[nrf noup] Add debug logs for sys_heap malloc

When CONFIG_CHIP_MALLOC_SYS_HEAP_DEBUG is enabled, log
every malloc/realloc/free to trace the source of memory
leaks in the application.

config/zephyr/Kconfig

@@ -462,6 +462,13 @@ config CHIP_MALLOC_SYS_HEAP_WATERMARKS_SUPPORT
 	  Enables support for getting current heap high watermark and resetting 
 	  watermarks. 
 
+config CHIP_MALLOC_SYS_HEAP_DEBUG
+	bool "Log every allocated or freed memory block"
+	help
+	  Enables debug logs printed whenever a heap memory block is allocated or
+	  freed. The logs can be used to trace the source of memory leaks in the
+	  application.
+
 endif
 
 module = MATTER

src/platform/Zephyr/SysHeapMalloc.cpp

@@ -84,7 +84,13 @@ void * Malloc(size_t size)
 {
     LockGuard lockGuard;
 
-    return lockGuard.Locked() ? sys_heap_aligned_alloc(&sHeap, kMallocAlignment, size) : nullptr;
+    void * const mem = lockGuard.Locked() ? sys_heap_aligned_alloc(&sHeap, kMallocAlignment, size) : nullptr;
+
+#ifdef CONFIG_CHIP_MALLOC_SYS_HEAP_DEBUG
+    ChipLogProgress(DeviceLayer, "Malloc(%u) = %p, caller: %p", size, mem, __builtin_return_address(0));
+#endif
+
+    return mem;
 }
 
 void * Calloc(size_t num, size_t size)
@@ -110,7 +116,13 @@ void * Realloc(void * mem, size_t size)
 {
     LockGuard lockGuard;
 
-    return lockGuard.Locked() ? sys_heap_aligned_realloc(&sHeap, mem, kMallocAlignment, size) : nullptr;
+    void * const new_mem = lockGuard.Locked() ? sys_heap_aligned_realloc(&sHeap, mem, kMallocAlignment, size) : nullptr;
+
+#ifdef CONFIG_CHIP_MALLOC_SYS_HEAP_DEBUG
+    ChipLogProgress(DeviceLayer, "Realloc(%p, %u) = %p, caller: %p", mem, size, new_mem, __builtin_return_address(0));
+#endif
+
+    return new_mem;
 }
 
 void Free(void * mem)
@@ -119,6 +131,10 @@ void Free(void * mem)
 
     VerifyOrReturn(lockGuard.Locked());
     sys_heap_free(&sHeap, mem);
+
+#ifdef CONFIG_CHIP_MALLOC_SYS_HEAP_DEBUG
+    ChipLogProgress(DeviceLayer, "Free(%p), caller: %p", mem, __builtin_return_address(0));
+#endif
 }
 
 #ifdef CONFIG_SYS_HEAP_RUNTIME_STATS