245 Commits

Author SHA1 Message Date
Pavel Labath
3d7177acd7 [lldb/DWARF] Remove one more auto-dwo method
Summary:
Our DWARFUnit was automatically forwarding the requests to the split
unit when looking for a DIE by offset. llvm::DWARFUnit does not do that,
and is not likely to start doing it any time soon.

This patch deletes the this logic and updates the callers to request the
correct unit instead. While doing that, I've found a bit of duplicated
code for lookup up a function and block by address, so I've extracted
that into a helper function.

Reviewers: JDevlieghere, aprantl, clayborg, jdoerfert

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73112
2020-01-22 13:03:57 +01:00
Pavel Labath
27df2d9f55 [lldb] Don't process symlinks deep inside DWARFUnit
Summary:
This code is handling debug info paths starting with /proc/self/cwd,
which is one of the mechanisms people use to obtain "relocatable" debug
info (the idea being that one starts the debugger with an appropriate
cwd and things "just work").

Instead of resolving the symlinks inside DWARFUnit, we can do the same
thing more elegantly by hooking into the existing Module path remapping
code. Since llvm::DWARFUnit does not support any similar functionality,
doing things this way is also a step towards unifying llvm and lldb
dwarf parsers.

Reviewers: JDevlieghere, aprantl, clayborg, jdoerfert

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71770
2020-01-20 13:05:00 +01:00
Vedant Kumar
f0120556c7 [DWARF] Emit DW_AT_call_return_pc as an address
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.

In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.

The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.

Differential Revision: https://reviews.llvm.org/D72489
2020-01-15 13:02:23 -08:00
Pavel Labath
4b5bc38802 [lldb/DWARF] Move location list sections into DWARFContext
These are the last sections not managed by the DWARFContext object. I
also introduce separate SectionType enums for dwo section variants, as
this is necessary for proper handling of single-file split dwarf.
2020-01-14 15:19:29 +01:00
Pavel Labath
cd5da94d80 [lldb/DWARF] Fix mixed v4+v5 location lists
Summary:
Our code was expecting that a single (symbol) file contains only one
kind of location lists. This is not correct (on non-apple platforms, at
least) as a file can compile units with different dwarf versions.

This patch moves the deteremination of location list flavour down to the
compile unit level, fixing this problem. I have also tried to rougly
align the code with the llvm DWARFUnit. Fully matching the API is not
possible because of how lldb's DWARFExpression lives separately from the
rest of the DWARF code, but this is at least a step in the right
direction.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71751
2020-01-09 13:19:29 +01:00
Pavel Labath
9bb01efa49 [lldb/DWARF] Add is_dwo member to DWARFUnit
Summary:
A skeleton unit can easily be detected by checking the m_dwo_symbol_file
member, but we cannot tell a split unit from a normal unit from the
"inside", which is sometimes useful.

This patch adds a m_is_dwo member to enable this, and align the code
with llvm::DWARFUnit. Right now it's only used to avoid creating a split
unit inside another split unit (which removes one override from
SymbolFileDWARFDwo and brings us a step closer to deleting it), but my
main motivation is fixing the handling of location lists in mixed v4&v5
files. This comes in a separate patch.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71750
2020-01-09 13:19:29 +01:00
Pavel Labath
f5767e284b [lldb/DWARF] Switch to llvm debug_rnglists parser
Summary:
Our rnglist support was working only for the trivial cases (one CU),
because we only ever parsed one contribution out of the debug_rnglists
section. This means we were never able to resolve range lists for the
second and subsequent units (DW_FORM_sec_offset references came out
blang, and DW_FORM_rnglistx references always used the ranges lists from
the first unit).

Since both llvm and lldb rnglist parsers are sufficiently
self-contained, and operate similarly, we can fix this problem by
switching to the llvm parser instead. Besides the changes which are due
to variations in the interface, the main thing is that now the range
list object is a member of the DWARFUnit, instead of the entire symbol
file. This ensures that each unit can get it's own private set of range
list indices, and is consistent with how llvm's DWARFUnit does it
(overall, I've tried to structure the code the same way as the llvm
version).

