Commit Graph

311 Commits

Author SHA1 Message Date
Alex Langford
14d95b26ae [lldb][NFCI] Remove unneeded ConstString conversions
ConstString can be implicitly converted into a llvm::StringRef. This is
very useful in many places, but it also hides places where we are
creating a ConstString only to use it as a StringRef for the entire
lifespan of the ConstString object.

I locally removed the implicit conversion and found some of the places we
were doing this.

Differential Revision: https://reviews.llvm.org/D159237
2023-08-31 11:27:59 -07:00
Michael Buch
92d7254a98 [lldb][CPlusPlus][NFCI] Remove redundant construction of ClangASTImporter
The usage of this variable was removed in `4f14c17df70916913d71914343dd4f6c709e218d`.

This is no longer used inside this file. Since the call to
`GetPersistentExpressionStateForLanguage` has side-effects I marked this
NFCI. But there is no good reason we need this here.

Differential Revision: https://reviews.llvm.org/D157992
2023-08-15 23:09:59 +01:00
Dave Lee
a6ff60ecdd [lldb] Delete unused LibcxxOptionalSummaryProvider (NFC)
No longer needed following refactoring in D115178.
2023-07-20 19:32:58 -07:00
Jonas Devlieghere
e0e36e3725 [lldb] Fix incorrect uses of LLDB_LOG_ERROR
Fix incorrect uses of LLDB_LOG_ERROR. The macro doesn't automatically
inject the error in the log message: it merely passes the error as the
first argument to formatv and therefore must be referenced with {0}.

Thanks to Nicholas Allegra for collecting a list of places where the
macro was misused.

rdar://111581655

Differential revision: https://reviews.llvm.org/D154530
2023-07-05 11:27:52 -07:00
Alex Langford
a2ff2921e8 [lldb][NFCI] TypeSystemClang::CreateStructForIdentifier should take a StringRef
This doesn't really use fast comparison or string uniqueness. In fact,
all of the current callers pass an empty string for type_name. The only
reason I don't remove it is because it looks like it is used downstream
for swift.

Differential Revision: https://reviews.llvm.org/D153810
2023-07-03 09:35:24 -07:00
Jim Ingham
f05e2fb013 Don't allow SBValue::Cast to cast from a smaller type to a larger,
as we don't in general know where the extra data should come from.

Differential Revision: https://reviews.llvm.org/D153657
2023-06-26 16:02:01 -07:00
Alex Langford
a9ddf45b8a [lldb][NFCI] Remove ProcessStructReader header where unused 2023-06-14 14:38:18 -07:00
Dave Lee
a1a74f7cde [lldb] Default can_create to true in GetChildAtIndex (NFC)
Existing callers of `GetChildAtIndex` pass true for can_create. This change
makes true the default value, callers don't have to pass an opaque true.

See also D151966 for the same change to `GetChildMemberWithName`.

Differential Revision: https://reviews.llvm.org/D152031
2023-06-13 15:51:32 -07:00
Dave Lee
7d4fcd411b [lldb] Default can_create to true in GetChildMemberWithName (NFC)
It turns out all existing callers of `GetChildMemberWithName` pass true for `can_create`.
This change makes `true` the default value, callers don't have to pass an opaque true.

Differential Revision: https://reviews.llvm.org/D151966
2023-06-13 11:37:41 -07:00
Fangrui Song
65ceb42d63 Replace deprecated startswith_insensitive with starts_with_insensitive 2023-06-05 11:01:27 -07:00
Dave Lee
00e52cc4a8 [lldb] Take StringRef names in GetChildAtNamePath (NFC)
Following D151810, this changes `GetChildAtNamePath` to take a path of `StringRef`
values instead of `ConstString`.

Differential Revision: https://reviews.llvm.org/D151813
2023-06-01 20:42:29 -07:00
Dave Lee
5dae706259 [lldb] Take StringRef name in GetIndexOfChildWithName (NFC)
As with D151615, which changed `GetIndexOfChildMemberWithName` to take a `StringRef`
instead of a `ConstString`, this change does the same for `GetIndexOfChildWithName`.

