Commit Graph

27 Commits

Author SHA1 Message Date
Alex Langford 1d2a62afaf Re-submit "[lldb] Filter DIEs based on qualified name where possible"
This reverts commit 967df65a36.

This fixes test/Shell/SymbolFile/NativePDB/find-functions.cpp. When
looking up functions with the PDB plugins, if we are looking for a
full function name, we should use `GetName` to populate the `name`
field instead of `GetLookupName` since `GetName` has the more
complete information.
2022-08-04 15:52:27 -07:00
Alex Langford 967df65a36 Revert "[lldb] Filter DIEs based on qualified name where possible"
This reverts commit befa77e59a.

Looks like this broke a SymbolFileNativePDB test. I'll investigate and
resubmit with a fix soon.
2022-08-04 11:52:30 -07:00
Alex Langford befa77e59a [lldb] Filter DIEs based on qualified name where possible
Context:
When setting a breakpoint by name, we invoke Module::FindFunctions to
find the function(s) in question. However, we use a Module::LookupInfo
to first process the user-provided name and figure out exactly what
we're looking for. When we actually perform the function lookup, we
search for the basename. After performing the search, we then filter out
the results using Module::LookupInfo::Prune. For example, given
a:🅱️:foo we would first search for all instances of foo and then filter
out the results to just names that have a:🅱️:foo in them. As one can
imagine, this involves a lot of debug info processing that we do not
necessarily need to be doing. Instead of doing one large post-processing
step after finding each instance of `foo`, we can filter them as we go
to save time.

Some numbers:
Debugging LLDB and placing a breakpoint on
llvm::itanium_demangle::StringView::begin without this change takes
approximately 70 seconds and resolves 31,920 DIEs. With this change,
placing the breakpoint takes around 30 seconds and resolves 8 DIEs.

Differential Revision: https://reviews.llvm.org/D129682
2022-08-04 11:18:08 -07:00
Kim-Anh Tran 0dda542531 [DWARF5] Fix offset check when using .debug_names
When going through the CU entries in the name index,
make sure to compare the name entry's CU
offset against the skeleton CU's offset.

Previously there would be a mismatch, since the
wrong offset was compared, and thus no suitable
entry was found.

Reviewed By: jankratochvil

Differential Revision: https://reviews.llvm.org/D106270
2021-08-09 13:15:14 +02:00
Jan Kratochvil d482fe2add [nfc] [lldb] DWARF callbacks: DIERef -> DWARFDIE
Pavel Labath wrote in D73206:
The internal representation of DebugNames and Apple indexes is fixed by
the relevant (pseudo-)standards, so we can't really change it. The
question is how to efficiently (and cleanly) convert from the internal
representation to some common thing. The conversion from AppleIndex to
DIERef is trivial (which is not surprising as it was the first and the
overall design was optimized for that). With debug_names, the situation
gets more tricky. The internal representation of debug_names uses
CU-relative DIE offsets, but DIERef wants an absolute offset. That means
the index has to do more work to produce the common representation. And
it needs to do that for all results, even though a lot of the index
users are really interested only in a single entry. With the switch to
user_id_t, _all_ indexes would have to do some extra work to encode it,
only for their users to have to immediately decode it back. Having
a iterator/callback based api would allow us to minimize the impact of
that, as it would only need to happen for the entries that are really
used. And /I think/ we could make it interface returns DWARFDies
directly, and each index converts to that using the most direct approach
available.

Jan Kratochvil:
It also makes all the callers shorter as they no longer need to fetch
DWARFDIE from DIERef (and handling if not found by ReportInvalidDIERef)
but the callers are already served DWARFDIE which they need.
In some cases the DWARFDIE had to be fetched both by callee (DWARFIndex
implementation) and caller.