I've also added a test case for the two unit scenario.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71021
2019-12-05 13:02:03 +01:00
Vedant Kumar
4fdbc0728d [DWARF] Handle call sites with indirect call targets
Split CallEdge into DirectCallEdge and IndirectCallEdge. Teach
DWARFExpression how to evaluate entry values in cases where the current
activation was created by an indirect call.

rdar://57094085

Differential Revision: https://reviews.llvm.org/D70100
2019-11-22 11:50:22 -08:00
Adrian Prantl
1cbe003894 [-gmodules] Let LLDB log a warning if the Clang module hash mismatches.
This feature is mostly there to aid debugging of Clang module issues,
since the only useful actual the end-user can to is to recompile their
program.

Differential Revision: https://reviews.llvm.org/D70272
2019-11-15 11:52:13 -08:00
Adrian Prantl
7d71dd928d Add RTTI support to the SymbolFile class hierarchy
Differential Revision: https://reviews.llvm.org/D70322
2019-11-15 11:52:13 -08:00
Adrian Prantl
0e45e60c6f Use ForEachExternalModule in ParseTypeFromClangModule (NFC)
I wanted to further simplify ParseTypeFromClangModule by replacing the
hand-rolled loop with ForEachExternalModule, and then realized that
ForEachExternalModule also had the problem of visiting the same leaf
node an exponential number of times in the worst-case. This adds a set
of searched_symbol_files set to the function as well as the ability to
early-exit from it.

Differential Revision: https://reviews.llvm.org/D70215
2019-11-14 08:58:31 -08:00
Adrian Prantl
3d30c142e1 Rename clang-module-related *DWO* functions to *ClangModule* (NFC)
This avoids confusing them with fission-related functionality.

I also moved two accessor functions from DWARFDIE into static
functions in DWARFASTParserClang were their only use is located.
2019-11-13 14:07:20 -08:00
Adrian Prantl
3b73dcdc96 Performance: Add a set of visited SymbolFiles to the other FindFiles variant.
This is basically the same bug as in r260434.

SymbolFileDWARF::FindTypes has exponential worst-case when digging
through dependency DAG of .pcm files because each object file and .pcm
file may depend on an already-visited .pcm file, which may again have
dependencies. Fixed here by carrying a set of already visited
SymbolFiles around.

rdar://problem/56993424

Differential Revision: https://reviews.llvm.org/D70106
2019-11-12 09:38:37 -08:00
Adrian Prantl
1ad655e255 Modernize the rest of the Find.* API (NFC)
This patch removes the size_t return value and the append parameter
from the remainder of the Find.* functions in LLDB's internal API. As
in the previous patches, this is motivated by the fact that these
parameters aren't really used, and in the case of the append parameter
were frequently implemented incorrectly.

Differential Revision: https://reviews.llvm.org/D69119

llvm-svn: 375160
2019-10-17 19:56:40 +00:00
Adrian Prantl
bf9d84c014 Remove size_t return parameter from FindTypes
In r368345 I accidentally introduced a regression that would
over-report the number of matches found by FindTypes if the
DeclContext Filter was hit.

This patch simply removes the size_t return parameter altogether —
it's not that useful.

rdar://problem/55500457

Differential Revision: https://reviews.llvm.org/D68169

llvm-svn: 373344
2019-10-01 15:40:41 +00:00
Adrian Prantl
d4d428ef92 Remove unused "append" parameter from FindTypes API
I noticed that SymbolFileDWARFDebugMap::FindTypes was implementing it
incorrectly (passing append=false in a for-loop to recursive calls to
FindTypes would yield only the very last set of results), but instead
of fixing it, removing it seemed like an even better option.

rdar://problem/54412692

Differential Revision: https://reviews.llvm.org/D68171

llvm-svn: 373224
2019-09-30 16:42:28 +00:00
Raphael Isemann
9379d19ff8 [lldb] Decouple importing the std C++ module from the way the program is compiled
Summary:
At the moment, when trying to import the `std` module in LLDB, we look at the imported modules used in the compiled program
and try to infer the Clang configuration we need from the DWARF module-import. That was the initial idea but turned out to
cause a few problems or inconveniences:

