ValueObject is part of lldbCore for historical reasons, but conceptually
it deserves to be its own library. This does introduce a (link-time) circular
dependency between lldbCore and lldbValueObject, which is unfortunate
but probably unavoidable because so many things in LLDB rely on
ValueObject. We already have cycles and these libraries are never built
as dylibs so while this doesn't improve the situation, it also doesn't
make things worse.
The header includes were updated with the following command:
```
find . -type f -exec sed -i.bak "s%include \"lldb/Core/ValueObject%include \"lldb/ValueObject/ValueObject%" '{}' \;
```
This PR adds a statistics provider cache, which allows an individual
target to keep a rolling tally of it's total time and number of
invocations for a given summary provider. This information is then
available in statistics dump to help slow summary providers, and gleam
more into insight into LLDB's time use.
This change by itself has no measurable effect on the LLDB
testsuite. I'm making it in preparation for threading through more
errors in the Swift language plugin.
For some data formatters, even getting the number of children can be an
expensive operations (e.g., needing to walk a linked list to determine
the number of elements). This is then wasted work when we know we will
be printing only small number of them.
This patch replaces the calls to GetNumChildren (at least those on the
"frame var" path) with the calls to the capped version, passing the
value of `max-children-count` setting (plus one)
But one made in a situation where that's impossible might only have an
error, and no symbol context, so that's not necessarily true. Check for
the target's validity before using it.
Fixes issue #93313
FormatManager::GetCategoryForLanguage and
FormatManager::GetCategory(can_create = true) can be called concurrently
and they both take the TypeCategory::m_map_mutex and the
FormatManager::m_language_categories_mutex but in reverse order.
On one thread, GetCategoryForLanguage takes m_language_categories_mutex
and then ends calling TypeCategoryMap::Get which takes m_map_mutex
On another thread GetCategory calls TypeCategoryMap::Add which takes
m_map_mutex and then calls FormatManager::Changed() which takes
m_language_categories_mutex
If both threads are running concurrently, we have a dead lock.
The patch releases the m_map_mutex before calling Changed which avoids
the dead lock.
---------
Co-authored-by: Vincent Belliard <v-bulle@github.com>
Change GetNumChildren()/CalculateNumChildren() methods return
llvm::Expected
This is an NFC change that does not yet add any error handling or change
any code to return any errors.
This is the second big change in the patch series started with
https://github.com/llvm/llvm-project/pull/83501
A follow-up PR will wire up error handling.
Change GetNumChildren()/CalculateNumChildren() methods return
llvm::Expected
This is an NFC change that does not yet add any error handling or change
any code to return any errors.
This is the second big change in the patch series started with
https://github.com/llvm/llvm-project/pull/83501
A follow-up PR will wire up error handling.
I get a small but fairly steady stream of crash reports which I can only
explain by ValueObjectPrinter trying to access its m_valobj field, and
finding it NULL. I have never been able to reproduce any of these, and
the reports show a state too long after the fact to know what went
wrong.
I've read through this section of lldb a bunch of times trying to figure
out how this could happen, but haven't ever found anything actually
wrong that could cause this. OTOH, ValueObjectPrinter is somewhat sloppy
about how it handles the ValueObject it is printing.
a) lldb allows you to make a ValueObjectPrinter with a Null incoming
ValueObject. However, there's no affordance to set the ValueObject in
the Printer after the fact, and it doesn't really make sense to do that.
So I change the ValueObjectPrinter API's to take a ValueObject
reference, rather than a pointer. All the places that make
ValueObjectPrinters already check the non-null status of their
ValueObject's before making the ValueObjectPrinter, so sadly, I didn't
find the bug, but this will enforce the intent.
b) The next step in printing the ValueObject is deciding which of the
associated DynamicValue/SyntheticValue we are actually printing (based
on the use_dynamic and use_synthetic settings in the original
ValueObject. This was put in a pointer by GetMostSpecializedValue, but
most of the printer code just accessed the pointer, and it was hard to
reason out whether we were guaranteed to always call this before using
m_valobj. So far as I could see we always do (sigh, didn't find the bug
there either) but this was way too hard to reason about.
