[DebugInfo] Fix /usr/lib/debug llvm-symbolizer lookup with relative paths
Summary:
rL189250 added a realpath call, and rL352916 because realpath breaks assumptions with some build systems. However, the /usr/lib/debug case has been clarified, falling back to /usr/lib/debug is currently broken if the obj passed in is a relative path. Adding a call to use absolute paths when falling back to /usr/lib/debug fixes that while still not making any realpath assumptions.
This also adds a --fallback-debug-path command line flag for testing (since we probably can't write to /usr/lib/debug from buildbot environments), but was also verified manually:
```
$ rm -f path/to/dwarfdump-test.elf-x86-64
$ strace llvm-symbolizer --obj=relative/path/to/dwarfdump-test.elf-x86-64.debuglink 0x40113f |& grep dwarfdump
```
Lookups went to relative/path/to/dwarfdump-test.elf-x86-64, relative/path/to/.debug/dwarfdump-test.elf-x86-64, and then finally /usr/lib/debug/absolute/path/to/dwarfdump-test.elf-x86-64.
Reviewers: dblaikie, samsonov
Reviewed By: dblaikie
Subscribers: krytarowski, aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57916
llvm-svn: 353730
diff --git a/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp b/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
index 5f7370c..73fe978 100644
--- a/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
+++ b/llvm/lib/DebugInfo/Symbolize/Symbolize.cpp
@@ -165,30 +165,40 @@
bool findDebugBinary(const std::string &OrigPath,
const std::string &DebuglinkName, uint32_t CRCHash,
+ const std::string &FallbackDebugPath,
std::string &Result) {
SmallString<16> OrigDir(OrigPath);
llvm::sys::path::remove_filename(OrigDir);
SmallString<16> DebugPath = OrigDir;
- // Try /path/to/original_binary/debuglink_name
+ // Try relative/path/to/original_binary/debuglink_name
llvm::sys::path::append(DebugPath, DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
Result = DebugPath.str();
return true;
}
- // Try /path/to/original_binary/.debug/debuglink_name
+ // Try relative/path/to/original_binary/.debug/debuglink_name
DebugPath = OrigDir;
llvm::sys::path::append(DebugPath, ".debug", DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
Result = DebugPath.str();
return true;
}
+ // Make the path absolute so that lookups will go to
+ // "/usr/lib/debug/full/path/to/debug", not
+ // "/usr/lib/debug/to/debug"
+ llvm::sys::fs::make_absolute(OrigDir);
+ if (!FallbackDebugPath.empty()) {
+ // Try <FallbackDebugPath>/absolute/path/to/original_binary/debuglink_name
+ DebugPath = FallbackDebugPath;
+ } else {
#if defined(__NetBSD__)
- // Try /usr/libdata/debug/path/to/original_binary/debuglink_name
- DebugPath = "/usr/libdata/debug";
+ // Try /usr/libdata/debug/absolute/path/to/original_binary/debuglink_name
+ DebugPath = "/usr/libdata/debug";
#else
- // Try /usr/lib/debug/path/to/original_binary/debuglink_name
- DebugPath = "/usr/lib/debug";
+ // Try /usr/lib/debug/absolute/path/to/original_binary/debuglink_name
+ DebugPath = "/usr/lib/debug";
#endif
+ }
llvm::sys::path::append(DebugPath, llvm::sys::path::relative_path(OrigDir),
DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
@@ -274,7 +284,8 @@
std::string DebugBinaryPath;
if (!getGNUDebuglinkContents(Obj, DebuglinkName, CRCHash))
return nullptr;
- if (!findDebugBinary(Path, DebuglinkName, CRCHash, DebugBinaryPath))
+ if (!findDebugBinary(Path, DebuglinkName, CRCHash, Opts.FallbackDebugPath,
+ DebugBinaryPath))
return nullptr;
auto DbgObjOrErr = getOrCreateObject(DebugBinaryPath, ArchName);
if (!DbgObjOrErr) {