Commit Graph

18 Commits

Author SHA1 Message Date
Raphael Isemann b8338983e6 [lldb] Add std::array to the supported template list of the CxxModuleHandler
Identical to the other patches that add STL containers to the supported
templated list.
2020-12-17 11:47:58 +01:00
Raphael Isemann 47e7ecdd7d [lldb] Introduce separate scratch ASTs for debug info types and types imported from C++ modules.
Right now we have one large AST for all types in LLDB. All ODR violations in
types we reconstruct are resolved by just letting the ASTImporter handle the
conflicts (either by merging types or somehow trying to introduce a duplicated
declaration in the AST). This works ok for the normal types we build from debug
information as most of them are just simple CXXRecordDecls or empty template
declarations.

However, with a loaded `std` C++ module we have alternative versions of pretty
much all declarations in the `std` namespace that are much more fleshed out than
the debug information declarations. They have all the information that is lost
when converting to DWARF, such as default arguments, template default arguments,
the actual uninstantiated template declarations and so on.

When we merge these C++ module types into the big scratch AST (that might
already contain debug information types) we give the ASTImporter the tricky task
of somehow creating a consistent AST out of all these declarations. Usually this
ends in a messy AST that contains a mostly broken mix of both module and debug
info declarations. The ASTImporter in LLDB is also importing types with the
MinimalImport setting, which usually means the only information we have when
merging two types is often just the name of the declaration and the information
that it contains some child declarations. This makes it pretty much impossible
to even implement a better merging logic (as the names of C++ module
declarations and debug info declarations are identical).

This patch works around this whole merging problem by separating C++ module
types from debug information types. This is done by splitting up the single
scratch AST into two: One default AST for debug information and a dedicated AST
for C++ module types.

The C++ module AST is implemented as a 'specialised AST' that lives within the
default ScratchTypeSystemClang. When we select the scratch AST we can explicitly
request that we want such a isolated sub-AST of the scratch AST. I kept the
infrastructure more general as we probably can use the same mechanism for other
features that introduce conflicting types (such as programs that are compiled
with a custom -wchar-size= option).

There are just two places where we explicitly have request the C++ module AST:
When we export persistent declarations (`$mytype`) and when we create our
persistent result variable (`$0`, `$1`, ...). There are a few formatters that
were previously assuming that there is only one scratch AST which I cleaned up
in a preparation revision here (D92757).

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D92759
2020-12-10 19:28:01 +01:00
Raphael Isemann 958608285e [lldb] Allow LLDB to automatically retry a failed expression with an imported std C++ module
By now LLDB can import the 'std' C++ module to improve expression evaluation,
but there are still a few problems to solve before we can do this by default.
One is that importing the C++ module is slightly slower than normal expression
evaluation (mostly because the disk access and loading the initial lookup data
is quite slow in comparison to the barebone Clang setup the rest of the LLDB
expression evaluator is usually doing). Another problem is that some complicated
types in the standard library aren't fully supported yet by the ASTImporter, so
we end up types that fail to import (which usually appears to the user as if the
type is empty or there is just no result variable).

To still allow people to adopt this mode in their daily debugging, this patch
adds a setting that allows LLDB to automatically retry failed expression with a
loaded C++ module. All success expressions will behave exactly as they would do
before this patch. Failed expressions get a another parse attempt if we find a
usable C++ module in the current execution context. This way we shouldn't have
any performance/parsing regressions in normal debugging workflows, while the
debugging workflows involving STL containers benefit from the C++ module type
info.

This setting is off by default for now with the intention to enable it by
default on macOS soon-ish.

The implementation is mostly just extracting the existing parse logic into its
own function and then calling the parse function again if the first evaluation
failed and we have a C++ module to retry the parsing with.

Reviewed By: shafik, JDevlieghere, aprantl

Differential Revision: https://reviews.llvm.org/D92784
2020-12-10 12:29:17 +01:00
Raphael Isemann 6face9119c [lldb][import-std-module] Add a test for typedef'd std types 2020-12-08 13:36:13 +01:00
Raphael Isemann 3f6c856bb5 [ASTImporter] Import the default argument of TemplateTypeParmDecl
The test case isn't using the AST matchers for all checks as there doesn't seem to be support for
matching TemplateTypeParmDecl default arguments. Otherwise this is simply importing the
default arguments.

