Commit Graph

7 Commits

Author SHA1 Message Date
David Blaikie 208a11ab3a Reapply "llvm-dwarfdump: Report errors when failing to parse loclist/debug_loc entries""
Originally committed as 416fa7720e
Reverted (due to buildbot failure - breaking lldb) in 7a45aeacf3.

I still can't seem to build lldb locally, but Pavel Labath has kindly
provided a potential fix to preserve the old behavior in lldb by
registering a simple recoverable error handler there that prints to the
desired stream in lldb, rather than stderr.
2020-04-14 14:44:32 -07:00
David Blaikie 7a45aeacf3 Revert "llvm-dwarfdump: Report errors when failing to parse loclist/debug_loc entries"
Broke an LLDB build bot & I can't seem to build LLDB locally to fix
forward...
http://lab.llvm.org:8011/builders/lldb-x64-windows-ninja/builds/15567/steps/test/logs/stdio

This reverts commit 416fa7720e.
2020-04-11 16:54:49 -07:00
David Blaikie 416fa7720e llvm-dwarfdump: Report errors when failing to parse loclist/debug_loc entries
This probably isn't ideal - the error was being printed specifically
inline with the dumping that was more legible - but then the error
wasn't reported to stderr and didn't produce a non-zero exit code.

Probably the error message could be improved by adding more context now
that it isn't printed in-situ of the DIE dumping as much.
2020-04-10 17:28:09 -07:00
Pavel Labath 0908093977 DWARFDebugLoc(v4): Add an incremental parsing function
Summary:
This adds a visitLocationList function to the DWARF v4 location lists,
similar to what already exists for DWARF v5. It follows the approach
outlined in previous patches (D69672), where the parsed form is always
stored in the DWARF v5 format, which makes it easier for generic code to
be built on top of that. v4 location lists are "upgraded" during
parsing, and then this upgrade is undone while dumping.

Both "inline" and section-based dumping is rewritten to reuse the
existing "generic" location list dumper. This means that the output
format is consistent for all location lists (the only thing one needs to
implement is the function which prints the "raw" form of a location
list), and that debug_loc dumping correctly processes base address
selection entries, etc.

The previous existing debug_loc functionality (e.g.,
parseOneLocationList) is rewritten on top of the new API, but it is not
removed as there is still code which uses them. This will be done in
follow-up patches, after I build the API to access the "interpreted"
location lists in a generic way (as that is what those users really
want).

Reviewers: dblaikie, probinson, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69847
2019-11-15 13:38:00 +01:00
Pavel Labath aaff1a631a MCRegisterInfo: Merge getLLVMRegNum and getLLVMRegNumFromEH
Summary:
The functions different in two ways:
- getLLVMRegNum could return both "eh" and "other" dwarf register
  numbers, while getLLVMRegNumFromEH only returned the "eh" number.
- getLLVMRegNum asserted if the register was not found, while the second
  function returned -1.

The second distinction was pretty important, but it was very hard to
infer that from the function name. Aditionally, for the use case of
dumping dwarf expressions, we needed a function which can work with both
kinds of number, but does not assert.

This patch solves both of these issues by merging the two functions into
one, returning an Optional<unsigned> value. While the same thing could
be achieved by adding an "IsEH" argument to the (renamed)
getLLVMRegNumFromEH function, it seemed better to avoid the confusion of
two functions and put the choice of asserting into the hands of the
caller -- if he checks the Optional value, he can safely process
"untrusted" input, and if he blindly dereferences the Optional, he gets
the assertion.

I've updated all call sites to the new API, choosing between the two
options according to the function they were calling originally, except
that I've updated the usage in DWARFExpression.cpp to use the "safe"
method instead, and added a test case which would have previously
triggered an assertion failure when processing (incorrect?) dwarf
expressions.

Reviewers: dsanders, arsenm, JDevlieghere

Subscribers: wdng, aprantl, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67154

llvm-svn: 372710
2019-09-24 09:31:02 +00:00
Pavel Labath 98634c2e11 Fix address sizes in the dwarfdump-debug-loc-error-cases test
the test is building a 64-bit executable, so the addresses should be
64-bit too. The test was still passing even with smaller address size,
but it was hitting the "unexpected end of data" error sooner than it
should.

llvm-svn: 370882
2019-09-04 11:47:20 +00:00
Pavel Labath bd546e5902 DWARFDebugLoc: Make parsing and error reporting more robust
Summary:
While examining this class for possible use in lldb, I noticed two
things:
- it spits out parsing errors directly to stderr
- the loclists parser can incorrectly return valid location lists when
  parsing malformed (truncated) data

I improve the stderr situation by making the parseOneLocationList
functions return Expected<T>s. The errors are still dumped to stderr by
their callers, so this is only a partial fix, but it is enough for my
use case, as I intend to parse the locations lists one by one.

I fix the behavior in the truncated scenario by using the newly
introduced DataExtractor Cursor API.

I also add tests for handling the error cases, as they currently have no
coverage.

Reviewers: dblaikie, JDevlieghere, probinson

Subscribers: lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63591

llvm-svn: 370363
2019-08-29 14:26:05 +00:00