Differential Revision: https://reviews.llvm.org/D151811
2023-06-01 20:24:01 -07:00
Dave Lee
cb463c34dd [lldb] Take StringRef name in GetChildMemberWithName (NFC)
`GetChildMemberWithName` does not need a `ConstString`. This change makes the function
take a `StringRef` instead, which alleviates the need for callers to construct a
`ConstString`. I don't expect this change to improve performance, only ergonomics.

This is in support of Alex's effort to replace `ConstString` where appropriate.

There are related `ValueObject` functions that can also be changed, if this is accepted.

Differential Revision: https://reviews.llvm.org/D151615
2023-05-31 08:08:40 -07:00
Michael Buch
44bb442fd5 [lldb][DataFormatter] Add dereference support to libstdcpp std::shared_ptr formatter
This mimicks the implementation of the libstdcpp std::unique_ptr
formatter.

This has been attempted several years ago in
`0789722d85cf1f1fdbe2ffb2245ea0ba034a9f94` but was reverted in
`e7dd3972094c2f2fb42dc9d4d5344e54a431e2ce`.

The difference to the original patch is that we now maintain
a `$$dereference$$` member and we only store weak pointers
to the other children inside the synthetic frontend. This is
what the libc++ formatters do to prevent the recursion mentioned
in the revert commit.
2023-05-24 13:01:11 +01:00
Alex Langford
ef73ea6cf6 [lldb][NFCI] Change return type of Language::GetInstanceVariableName
I don't think this needs to be a ConstString.

Differential Revision: https://reviews.llvm.org/D150709
2023-05-22 10:16:20 -07:00
Jeffrey Tan
25159ee3af Fix libstdc++ data formatter for reference/pointer to std::string
This patch fixes libstdc++ data formatter for reference/pointer to std::string.
The failure testcases are added which succeed with the patch.

Differential Revision: https://reviews.llvm.org/D150313
2023-05-12 10:09:58 -07:00
Jorge Gorbe Moya
d69518b4e5 Re-land "[lldb] Make the libcxx unique_ptr prettyprinter support custom deleters."
This reverts commit 4535112010.
2023-05-01 16:19:01 -07:00
Jorge Gorbe Moya
4535112010 Revert "[lldb] Make the libcxx unique_ptr prettyprinter support custom deleters."
This reverts commit d366da97bd.
2023-05-01 14:14:09 -07:00
Jorge Gorbe Moya
d366da97bd [lldb] Make the libcxx unique_ptr prettyprinter support custom deleters.
The unique_ptr prettyprinter calls `GetValueOfLibCXXCompressedPair`,
which looks for a `__value_` child. However, when the second value in
the compressed pair is not an empty class, there are two `__value_`
children because `__compressed_pair` derives twice from
`__compressed_pair_elem`, one for each member of the pair. And then the
lookup fails because it's ambiguous.

This patch makes the following changes:

- Rename `GetValueOfLibCXXCompressedPair` to
  `GetFirstValueOfLibCXXCompressedPair`, and add a similar function to
  get the second value. Put both functions in
  Plugin/Language/CPlusPlus/LibCxx.cpp because it seems inappropriate to
  have libcxx-specific helpers separate from all the libcxx-dependent
  code.

- Read the second value of the `__ptr_` pair and display a "deleter"
  child in the unique_ptr synthetic child provider, when available.

- Add a test case for the non-empty deleter case.

Differential Revision: https://reviews.llvm.org/D148662
2023-05-01 13:08:04 -07:00
Michael Buch
89cd0e8c26 [lldb] Allow evaluating expressions in C++20 mode
This patch allows users to evaluate expressions using
`expr -l c++20`. Currently DWARF keeps the CU's at
`DW_AT_language` at `DW_LANG_C_plus_plus_14` even
when compiling with `-std=c++20`. So even in "C++20
programs" expression evaluation will by default be
performed in `C++11` mode for now.

