Summary:
When dwo support was introduced, it used a trick where debug info
entries were referenced by the offset of the compile unit in the main
file, but the die offset was relative to the dwo file. Although there
was some elegance to it, this representation was starting to reach its
breaking point:
- the fact that the skeleton compile unit owned the DWO file meant that
it was impossible (or at least hard and unintuitive) to support DWO
files containing more than one compile unit. These kinds of files are
produced by LTO for example.
- it made it impossible to reference any DIEs in the skeleton compile
unit (although the skeleton units are generally empty, clang still
puts some info into them with -fsplit-dwarf-inlining).
- (current motivation) it made it very hard to support type units placed
in DWO files, as type units don't have any skeleton units which could
be referenced in the main file
This patch addresses this problem by introducing an new
"dwo_num" field to the DIERef class, whose purpose is to identify the
dwo file. It's kind of similar to the dwo_id field in DWARF5 unit
headers, but while this is a 64bit hash whose main purpose is to catch
file mismatches, this is just a smaller integer used to indentify a
loaded dwo file. Currently, this is based on the index of the skeleton
compile unit which owns the dwo file, but it is intended to be
eventually independent of that (to support the LTO use case).
Simultaneously the cu_offset is dropped to conserve space, as it is no
longer necessary. This means we can remove the "BaseObjectOffset" field
from the DWARFUnit class. It also means we can remove some of the
workarounds put in place to support the skeleton-unit+dwo-die combo.
More work is needed to remove all of them, which is out of scope of this
patch.
Reviewers: JDevlieghere, clayborg, aprantl
Subscribers: mehdi_amini, dexonsmith, arphaman, lldb-commits
Differential Revision: https://reviews.llvm.org/D63428
llvm-svn: 364009
In a dwo/debug_types world, the die offset is not enough to uniquely
idendify a debug info entry. Pass the the entire DIERef object instead.
This is technically NFC, because only AppleIndex implemented this
method (and there, the die offset *is* enough for unique
identification). However, this makes the code simpler, and simplifies
some of the follow-up patches.
llvm-svn: 363373
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
This patch implements the non-regex variant of GetFunctions. To share
more code with the Apple implementation, I've extracted the common
filtering code from that class into a utility function on the DWARFIndex
base class.
The new implementation also searching the accelerator table multiple
times -- previously it could happen that the apple table would return
the same die more than once if one specified multiple search flags in
name_type_mask. This way, I separate table iteration from filtering, and
so we can be sure each die is inserted at most once.
Reviewers: clayborg, JDevlieghere
Subscribers: aprantl, lldb-commits
Differential Revision: https://reviews.llvm.org/D47881
llvm-svn: 334273
Summary:
This places the `if(m_using_apple_tables)` branches inside the
SymbolFileDWARF class behind an abstract DWARFIndex class. The class
currently has two implementations:
- AppleIndex, which searches using .apple_names and friends
- ManualIndex, which searches using a manually built index
Most of the methods of the class are very simple, and simply extract the
list of DIEs for the given name from the appropriate sub-table. The main
exception are the two GetFunctions overloads, which take a couple of
extra paramenters, including some callbacks. It was not possible to
split these up the same way as other methods, as here we were doing a
lot of post-processing on the results. The post-processing is similar
for the two cases, but not identical. I hope to factor these further in
separate patches.
Other interesting methods are:
- Preload(): do any preprocessing to make lookups faster (noop for
AppleIndex, forces a build of the lookup tables for ManualIndex).
- ReportInvalidDIEOffset(): Used to notify the users of an invalid index
(prints a message for AppleIndex, noop for ManualIndex).
- Dump(): dumps the index state (noop for AppleIndex, prints the lookup
tables for ManualIndex).
Reviewers: clayborg, JDevlieghere
Subscribers: mgorny, aprantl, lldb-commits
Differential Revision: https://reviews.llvm.org/D46889
llvm-svn: 332719
Pavel Labath