73 Commits

Author SHA1 Message Date
Pavel Labath
05dfbc146d
[lldb] Regularize DWARFDIE::Get{TypeLookup,Decl}Context names (#122273)
The functions call GetName for everything except variables, where they
call GetPubname instead. The difference is that the latter prefers to
return the linkage name, if it is available.

This doesn't seem particularly useful given that the linkage name
already kind of contains the context of the variable, and I doubt that
anything depends on it as these functions are currently called on type
and subprogram DIEs -- not variables.

This makes it easier to simplify/deduplicate these functions later.
2025-01-10 09:23:52 +01:00
Pavel Labath
fb8df8cb65
[lldb/DWARF] s/DWARFRangeList/llvm::DWARFAddressRangeVector (#116620)
The main difference is that the llvm class (just a std::vector in
disguise) is not sorted. It turns out this isn't an issue because the
callers either:
- ignore the range list;
- convert it to a different format (which is then sorted);
- or query the minimum value (which is faster than sorting)

The last case is something I want to get rid of in a followup as a part
of removing the assumption that function's entry point is also its
lowest address.
2024-12-13 14:29:59 +01:00
Zequan Wu
2e425bf629 Reapply "[lldb][dwarf] Compute fully qualified names on simplified template names with DWARFTypePrinter (#117071)"
9de73b20404f0b2db1cbf70d164cfe0789d5bb94 lands a fix to DWARFTypePrinter that is used by lldb in this change.
2024-12-04 13:05:36 -08:00
Mikhail Goncharov
11ee21671f Revert " [lldb][dwarf] Compute fully qualified names on simplified template names with DWARFTypePrinter (#117071)"
This reverts commit f06c187799d910fd3ac3e9106397e5eecff9f265.

Temporary revert: there is https://github.com/llvm/llvm-project/pull/117239 that is suppose to fix the issue.
Reverting to keep things rolling.
2024-11-22 13:49:37 +01:00
Zequan Wu
f06c187799
[lldb][dwarf] Compute fully qualified names on simplified template names with DWARFTypePrinter (#117071)
This is a reland of https://github.com/llvm/llvm-project/pull/112811.
Fixed the bot breakage by running ld.lld explicitly.
2024-11-20 17:19:35 -05:00
Shubham Sandeep Rastogi
c51786b022 Revert "[lldb][dwarf] Compute fully qualified names on simplified template names with DWARFTypePrinter (#112811)"
This reverts commit 94d100f2ba81c2bf0ef495f68d66ba8c94c71d2a.

Reverted because of greendragon failure on the incremental arm64 bot

******************** TEST 'lldb-shell :: SymbolFile/DWARF/x86/simplified-template-names.cpp' FAILED ********************
Exit Code: 1

RUN: at line 7: /Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-pc-linux -g -gsimple-template-names /Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/simplified-template-names.cpp -o /Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/simplified-template-names.cpp.tmp

/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/bin/clang --driver-mode=g++ --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-pc-linux -g -gsimple-template-names /Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/simplified-template-names.cpp -o /Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/lldb-build/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/simplified-template-names.cpp.tmp
ld: warning: -m is obsolete
ld: unknown option: --hash-style=gnu
clang: error: linker command failed with exit code 1 (use -v to see invocation)
2024-11-18 17:19:38 -08:00
Zequan Wu
94d100f2ba
[lldb][dwarf] Compute fully qualified names on simplified template names with DWARFTypePrinter (#112811)
This is the second half of
https://github.com/llvm/llvm-project/pull/90008.

Essentially, it replaces the work of resolving template types when we
just need the qualified names with walking the DIE tree using
`DWARFTypePrinter`.

### Result
For an internal target, the time spent on `expr *this` for the first
time reduced from 28 secs to 17 secs.
2024-11-18 17:45:54 -05:00
Augusto Noronha
d6b9028257
[lldb] Extend FindTypes to optionally search by mangled type name (#113007)
Swift types have mangled type names. This adds functionality to look up
those types through the FindTypes API by searching for the mangled type
name instead of the regular name.
2024-10-31 09:45:58 -07:00
Pavel Labath
925b220ee4
[lldb] Recurse through DW_AT_signature when looking for attributes (#107241)
This allows e.g. DWARFDIE::GetName() to return the name of the type when
looking at its declaration (which contains only
DW_AT_declaration+DW_AT_signature). This is similar to how we recurse
through DW_AT_specification when looking for a function name. Llvm dwarf
parser has obtained the same functionality through #99495.

