ TTimo: added some verbosity in debug
 =================
 */
 static void *VM_TryLoadNativeModule( const char *moduleName, char *filename, int filenameSize ) {
-	void		*libHandle;
-
-	Com_sprintf( filename, filenameSize, "%s.so", moduleName );
-	libHandle = FS_LoadLibrary( filename );
-	if ( libHandle ) {
-		return libHandle;
-	}
+	int candidateIndex;
 
-	/* module.arch.so (e.g. client.aarch64.so, ui.x86_64.so) */
-	Com_sprintf( filename, filenameSize, "%s." ARCH_STRING DLL_EXT, moduleName );
-	libHandle = FS_LoadLibrary( filename );
-	if ( libHandle ) {
-		return libHandle;
+	for ( candidateIndex = 0; candidateIndex < VM_NATIVE_MODULE_CANDIDATE_COUNT; ++candidateIndex ) {
+		void *libHandle;
+		if ( !VM_BuildNativeModuleCandidate( moduleName, candidateIndex, filename, filenameSize ) ) {
+			continue;
+		}
+		libHandle = FS_LoadLibrary( filename );
+		if ( libHandle ) {
+			return libHandle;
+		}
 	}
 
-	/* modulearch.so (e.g. clientaarch64.so, uix86_64.so) */
-	Com_sprintf( filename, filenameSize, "%s" ARCH_STRING DLL_EXT, moduleName );
-	libHandle = FS_LoadLibrary( filename );
-	return libHandle;
+	return NULL;
 }
 
 static void * QDECL loadNative( const char *name, vmMainFunc_t *entryPoint, dllSyscall_t systemcalls ) {

src/qcommon/vm_native_loader.c

@@ -0,0 +1,21 @@
+#include "vm_native_loader.h"
+
+qboolean VM_BuildNativeModuleCandidate( const char *moduleName, int candidateIndex, char *filename, int filenameSize ) {
+	if ( !moduleName || !moduleName[0] || !filename || filenameSize <= 0 ) {
+		return qfalse;
+	}
+
+	switch ( candidateIndex ) {
+		case 0:
+			Com_sprintf( filename, filenameSize, "%s.so", moduleName );
+			return qtrue;
+		case 1:
+			Com_sprintf( filename, filenameSize, "%s." ARCH_STRING DLL_EXT, moduleName );
+			return qtrue;
+		case 2:
+			Com_sprintf( filename, filenameSize, "%s" ARCH_STRING DLL_EXT, moduleName );
+			return qtrue;
+		default:
+			return qfalse;
+	}
+}

src/qcommon/vm_native_loader.h

@@ -0,0 +1,24 @@
+#ifndef VM_NATIVE_LOADER_H
+#define VM_NATIVE_LOADER_H
+
+#include "q_shared.h"
+#include "q_platform.h"
+
+#define VM_NATIVE_MODULE_CANDIDATE_COUNT 3
+
+/*
+=================
+VM_BuildNativeModuleCandidate
+
+Build one native module filename candidate for VM loading.
+candidateIndex order is intentionally stable:
+  0 -> module.so
+  1 -> module.arch.so
+  2 -> modulearch.so
+Returns qtrue on success, qfalse when candidateIndex is out of range or
+input/output buffers are invalid.
+=================
+*/
+qboolean VM_BuildNativeModuleCandidate( const char *moduleName, int candidateIndex, char *filename, int filenameSize );
+
+#endif

tests/unit/test_vm_native_loader.c

@@ -0,0 +1,90 @@
+/*
+ * Unit test: VM native module filename candidate generation
+ * Run: ctest -R unit_vm_native_loader
+ */
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+
+#include "qcommon/vm_native_loader.h"
+
+#define ASSERT(cond, msg) do { \
+	if (!(cond)) { \
+		fprintf(stderr, "FAIL: %s\n", msg); \
+		return 1; \
+	} \
+} while (0)
+
+/*
+ * Standalone unit target shim for vm_native_loader.c:
+ * provide Com_sprintf without linking the full engine runtime.
+ */
+int QDECL Com_sprintf( char *dest, int size, const char *fmt, ... ) {
+	int written;
+	va_list args;
+
+	va_start( args, fmt );
+	written = vsnprintf( dest, (size_t)size, fmt, args );
+	va_end( args );
+
+	if ( written < 0 ) {
+		if ( size > 0 ) {
+			dest[0] = '\0';
+		}
+		return 0;
+	}
+
+	if ( written >= size && size > 0 ) {
+		dest[size - 1] = '\0';
+		return size - 1;
+	}
+
+	return written;
+}
+
+static int test_candidate_order(void) {
+	char candidate[128];
+	char expected0[128];
+	char expected1[128];
+	char expected2[128];
+
+	Com_sprintf(expected0, sizeof(expected0), "%s.so", "client");
+	Com_sprintf(expected1, sizeof(expected1), "%s." ARCH_STRING DLL_EXT, "client");
+	Com_sprintf(expected2, sizeof(expected2), "%s" ARCH_STRING DLL_EXT, "client");
+
+	ASSERT(VM_BuildNativeModuleCandidate("client", 0, candidate, sizeof(candidate)) == qtrue, "candidate 0 valid");
+	ASSERT(strcmp(candidate, expected0) == 0, "candidate 0 value");
+
+	ASSERT(VM_BuildNativeModuleCandidate("client", 1, candidate, sizeof(candidate)) == qtrue, "candidate 1 valid");
+	ASSERT(strcmp(candidate, expected1) == 0, "candidate 1 value");
+
+	ASSERT(VM_BuildNativeModuleCandidate("client", 2, candidate, sizeof(candidate)) == qtrue, "candidate 2 valid");
+	ASSERT(strcmp(candidate, expected2) == 0, "candidate 2 value");
+
+	return 0;
+}
+
+static int test_input_validation(void) {
+	char candidate[64];
+
+	ASSERT(VM_BuildNativeModuleCandidate("client", -1, candidate, sizeof(candidate)) == qfalse, "negative index invalid");
+	ASSERT(VM_BuildNativeModuleCandidate("client", VM_NATIVE_MODULE_CANDIDATE_COUNT, candidate, sizeof(candidate)) == qfalse, "out of range index invalid");
+	ASSERT(VM_BuildNativeModuleCandidate(NULL, 0, candidate, sizeof(candidate)) == qfalse, "null module invalid");
+	ASSERT(VM_BuildNativeModuleCandidate("", 0, candidate, sizeof(candidate)) == qfalse, "empty module invalid");
+	ASSERT(VM_BuildNativeModuleCandidate("client", 0, NULL, sizeof(candidate)) == qfalse, "null output invalid");
+	ASSERT(VM_BuildNativeModuleCandidate("client", 0, candidate, 0) == qfalse, "zero size invalid");
+
+	return 0;
+}
+
+int main(void) {
+	if (test_candidate_order() != 0) {
+		return 1;
+	}
+	if (test_input_validation() != 0) {
+		return 1;
+	}
+
+	printf("PASS: unit_vm_native_loader\n");
+	return 0;
+}