Enabling `C++14` has been previously attempted at
https://reviews.llvm.org/D80308

There are some remaining issues around evaluating C++20
expressions. Mainly, lack of support for C++20 AST nodes in
`clang::ASTImporter`. But these can be addressed in follow-up
patches.
2023-04-14 17:10:18 +01:00
Alex Langford
0e22b8cba7 [lldb] Change formatter helper function parameter list to remove ConstString
All of these functions take a ConstString for the type_name,
but this isn't really needed for two reasons:
1.) This parameter is always constructed from a static c-string
  constant.
2.) They are passed along to to `AddTypeSummary` as a StringRef anyway.

Differential Revision: https://reviews.llvm.org/D148050
2023-04-12 11:20:24 -07:00
Dave Lee
c327f99254 [lldb] Refactor deduction of the instance variable's name (NFC)
Move responsibility of providing the instance variable name (`this`, `self`) from
`TypeSystem` to `Language`.

`Language` the natural place for this, but also has downstream benefits. Some languages
have multiple `TypeSystem` implementations (ex Swift), and by placing this logic in the
`Language`, redundancy is avoided.

This change relies on the tests from D145348 and D146320.

Differential Revision: https://reviews.llvm.org/D146548
2023-03-21 15:22:07 -07:00
Yuanfang Chen
9aae408d55 [NFC] fix typo funciton -> function
credits to @jmagee
2023-03-10 18:05:25 -08:00
Michael Buch
8200848c41 Reland "[lldb][TypeSystemClang] Use the CXXFunctionPointerSummaryProvider for member-function pointers"
With this patch member-function pointers are formatted using
`CXXFunctionPointerSummaryProvider`.

This turns,
```
(lldb) v pointer_to_member_func
(void (Foo::*)()) ::pointer_to_member_func = 0x00000000000000000000000100003f94
```
into
```
(lldb) v pointer_to_member_func
(void (Foo::*)()) ::pointer_to_member_func = 0x00000000000000000000000100003f94 (a.out`Foo::member_func() at main.cpp:3)
```

Differential Revision: https://reviews.llvm.org/D145242
2023-03-07 19:45:50 +00:00
Michael Buch
6e3f2dedc8 Revert "[lldb][TypeSystemClang] Use the CXXFunctionPointerSummaryProvider for member-function pointers"
Reverted because Windows buildbot started failing

This reverts commit 6bd46e713c.
2023-03-07 11:18:38 +00:00
Michael Buch
6bd46e713c [lldb][TypeSystemClang] Use the CXXFunctionPointerSummaryProvider for member-function pointers
With this patch member-function pointers are formatted using
`CXXFunctionPointerSummaryProvider`.

This turns,
```
(lldb) v pointer_to_member_func
(void (Foo::*)()) ::pointer_to_member_func = 0x00000000000000000000000100003f94
```
into
```
(lldb) v pointer_to_member_func
(void (Foo::*)()) ::pointer_to_member_func = 0x00000000000000000000000100003f94 (a.out`Foo::member_func() at main.cpp:3)
```

Differential Revision: https://reviews.llvm.org/D145242
2023-03-03 17:44:36 +00:00
Adrian Vogelsgesang
54d4a2550d [LLDB] Fix assertion failure by removing CopyType in std::coroutine_handle pretty printer
The pretty printer for `std::coroutine_handle` was running into
> Assertion failed: (target_ctx != source_ctx && "Can't import into itself")
from ClangASTImporter.h, line 270.

This commit fixes the issue by removing the `CopyType` call from the
pretty printer. While this call was necessary in the past, it seems to
be no longer required, at least all test cases are still passing. Maybe
something changed in the meantime around the handling of `TypesystemClang`
instances. I don't quite understand why `CopyType` was necessary earlier.

I am not sure how to add a regression test for this, though. It seems
the issue is already triggered by the exising `TestCoroutineHandle.py`,
but API tests seem to ignore all violations of `lldbassert` and still
report the test as "passed", even if assertions were triggered

Differential Revision: https://reviews.llvm.org/D143127
2023-02-08 10:22:50 -08:00
Adrian Vogelsgesang
8aa3137551 [LLDB] Do not dereference promise pointer in coroutine_handle pretty printer
So far, the pretty printer for `std::coroutine_handle` internally
dereferenced the contained frame pointer displayed the `promise`
as a sub-value. As noticed in https://reviews.llvm.org/D132624
by @labath, this can lead to an endless loop in lldb during printing
if the coroutine frame pointers form a cycle.