This fixes a bug where we would confuse a type like NS::Outer::Struct
with NS::Struct (because NS::Outer (and its name) was in a type unit).
2024-09-10 12:57:54 +02:00
Pavel Labath
dd5d730072
[lldb] Better matching of types in anonymous namespaces (#102111)
This patch extends TypeQuery matching to support anonymous namespaces. A
new flag is added to control the behavior. In the "strict" mode, the
query must match the type exactly -- all anonymous namespaces included.
The dynamic type resolver in the itanium abi (the motivating use case
for this) uses this flag, as it queries using the name from the
demangles, which includes anonymous namespaces.

This ensures we don't confuse a type with a same-named type in an
anonymous namespace. However, this does *not* ensure we don't confuse
two types in anonymous namespacs (in different CUs). To resolve this, we
would need to use a completely different lookup algorithm, which
probably also requires a DWARF extension.

In the "lax" mode (the default), the anonymous namespaces in the query
are optional, and this allows one search for the type using the usual
language rules (`::A` matches `::(anonymous namespace)::A`).

This patch also changes the type context computation algorithm in
DWARFDIE, so that it includes anonymous namespace information. This
causes a slight change in behavior: the algorithm previously stopped
computing the context after encountering an anonymous namespace, which
caused the outer namespaces to be ignored. This meant that a type like
`NS::(anonymous namespace)::A` would be (incorrectly) recognized as
`::A`). This can cause code depending on the old behavior to misbehave.
The fix is to specify all the enclosing namespaces in the query, or use
a non-exact match.
2024-09-02 08:34:14 +02:00
Pavel Labath
599ca7165e
[lldb] Merge CompilerContextKind::{Class,Struct} (#96145)
Our dwarf parsing code treats structures and classes as interchangable.
CompilerContextKind is used when looking DIEs for types. This makes sure
we always they're treated the same way.

See also
[#95905#discussion_r1645686628](https://github.com/llvm/llvm-project/pull/95905#discussion_r1645686628).
2024-06-24 08:56:21 +02:00
Pavel Labath
b37f9e0bdf
[lldb] Move DWARFDeclContext functions from DWARFDebugInfoEntry to DW… (#95227)
…ARFDIE

This puts them closer to the other two functions doing something very
similar. I've tried to stick to the original logic of the functions as
much as possible, though I did apply some easy simplifications.

The changes in DWARFDeclContext.h are there to make the unit tests
produce more useful error messages.
2024-06-13 10:44:45 +02:00
Greg Clayton
a118f5f398
Fix type lookup bug where wrong decl context was being used for a DIE. (#94846)
The function that calculated the declaration context for a DIE was incorrectly transparently traversing acrosss DW_TAG_subprogram dies when climbing the parent DIE chain. This meant that types defined in functions would appear to have the declaration context of anything above the function. I fixed the GetTypeLookupContextImpl(...) function in DWARFDIE.cpp to not transparently skip over functions, lexical blocks and inlined functions and compile and type units. Added a test to verify things are working.
2024-06-11 13:58:26 -07:00
Pavel Labath
56f668c12b
[lldb/DWARF] Remove some dead code (#95127)
`GetDeclContextDIEs` and `DIEDeclContextsMatch` are unused (possibly
since we added support for simplified template names, but I haven't
checked). `GetDeclContextDIEs` is also very similar (but subtly
different) from `GetDeclContext` and `GetTypeLookupContext`.