Differential Revision: https://reviews.llvm.org/D77970
2020-04-22 17:11:50 +02:00
Jan Kratochvil 5e04b5f2fa [nfc] [lldb] Introduce DWARF callbacks (fixed-up)
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

It is a re-landing of the patch with a regression fix the previous
commit had.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 23:40:54 +02:00
Jan Kratochvil 9289f34390 Revert "[nfc] [lldb] Introduce DWARF callbacks"
This reverts commit bd47c470d1.

It broke Green Dragon, reason is unknown to me so far:
  http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/15323/consoleFull

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 15:12:59 +02:00
Jan Kratochvil bd47c470d1 [nfc] [lldb] Introduce DWARF callbacks
As requested by @labath in https://reviews.llvm.org/D73206#1949516
providing DWARF index callbacks refactorization.

Differential Revision: https://reviews.llvm.org/D77327
2020-04-15 10:37:38 +02:00
Pavel Labath 0f7cfb2543 [lldb/DWARF] Don't index dwp file multiple times
Summary:
When we added support for type units in dwo files, we changed the
"manual" dwarf index to index _all_ dwarf units in the dwo file instead
of just the split unit belonging to our skeleton unit. This was fine for
dwo files, as they contain only a single compile units and type units do
not have a split type unit which would point to them.

However, this does not work for dwp files because, these files do
contain multiple split compile units, and the current approach means
that each unit gets indexed multiple times (once for each split unit =>
n^2 complexity).

This patch teaches the manual dwarf index to treat dwp files specially.
Any type units in the dwp file added to the main list of compile units
and indexed with them in a single batch. Split compile units in dwp
files are still indexed as a part of their skeleton unit -- this is done
because we need the DW_AT_language attribute from the skeleton unit to
index them properly.

Handling of dwo files remains unchanged -- all units (type and skeleton)
are indexed when we reach the dwo file through the split unit.

Reviewers: clayborg, JDevlieghere, aprantl

Subscribers: arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74964
2020-02-24 08:50:51 +01:00
Pavel Labath ddf60ba09f [lldb/DWARF] Always construct a DWARFDebugInfo object
Change the return value of SymbolFileDWARF::DebugInfo from a pointer to
a reference, and remove all null checks.

Previously, we were not constructing the DebugInfo object when the
debug_info section was empty. Now we always construct the object but
it will return an empty list of dwarf units (a thing which it already
supported).
2020-02-20 10:51:40 +01:00
Jonas Devlieghere cdc514e4c6 [lldb] Update header guards to be consistent and compliant with LLVM (NFC)
LLDB has a few different styles of header guards and they're not very
consistent because things get moved around or copy/pasted. This patch
unifies the header guards across LLDB and converts everything to match
LLVM's style.

Differential revision: https://reviews.llvm.org/D74743
2020-02-17 23:15:40 -08:00
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 67b45acefe DWARF: Make DIERefs always valid
Summary:
This patch makes the DIERef class always valid by default constructor
and operator bool. This allows one to express the validity of a DIERef
in the type system. Places which are working with potentially-invalid
DIERefs have been updated to use Optional<DIERef> instead.

The constructor taking a DWARFFormValue was not needed, as all places
which were constructing a DIERef this way were immediately converting it
into a DWARFDIE or a user_id. This can be done without constructing an
intermediate DIERef.

Reviewers: JDevlieghere, clayborg, aprantl

Subscribers: arphaman, lldb-commits

Differential Revision: https://reviews.llvm.org/D63399

llvm-svn: 363767
2019-06-19 07:32:39 +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
Jonas Devlieghere 8e93917e8d [SymbolFile] Implement GetCompleteObjCClass for .debug_names
When running the test suite with .debug_names a bunch of tests were
failing because GetCompleteObjCClass was not yet implemented for
DebugNamesDWARFIndex. This patch adds the required logic.

We use the .debug_names to find the Objective-C class and then rely on
DW_AT_APPLE_objc_complete_type to find the complete type. If we can't
find it or the attribute is not supported, we return a list of potential
complete types.

