Split libc_debug.so into two .so modules loaded on demand from libc.so

This change is intended to eliminate need to replace libc.so with libc_debug.so in order to enablememory allocation debugging.
This is also the first step towards implementing extended memoryallocation debugging using emulator's capabilities in monitoring memory access.

libc/bionic/malloc_debug_common.h

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Contains declarations of types and constants used by malloc leak
+ * detection code in both, libc and libc_malloc_debug libraries.
+ */
+#ifndef MALLOC_DEBUG_COMMON_H
+#define MALLOC_DEBUG_COMMON_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define HASHTABLE_SIZE      1543
+#define BACKTRACE_SIZE      32
+/* flag definitions, currently sharing storage with "size" */
+#define SIZE_FLAG_ZYGOTE_CHILD  (1<<31)
+#define SIZE_FLAG_MASK          (SIZE_FLAG_ZYGOTE_CHILD)
+
+#define MAX_SIZE_T           (~(size_t)0)
+
+// =============================================================================
+// Structures
+// =============================================================================
+
+typedef struct HashEntry HashEntry;
+struct HashEntry {
+    size_t slot;
+    HashEntry* prev;
+    HashEntry* next;
+    size_t numEntries;
+    // fields above "size" are NOT sent to the host
+    size_t size;
+    size_t allocations;
+    intptr_t backtrace[0];
+};
+
+typedef struct HashTable HashTable;
+struct HashTable {
+    size_t count;
+    HashEntry* slots[HASHTABLE_SIZE];
+};
+
+/* Entry in malloc dispatch table. */
+typedef struct MallocDebug MallocDebug;
+struct MallocDebug {
+    void* (*malloc)(size_t bytes);
+    void  (*free)(void* mem);
+    void* (*calloc)(size_t n_elements, size_t elem_size);
+    void* (*realloc)(void* oldMem, size_t bytes);
+    void* (*memalign)(size_t alignment, size_t bytes);
+};
+
+#ifdef __cplusplus
+};  /* end of extern "C" */
+#endif
+
+#endif  // MALLOC_DEBUG_COMMON_H