I am keeping `GetParentDeclContextDIE` as that one still has some
callers, but I want to look into the possibility of merging it with at
least one of the functions mentioned above.
2024-06-11 19:49:10 +02:00
Pavel Labath
540a36ad7e
[lldb/DWARF] Follow DW_AT_signature when computing type contexts (#93675)
This is necessary to correctly resolve the context within types, as the
name of the type is only present in the type unit.
2024-05-30 09:57:51 +02:00
Pavel Labath
8e1290432a
[lldb/DWARF] Refactor DWARFDIE::Get{Decl,TypeLookup}Context (#93291)
After a bug (the bug is that the functions don't handle DW_AT_signature,
aka type units) led me to one of these similar-but-different functions,
I started to realize that most of the differences between these two
functions are actually bugs.

As a first step towards merging them, this patch rewrites both of them
to follow the same pattern, while preserving all of their differences.
The main change is that GetTypeLookupContext now also uses a `seen` list
to avoid reference loops (currently that's not necessary because the
function strictly follows parent links, but that will change with
DW_AT_signatures).

I've also optimized both functions to avoid recursion by starting contruction
with the deepest scope first (and then reversing it).
2024-05-29 14:19:49 +02:00
Jonas Devlieghere
513d9f2395
[ptrauth] Teach LLVM & LLDB about LLVM_ptrauth_authentication_mode (#82272)
Teach LLVM & LLDB about `DW_AT_LLVM_ptrauth_authentication_mode`
2024-02-19 15:29:00 -08:00
Adrian Prantl
fa9284589f
[lldb] DWARFDIE: Follow DW_AT_specification when computing CompilerCo… (#77157)
…ntext

Following the specification chain seems to be clearly the expected
behavior of GetDeclContext(). Otherwise C++ methods have an empty
CompilerContext instead of being nested in their struct/class.

Theprimary motivation for this functionality is the Swift plugin. In
order to test the change I added a proof-of-concept implementation of a
Module::FindFunction() variant that takes a CompilerContext, expesed via
lldb-test.

rdar://120553412
2024-01-09 10:45:30 -08:00
Greg Clayton
dd95877958
[lldb] Make only one function that needs to be implemented when searching for types (#74786)
This patch revives the effort to get this Phabricator patch into
upstream:

https://reviews.llvm.org/D137900

This patch was accepted before in Phabricator but I found some
-gsimple-template-names issues that are fixed in this patch.

A fixed up version of the description from the original patch starts
now.

This patch started off trying to fix Module::FindFirstType() as it
sometimes didn't work. The issue was the SymbolFile plug-ins didn't do
any filtering of the matching types they produced, and they only looked
up types using the type basename. This means if you have two types with
the same basename, your type lookup can fail when only looking up a
single type. We would ask the Module::FindFirstType to lookup "Foo::Bar"
and it would ask the symbol file to find only 1 type matching the
basename "Bar", and then we would filter out any matches that didn't
match "Foo::Bar". So if the SymbolFile found "Foo::Bar" first, then it
would work, but if it found "Baz::Bar" first, it would return only that
type and it would be filtered out.

Discovering this issue lead me to think of the patch Alex Langford did a
few months ago that was done for finding functions, where he allowed
SymbolFile objects to make sure something fully matched before parsing
the debug information into an AST type and other LLDB types. So this
patch aimed to allow type lookups to also be much more efficient.

As LLDB has been developed over the years, we added more ways to to type
lookups. These functions have lots of arguments. This patch aims to make
one API that needs to be implemented that serves all previous lookups:

- Find a single type
- Find all types
- Find types in a namespace

This patch introduces a `TypeQuery` class that contains all of the state
needed to perform the lookup which is powerful enough to perform all of
the type searches that used to be in our API. It contain a vector of
CompilerContext objects that can fully or partially specify the lookup
that needs to take place.

If you just want to lookup all types with a matching basename,
regardless of the containing context, you can specify just a single
CompilerContext entry that has a name and a CompilerContextKind mask of
CompilerContextKind::AnyType.

Or you can fully specify the exact context to use when doing lookups
like: CompilerContextKind::Namespace "std"
CompilerContextKind::Class "foo"
CompilerContextKind::Typedef "size_type"

This change expands on the clang modules code that already used a
vector<CompilerContext> items, but it modifies it to work with
expression type lookups which have contexts, or user lookups where users
query for types. The clang modules type lookup is still an option that
can be enabled on the `TypeQuery` objects.