* It requires that users compile their programs with C++ modules. Given how experimental C++ modules are makes this feature inaccessible
for many users. Also it means that people can't just get the benefits of this feature for free when we activate it by default
(and we can't just close all the associated bug reports).
* Relying on DWARF's imported module tags (that are only emitted by default on macOS) means this can only be used when using DWARF (and with -glldb on Linux).
* We essentially hardcoded the C standard library paths on some platforms (Linux) or just couldn't support this feature on other platforms (macOS).

This patch drops the whole idea of looking at the imported module DWARF tags and instead just uses the support files of the compilation unit.
If we look at the support files and see file paths that indicate where the C standard library and libc++ are, we can just create the module
configuration this information. This fixes all the problems above which means we can enable all the tests now on Linux, macOS and with other debug information
than what we currently had. The only debug information specific code is now the iteration over external type module when -gmodules is used (as `std` and also the
`Darwin` module are their own external type module with their own files).

The meat of this patch is the CppModuleConfiguration which looks at the file paths from the compilation unit and then figures out the include paths
based on those paths. It's quite conservative in that it only enables modules if we find a single C library and single libc++ library. It's still missing some
test mode where we try to compile an expression before we actually activate the config for the user (which probably also needs some caching mechanism),
but for now it works and makes the feature usable.

Reviewers: aprantl, shafik, jdoerfert

Reviewed By: aprantl

Subscribers: mgorny, abidh, JDevlieghere, lldb-commits

Tags: #c_modules_in_lldb, #lldb

Differential Revision: https://reviews.llvm.org/D67760

llvm-svn: 372716
2019-09-24 10:08:18 +00:00
Adrian Prantl
aa97a89d83 Extend FindTypes with CompilerContext to allow filtering by language.
This patch is also motivated by the Swift branch and is effectively NFC for the single-TypeSystem llvm.org branch.

In multi-language projects it is extremely common to have, e.g., a
Clang type and a similarly-named rendition of that same type in
another language. When searching for a type It is much cheaper to pass
a set of supported languages to the SymbolFile than having it
materialize every result and then rejecting the materialized types
that have the wrong language.

Differential Revision: https://reviews.llvm.org/D66546

<rdar://problem/54471165>

This reapplies r369690 with a previously missing constructor for LanguageSet.

llvm-svn: 369710
2019-08-22 21:45:58 +00:00
Adrian Prantl
b041602e3f Revert Extend FindTypes with CompilerContext to allow filtering by language.
This reverts r369690 (git commit aa3a564efa6b5fff2129f81a4041069a0233168f)

llvm-svn: 369702
2019-08-22 20:41:16 +00:00
Adrian Prantl
aa3a564efa Extend FindTypes with CompilerContext to allow filtering by language.
This patch is also motivated by the Swift branch and is effectively NFC for the single-TypeSystem llvm.org branch.

In multi-language projects it is extremely common to have, e.g., a
Clang type and a similarly-named rendition of that same type in
another language. When searching for a type It is much cheaper to pass
a set of supported languages to the SymbolFile than having it
materialize every result and then rejecting the materialized types
that have the wrong language.

Differential Revision: https://reviews.llvm.org/D66546

<rdar://problem/54471165>

llvm-svn: 369690
2019-08-22 19:24:55 +00:00
Adrian Prantl
330ae19a1a Generalize FindTypes with CompilerContext to support fuzzy lookup
This patch generalizes the FindTypes with CompilerContext interface to
support looking up a type of unknown kind by name, as well as looking
up a type inside an unspecified submodule. These features are
motivated by the Swift branch, but are fully tested via unit tests and
lldb-test on llvm.org.  Specifically, this patch adds an AnyModule and
an AnyType CompilerContext kind.

