ImDebugger: fix stale symbol list after a game is reloaded

The disasm window cached the flattened symbol list and only rebuilt it when one
of three menu items said so. Nothing marked it dirty when a game booted or
exited, and a new SymbolMap is allocated per boot, so the list kept showing the
previous game's functions.

Give SymbolMap a version counter that every mutator bumps, and let the window
compare against it instead. The counter is process-wide rather than per-map, so
a fresh map can't hand out a version a cached copy already holds.

Also re-find the selected symbol by address after a rebuild (the index means
something else afterwards), and drop the unused symbol cache members in
ImMemWindow.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01SfY7iFJEjmRXf1XGrTs4MF

UI/ImDebugger/ImDebugger.cpp

@@ -2626,12 +2626,11 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug, GPUCommon *gpuDebug, Draw:
 				ImGui::Separator();
 
 				if (ImGui::MenuItem("Load .ppmap...")) {
-					System_BrowseForFile(reqToken_, "Load PPSSPP symbol map", BrowseFileType::SYMBOL_MAP, [this](std::string_view responseString, int) {
+					System_BrowseForFile(reqToken_, "Load PPSSPP symbol map", BrowseFileType::SYMBOL_MAP, [](std::string_view responseString, int) {
 						Path path(responseString);
 						if (!g_symbolMap->LoadSymbolMap(path)) {
 							ERROR_LOG(Log::Common, "Failed to load symbol map");
 						}
-						disasm_.DirtySymbolMap();
 					});
 				}
 				if (ImGui::MenuItem("Save .ppmap...")) {
@@ -2643,12 +2642,11 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug, GPUCommon *gpuDebug, Draw:
 					});
 				}
 				if (ImGui::MenuItem("Load No$ .sym...")) {
-					System_BrowseForFile(reqToken_, "Load No$ symbol map", BrowseFileType::SYMBOL_MAP, [this](std::string_view responseString, int) {
+					System_BrowseForFile(reqToken_, "Load No$ symbol map", BrowseFileType::SYMBOL_MAP, [](std::string_view responseString, int) {
 						Path path(responseString);
 						if (!g_symbolMap->LoadNocashSym(path)) {
 							ERROR_LOG(Log::Common, "Failed to load No$ symbol map");
 						}
-						disasm_.DirtySymbolMap();
 					});
 				}
 				if (ImGui::MenuItem("Save No$ .sym...")) {
@@ -2663,7 +2661,6 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug, GPUCommon *gpuDebug, Draw:
 				ImGui::MenuItem("Compress .ppmap files", nullptr, &g_Config.bCompressSymbols);
 				if (ImGui::MenuItem("Reset symbol map")) {
 					g_symbolMap->Clear();
-					disasm_.DirtySymbolMap();
 					// NotifyDebuggerMapLoaded();
 				}
 				ImGui::EndMenu();

UI/ImDebugger/ImDisasmView.cpp

@@ -1323,18 +1323,30 @@ void ImDisasmWindow::Draw(MIPSDebugInterface *mipsDebug, ImConfig &cfg, ImContro
 	avail.y -= ImGui::GetTextLineHeightWithSpacing();
 
 	if (ImGui::BeginChild("left", ImVec2(150.0f, avail.y), ImGuiChildFlags_ResizeX)) {
-		if (symCache_.empty() || symsDirty_) {
+		if (symCacheVersion_ != g_symbolMap->Version()) {
+			// The index into symCache_ means something different after a rebuild, and nothing at
+			// all if the map was replaced (which is what happens when a game exits), so re-find
+			// the selection by address instead of carrying the index over.
+			const u32 selectedAddr = (selectedSymbol_ >= 0 && selectedSymbol_ < (int)symCache_.size()) ? symCache_[selectedSymbol_].address : (u32)INVALID_ADDR;
 			symCache_ = g_symbolMap->GetAllActiveSymbols(SymbolType::ST_FUNCTION);
-			symsDirty_ = false;
+			symCacheVersion_ = g_symbolMap->Version();
 			symMatchesDirty_ = true;
+			selectedSymbol_ = -1;
+			if (selectedAddr != INVALID_ADDR) {
+				for (int i = 0; i < (int)symCache_.size(); i++) {
+					if (symCache_[i].address == selectedAddr) {
+						selectedSymbol_ = i;
+						break;
+					}
+				}
+			}
 		}
 
-		if (selectedSymbol_ >= 0 && selectedSymbol_ < symCache_.size()) {
+		if (selectedSymbol_ >= 0 && selectedSymbol_ < (int)symCache_.size()) {
 			auto &sym = symCache_[selectedSymbol_];
 			if (ImGui::TreeNode("Edit Symbol", "Edit %s", sym.name.c_str())) {
 				if (ImGui::InputText("Name", selectedSymbolName_, sizeof(selectedSymbolName_), ImGuiInputTextFlags_EnterReturnsTrue)) {
 					g_symbolMap->SetLabelName(selectedSymbolName_, sym.address);
-					symsDirty_ = true;
 				}
 				ImGui::Text("%08x (size: %0d)", sym.address, sym.size);
 				ImGui::TreePop();

UI/ImDebugger/ImDisasmView.h

@@ -202,9 +202,6 @@ public:
 	void NotifyStep() {
 		disasmView_.NotifyStep();
 	}
-	void DirtySymbolMap() {
-		symsDirty_ = true;
-	}
 	const char *Title() const {
 		return "CPU Debugger";
 	}
@@ -218,9 +215,11 @@ private:
 
 	u32 gotoAddr_ = 0x08800000;
 
-	// Symbol cache
+	// Symbol cache. Rebuilt whenever the symbol map's version no longer matches the one the
+	// cache was built from - that covers the map being replaced wholesale when a game boots or
+	// exits, not just edits made from here.
 	std::vector<SymbolEntry> symCache_;
-	bool symsDirty_ = true;
+	uint32_t symCacheVersion_ = 0;
 	int selectedSymbol_ = -1;
 	char selectedSymbolName_[128];
 

UI/ImDebugger/ImMemView.h

@@ -180,9 +180,6 @@ public:
 	ImMemView &View() {
 		return memView_;
 	}
-	void DirtySymbolMap() {
-		symsDirty_ = true;
-	}
 	void GotoAddr(u32 addr) {
 		gotoAddr_ = addr;
 		memView_.gotoAddr(addr);
@@ -195,11 +192,6 @@ private:
 		INVALID_ADDR = 0xFFFFFFFF,
 	};
 	void ProcessKeyboardShortcuts();
-	// Symbol cache
-	std::vector<SymbolEntry> symCache_;
-	bool symsDirty_ = true;
-	int selectedSymbol_ = -1;
-	char selectedSymbolName_[128];
 
 	bool drawZeroDark_ = false;
 	bool editableMemory_ = false;