Commit Graph

9 Commits

Author SHA1 Message Date
Pavel Labath 3b9269882e DWARF: Add "dwo_num" field to the DIERef class
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
2019-06-21 07:56:50 +00:00
Pavel Labath 78b2cf71f5 DWARFIndex: s/ReportInvalidDIEOffset/ReportInvalidDIERef
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
2019-06-14 12:01:18 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Pavel Labath e1d18758eb DebugNamesDWARFIndex: Add ability to lookup variables
Summary:
This patch adds the ability to lookup variables to the DWARF v5 index
class.

During review we discovered an inconsistency between how the existing
two indexes handle looking up qualified names of the variables:
- manual index would return a value if the input string exactly matched
  the demangled name of some variable.
- apple index ignored the context and returned any variable with the
  same base name.

So, this patch also rectifies that situation:
- it removes all context handling from the index classes. The
  GetGlobalVariables functions now just take a base name. For manual
  index, this meant we can stop putting demangled names into the
  variable index (this matches the behavior for functions).
- context extraction is put into SymbolFileDWARF, so that it is common
  to all indexes.
- additional filtering based on the context is also done in
  SymbolFileDWARF. This is done via a simple substring search, which is
  not ideal, but it matches what we are doing for functions (cf.
  Module::LookupInfo::Prune).

Reviewers: clayborg, JDevlieghere

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D47781

llvm-svn: 334181
2018-06-07 10:04:44 +00:00
Pavel Labath 6de9c79e71 DWARFIndex: more GetFunctions cleanup
This applies similar simplification as r334004, only it touches the
regex version of the method.

llvm-svn: 334012
2018-06-05 12:13:22 +00:00
Pavel Labath 5af11ab259 DWARFIndex: simplify GetFunctions methods
Now that Apple index determines method-ness straight from the debug
info, we don't need to resolve the functions into SymbolContexts inside
the Index classes. This removes the need for callback arguments and
allows us to pull the common parts out of the two implementations of
these functions back into the SymbolFileDWARF class.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D47147

llvm-svn: 334004
2018-06-05 10:33:56 +00:00
Pavel Labath b13f033818 Reland "[DWARF] Extract indexing code into a separate class hierarchy"
After this commit, the xcode project will need to be updated to include
the new files added here.

llvm-svn: 332841
2018-05-21 14:12:52 +00:00
Amara Emerson 29b8df607e Revert "[DWARF] Extract indexing code into a separate class hierarchy"
This reverts commit r332719 due to breaking this green dragon build:
http://green.lab.llvm.org/green/job/lldb-xcode/6644

llvm-svn: 332730
2018-05-18 15:59:42 +00:00
Pavel Labath 1237095b3c [DWARF] Extract indexing code into a separate class hierarchy
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
2018-05-18 14:15:46 +00:00