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| author | Sterling Augustine <saugustine@google.com> | 2020-03-31 01:20:26 +0300 |
|---|---|---|
| committer | Sterling Augustine <saugustine@google.com> | 2020-04-02 20:52:25 +0300 |
| commit | 71fbd6e40632f437049215904c28ad9d63cff4bc (patch) | |
| tree | 6ee77fe00c2c3add59f4a472ab0990357b190004 /libunwind/src/UnwindCursor.hpp | |
| parent | f4448063ccf1c2eda518ad326018276baff870d2 (diff) | |
Exit unwinding early when at the top of the stack and additional info won't be found.
Summary:
This patch follows libgcc's lead: When the return-address register is
zero, there won't be additional stack frames to examine, or gather
information about. Exit before spending time looking for something
known not to be found.
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77099
Diffstat (limited to 'libunwind/src/UnwindCursor.hpp')
| -rw-r--r-- | libunwind/src/UnwindCursor.hpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp index e7fb70cc5718..32d71c2c1ed3 100644 --- a/libunwind/src/UnwindCursor.hpp +++ b/libunwind/src/UnwindCursor.hpp @@ -1848,6 +1848,12 @@ void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) { pc &= (pint_t)~0x1; #endif + // Exit early if at the top of the stack. + if (pc == 0) { + _unwindInfoMissing = true; + return; + } + // If the last line of a function is a "throw" the compiler sometimes // emits no instructions after the call to __cxa_throw. This means // the return address is actually the start of the next function. |