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.
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
This patch add the ability to cache the manual DWARF indexing results to disk for faster subsequent debug sessions. Manual DWARF indexing is time consuming and causes all DWARF to be fully parsed and indexed each time you debug a binary that doesn't have an acceptable accelerator table. Acceptable accelerator tables include .debug_names in DWARF5 or Apple accelerator tables.
This patch breaks up testing by testing all of the encoding and decoding of required C++ objects in a gtest unit test, and then has a test to verify the debug info cache is generated correctly.
This patch also adds the ability to track when a symbol table or DWARF index is loaded or saved to the cache in the "statistics dump" command. This is essential to know in statistics as it can help explain why a debug session was slower or faster than expected.
Reviewed By: labath, wallace
Differential Revision: https://reviews.llvm.org/D115951
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
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
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
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).
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
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
The fix form sizes use to have two arrays: one for 4 byte addresses and in for 8 byte addresses. The table had an issue where DW_FORM_flag_present wasn't being represented as a fixed size form because its actual size _is_ zero and zero was used to indicate the form isn't fixed in size. Any code that needed to quickly access the DWARF had to get a FixedFormSizes instance using the address byte size.
This fix cleans things up by adding a DWARFFormValue::GetFixedSize() both as a static method and as a member function on DWARFFormValue. It correctly can indicate if a form size is zero. This cleanup is a precursor to a follow up patch where I hope to speed up DWARF parsing.
I verified performance doesn't regress by loading hundreds of DWARF files and setting a breakpoint by file and line and by name in files that do not have DWARF indexes. Performance remained consistent between the two approaches.
Differential Revision: https://reviews.llvm.org/D62416
llvm-svn: 361675
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:
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
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
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
Several functions were passing a list of 8 NameToDIE arguments around.
This puts those variables in a struct and passes that instead, reducing
code duplication and the possibility of error (swapping two arguments
accidentally).
llvm-svn: 333264
Summary:
I think this makes sense for several reasons:
- better separation of concerns: DWARFUnit's job should be to provide a
nice interface to its users to access the unit contents.
ManualDWARFIndex can then use this interface to build an index and
provide it to its users.
- closer alignment with llvm parsers: there is no indexing equivalent in
llvm, and there probably never will be, as the index is very centered
around how lldb wants to access debug info. If we ever switch to
llvm's parser, this will allow us swap out DWARFUnit implementations
and keep indexing as-is.
- closer proximity of the indexing code to AppleDWARFIndex will make it
easier to keep the two in sync (e.g. right now the two use very
different algorithms to determine whether a DW_TAG_subroutine
represents a "method"). This is my primary motivation for making this
change now, but I am leaving this work to a separate patch.
The only interface change to DWARFUnit I needed to make was to add an
efficient way to iterate over the list of all DIEs. Adding this also
aligns us closer to the llvm parser.
Reviewers: JDevlieghere, clayborg, aprantl
Subscribers: lldb-commits
Differential Revision: https://reviews.llvm.org/D47253
llvm-svn: 333178
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
Alex Langford