b.sh: Add a build option for address sanitizer. When enabled, we turn on some compatibility options to make it work right.

CMakeLists.txt

@@ -114,6 +114,7 @@ option(SIMULATOR "Set to ON when targeting an x86 simulator of an ARM platform"
 option(USE_FFMPEG "Build with FFMPEG support" ${USE_FFMPEG})
 option(USE_SYSTEM_FFMPEG "Dynamically link against system FFMPEG" ${USE_SYSTEM_FFMPEG})
 option(USE_WAYLAND_WSI "Set to ON to require Wayland support for Vulkan" ${USE_WAYLAND_WSI})
+option(USE_ADDRESS_SANITIZER "Use Clang memory sanitizer" ${USE_ADDRESS_SANITIZER})
 
 if(UNIX AND NOT (APPLE OR ANDROID) AND VULKAN)
 	add_definitions(-DVK_USE_PLATFORM_XLIB_KHR)
@@ -214,6 +215,13 @@ if(NOT MSVC)
 		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-switch -Wno-uninitialized")
 	endif()
 
+	if(USE_ADDRESS_SANITIZER)
+		message("Address sanitizer enabled (DEBUG only)")
+		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} -fsanitize=address")
+		set(CMAKE_LINKER_FLAGS_DEBUG "${CMAKE_LINKER_FLAGS_DEBUG} -fsanitize=address")
+		add_definitions(-DUSE_ADDRESS_SANITIZER)
+	endif()
+
 	set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g -D_DEBUG")
 	set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} -Os -D_NDEBUG")
 	set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -D_NDEBUG")

Common/MemArenaPosix.cpp

@@ -102,7 +102,7 @@ void MemArena::ReleaseView(void* view, size_t size) {
 
 u8* MemArena::Find4GBBase() {
 	// Now, create views in high memory where there's plenty of space.
-#if PPSSPP_ARCH(64BIT)
+#if PPSSPP_ARCH(64BIT) && !defined(USE_ADDRESS_SANITIZER)
 	// Very precarious - mmap cannot return an error when trying to map already used pages.
 	// This makes the Windows approach above unusable on Linux, so we will simply pray...
 	return reinterpret_cast<u8*>(0x2300000000ULL);

Core/MemMap.h

@@ -83,8 +83,8 @@ extern u32 g_MemorySize;
 extern u32 g_PSPModel;
 
 // UWP has such limited memory management that we need to mask
-// even in 64-bit mode.
-#if PPSSPP_ARCH(32BIT) || PPSSPP_PLATFORM(UWP)
+// even in 64-bit mode. Also, when using the sanitizer, we need to mask as well.
+#if PPSSPP_ARCH(32BIT) || PPSSPP_PLATFORM(UWP) || USE_ADDRESS_SANITIZER
 #define MASKED_PSP_MEMORY
 #endif
 

b.sh

@@ -43,6 +43,9 @@ do
 			export CC=/usr/bin/clang
 			export CXX=/usr/bin/clang++
 			;;
+		--sanitize) echo "Enabling address-sanitizer if available"
+			CMAKE_ARGS="-DUSE_ADDRESS_SANITIZER=ON ${CMAKE_ARGS}"
+			;;
 		*) MAKE_OPT="$1 ${MAKE_OPT}"
 			;;
 	esac