This commit breaks the cycle by exposing the `promise` as a pointer
type instead of a value type. The depth to which the `frame variable`
and the `expression` commands dereference those pointers can be
controlled using the `--ptr-depth` argument.

Differential Revision: https://reviews.llvm.org/D132815
2023-01-31 07:40:31 -08:00
Pavel Kosov
92f0e4ccaf [LLDB] Fixes summary formatter for libc++ map allowing modification of contained value
Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D140624
2023-01-25 10:48:04 +03:00
Pavel Kosov
ff9c31b23b [LLDB] Fix for libc++ atomic allowing modification of contained value
Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D140623
2023-01-25 10:39:50 +03:00
Adrian Prantl
f8d7ab8cf8 Return a shared_ptr from ScratchTypeSystemClang::GetForTarget()
The current interface theoretically could lead to a use-after-free
when a client holds on to the returned pointer. Fix this by returning
a shared_ptr to the scratch typesystem.

rdar://103619233

Differential Revision: https://reviews.llvm.org/D141100
2023-01-09 15:04:53 -08:00
Kazu Hirata
570117b6a5 [lldb] Remove remaining uses of llvm::Optional (NFC)
This patch removes the unused "using" declarations, updates comments,
and removes #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 14:36:35 -08:00
Kazu Hirata
2fe8327406 [lldb] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 14:18:35 -08:00
Kazu Hirata
f190ce625a [lldb] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-07 13:43:00 -08:00
Fangrui Song
f43886e7ba [lldb] llvm::Optional::value() && => operator*/operator->
std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
call sites block std::optional migration.
2022-12-17 20:37:13 +00:00
Fangrui Song
9464bd8c78 [lldb] llvm::Optional::value => operator*/operator->
std::optional::value() has undesired exception checking semantics and is
unavailable in some older Xcode. The call sites block std::optional migration.
2022-12-17 05:01:54 +00:00
Kazu Hirata
9ba308f71c Remove "using llvm::None;" in *.cpp
These .cpp files do not use llvm::None anymore.

Since these are not header files, we can remove them pretty safely
without deprecating them first.
2022-12-05 20:39:10 -08:00
Kazu Hirata
343523d040 [lldb] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-04 16:51:25 -08:00
Jordan Rupprecht
3c51ea3619 [DataFormatter] Fix variant npos with _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION enabled.
This data formatter should print "No Value" if a variant is unset. It does so by checking if `__index` has a value of `-1`, however it does so by interpreting it as a signed int.

By default, `__index` has type `unsigned int`. When `_LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION` is enabled, the type of `__index` is either `unsigned char`, `unsigned short`, or `unsigned int`, depending on how many fields there are -- as small as possible. For example, when `std::variant` has only a few types, the index type is `unsigned char`, and the npos value will be interpreted by LLDB as `255` when it should be `-1`.

This change does not special case the variant optimization; it just reads the type instead of assuming it's `unsigned int`.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D138892
2022-11-30 13:20:13 -08:00
Michael Buch
77b2205245 [lldb][DataFormatter] Add std::ranges::ref_view formatter
This patch adds a formatter for `std::ranges::ref_view<T>`.
It simply holds a `T*`, so all this formatter does is dereference
this pointer and format it as `T` would be.

**Testing**

* Added API tests

Differential Revision: https://reviews.llvm.org/D138558
2022-11-30 14:39:39 +00:00
Jason Molenda
2b2f2f6614 Revert "[LLDB] Recognize std::noop_coroutine() in std::coroutine_handle pretty printer"
This reverts commit 4346318f5c.