Also updates several LLDB tests that now as intended omit the default template
arguments of several std templates.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D92103
2020-11-26 18:01:30 +01:00
Raphael Isemann a703998e66 [lldb] Remove legacy casts from TestStackFromStdModule
We can handle all the types in the expression evaluator now without casting.
On Linux, we have a system header declaration that is still causing issues, so
I'm skipping the test there until I get around to fix this.
2020-11-19 17:07:12 +01:00
Raphael Isemann dc848a0888 [lldb][NFC] Fix flaky TestForwardDeclFromStdModule test
"[lldb/DataFormatters] Display null C++ pointers as nullptr" added an assumption
that the member we check for is always a nullptr, but it is actually never
initialized. That causes the test to randomly fail due to the pointer having
some random value that isn't 0.
2020-11-13 11:40:51 +01:00
Jonas Devlieghere 406ad18748 [lldb/DataFormatters] Display null C++ pointers as nullptr
Display null pointer as `nullptr`, `nil` and `NULL` for C++,
Objective-C/Objective-C++ and C respectively. The original motivation
for this patch was to display a null std::string pointer as nullptr
instead of "", but the fix seemed generic enough to be done for all
summary providers.

Differential revision: https://reviews.llvm.org/D77153
2020-11-12 15:24:06 -08:00
Michał Górny 311cca8bbf [lldb] [test] Rename '.categories' to 'categories'
Make category-specifying files visible.  There is really no good reason
to keep them hidden, and having them visible increases the chances
that someone will actually spot them.

Differential Revision: https://reviews.llvm.org/D91065
2020-11-10 12:02:38 +01:00
Raphael Isemann 15ea45f16b [lldb] Skip unique_ptr import-std-module tests on Linux
This seems to fail on ubuntu 18.04.5 with Clang 9 due to:

Error output:
error: Couldn't lookup symbols:
  std::__1::default_delete<int>::operator()(int) const
2020-10-01 23:04:36 +02:00
Raphael Isemann cabee89bed [lldb] Reference STL types in import-std-module tests
With the recent patches to the ASTImporter that improve template type importing
(D87444), most of the import-std-module tests can now finally import the
type of the STL container they are testing. This patch removes most of the casts
that were added to simplify types to something the ASTImporter can import
(for example, std::vector<int>::size_type was casted to `size_t` until now).
Also adds the missing tests that require referencing the container type (for
example simply printing the whole container) as here we couldn't use a casting
workaround.

The only casts that remain are in the forward_list tests that reference
the iterator and the stack test. Both tests are still failing to import the
respective container type correctly (or crash while trying to import).
2020-09-28 10:37:03 +02:00
Raphael Isemann b85222520f [lldb] Enable std::pair in CxxModuleHandler
This adds support for substituting std::pair instantiations with enabled
import-std-module.

With the fixes in parent revisions we can currently substitute a single pair
(however, a result that returns a second pair currently causes LLDB to crash
while importing the second template instantiation).

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D85141
2020-09-09 10:49:53 +02:00
Raphael Isemann 32c8da41dc [lldb] Don't infinite loop in SemaSourceWithPriorities::CompleteType when trying to complete a forward decl
SemaSourceWithPriorities is a special SemaSource that wraps our normal LLDB
ExternalASTSource and the ASTReader (which is used for the C++ module loading).
It's only active when the `import-std-module` setting is turned on.

The `CompleteType` function there in `SemaSourceWithPriorities` is looping over
all ExternalASTSources and asks each to complete the type. However, that loop is
in another loop that keeps doing that until the type is complete. If that
function is ever called on a type that is a forward decl then that causes LLDB
to go into an infinite loop.