This mirrors the most recent addition of type lookups that took a
vector<CompilerContext> that allowed lookups to happen for the
expression parser in certain places.

Prior to this we had the following APIs in Module:

```
void
Module::FindTypes(ConstString type_name, bool exact_match, size_t max_matches,
                  llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
                  TypeList &types);

void
Module::FindTypes(llvm::ArrayRef<CompilerContext> pattern, LanguageSet languages,
                  llvm::DenseSet<lldb_private::SymbolFile *> &searched_symbol_files,
                  TypeMap &types);

void Module::FindTypesInNamespace(ConstString type_name,
                                  const CompilerDeclContext &parent_decl_ctx,
                                  size_t max_matches, TypeList &type_list);
```

The new Module API is much simpler. It gets rid of all three above
functions and replaces them with:

```
void FindTypes(const TypeQuery &query, TypeResults &results);
```
The `TypeQuery` class contains all of the needed settings:

- The vector<CompilerContext> that allow efficient lookups in the symbol
file classes since they can look at basename matches only realize fully
matching types. Before this any basename that matched was fully realized
only to be removed later by code outside of the SymbolFile layer which
could cause many types to be realized when they didn't need to.
- If the lookup is exact or not. If not exact, then the compiler context
must match the bottom most items that match the compiler context,
otherwise it must match exactly
- If the compiler context match is for clang modules or not. Clang
modules matches include a Module compiler context kind that allows types
to be matched only from certain modules and these matches are not needed
when d oing user type lookups.
- An optional list of languages to use to limit the search to only
certain languages

The `TypeResults` object contains all state required to do the lookup
and store the results:
- The max number of matches
- The set of SymbolFile objects that have already been searched
- The matching type list for any matches that are found

The benefits of this approach are:
- Simpler API, and only one API to implement in SymbolFile classes
- Replaces the FindTypesInNamespace that used a CompilerDeclContext as a
way to limit the search, but this only worked if the TypeSystem matched
the current symbol file's type system, so you couldn't use it to lookup
a type in another module
- Fixes a serious bug in our FindFirstType functions where if we were
searching for "foo::bar", and we found a "baz::bar" first, the basename
would match and we would only fetch 1 type using the basename, only to
drop it from the matching list and returning no results
2023-12-12 16:51:49 -08:00
Adrian Prantl
49504674db
Expose DWARFDIE::GetDeclContext() in lldb_private::Function. (#69981)
I need this API in the Swift plugin, but it seems generally useful
enough to expose it in the main branch.
2023-10-24 10:55:23 -07:00
Walter Erquinigo
1673a1ba5d
[LLDB][NFC] Create a namespace for the DWARF plugin (#68150)
As a followup of https://github.com/llvm/llvm-project/pull/67851, I'm
defining a new namespace `lldb_plugin::dwarf` for the classes in this
Plugins/SymbolFile/DWARF folder. This change is very NFC and helped me
with exporting the necessary symbols for my out-of-tree language plugin.
The only class that I didn't change is ClangDWARFASTParser, because that
shouldn't be in the same namespace as the generic language-agnostic
dwarf parser.
It would be a good idea if other plugins follow the same namespace
scheme.
2023-10-13 16:51:24 -04:00
Felipe de Azevedo Piovezan
346afb8572 [lldb][nfc] Refactor methods with out parameter
Currently, the method `GetAttributeAddressRanges` takes a DWARFRangeList as a
parameter, just to immediately clear it. The method also returns the size of
this list. Such an API was obfuscating the intent of the call sites (it's not
clear from the method name what it returns) and it was obfuscating redundant
checks on the size of the list.

This commit refactors the method to return the list and to also make the call
sites use the more explicit `IsEmpty` method.

Differential Revision: https://reviews.llvm.org/D151451
2023-05-25 13:38:35 -04:00
David Stenberg
98c3dc3fa7 [lldb] Make GetDIENamesAndRanges() allow 0-valued decl and call lines
In an upcoming patch, D142556, Clang is proposed to be changed to emit
line locations that are inlined at line 0. This clashed with the behavior of
GetDIENamesAndRanges() which used 0 as a default value to determine if
file, line or column numbers had been set. Users of that function then
checked for any non-0 values when setting up the call site:

  if (call_file != 0 || call_line != 0 || call_column != 0)
    [...]

which did not work with the Clang change since all three values then
could be 0.