Differential Revision: https://reviews.llvm.org/D66507

rdar://problem/54471165

llvm-svn: 369555
2019-08-21 18:06:56 +00:00
Pavel Labath
d2deeb4490 SymbolVendor: Remove the object file member variable
Summary:
The last responsibility of the SymbolVendor was to hold an owning
reference to the object file (in case symbols are being read from a
different file than the main module). As SymbolFile classes already hold
a non-owning reference to the object file, we can easily remove this
responsibility of the SymbolVendor by making the SymbolFile reference
owning.

Reviewers: JDevlieghere, clayborg, jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D65401

llvm-svn: 367392
2019-07-31 08:25:25 +00:00
Alex Langford
0e252e38ef [Symbol] Use llvm::Expected when getting TypeSystems
Summary:
This commit achieves the following:
- Functions used to return a `TypeSystem *` return an
  `llvm::Expected<TypeSystem *>` now. This means that the result of a call
  is always checked, forcing clients to move more carefully.
- `TypeSystemMap::GetTypeSystemForLanguage` will either return an Error or a
  non-null pointer to a TypeSystem.

Reviewers: JDevlieghere, davide, compnerd

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D65122

llvm-svn: 367360
2019-07-30 22:12:34 +00:00
Pavel Labath
d67b550df5 DWARF: Improve type safety or range lists parsing
Delete the abstract GetOffset function, which is only defined for
rnglists entries. Instead fix up entries which refer to the range list
classes so that one can statically know that he is dealing with the
rnglists section and call the function that way.

llvm-svn: 367106
2019-07-26 13:15:28 +00:00
Pavel Labath
f46e8974de SymbolVendor: Remove the type list member
Summary:
Similarly to the compile unit lists, the list of types can also be
managed by the symbol file itself.

Since the only purpose of this list seems to be to maintain an owning
reference to all the types a symbol file has created (items are only
ever added to the list, never retrieved), I remove the passthrough
functions in SymbolVendor and Module. I also tighten the interface of
the function (return a reference instead of a pointer, make it protected
instead of public).

Reviewers: clayborg, JDevlieghere, jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D65135

llvm-svn: 366994
2019-07-25 08:22:05 +00:00
Pavel Labath
e0119909a6 SymbolVendor: Move compile unit handling into the SymbolFile class
Summary:
SymbolFile classes are responsible for creating CompileUnit instances
and they already need to have a notion of the id<->CompileUnit mapping
(because of APIs like ParseCompileUnitAtIndex). However, the
SymbolVendor has remained as the thing responsible for caching created
units (which the SymbolFiles were calling via convoluted constructs like
"m_obj_file->GetModule()->GetSymbolVendor()->SetCompileUnitAtIndex(...)").

This patch moves the responsibility of caching the units into the
SymbolFile class. It does this by moving the implementation of
SymbolVendor::{GetNumCompileUnits,GetCompileUnitAtIndex} into the
equivalent SymbolFile functions. The SymbolVendor functions become just
a passthrough much like the rest of SymbolVendor.

The original implementations of SymbolFile::GetNumCompileUnits is moved
to "CalculateNumCompileUnits", and are made protected, as the "Get"
function is the external api of the class.
SymbolFile::ParseCompileUnitAtIndex is made protected for the same
reason.

This is the first step in removing the SymbolVendor indirection, as
proposed in
<http://lists.llvm.org/pipermail/lldb-dev/2019-June/015071.html>. After
removing all interesting logic from the SymbolVendor class, I'll proceed
with removing the indirection itself.

Reviewers: clayborg, jingham, JDevlieghere

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D65089

llvm-svn: 366791
2019-07-23 09:24:02 +00:00
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
5418d335e1 Fix -Wmismatched-tags introduced in r363910
That commit changed DIERef from a struct to a class, but did not update
the forward-declarations. This fixes one forward-declaration, and
removes other (unused) decls.

llvm-svn: 363915
2019-06-20 09:46:37 +00:00
Pavel Labath
0de98ebd00 DWARF: Provide accessors to DIERef fields
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
2019-06-20 08:24:46 +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
a71ce4f1e8 DWARF: Avoid storing DIERefs in long-lived containers
Summary:
A user_id_t carries the same information as a DIERef, but it takes up
less space.

