This mirrors the behavior of `clang-cl.exe` by adding a `CodeView` global
variable when emitting debug information. This should in turn help stack traces
that are generated when code is compiled with debuginfo enabled.
Closes#28133
Fix formatting
Remove unused imports
Refactor
Fix msvc build
Fix line lengths
Formatting
Enable backtrace tests
Fix using directive on mac
pwd info
Work-around buildbot PWD bug, and fix libbacktrace configuration
Use alternative to `env -u` which is not supported on bitrig
Disable tests on 32-bit windows gnu
LLVM might perform tail merging on the calls that initiate the unwinding
process which breaks debuginfo and therefore this test. Since tail
merging is guaranteed to break debuginfo, it should be disabled for this
test.
This allows us to restore a testcase that I had to remove earlier
because of the same problem, because back then I didn't realize that
disabling tail merging was an option.
cc #27619
This has a number of advantages compared to creating a copy in memory
and passing a pointer. The obvious one is that we don't have to put the
data into memory but can keep it in registers. Since we're currently
passing a pointer anyway (instead of using e.g. a known offset on the
stack, which is what the `byval` attribute would achieve), we only use a
single additional register for each fat pointer, but save at least two
pointers worth of stack in exchange (sometimes more because more than
one copy gets eliminated). On archs that pass arguments on the stack, we
save a pointer worth of stack even without considering the omitted
copies.
Additionally, LLVM can optimize the code a lot better, to a large degree
due to the fact that lots of copies are gone or can be optimized away.
Additionally, we can now emit attributes like nonnull on the data and/or
vtable pointers contained in the fat pointer, potentially allowing for
even more optimizations.
This results in LLVM passes being about 3-7% faster (depending on the
crate), and the resulting code is also a few percent smaller, for
example:
text data filename
5671479 3941461 before/librustc-d8ace771.so
5447663 3905745 after/librustc-d8ace771.so
1944425 2394024 before/libstd-d8ace771.so
1896769 2387610 after/libstd-d8ace771.so
I had to remove a call in the backtrace-debuginfo test, because LLVM can
now merge the tails of some blocks when optimizations are turned on,
which can't correctly preserve line info.
Fixes#22924
Cc #22891 (at least for fat pointers the code is good now)
This commit removes the reexports of `old_io` traits as well as `old_path` types
and traits from the prelude. This functionality is now all deprecated and needs
to be removed to make way for other functionality like `Seek` in the `std::io`
module (currently reexported as `NewSeek` in the io prelude).
Closes#23377Closes#23378
- Fixed a couple of dead code warnings in std::sys::backtrace.
- Made `backtrace-debuginfo` test a no-op on non-Linux platforms.
- `backtrace-debuginfo` is no longer tested on pretty-rpass.
Fixes#20978 for supported platforms (i.e. non-Android POSIX).
This uses `backtrace_pcinfo` to inspect the DWARF debug info
and list the file and line pairs for given stack frame.
Such pair is not unique due to the presence of inlined functions
and the updated routine correctly handles this case.
The code is modelled after libbacktrace's `backtrace_full` routine.
There is one known issue with this approach. Macros, when invoked,
take over the current frame and shadows the file and line pair
which has invoked a macro. In particular, this makes many panicking
macros a bit harder to inspect. This really is a debuginfo problem,
and the backtrace routine should print them correctly with
a correct debuginfo.