Differential revision: https://reviews.llvm.org/D48596

llvm-svn: 335776
2018-06-27 19:58:39 +00:00
Pavel Labath 234c681686 DebugNamesDWARFIndex: fix handling of compressed sections
This fixes a silly bug where we were accidentally freeing the memory
used to store the decompressed .debug_names data. I had actually
considered this scenario when writing the class and put appropriate
precautions in place -- I just failed to wire it all up correctly.

This was only an issue for compressed sections because in case of
uncompressed ones we would access the data straight out of the mmapped
object file.

llvm-svn: 334717
2018-06-14 14:41:30 +00:00
Pavel Labath 0e33a0cd58 DebugNamesDWARFIndex: Implement DWARFDeclContext variant of GetTypes method
This method is used to find complete definitions of a type when one
parses a compile unit with only forward declaration available.

Since it is only accessed from DWARFASTParserClang, it was not
possible/easy to trigger this codepath from lldb-test. Therefore, I
adapt add a debug-names variant to an existing dotest test to cover this
scenario.

llvm-svn: 334516
2018-06-12 16:50:01 +00:00
Pavel Labath dc4bd2e441 DWARFDebugNames: Implement last GetGlobalVariables overload
This function implements the search for all global variables within a
given compilation unit.

llvm-svn: 334500
2018-06-12 13:11:25 +00:00
Pavel Labath 08dae4bb3c DWARFDebugNames: Fix lookup in dwo files
The getDIESectionOffset function is not correct for split dwarf files
(and will probably be removed in D48009).

This patch implements correct section offset computation for split and
non-split compile units -- we first need to check if the referenced unit
is a skeleton unit, and if it is, we add the die offset to the full unit
base offset (as the full unit is the one which contains the die).

llvm-svn: 334402
2018-06-11 13:22:31 +00:00
Pavel Labath a3ee1e7f92 DebugNamesDWARFIndex: Implement regex version of the GetFunctions method
This also fixes a bug where SymbolFileDWARF was returning the same
function multiple times - this can happen if both mangled and demangled
names match the regex. Other lookup lookup functions had code to handle
this case, but it was forgotten here.

llvm-svn: 334277
2018-06-08 10:31:55 +00:00
Pavel Labath 257ff33989 DebugNamesDWARFIndex: Implement GetFunctions method
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
2018-06-08 09:10:31 +00:00
Pavel Labath 6938969223 DebugNamesDWARFIndex: Add type lookup suport
This implements just one of the GetTypes overloads. The other is not
testable from lldb-test so I'm leaving it unimplemented until I figure
out what to do with testing.

llvm-svn: 334190
2018-06-07 12:26:18 +00:00
Pavel Labath 6675e652a3 DebugNamesDWARFIndex: add namespace lookup support
llvm-svn: 334186
2018-06-07 10:56:16 +00:00
Pavel Labath 452bd87cc4 DebugNamesDWARFIndex: Add support for partial indexes
Summary:
It possible that a single module has indexed and non-indexed compile
units. In this case, we can use the fast indexed lookup for the first
ones and fall back to the manual index for the others.

This patch implements this functionality by adding a units_to_avoid
argument to the ManualDWARFIndex constructor. Any units present in that
list will be ignored for the purposes of manual index. Individual
DebugNamesDWARFIndex then always consult both the manual fallback index
as well as the index in the .debug_names section.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D47832

llvm-svn: 334185
2018-06-07 10:35:28 +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 9337b41cb5 [DWARF] Add (empty) DebugNamesDWARFIndex class and a setting to control its use
Summary:
This patch adds the skeleton for implementing the DWARF v5 name index
class. All of the methods are stubbed out and will be implemented in
subsequent patches. The interesting part of the patch is the addition of
a "ignore-file-indexes" setting to the dwarf plugin which enables a
user to force using manual indexing path in lldb (for example as a
debugging aid). I have also added a test that verifies that file indexes
are used by default.

Reviewers: JDevlieghere, clayborg, jingham

Subscribers: mgorny, mehdi_amini, aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D47629

llvm-svn: 334088
2018-06-06 11:35:23 +00:00