Furthermore, DIERef::operator<'s implementation is very
questionable, as it does not take the cu_offset and section fields into
account. Using just the die offset was correct in the days when all
debug info lived in a single section, but since we started supporting
DWO debug info, this was no longer true. The comparison operator could
be fixed, but it seems like using the user_id_t for these purposes is a
better idea overall.

I think this did not cause any bugs, because the only place the
comparison operator was used is in m_function_scope_qualified_name_map,
and this one is local to a dwo file, but I am not 100% sure of that.

Reviewers: clayborg, JDevlieghere

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D63322

llvm-svn: 363528
2019-06-17 07:32:56 +00:00
Pavel Labath
00e3968b8a DWARF: port debug_ranges/rnglists over to DWARFContext
llvm-svn: 363400
2019-06-14 14:12:25 +00:00
Pavel Labath
ad17e289f0 DWARF: Don't create lldb CompileUnits for DWARF type units
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
2019-06-13 11:22:47 +00:00
Pavel Labath
ca9c3de17e DWARF: Share line tables of type units
Summary:
This patch creates a cache of file lists in line tables referenced by
type units.  This cache is used to avoid parsing a line table twice
(since a file list will generally be shared by many type units).

It also sets things up in a way that parsing of DW_AT_decl_file
attributes will keep working even when we stop creating lldb compile
units for dwarf type units, but it stops short of actually doing that.
This means that the request for files now go directly to SymbolFileDWARF
instead of being routed there indirectly via the
lldb_private::CompileUnit class.

As a result of this, a number of occurences of SymbolContext variables
in DWARFASTParserClang have become unused, so I remove them.

This patch reduces the number of times a file list is being parsed, but
the situation is still suboptimal, as the parsed list is being copied
multiple times. This will be fixed when we stop creating CompileUnits
for DWARF type units.

Reviewers: clayborg, aprantl, JDevlieghere

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D62894

llvm-svn: 363143
2019-06-12 11:29:50 +00:00
Pavel Labath
78cfe1e6fe DWARF: Fix address range support in mixed 4+5 scenario
Summary:
debug_ranges got renamed to debug_rnglists in DWARF 5. Prior to this
patch lldb was just picking the first section it could find in the file,
and using that for all address ranges lookups. This is not correct in
case the file contains a mixture of compile units with various standard
versions (not a completely unlikely scenario).

In this patch I make lldb support reading from both sections
simulaneously, and decide the correct section to use based on the
version number of the compile unit. SymbolFileDWARF::DebugRanges is
split into GetDebugRanges and GetDebugRngLists (the first one is renamed
mainly so we can catch all incorrect usages).

I tried to structure the code similarly to how llvm handles this logic
(hence DWARFUnit::FindRnglistFromOffset/Index), but the implementations
are still relatively far from each other.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D62302

llvm-svn: 361938
2019-05-29 09:22:36 +00:00
Jonas Devlieghere
d02da8f42c [SymbolFileDWARF] Remove unused member (NFC)
Removes the unused debug line instance.

llvm-svn: 361886
2019-05-28 22:33:30 +00:00
Pavel Labath
519ef6afdf DWARF: Remove cu_idx variables from parsing functions
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
2019-05-27 10:10:59 +00:00
Konrad Kleine
248a13057a [lldb] NFC modernize codebase with modernize-use-nullptr
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.

This is the command I ran and I to fix and format the code base:

```
run-clang-tidy.py \
	-header-filter='.*' \
	-checks='-*,modernize-use-nullptr' \
	-fix ~/dev/llvm-project/lldb/.* \
	-format \
	-style LLVM \
	-p ~/llvm-builds/debug-ninja-gcc
```

NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.

NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.

Reviewers: martong, espindola, shafik, #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D61847

llvm-svn: 361484
2019-05-23 11:14:47 +00:00
Pavel Labath
324396466c DWARF: Don't compute address ranges for type units
Summary:
Type units don't describe any code, so they should never be the result
of any address lookup queries.