This test case is failing on macOS, reverting until it can be
looked at more closely to unblock the macOS CI bots.

```
  File "/Volumes/work/llvm/llvm-project/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py", line 121, in test_libcpp
    self.do_test(USE_LIBCPP)
  File "/Volumes/work/llvm/llvm-project/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py", line 45, in do_test
    self.expect_expr("noop_hdl",
  File "/Volumes/work/llvm/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2441, in expect_expr
    value_check.check_value(self, eval_result, str(eval_result))
  File "/Volumes/work/llvm/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 306, in check_value
    test_base.assertEqual(self.expect_summary, val.GetSummary(),
AssertionError: 'noop_coroutine' != 'coro frame = 0x100004058'
- noop_coroutine+ coro frame = 0x100004058 : (std::coroutine_handle<void>) $1 = coro frame = 0x100004058 {
  resume = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
  destroy = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
}
Checking SBValue: (std::coroutine_handle<void>) $1 = coro frame = 0x100004058 {
  resume = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
  destroy = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
}
```

Those lldb_unnamed_symbols are synthetic names that ObjectFileMachO
adds to the symbol table, most often seen with stripped binaries,
based off of the function start addresses for all the functions -
if a function has no symbol name, lldb adds one of these names.
This change was originally landed via https://reviews.llvm.org/D132624
2022-11-25 12:32:33 -08:00
Jason Molenda
f6d4e68717 Revert "[LLDB] Do not dereference promise pointer in coroutine_handle pretty printer"
This reverts commit cd3091a88f.

This change crashes on macOS systems in
formatters::StdlibCoroutineHandleSyntheticFrontEnd when
it fails to create the `ValueObjectSP promise` and calls
a method on it.  The failure causes a segfault while running
TestCoroutineHandle.py on the "LLDB Incremental" CI bot,
https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/

This change originally landed via https://reviews.llvm.org/D132815
2022-11-25 12:22:58 -08:00
Adrian Vogelsgesang
cd3091a88f [LLDB] Do not dereference promise pointer in coroutine_handle pretty printer
So far, the pretty printer for `std::coroutine_handle` internally
dereferenced the contained frame pointer displayed the `promise`
as a sub-value. As noticed in https://reviews.llvm.org/D132624
by @labath, this can lead to an endless loop in lldb during printing
if the coroutine frame pointers form a cycle.

This commit breaks the cycle by exposing the `promise` as a pointer
type instead of a value type. The depth to which the `frame variable`
and the `expression` commands dereference those pointers can be
controlled using the `--ptr-depth` argument.

Differential Revision: https://reviews.llvm.org/D132815
2022-11-20 14:26:36 -08:00
Adrian Vogelsgesang
4346318f5c [LLDB] Recognize std::noop_coroutine() in std::coroutine_handle pretty printer
With this commit, the `std::coroutine_handle` pretty printer now
recognizes `std::noop_coroutine()` handles. For noop coroutine handles,
we identify use the summary string `noop_coroutine` and we don't print
children

Instead of
```
(std::coroutine_handle<void>) $3 = coro frame = 0x555555559058 {
  resume = 0x00005555555564f0 (a.out`std::__1::coroutine_handle<std::__1::noop_coroutine_promise>::__noop_coroutine_frame_ty_::__dummy_resume_destroy_func() at noop_coroutine_handle.h:79)
  destroy = 0x00005555555564f0 (a.out`std::__1::coroutine_handle<std::__1::noop_coroutine_promise>::__noop_coroutine_frame_ty_::__dummy_resume_destroy_func() at noop_coroutine_handle.h:79)
}
```

we now print

```
(std::coroutine_handle<void>) $3 = noop_coroutine
```

Differential Revision: https://reviews.llvm.org/D132735
2022-11-20 11:18:52 -08:00
Adrian Vogelsgesang
01f4c305fa Reapply "[LLDB] Devirtualize coroutine promise types for std::coroutine_handle"
The original commit was missing a `ClangASTImporter::CopyType` call.
Original commit message:

This commit teaches the `std::coroutine_handle` pretty-printer to
devirtualize type-erased promise types. This is particularly useful to
resonstruct call stacks, either of asynchronous control flow or of
recursive invocations of `std::generator`. For the example recently
introduced by https://reviews.llvm.org/D132451, printing the `__promise`
variable now shows

```
(std::__coroutine_traits_sfinae<task, void>::promise_type) __promise = {
  continuation = coro frame = 0x555555562430 {
    resume = 0x0000555555556310 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    destroy = 0x0000555555556700 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    promise = {
      continuation = coro frame = 0x5555555623e0 {
        resume = 0x0000555555557070 (a.out`task detail::chain_fn<2>() at llvm-nested-example.cpp:66)
        destroy = 0x0000555555557460 (a.out`task detail::chain_fn<2>() at llvm-nested-example.cpp:66)
        promise = {
          ...
        }
      }
      result = 0
    }
  }
  result = 0
}
```

(shortened to keep the commit message readable) instead of

```
(std::__coroutine_traits_sfinae<task, void>::promise_type) __promise = {
  continuation = coro frame = 0x555555562430 {
    resume = 0x0000555555556310 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    destroy = 0x0000555555556700 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
  }
  result = 0
}
```

Note how the new debug output reveals the complete asynchronous call
stack: our own function resumes `chain_fn<1>` which in turn will resume
`chain_fn<2>` and so on. Thereby this change allows users of lldb to
inspect the logical coroutine call stack without using any custom debug
scripts (although the display is still a bit clumsy. It would be nicer
to also integrate this into lldb's backtrace feature, but I don't know
how to do so)

The devirtualization currently works by introspecting the function
pointed to by the `destroy` pointer. (The `resume` pointer is not worth
much, given that for the final suspend point `resume` is set to a
nullptr. We have to use the `destroy` pointer instead.) We then look
for a `__promise` variable inside the `destroy` function. This
`__promise` variable is synthetically generated by LLVM, and looking at
its type reveals the type-erased promise_type.

This approach only works for clang-generated code, though. While gcc
also adds a `_Coro_promise` variable to the `resume` function, it does
not do so for the `destroy` function. However, we can't use the `resume`
function, as it will be reset to a nullptr at the final suspension
point. For the time being, I am happy with de-virtualization only working
for clang. A follow-up commit will further improve devirtualization and
also expose the variables spilled to the coroutine frame. As part of
this, I will also revisit gcc support.

Differential Revision: https://reviews.llvm.org/D132624
2022-11-20 06:35:16 -08:00
Adrian Prantl
6eaedbb52f Make CompilerType safe
When a process gets restarted TypeSystem objects associated with it
may get deleted, and any CompilerType objects holding on to a
reference to that type system are a use-after-free in waiting. Because
of the SBAPI, we don't have tight control over where CompilerTypes go
and when they are used. This is particularly a problem in the Swift
plugin, where the scratch TypeSystem can be restarted while the
process is still running. The Swift plugin has a lock to prevent
abuse, but where there's a lock there can be bugs.

This patch changes CompilerType to store a std::weak_ptr<TypeSystem>.
Most of the std::weak_ptr<TypeSystem>* uglyness is hidden by
introducing a wrapper class CompilerType::WrappedTypeSystem that has a
dyn_cast_or_null() method. The only sites that need to know about the
weak pointer implementation detail are the ones that deal with
creating TypeSystems.

rdar://101505232

Differential Revision: https://reviews.llvm.org/D136650
2022-11-16 15:51:26 -08:00
Dave Lee
b66da73a05 [lldb] Don't assume name of libc++ inline namespace in LibCxxUnorderedMap
Follow up to D117383, fixing the assumption that libc++ always uses `__1` as
its inline namespace name.

