Add the ability to get a C++ vtable ValueObject from another
ValueObject.
This patch adds the ability to ask a ValueObject for a ValueObject that
represents the virtual function table for a C++ class. If the
ValueObject is not a C++ class with a vtable, a valid ValueObject value
will be returned that contains an appropriate error. If it is successful
a valid ValueObject that represents vtable will be returned. The
ValueObject that is returned will have a name that matches the demangled
value for a C++ vtable mangled name like "vtable for <class-name>". It
will have N children, one for each virtual function pointer. Each
child's value is the function pointer itself, the summary is the
symbolication of this function pointer, and the type will be a valid
function pointer from the debug info if there is debug information
corresponding to the virtual function pointer.
The vtable SBValue will have the following:
- SBValue::GetName() returns "vtable for <class>"
- SBValue::GetValue() returns a string representation of the vtable
address
- SBValue::GetSummary() returns NULL
- SBValue::GetType() returns a type appropriate for a uintptr_t type for
the current process
- SBValue::GetLoadAddress() returns the address of the vtable adderess
- SBValue::GetValueAsUnsigned(...) returns the vtable address
- SBValue::GetNumChildren() returns the number of virtual function
pointers in the vtable
- SBValue::GetChildAtIndex(...) returns a SBValue that represents a
virtual function pointer
The child SBValue objects that represent a virtual function pointer has
the following values:
- SBValue::GetName() returns "[%u]" where %u is the vtable function
pointer index
- SBValue::GetValue() returns a string representation of the virtual
function pointer
- SBValue::GetSummary() returns a symbolicated respresentation of the
virtual function pointer
- SBValue::GetType() returns the function prototype type if there is
debug info, or a generic funtion prototype if there is no debug info
- SBValue::GetLoadAddress() returns the address of the virtual function
pointer
- SBValue::GetValueAsUnsigned(...) returns the virtual function pointer
- SBValue::GetNumChildren() returns 0
- SBValue::GetChildAtIndex(...) returns invalid SBValue for any index
Examples of using this API via python:
```
(lldb) script vtable = lldb.frame.FindVariable("shape_ptr").GetVTable()
(lldb) script vtable
vtable for Shape = 0x0000000100004088 {
[0] = 0x0000000100003d20 a.out`Shape::~Shape() at main.cpp:3
[1] = 0x0000000100003e4c a.out`Shape::~Shape() at main.cpp:3
[2] = 0x0000000100003e7c a.out`Shape::area() at main.cpp:4
[3] = 0x0000000100003e3c a.out`Shape::optional() at main.cpp:7
}
(lldb) script c = vtable.GetChildAtIndex(0)
(lldb) script c
(void ()) [0] = 0x0000000100003d20 a.out`Shape::~Shape() at main.cpp:3
```
Since D101206 (`ba79fb2e1ff7130cde02fbbd325f0f96f8a522ca`) the `__hash_node::__value_`
member is wrapped in an anonymous union. `ValueObject::GetChildMemberWithName` doesn't see
through the union.
This patch accounts for this possible new layout by getting a handle to
the union before doing the by-name `__value_` lookup.
## Description
This pull request adds a new `stop-at-user-entry` option to LLDB
`process launch` command, allowing users to launch a process and pause
execution at the entry point of the program (for C-based languages,
`main` function).
## Motivation
This option provides a convenient way to begin debugging a program by
launching it and breaking at the desired entry point.
## Changes Made
- Added `stop-at-user-entry` option to `Options.td` and the
corresponding case in `CommandOptionsProcessLaunch.cpp` (short option is
'm')
- Implemented `GetUserEntryPointName` method in the Language plugins
available at the moment.
- Declared the `CreateBreakpointAtUserEntry` method in the Target API.
- Create Shell test for the command
`command-process-launch-user-entry.test`.
## Usage
`process launch --stop-at-user-entry` or `process launch -m` launches
the process and pauses execution at the entry point of the program.