In fact, we figure out once which ValueObject we're going to print and
don't change that through the life of the printer. So I changed this to
both set the "most specialized value" in the constructor, and then to
always access it through GetMostSpecializedValue(). That makes it easier
to reason about the use of this ValueObject as well.
This is an NFC change, all it does is make the code easier to reason
about.
Refactors logic in `ParseInternal` that was previously calling
`GetFormatFromCString` twice, once with `partial_match_ok` set to false,
and the second time set to true.
With this change, lldb formats (ie `%@`, `%S`, etc) are checked first.
If a format is not one of those, then `GetFormatFromCString` is called
once, and now always checks for partial matches.
The implementation of `FormatCache::Entry
&FormatCache::GetEntry(ConstString)` is effectively a duplication of
`std::map::operator[]`. This change deletes `GetEntry` and replaces its
use with `operator[]`.
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
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
```
To get the number of children for a VectorType (i.e.,
a type declared with a `vector_size`/`ext_vector_type` attribute)
LLDB previously did following calculation:
1. Get byte-size of the vector container from Clang (`getTypeInfo`).
2. Get byte-size of the element type we want to interpret the array as.
(e.g., sometimes we want to interpret an `unsigned char vec[16]`
as a `float32[]`).
3. `numChildren = containerSize / reinterpretedElementSize`
However, for step 1, clang will return us the *aligned* container
byte-size.
So for a type such as `float __attribute__((ext_vector_type(3)))`
(which is an array of 3 4-byte floats), clang will round up the
byte-width of the array to `16`.
(see
[here](ab6a66dbec/clang/lib/AST/ASTContext.cpp (L1987-L1992)))
This means that for vectors where the size isn't a power-of-2, LLDB
will miscalculate the number of elements.
**Solution**
This patch changes step 1 such that we calculate the container size
as `numElementsInSource * byteSizeOfElement`.
The type formatter code is effectively considering empty strings as read
errors, which is wrong. The fix is very simple. We should rely on the
error object and stop checking the size. I also added a test.
lldb already has a `ValueSP` type. This was confusing to me when reading
TypeCategoryMap, especially when `ValueSP` is not qualified. From first
glance it looks like it's referring to a
`std::shared_ptr<lldb_private::Value>` when it's really referring to a
`std::shared_ptr<lldb_private::TypeCategoryImpl>`.
- Allow the definition of synthetic formatters in C++ even when LLDB is built without python scripting support.
- Fix linking problems with the CXXSyntheticChildren
Differential Revision: https://reviews.llvm.org/D158010
The `formatter` logs include a function name, but these functions are mostly templates
and the template type parameter is not printed, which is useful context.
This change adds a new log which is printed upon entry of `FormatManager::Get`, which
shows the formatter context as either `format`, `summary`, or `synthetic`.
Differential Revision: https://reviews.llvm.org/D154128
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
When formatting a variable, the max depth would potentially be ignored
if the current value object failed to print itself. Change that to
always respect the max depth, even if failure occurs.
rdar://109855463
Differential Revision: https://reviews.llvm.org/D152409
The `target.max-children-depth` setting and `--depth` flag would be
ignored if treating pointer as arrays, fix that by always incrementing
the current depth when printing a new child.
rdar://109855463
Differential Revision: https://reviews.llvm.org/D151950
When printing the root of a value, if it's a reference its children are unconditionally
printed - in contrast to pointers whose children are only printed if a sufficient
pointer depth is given.
However, the children are printed even when there's a summary provider that says not to.
If a summary provider exists, this change consults it to determine if children should be
printed.
