libbacktrace: export offline unwinding failures.

This is to help debugging different offline unwiding failures.

Bug: http://b/69383534
Test: run backtrace_test.
Change-Id: I5ed4837027a9f17d032925e97e9f5927161444b3

1 files changed, 28 insertions, 17 deletions

diff --git a/libbacktrace/Backtrace.cpp b/libbacktrace/Backtrace.cpp
index e18dbf3db..5bb6edc8f 100644
--- a/libbacktrace/Backtrace.cpp
+++ b/libbacktrace/Backtrace.cpp
@@ -142,22 +142,33 @@ Backtrace* Backtrace::Create(pid_t pid, pid_t tid, BacktraceMap* map) {
 }
 
 std::string Backtrace::GetErrorString(BacktraceUnwindError error) {
-  switch (error) {
-  case BACKTRACE_UNWIND_NO_ERROR:
-    return "No error";
-  case BACKTRACE_UNWIND_ERROR_SETUP_FAILED:
-    return "Setup failed";
-  case BACKTRACE_UNWIND_ERROR_MAP_MISSING:
-    return "No map found";
-  case BACKTRACE_UNWIND_ERROR_INTERNAL:
-    return "Internal libbacktrace error, please submit a bugreport";
-  case BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST:
-    return "Thread doesn't exist";
-  case BACKTRACE_UNWIND_ERROR_THREAD_TIMEOUT:
-    return "Thread has not responded to signal in time";
-  case BACKTRACE_UNWIND_ERROR_UNSUPPORTED_OPERATION:
-    return "Attempt to use an unsupported feature";
-  case BACKTRACE_UNWIND_ERROR_NO_CONTEXT:
-    return "Attempt to do an offline unwind without a context";
+  switch (error.error_code) {
+    case BACKTRACE_UNWIND_NO_ERROR:
+      return "No error";
+    case BACKTRACE_UNWIND_ERROR_SETUP_FAILED:
+      return "Setup failed";
+    case BACKTRACE_UNWIND_ERROR_MAP_MISSING:
+      return "No map found";
+    case BACKTRACE_UNWIND_ERROR_INTERNAL:
+      return "Internal libbacktrace error, please submit a bugreport";
+    case BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST:
+      return "Thread doesn't exist";
+    case BACKTRACE_UNWIND_ERROR_THREAD_TIMEOUT:
+      return "Thread has not responded to signal in time";
+    case BACKTRACE_UNWIND_ERROR_UNSUPPORTED_OPERATION:
+      return "Attempt to use an unsupported feature";
+    case BACKTRACE_UNWIND_ERROR_NO_CONTEXT:
+      return "Attempt to do an offline unwind without a context";
+    case BACKTRACE_UNWIND_ERROR_EXCEED_MAX_FRAMES_LIMIT:
+      return "Exceed MAX_BACKTRACE_FRAMES limit";
+    case BACKTRACE_UNWIND_ERROR_ACCESS_MEM_FAILED:
+      return android::base::StringPrintf("Failed to read memory at addr 0x%" PRIx64,
+                                         error.error_info.addr);
+    case BACKTRACE_UNWIND_ERROR_ACCESS_REG_FAILED:
+      return android::base::StringPrintf("Failed to read register %" PRIu64, error.error_info.regno);
+    case BACKTRACE_UNWIND_ERROR_FIND_PROC_INFO_FAILED:
+      return "Failed to find a function in debug sections";
+    case BACKTRACE_UNWIND_ERROR_EXECUTE_DWARF_INSTRUCTION_FAILED:
+      return "Failed to execute dwarf instructions in debug sections";
   }
 }