Create a single backtrace library.

This library will be used to abstract away getting backtrace
data from how it is implemented. This is the first step to
replacing libcorkscrew with libunwind.

Bug: 8410085
Change-Id: Ie8f159e96a055d378e1ddc72d40239fba4cf52b7

1 files changed, 104 insertions, 0 deletions

diff --git a/include/backtrace/backtrace.h b/include/backtrace/backtrace.h
new file mode 100644
index 0000000..38a9645
--- /dev/null
+++ b/include/backtrace/backtrace.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _BACKTRACE_H
+#define _BACKTRACE_H
+
+#include <sys/types.h>
+#include <stdbool.h>
+#include <inttypes.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MAX_BACKTRACE_FRAMES 64
+
+typedef struct backtrace_map_info {
+  struct backtrace_map_info* next;
+  uintptr_t start;
+  uintptr_t end;
+  bool is_readable;
+  bool is_writable;
+  bool is_executable;
+  char name[];
+} backtrace_map_info_t;
+
+typedef struct {
+  uintptr_t pc;           /* The absolute pc. */
+  uintptr_t sp;           /* The top of the stack. */
+  size_t stack_size;      /* The size of the stack, zero indicate an unknown stack size. */
+  const char* map_name;   /* The name of the map to which this pc belongs, NULL indicates the pc doesn't belong to a known map. */
+  uintptr_t map_offset;   /* pc relative to the start of the map, only valid if map_name is not NULL. */
+  char* proc_name;        /* The function name associated with this pc, NULL if no not found. */
+  uintptr_t proc_offset;  /* pc relative to the start of the procedure, only valid if proc_name is not NULL. */
+} backtrace_frame_data_t;
+
+typedef struct {
+  backtrace_frame_data_t frames[MAX_BACKTRACE_FRAMES];
+  size_t num_frames;
+
+  pid_t tid;
+  backtrace_map_info_t* map_info_list;
+  void* private_data;
+} backtrace_t;
+
+/* Gather the backtrace data for tid and fill in the backtrace structure.
+ * If tid < 0, then gather the backtrace for the current thread.
+ */
+bool backtrace_get_data(backtrace_t* backtrace, pid_t tid);
+
+/* Free any memory associated with the backtrace structure. */
+void backtrace_free_data(backtrace_t* backtrace);
+
+/* Read data at a specific address for a process. */
+bool backtrace_read_word(
+    const backtrace_t* backtrace, uintptr_t ptr, uint32_t* value);
+
+/* Get information about the map associated with a pc. If NULL is
+ * returned, then map_start is not set.
+ */
+const char* backtrace_get_map_info(
+    const backtrace_t* backtrace, uintptr_t pc, uintptr_t* map_start);
+
+/* Get the procedure name and offest given the pc. If NULL is returned,
+ * then proc_offset is not set. The returned string is allocated using
+ * malloc and must be freed by the caller.
+ */
+char* backtrace_get_proc_name(
+    const backtrace_t* backtrace, uintptr_t pc, uintptr_t* proc_offset);
+
+/* Loads memory map from /proc/<tid>/maps. If tid < 0, then load the memory
+ * map for the current process.
+ */
+backtrace_map_info_t* backtrace_create_map_info_list(pid_t tid);
+
+/* Frees memory associated with the map list. */
+void backtrace_destroy_map_info_list(backtrace_map_info_t* map_info_list);
+
+/* Finds the memory map that contains the specified pc. */
+const backtrace_map_info_t* backtrace_find_map_info(
+    const backtrace_map_info_t* map_info_list, uintptr_t pc);
+
+/* Create a formatted line of backtrace information for a single frame. */
+void backtrace_format_frame_data(
+    const backtrace_frame_data_t* frame, size_t frame_num, char *buf, size_t buf_size);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _BACKTRACE_H */