This changes the function to use std::optional to catch non-set values
instead.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D142552
2023-03-06 14:23:29 +01:00
Arthur Eubanks
8a98287f25 [lldb][NFCish] Move DWARFDebugInfoEntry::GetQualifiedName() into DWARFASTParserClang
In D134378, we'll need the clang AST to be able to construct the qualified in some cases.

This makes logging in one place slightly less informative.

Reviewed By: dblaikie, Michael137

Differential Revision: https://reviews.llvm.org/D135979
2022-10-14 15:36:58 -07:00
Nico Weber
a314a36aaa [lldb] Fix deprecation warning for using std::iterator
std::iterator was deprecated in C++17.

No behavior change.

Differential Revision: https://reviews.llvm.org/D134844
2022-09-30 10:19:08 -04:00
Jonas Devlieghere
a8c3d9815e
[DebugInfo] Teach LLVM and LLDB about ptrauth in DWARF
Teach libDebugInfo (llvm-dwarfdump) and lldb about DWARF tags and
attributes for pointer authentication. These values have been emitted by
Apple clang for several releases. Although upstream LLVM doesn't emit
these values yet, we hope to upstream that part sometime soon.

Differential revision: https://reviews.llvm.org/D130215
2022-07-27 11:48:35 -07:00
Zequan Wu
b74a01a80b Reland "[LLDB][NFC] Decouple dwarf location table from DWARFExpression."
This reland 227dffd0b6d78154516ace45f6ed28259c7baa48 and
562c3467a6738aa89203f72fc1d1343e5baadf3c with failed api tests fixed by keeping
function base file addres in DWARFExpressionList.
2022-07-12 10:54:24 -07:00
Jonas Devlieghere
e4c5bca597
Revert "[LLDB][NFC] Decouple dwarf location table from DWARFExpression."
This reverts commit 227dffd0b6d78154516ace45f6ed28259c7baa48 and its
follow up 562c3467a6738aa89203f72fc1d1343e5baadf3c because it breaks a
bunch of tests on GreenDragon:

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45155/
2022-07-07 16:36:10 -07:00
Zequan Wu
227dffd0b6 [LLDB][NFC] Decouple dwarf location table from DWARFExpression.
Differential Revision: https://reviews.llvm.org/D125509
2022-07-07 10:26:58 -07:00
Shafik Yaghmour
ae869d4484 [LLDB] Remove cases of using namespace llvm:: from header file
We have using namespace llvm::dwarf in dwarf.h header globally. Replacing that
with a using namespace within lldb_private::dwarf and moving to a
using namespace lldb_private::dwarf in .cpp files and fully qualified names
in the few header files.

Differential Revision: https://reviews.llvm.org/D120836
2022-03-03 10:39:06 -08:00
Raphael Isemann
b2c262cfb1 [lldb][NFC] Define DWARFDIE::children out-of-line instead of using template magic
As pointed out by David in D103172 (thanks!)

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D106743
2021-08-11 19:19:41 +02:00
Raphael Isemann
77440d644b [lldb][NFC] Allow range-based for loops over DWARFDIE's children
This patch adds the ability to get a DWARFDIE's children as an LLVM range.

This way we can use for range loops to iterate over them and we can use LLVM's
algorithms like `llvm::all_of` to query all children.

The implementation has to do some small shenanigans as the iterator needs to
store a DWARFDIE, but a DWARFDIE container is also a DWARFDIE so it can't return
the iterator by value. I just made the `children` getter a templated function to
avoid the cyclic dependency.