We noticed some performance issue while in lldb-vscode for grabing the
name of the SBValue. Profiling shows SBValue::GetName() can cause
synthetic children provider of shared/unique_ptr to deference underlying
object and complete it type.
This patch lazily moves the dereference from synthetic child provider's
Update() method to GetChildAtIndex() so that SBValue::GetName() won't
trigger the slow code path.
Here is the culprit slow code path:
```
...
frame #59: 0x00007ff4102e0660 liblldb.so.15`SymbolFileDWARF::CompleteType(this=<unavailable>, compiler_type=0x00007ffdd9829450) at SymbolFileDWARF.cpp:1567:25 [opt]
...
frame #67: 0x00007ff40fdf9bd4 liblldb.so.15`lldb_private::ValueObject::Dereference(this=0x0000022bb5dfe980, error=0x00007ffdd9829970) at ValueObject.cpp:2672:41 [opt]
frame #68: 0x00007ff41011bb0a liblldb.so.15`(anonymous namespace)::LibStdcppSharedPtrSyntheticFrontEnd::Update(this=0x000002298fb94380) at LibStdcpp.cpp:403:40 [opt]
frame #69: 0x00007ff41011af9a liblldb.so.15`lldb_private::formatters::LibStdcppSharedPtrSyntheticFrontEndCreator(lldb_private::CXXSyntheticChildren*, std::shared_ptr<lldb_private::ValueObject>) [inlined] (anonymous namespace)::LibStdcppSharedPtrSyntheticFrontEnd::LibStdcppSharedPtrSyntheticFrontEnd(this=0x000002298fb94380, valobj_sp=<unavailable>) at LibStdcpp.cpp:371:5 [opt]
...
frame #78: 0x00007ff40fdf6e42 liblldb.so.15`lldb_private::ValueObject::CalculateSyntheticValue(this=0x000002296c66a500) at ValueObject.cpp:1836:27 [opt]
frame #79: 0x00007ff40fdf1939 liblldb.so.15`lldb_private::ValueObject::GetSyntheticValue(this=<unavailable>) at ValueObject.cpp:1867:3 [opt]
frame #80: 0x00007ff40fc89008 liblldb.so.15`ValueImpl::GetSP(this=0x0000022c71b90de0, stop_locker=0x00007ffdd9829d00, lock=0x00007ffdd9829d08, error=0x00007ffdd9829d18) at SBValue.cpp:141:46 [opt]
frame #81: 0x00007ff40fc7d82a liblldb.so.15`lldb::SBValue::GetSP(ValueLocker&) const [inlined] ValueLocker::GetLockedSP(this=0x00007ffdd9829d00, in_value=<unavailable>) at SBValue.cpp:208:21 [opt]
frame #82: 0x00007ff40fc7d817 liblldb.so.15`lldb::SBValue::GetSP(this=0x00007ffdd9829d90, locker=0x00007ffdd9829d00) const at SBValue.cpp:1047:17 [opt]
frame #83: 0x00007ff40fc7da6f liblldb.so.15`lldb::SBValue::GetName(this=0x00007ffdd9829d90) at SBValue.cpp:294:32 [opt]
...
```
Differential Revision: https://reviews.llvm.org/D159542
`std::basic_string<char>` is not a regex, and treating it as such could
unintentionally
cause a formatter to substring match a template type parameter, for
example:
`std::vector<std::basic_string<char>>`.
Differential Revision: https://reviews.llvm.org/D158663
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
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
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
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
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
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
Following D151810, this changes `GetChildAtNamePath` to take a path of `StringRef`
values instead of `ConstString`.
Differential Revision: https://reviews.llvm.org/D151813
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
`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
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.
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
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
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.
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
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
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
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
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
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
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
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.
std::optional::value() has undesired exception checking semantics and is
unavailable in some older Xcode. The call sites block std::optional migration.
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
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
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
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
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
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
