Test add address sanitizer to arena

code/arena.c

@@ -33,6 +33,40 @@ MA_API void MA_MemoryCopy(void *dst, void *src, size_t size) {
     #endif
 #endif
 
+// Marks memory region [addr, addr+size) as unaddressable.
+// This memory must be previously allocated by the user program. Accessing
+// addresses in this region from instrumented code is forbidden until
+// this region is unpoisoned. This function is not guaranteed to poison
+// the whole region - it may poison only subregion of [addr, addr+size) due
+// to ASan alignment restrictions.
+// Method is NOT thread-safe in the sense that no two threads can
+// (un)poison memory in the same memory region simultaneously.
+void __asan_poison_memory_region(void const volatile *addr, size_t size);
+// Marks memory region [addr, addr+size) as addressable.
+// This memory must be previously allocated by the user program. Accessing
+// addresses in this region is allowed until this region is poisoned again.
+// This function may unpoison a superregion of [addr, addr+size) due to
+// ASan alignment restrictions.
+// Method is NOT thread-safe in the sense that no two threads can
+// (un)poison memory in the same memory region simultaneously.
+void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
+
+// User code should use macros instead of functions.
+#if defined(__clang__)
+    #if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer)
+        #define ASAN_POISON_MEMORY_REGION(addr, size) \
+            __asan_poison_memory_region((addr), (size))
+        #define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
+            __asan_unpoison_memory_region((addr), (size))
+    #endif
+#endif
+#ifndef ASAN_POISON_MEMORY_REGION
+    #define ASAN_POISON_MEMORY_REGION(addr, size) \
+        ((void)(addr), (void)(size))
+    #define ASAN_UNPOISON_MEMORY_REGION(addr, size) \
+        ((void)(addr), (void)(size))
+#endif
+
 MA_API size_t MA_GetAlignOffset(size_t size, size_t align) {
     size_t mask = align - 1;
     size_t val = size & mask;
@@ -71,7 +105,9 @@ MA_StaticFunc uint8_t *MV__AdvanceCommit(MV_Memory *m, size_t *commit_size, size
 MA_API void MA_PopToPos(MA_Arena *arena, size_t pos) {
     MA_ASSERT(arena->len >= arena->base_len);
     pos = MA_CLAMP(pos, arena->base_len, arena->len);
+    size_t size = arena->len - pos;
     arena->len = pos;
+    ASAN_POISON_MEMORY_REGION(arena->memory.data + pos, size);
 }
 
 MA_API void MA_PopSize(MA_Arena *arena, size_t size) {
@@ -122,6 +158,7 @@ MA_API void *MA_PushSizeNonZeroed(MA_Arena *a, size_t size) {
     uint8_t *result = a->memory.data + aligned_len;
     a->len += size_with_alignment;
     MA_ASSERT(a->len <= a->memory.commit);
+    ASAN_UNPOISON_MEMORY_REGION(result, a->len);
     return (void *)result;
 }
 
@@ -133,6 +170,7 @@ MA_API void *MA_PushSize(MA_Arena *arena, size_t size) {
 
 MA_API void MA_InitEx(MA_Arena *a, size_t reserve) {
     a->memory = MV_Reserve(reserve);
+    ASAN_POISON_MEMORY_REGION(a->memory.data, a->memory.reserve);
     a->alignment = MA_DEFAULT_ALIGNMENT;
 }