Reviewed By: #lldb, werat, JDevlieghere

Differential Revision: https://reviews.llvm.org/D103172
2021-07-22 15:03:30 +02:00
Jonas Devlieghere
fd2433e139 [lldb] Replace default bodies of special member functions with = default;
Replace default bodies of special member functions with = default;

$ run-clang-tidy.py -header-filter='lldb' -checks='-*,modernize-use-equals-default' -fix ,

https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-equals-default.html

Differential revision: https://reviews.llvm.org/D104041
2021-07-02 11:31:16 -07:00
Pavel Labath
034c2c6771 [lldb/DWARF] Use DWARFDebugInfoEntry * in ElaboratingDIEIterator
This is simpler, faster, and sufficient to uniquely idenify a DIE.
2020-02-12 12:48:49 +01:00
Jan Kratochvil
789beeeca3 [lldb] Move non-DWARF code: DWARFUnit -> SymbolFileDWARF
This patchset is removing non-DWARF code from DWARFUnit for better
future merge with LLVM DWARF as discussed with @labath.

Differential revision: https://reviews.llvm.org/D70646
2020-01-31 15:16:31 +01:00
Raphael Isemann
808142876c [lldb][NFC] Fix all formatting errors in .cpp file headers
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).

This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).

Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73258
2020-01-24 08:52:55 +01:00
Pavel Labath
b7af1bfa6e [lldb/DWARF] Simplify DWARFDebugInfoEntry::LookupAddress
Summary:
This method was doing a lot more than it's only caller needed
(DWARFDIE::LookupDeepestBlock) needed, so I inline it into the caller,
and remove any code which is not actually used. This includes code for
searching for the deepest function, and the code for working around
incomplete DW_AT_low_pc/high_pc attributes on a compile unit DIE (modern
compiler get this right, and this method is called on function DIEs
anyway).

This also improves our llvm consistency, as llvm::DWARFDebugInfoEntry is
just a very simple struct with no nontrivial logic.

Reviewers: JDevlieghere, aprantl

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D72920
2020-01-20 12:39:59 +01:00
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
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
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
Jan Kratochvil
19a3c30731 Simplify GetName+AppendTypeName by DWARFDIE
In D61502#1503247 @clayborg suggested that DWARFUnit *+dw_offset_t can be now
replaced by DWARFDIE.

It is moved from DWARFDebugInfoEntry to DWARFDIE as noted by @clayborg.

I have also removed return type as (1) it was wrong in one case and (2) no
existing caller used the return type. I also refactored the deep nesting noted
by @JDevlieghere.

Differential Revision: https://reviews.llvm.org/D62211

llvm-svn: 361463
2019-05-23 08:00:49 +00:00
Jan Kratochvil
b7a1932144 Remove SymbolFileDWARF * when there is already DWARFUnit *
In D61502#1503247 @clayborg suggested that SymbolFileDWARF *dwarf2Data is
really redundant in all the calls with also having DWARFUnit *cu. So remove it.

One `SymbolFileDWARF *` nullptr check
(DWARFDebugInfoEntry::GetDIENamesAndRanges) could be removed, other two nullptr
checks (DWARFDebugInfoEntry::GetName and DWARFDebugInfoEntry::AppendTypeName)
need to stay in place (now for `DWARFUnit *`).

Differential Revision: https://reviews.llvm.org/D62011

llvm-svn: 361277
2019-05-21 17:38:56 +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
Jan Kratochvil
e8a039d62c Permit cross-CU references
So far dw_offset_t was global for the whole SymbolFileDWARF but with
.debug_types the same dw_offset_t may mean two different things depending on
its section (=CU). So references now return whole new referenced DWARFDIE
instead of just dw_offset_t.

This means that some functions have to now handle 16 bytes instead of 8 bytes
but I do not see that anywhere performance critical.

Differential Revision: https://reviews.llvm.org/D61502

llvm-svn: 360795
2019-05-15 19:22:33 +00:00
Jan Kratochvil
605627374e Finish renaming CompileUnit -> Unit
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
2019-05-10 17:14:37 +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
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
Zachary Turner
d5364dfa6d Move ElaboratingDIEIterator into implementation file.
This is not used outside of the private implementation of the class,
so hiding in the implementation file is a nice way of simplifying
the external interface.

Differential Revision: https://reviews.llvm.org/D59164

llvm-svn: 355973
2019-03-12 20:50:29 +00:00