Summary:
With the last round of refactors, supporting type units in dwo files
becomes almost trivial. This patch contains a couple of small fixes,
which taken as a whole make type units work in the split dwarf scenario
(both DWARF4 and DWARF5):
- DWARFContext: make sure we actually read the debug_types.dwo section
- DWARFUnit: set string offsets base on all units in the dwo file, not
just the main CU
- ManualDWARFIndex: index all units in the file
- SymbolFileDWARFDwo: Search for the single compile unit in the file, as
we can no longer assume it will be the first one
The last part makes it obvious that there is still some work to be done
here, namely that we do not support dwo files with multiple compile
units. That is something that should be easier after the DIERef
refactors, but it still requires more work.
Tests are added for the type units+split dwarf + dwarf4/5 scenarios, as
well as a test that checks we behave reasonably in the presence of dwo
files with multiple CUs.
Reviewers: clayborg, JDevlieghere, aprantl
Subscribers: arphaman, lldb-commits
Differential Revision: https://reviews.llvm.org/D63643
llvm-svn: 364274
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
Summary:
Instead of accessing the fields directly, use accessor functions to
provide access to the DIERef components. This allows us to decouple the
external interface, from the internal representation. The external
interface can use llvm::Optional and similar goodies, while the data can
still be stored internally in a more compact representation.
I also document the purpose of the existing DIERef fields.
The main motivation for this change is a need to introduce an additional
field to the DIERef class, but I believe the change has its own merit.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: arphaman, lldb-commits
Differential Revision: https://reviews.llvm.org/D63400
llvm-svn: 363910
Previously it was storing a *pointer*, which left open the possibility
of this pointer being null. We never made use of that possibility (it
does not make sense), and most of the code was already assuming that.
However, there were a couple of null-checks scattered around the code.
This patch replaces the reference with a pointer, making the
non-null-ness explicit, and removes the remaining null-checks.
llvm-svn: 363381
Summary:
Type units don't represent actual compilations and a lot of the
operations that we do with lldb compile units (getting their line
tables, variables, etc.) don't make sense for them. There is also a lot
more of them (sometimes over 100x), so making them more lightweight pays
off.
The main change in this patch is that we stop creating lldb CompileUnits
for DWARF type units. The trickiest part here is that the SymbolFile
interface requires that we assign consecutive sequence IDs to the
compile units we create. As DWARF type and compile units can come in any
order (in v5), this means we can no longer use 1-1 mapping between DWARF
and lldb compile units. Instead I build a translation table between the
two indices. To avoid pessimizing the case where there are no type
units, I build the translation table only in case we have at least one
type unit.
Additionaly, I also tried to strenghted type safete by replacing
DWARFUnit with DWARFCompileUnit where applicable. Though that was not
stricly necessary, I found it a good way to ensure that the
transformations I am doing here make sense. In the places where I was
changing the function signatures, and where it was obvious that the
objects being handled were not null, I also replaced pointers with
references.
There shouldn't be any major functional change with this patch. The only
change I observed is that now the types in the type units will not be
parsed when one calls Module::ParseAllDebugSymbols, unless they are
referenced from other compile units. This makes sense, given how
ParseAllDebugSymbols is implemented (it iterates over all compile
units), and it only matters for one hand-writted test where I did not
bother to reference the types from the compile units (which I now do).
Reviewers: clayborg, JDevlieghere, aprantl
Subscribers: jdoerfert, lldb-commits
Differential Revision: https://reviews.llvm.org/D63005
llvm-svn: 363250
These variables were useful when looking up the compile unit index
required a binary search. Now that we can look up a compile unit index
in constant time, they are no longer needed.
llvm-svn: 361754
This moves the sections from SymbolFileDWARF to DWARFContext, where it
was trivial to do so. A couple of sections are still left in
SymbolFileDWARF. These will be handled by separate patches.
llvm-svn: 361127
Summary:
The previous attempt and moving section handling over to DWARFContext
(D59611) failed because it did not take into account the dwo sections
correctly. All DWARFContexts (even those in SymbolFileDWARFDwo) used the
main module for loading the sections, but in the dwo scenario some
sections should come from the dwo file.
This patch fixes that by making the DWARFContext aware of whether it a
dwo context or a regular one. A dwo context gets two sections lists, and
it knows where to look for a particular type of a section. This isn't
fully consistent with how the llvm DWARFContext behaves, because that
one leaves it up to the user to know whether it should ask for a dwo
section or not. However, for the time being, it seems useful to have a
single entity which knows how to peice together the debug info in dwo
and non-dwo scenarios. The rough roadmap for the future is:
- port over the rest of the sections to DWARFContext
- find a way to get rid of SymbolFileDWARFDwo/Dwp/DwpDwo. This will
likely involve adding the ability for the DWARFContext to spawn
dwo sub-contexts, similarly to how it's done in llvm.