Previously, we would compute the address ranges for the type units for
via the line tables they reference because the type units looked a lot
like line-tables-only compile units. However, this is not correct, as
the line tables are only referenced from type units so that other
declarations can use the file names contained in them.

In this patch I make the BuildAddressRangeTable function virtual, and
implement it only for compile units.

Testing this was a bit tricky, because the behavior depends on the order
in which we add things to the address range map. This rarely caused a
problem with DWARF v4 type units, as they are always added after all
CUs. It happened more frequently with DWARF v5, as there clang emits the
type units first. However, this is still not something that it is
required to do, so for testing I've created an assembly file where I've
deliberately sandwiched a compile unit between two type units, which
should isolate us from both changes in how the compiler emits the units
and changes in the order we process them.

Reviewers: clayborg, aprantl, JDevlieghere

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D62178

llvm-svn: 361465
2019-05-23 09:07:51 +00:00
Pavel Labath
f33f181678 DWARF: Port debug_addr over to DWARFContext
llvm-svn: 361232
2019-05-21 09:11:11 +00:00
Pavel Labath
0261b9498b DWARF: Port most of other sections over to DWARFContext
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
2019-05-20 08:38:47 +00:00
Pavel Labath
ff9b4263f9 Make DWARFContext dwo-aware and port debug_info sections over
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
2019-05-17 08:26:58 +00:00
Pavel Labath
f4014e116e DWARF: Add ability to reference debug info coming from multiple sections
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
2019-05-16 11:07:58 +00:00
Pavel Labath
2841e6edc8 [DWARF] Centralize user_id <-> DWARFDIE conversions
Summary:
The logic for translating a user_id into a DWARFDIE was replicated in
several places. This removes that redundancy and settles on a single
implementation in SymbolFileDWARF.

The reason for choosing that instead of DIERef was that we were
always immediately converting the returned DIERef into a DWARFDIE
anyway, which meant that one had to specify the SymbolFileDWARF argument
twice (once to get the DIERef, and once to get the actual DIE). Also,
passing a higher-level object (SymbolFileDWARF) into a lower-level one
(DIERef) seemed like a less intuitive arrangement than doing things the
other way around.

Reviewers: JDevlieghere, clayborg, aprantl

Subscribers: tberghammer, jankratochvil, lldb-commits

Differential Revision: https://reviews.llvm.org/D61648

llvm-svn: 360246
2019-05-08 11:43:05 +00:00
Frederic Riss
acbf0058e9 Lock accesses to OptionValueFileSpecList objects
Before a Debugger gets a Target, target settings are routed to a global set
of settings. Even without this, some part of the LLDB which exist independently
of the Debugger object (the Module cache, the Symbol vendors, ...) access
directly the global default store for those settings.

Of course, if you modify one of those global settings while they are being read,
bad things happen. We see this quite a bit with FileSpecList settings. In
particular, we see many cases where one debug session changes
target.exec-search-paths while another session starts up and it crashes when
one of those accesses invalid FileSpecs.

This patch addresses the specific FileSpecList issue by adding locking to
OptionValueFileSpecList and never returning by reference.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D60468

llvm-svn: 359028
2019-04-23 20:17:04 +00:00
Jonas Devlieghere
8b3af63b89 [NFC] Remove ASCII lines from comments
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.

Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.

I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.

Differential revision: https://reviews.llvm.org/D60508

llvm-svn: 358135
2019-04-10 20:48:55 +00:00
Pavel Labath
4c2ef9a02b Revert "Move the rest of the sections over to DWARFContext."
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
2019-03-22 16:07:58 +00:00
Zachary Turner
b4fe87d0c9 Move the rest of the sections over to DWARFContext.
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
2019-03-21 16:34:58 +00:00
Zachary Turner
6e66512758 Introduce DWARFContext.
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
2019-03-20 20:49:25 +00:00
Zachary Turner
0eaa6d5b01 Remove DWARFDIECollection.
This is a very thin wrapper over a std::vector<DWARFDIE> and does
not seem to provide any real value over just using a container
directly.

Differential Revision: https://reviews.llvm.org/D59165

llvm-svn: 355974
2019-03-12 20:50:46 +00:00