Reviewed By: rupprecht

Differential Revision: https://reviews.llvm.org/D133259
2022-11-11 11:59:36 -08:00
Adrian Vogelsgesang
d7e1c2770f Revert "[LLDB] Devirtualize coroutine promise types for std::coroutine_handle"
This reverts commit 558db77870 due to
buildbot failures on ARM
* https://lab.llvm.org/buildbot/#/builders/96/builds/31416
* https://lab.llvm.org/buildbot/#/builders/17/builds/30086
2022-11-11 10:00:58 -08:00
Adrian Vogelsgesang
558db77870 [LLDB] Devirtualize coroutine promise types for std::coroutine_handle
This commit teaches the `std::coroutine_handle` pretty-printer to
devirtualize type-erased promise types. This is particularly useful to
resonstruct call stacks, either of asynchronous control flow or of
recursive invocations of `std::generator`. For the example recently
introduced by https://reviews.llvm.org/D132451, printing the `__promise`
variable now shows

```
(std::__coroutine_traits_sfinae<task, void>::promise_type) __promise = {
  continuation = coro frame = 0x555555562430 {
    resume = 0x0000555555556310 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    destroy = 0x0000555555556700 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    promise = {
      continuation = coro frame = 0x5555555623e0 {
        resume = 0x0000555555557070 (a.out`task detail::chain_fn<2>() at llvm-nested-example.cpp:66)
        destroy = 0x0000555555557460 (a.out`task detail::chain_fn<2>() at llvm-nested-example.cpp:66)
        promise = {
          ...
        }
      }
      result = 0
    }
  }
  result = 0
}
```

(shortened to keep the commit message readable) instead of

```
(std::__coroutine_traits_sfinae<task, void>::promise_type) __promise = {
  continuation = coro frame = 0x555555562430 {
    resume = 0x0000555555556310 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
    destroy = 0x0000555555556700 (a.out`task detail::chain_fn<1>() at llvm-nested-example.cpp:66)
  }
  result = 0
}
```

Note how the new debug output reveals the complete asynchronous call
stack: our own function resumes `chain_fn<1>` which in turn will resume
`chain_fn<2>` and so on. Thereby this change allows users of lldb to
inspect the logical coroutine call stack without using any custom debug
scripts (although the display is still a bit clumsy. It would be nicer
to also integrate this into lldb's backtrace feature, but I don't know
how to do so)

The devirtualization currently works by introspecting the function
pointed to by the `destroy` pointer. (The `resume` pointer is not worth
much, given that for the final suspend point `resume` is set to a
nullptr. We have to use the `destroy` pointer instead.) We then look
for a `__promise` variable inside the `destroy` function. This
`__promise` variable is synthetically generated by LLVM, and looking at
its type reveals the type-erased promise_type.

This approach only works for clang-generated code, though. While gcc
also adds a `_Coro_promise` variable to the `resume` function, it does
not do so for the `destroy` function. However, we can't use the `resume`
function, as it will be reset to a nullptr at the final suspension
point. For the time being, I am happy with de-virtualization only working
for clang. A follow-up commit will further improve devirtualization and
also expose the variables spilled to the coroutine frame. As part of
this, I will also revisit gcc support.

Differential Revision: https://reviews.llvm.org/D132624
2022-11-11 09:37:08 -08:00
Michael Buch
031096d04d [lldb][CPlusPlus] Implement CPlusPlusLanguage::GetFunctionDisplayName
This patch implements the `GetFunctionDisplayName` API which gets
used by the frame-formatting code to decide how to print a
function name.

Currently this API trivially returns `false`, so we try to parse
the demangled function base-name by hand. We try find the closing
parenthesis by doing a forward scan through the demangled name. However,
for arguments that contain parenthesis (e.g., function pointers)
this would leave garbage in the frame function name.

By re-using the `CPlusPlusLanguage` parser for this we offload the
need to parse function names to a component that knows how to do this
already.

We leave the existing parsing code in `FormatEntity` since it's used
in cases where a language-plugin is not available (and is not
necessarily C++ specific).

**Example**

For following function:
```
int foo(std::function<int(void)> const& func) { return 1; }
```

Before patch:
```
frame #0: 0x000000010000151c a.out`foo(func= Function = bar() )> const&) at sample.cpp:11:49
```

After patch:
```
frame #0: 0x000000010000151c a.out`foo(func= Function = bar() ) at sample.cpp:11:49
```

**Testing**

* Added shell test
2022-10-31 12:25:19 +00:00