- get rid of the special handling of the "dwo" contexts by making
sure everything knows whether it should ask for the .dwo version of
the section or not (similarly to how llvm's DWARFUnits do that)
To demonstrate how the DWARFContext should behave in this new world, I
port the debug_info section (which is debug_info.dwo in the dwo file)
handling to DWARFContext. The rest of the sections will come in
subsequent patches.
Reviewers: aprantl, clayborg, JDevlieghere
Subscribers: zturner, lldb-commits
Differential Revision: https://reviews.llvm.org/D62012
llvm-svn: 361000
Summary:
This patch adds the ability to precisely address debug info in
situations when a single file can have more than one debug-info-bearing
sections (as is the case with type units in DWARF v4).
The changes here can be classified into roughly three categories:
- the code which addresses a debug info by offset gets an additional
argument, which specifies the section one should look into.
- the DIERef class also gets an additional member variable specifying
the section. This way, code dealing with DIERefs can know which
section is the object referring to.
- the user_id_t encoding steals one bit from the dwarf_id field to store
the section. This means the total number of separate object files
(apple .o, or normal .dwo) is limited to 2 billion, but that is fine
as it's not possible to hit that number without switching to DWARF64
anyway.
This patch is functionally equivalent to (and inspired by) the two
patches (D61503 and D61504) by Jan Kratochvil, but there are differences
in the implementation:
- it uses an enum instead of a bool flag to differentiate the sections
- it increases the size of DIERef struct instead of reducing the amount
of addressable debug info
- it sets up DWARFDebugInfo to store the units in a single vector
instead of two. This sets us up for the future in which type units can
also live in the debug_info section, and I believe it's cleaner
because there's no need for unit index remapping
There are no tests with this patch as this is essentially NFC until
we start parsing type units from the debug_types section.
Reviewers: JDevlieghere, clayborg, aprantl
Subscribers: arphaman, jankratochvil, lldb-commits
Differential Revision: https://reviews.llvm.org/D61908
llvm-svn: 360872
Summary:
Instead of using the offset of the contained compile unit, we use it's
ID. The goal of this change is two-fold:
- free up space in the user_id_t representation to enable storing the
debug-info-carrying section (debug_types/debug_info) without
decreasing the amount of debug info we can address (as would be the
case with D61503).
- be a step towards supporting DWO files containing more than one unit
(important for debug_types+dwo, but can also happen with regular
dwo+lto). For this part to fully work we'd still need to add a way to
lookup the SymbolFileDWO without going through GetCompileUnitAtIndex,
but making sure things don't accidentally work because the SymbolFile
ID is the same as compile unit offset is a step towards that.
Reviewers: JDevlieghere, clayborg, aprantl
Subscribers: mehdi_amini, dexonsmith, tberghammer, jankratochvil, lldb-commits
Differential Revision: https://reviews.llvm.org/D61783
llvm-svn: 360565
D42892 changed a lot of code to use superclass DWARFUnit instead of its
subclass DWARFCompileUnit.
Finish this change more thoroughly for any *CompileUnit* -> *Unit* names.
Later patch will introduce DWARFTypeUnit which needs to be sometimes different
from DWARFCompileUnit and it would be confusing without this renaming.
Differential Revision: https://reviews.llvm.org/D61501
llvm-svn: 360443
This reverts commit r356682 because it breaks the DWO flavours of some
tests:
lldb-Suite :: lang/c/const_variables/TestConstVariables.py
lldb-Suite :: lang/c/local_variables/TestLocalVariables.py
lldb-Suite :: lang/c/vla/TestVLA.py
llvm-svn: 356773
This is mostly mechanical, and just moves the remaining non-DWO
related sections over to DWARFContext.
Differential Revision: https://reviews.llvm.org/D59611
llvm-svn: 356682
LLVM's DWARF parsing library has a class called DWARFContext which holds
all of the various DWARF data sections and lots of other information.
LLDB's on the other hand stores all of this directly in SymbolFileDWARF
/ SymbolFileDWARFDwo and passes this interface around through the
parsing library. Obviously this is incompatible with a world where the
low level interface does not depend on the high level interface, so we
need to move towards a model similar to LLVM's - i.e. all of the context
needed for low level parsing should be in a single class, and that class
gets passed around.
This patch is a small incremental step towards achieving this. The
interface and internals deviate from LLVM's for technical reasons, but
the high level idea is the same. The goal is, eventually, to remove all
occurrences of SymbolFileDWARF from the low level parsing code.