I remember I added that second loop and the comment because I thought I saw a
similar pattern in some other Clang code, but after some grepping I can't find
that code anywhere and it seems the rest of the code base only calls
CompleteType once (It would also be kinda silly to have calling it multiple
times). So it seems that's just a silly mistake.

The is implicitly tested by importing `std::pair`, but I also added a simpler
dedicated test that creates a dummy libc++ module with some forward declarations
and then imports them into the scratch AST context. At some point the
ASTImporter will check if one of the forward decls could be completed by the
ExternalASTSource, which will cause the `SemaSourceWithPriorities` to go into an
infinite loop once it receives the `CompleteType` call.

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D87289
2020-09-09 10:05:57 +02:00
Jonas Devlieghere 351823fbf1 [lldb/Test] Add 'std-module' category and skip them with reproducers
These tests are flaky on the reproducer bot. I suspect it has something
to do with the module cache. Skipping the whole category while I
investigate the issue.
2020-06-10 14:59:05 -07:00
Fred Riss 52b2bae777 [lldb/testsuite] Skip TestEmptyStdModule.py if using a remote platform
The test runs `platform select host`, so it make no sense to run it
when remote debugging.
2020-03-18 20:52:28 -07:00
Raphael Isemann 785df61680 [lldb] Let TypeSystemClang::GetDisplayTypeName remove anonymous and inline namespaces.
Summary:
Currently when printing data types we include implicit scopes such as inline namespaces or anonymous namespaces.
This leads to command output like this (for `std::set<X>` with X being in an anonymous namespace):

```
(lldb) print my_set
(std::__1::set<(anonymous namespace)::X, std::__1::less<(anonymous namespace)::X>, std::__1::allocator<(anonymous namespace)::X> >) $0 = size=0 {}
```

This patch removes all the implicit scopes when printing type names in TypeSystemClang::GetDisplayTypeName
so that our output now looks like this:

```
(lldb) print my_set
(std::set<X, std::less<X>, std::allocator<X> >) $0 = size=0 {}
```

As previously GetDisplayTypeName and GetTypeName had the same output we actually often used the
two as if they are the same method (they were in fact using the same implementation), so this patch also
fixes the places where we actually want the display type name and not the actual type name.

Note that this doesn't touch the `GetTypeName` class that for example the data formatters use, so this patch
is only changes the way we display types to the user. The full type name can also still be found when passing
'-R' to see the raw output of a variable in case someone is somehow interested in that.

Partly fixes rdar://problem/59292534

Reviewers: shafik, jingham

Reviewed By: shafik

Subscribers: christof, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74478
2020-02-19 10:30:11 +01:00
Raphael Isemann cfb29e4a54 [lldb] Fix some tests failing with gmodules after change to stdlib.h
Commit 82b47b2978 changes the way the stdlib.h
header is structured which seems to cause strange lookup failures in the modules
build. This updates a few failing tests so that they pass with the new
behavior of stdlib.h.

See the discussion in https://reviews.llvm.org/rG82b47b2978405f802a33b00d046e6f18ef6a47be
2020-02-17 09:39:09 +01:00
Jordan Rupprecht 99451b4453 [lldb][test] Remove symlink for API tests.
Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdir -p lldb/test/API/{test_runner/test,tools/lldb-{server,vscode}}
mv lldb/packages/Python/lldbsuite/test/test_runner/test lldb/test/API/test_runner
for d in $(find lldb/packages/Python/lldbsuite/test/* -maxdepth 0 -type d | egrep -v "make|plugins|test_runner|tools"); do mv $d lldb/test/API; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-vscode -maxdepth 1 -mindepth 1 | grep -v ".py"); do mv $d lldb/test/API/tools/lldb-vscode; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-server -maxdepth 1 -mindepth 1 | egrep -v "gdbremote_testcase.py|lldbgdbserverutils.py|socket_packet_pump.py"); do mv $d lldb/test/API/tools/lldb-server; done
```

lldb/packages/Python/lldbsuite/__init__.py and lldb/test/API/lit.cfg.py were also updated with the new directory structure.

Reviewers: labath, JDevlieghere

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71151
2020-02-11 10:03:53 -08:00