Display the map offset for each frame.

The dlopen of a shared library in an apk results in large map offsets.
Unfortunately, the current way that the frame data is printed, it's
impossible to tell what the relative pc is relative to. With the
addition of the offset, it's possible to figure out what the relative
pc actually references.

Bug: 23348999
(cherry picked from commit e0ab23223a)

Change-Id: I950f92c1cb29ee05eed777f47453efa03318cf3e
This commit is contained in:
Christopher Ferris 2015-08-20 11:16:54 -07:00
parent 565d20ef04
commit 600017332c
2 changed files with 14 additions and 0 deletions

View File

@ -102,6 +102,11 @@ std::string Backtrace::FormatFrameData(const backtrace_frame_data_t* frame) {
uintptr_t relative_pc = BacktraceMap::GetRelativePc(frame->map, frame->pc);
std::string line(StringPrintf("#%02zu pc %" PRIPTR " %s", frame->num, relative_pc, map_name));
// Special handling for non-zero offset maps, we need to print that
// information.
if (frame->map.offset != 0) {
line += " (offset " + StringPrintf("0x%" PRIxPTR, frame->map.offset) + ")";
}
if (!frame->func_name.empty()) {
line += " (" + frame->func_name;
if (frame->func_offset) {

View File

@ -823,6 +823,15 @@ TEST(libbacktrace, format_test) {
EXPECT_EQ("#01 pc 00000000123456dc MapFake (ProcFake+645)",
#else
EXPECT_EQ("#01 pc 123456dc MapFake (ProcFake+645)",
#endif
backtrace->FormatFrameData(&frame));
// Check a non-zero map offset.
frame.map.offset = 0x1000;
#if defined(__LP64__)
EXPECT_EQ("#01 pc 00000000123456dc MapFake (offset 0x1000) (ProcFake+645)",
#else
EXPECT_EQ("#01 pc 123456dc MapFake (offset 0x1000) (ProcFake+645)",
#endif
backtrace->FormatFrameData(&frame));
}