For now I've chosen a very simple section - the .debug_aranges section
to move into DWARFContext while leaving everything else unchanged. In
the short term this is a bit confusing because now the information you
need might come from either of 2 different locations. But it's a huge
refactor to do this all at once and runs a much higher risk of breaking
things. So I think it would be wise to do this in very small pieces.
TL;DR - No functional change
Differential Revision: https://reviews.llvm.org/D59562
llvm-svn: 356612
My apologies for the large patch. With the exception of ConstString.h
itself it was entirely produced by sed.
ConstString has exactly one const char * data member, so passing a
ConstString by reference is not any more efficient than copying it by
value. In both cases a single pointer is passed. But passing it by
value makes it harder to accidentally return the address of a local
object.
(This fixes rdar://problem/48640859 for the Apple folks)
Differential Revision: https://reviews.llvm.org/D59030
llvm-svn: 355553
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
Test cases were updated to not use the local compilation dir which
is different between development pc and build bots.
Original commit message:
[LLDB] - Support the single file split DWARF.
DWARF5 spec describes a single file split dwarf case
(when .dwo sections are in the .o files).
Problem is that LLDB does not work correctly in that case.
The issue is that, for example, both .debug_info and .debug_info.dwo
has the same type: eSectionTypeDWARFDebugInfo. And when code searches
section by type it might find the regular debug section
and not the .dwo one.
The patch fixes that. With it, LLDB is able to work with
output compiled with -gsplit-dwarf=single flag correctly.
Differential revision: https://reviews.llvm.org/D52403
llvm-svn: 346855
DWARF5 spec describes a single file split dwarf case
(when .dwo sections are in the .o files).
Problem is that LLDB does not work correctly in that case.
The issue is that, for example, both .debug_info and .debug_info.dwo
has the same type: eSectionTypeDWARFDebugInfo. And when code searches
section by type it might find the regular debug section
and not the .dwo one.
The patch fixes that. With it, LLDB is able to work with
output compiled with -gsplit-dwarf=single flag correctly.
Differential revision: https://reviews.llvm.org/D52296
llvm-svn: 346848
Now the codebase can use the DWARFUnit superclass. It will make it later
seamlessly work also with DWARFPartialUnit for DWZ.
This patch is only a search-and-replace easily undone, nothing interesting
in it.
Differential revision: https://reviews.llvm.org/D42892
llvm-svn: 327810
DWO/DWP should not be indexed directly.
Instead, the corresponding base file should be used.
This diff adds an assert to DWARFCompileUnit::Index
and adjusts the methods
SymbolFileDWARF::FindCompleteObjCDefinitionTypeForDIE,
SymbolFileDWARF::GetObjCMethodDIEOffsets accordingly.
Differential revision: https://reviews.llvm.org/D39825
llvm-svn: 318554
This reapplies https://reviews.llvm.org/D35740 with a tweak to find
the section by name rather than type. Section types don't distinguish
between regular sections and their DWO counterparts.
llvm-svn: 308905
The DWO handling code can get confused by clang modules which also use
skeleton CUs to point to the object file with the full debug
info. This patch detects whether an object is a "real" DWO or a clang
module and prevents LLDB from interpreting clang modules as DWO. This
fixes the regression in TestWithModuleDebugging.
http://llvm.org/bugs/show_bug.cgi?id=33875
Differential Revision: https://reviews.llvm.org/D35740
llvm-svn: 308850
*** to conform to clang-format’s LLVM style. This kind of mass change has
*** two obvious implications:
Firstly, merging this particular commit into a downstream fork may be a huge
effort. Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit. The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):
find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;
The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.
Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit. There are alternatives available that will attempt
to look through this change and find the appropriate prior commit. YMMV.
llvm-svn: 280751
Summary:
In case of Dwo, DIERef stores a compile unit offset in the main object file, and not in the dwo.
The implementation of SymbolFileDWARFDwo::GetDIE inherited from SymbolFileDWARF tried to lookup
the compilation unit in the DWO based on the main object file offset (and failed). I change the
implementation to verify the DIERef indeed references compile unit belonging to this dwo and then
lookup the die based on the die offset alone.
Includes a couple of fixes for mismatched struct/class tags.
Reviewers: tberghammer, clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D18646
llvm-svn: 265011
Split-dwarf uses a different header format to specify the address range
for the elements of the location lists.
Differential revision: http://reviews.llvm.org/D12880
llvm-svn: 247789
* Create new dwo symbol file class
* Add handling for .dwo sections
* Change indexes in SymbolFileDWARF to store compile unit offset next to
DIE offset
* Propagate queries from dwarf compile unit to the dwo compile unit
where applicable
Differential revision: http://reviews.llvm.org/D12291
llvm-svn: 247132
Pavel Labath