For example, given a variable of type `std::string &`, this change has the following
effect:
Before:
```
(lldb) p string_ref
(std::string &) string_ref = "one two three four five six seven eight nine ten": {
__r_ = {
std::__1::__compressed_pair_elem<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__rep, 0, false> = {
__value_ = {
= {
__l = (__data_ = "one two three four five six seven eight nine ten", __size_ = 48, __cap_ = 64, __is_long_ = 1)
__s = (__data_ = "@\0p\U00000001\0`\0\00\0\0\0\0\0\0\0@", __padding_ = "\x80t<", __size_ = '\0', __is_long_ = '\x01')
__r = {
__words ={...}
}
}
}
}
}
}
```
After:
```
(lldb) p string_ref
(std::string &) string_ref = "one two three four five six seven eight nine ten"
```
rdar://73248786
Differential Revision: https://reviews.llvm.org/D151748
When `ValueObjectPrinter` calls its `m_decl_printing_helper`, not all state is passed to
the helper. In particular, the helper doesn't have access to `m_curr_depth`, and thus
can't act on the logic within `ShouldShowName`.
To address this, this change passes in a modified copy of `m_options`. The modified copy
has has `m_hide_name` set according to the results of `ShouldShowName`. This allows
helper functions to know whether the name should be shown or hidden, without having
access to `ValueObjectPrinter`'s full state.
This is NFC in mainline lldb, as the only decl printing helper doesn't make use of this.
However in swift-lldb at least, there are decl printing helpers that do need this
information passed to them. See https://github.com/apple/llvm-project/pull/6795 where a
test is also included.
Differential Revision: https://reviews.llvm.org/D150129
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 change uses the information from target.xml sent by
the GDB stub to produce C types that we can use to print
register fields.
lldb-server *does not* produce this information yet. This will
only work with GDB stubs that do. gdbserver or qemu
are 2 I know of. Testing is added that uses a mocked lldb-server.
```
(lldb) register read cpsr x0 fpcr fpsr x1
cpsr = 0x60001000
= (N = 0, Z = 1, C = 1, V = 0, TCO = 0, DIT = 0, UAO = 0, PAN = 0, SS = 0, IL = 0, SSBS = 1, BTYPE = 0, D = 0, A = 0, I = 0, F = 0, nRW = 0, EL = 0, SP = 0)
```
Only "register read" will display fields, and only when
we are not printing a register block.
For example, cpsr is a 32 bit register. Using the target's scratch type
system we construct a type:
```
struct __attribute__((__packed__)) cpsr {
uint32_t N : 1;
uint32_t Z : 1;
...
uint32_t EL : 2;
uint32_t SP : 1;
};
```
If this register had unallocated bits in it, those would
have been filled in by RegisterFlags as anonymous fields.
A new option "SetChildPrintingDecider" is added so we
can disable printing those.
Important things about this type:
* It is packed so that sizeof(struct cpsr) == sizeof(the real register).
(this will hold for all flags types we create)
* Each field has the same storage type, which is the same as the type
of the raw register value. This prevents fields being spilt over
into more storage units, as is allowed by most ABIs.
* Each bitfield size matches that of its register field.
* The most significant field is first.
The last point is required because the most significant bit (MSB)
being on the left/top of a print out matches what you'd expect to
see in an architecture manual. In addition, having lldb print a
different field order on big/little endian hosts is not acceptable.
As a consequence, if the target is little endian we have to
reverse the order of the fields in the value. The value of each field
remains the same. For example 0b01 doesn't become 0b10, it just shifts
up or down.
This is needed because clang's type system assumes that for a struct
like the one above, the least significant bit (LSB) will be first
for a little endian target. We need the MSB to be first.
Finally, if lldb's host is a different endian to the target we have
to byte swap the host endian value to match the endian of the target's
typesystem.
| Host Endian | Target Endian | Field Order Swap | Byte Order Swap |
|-------------|---------------|------------------|-----------------|
| Little | Little | Yes | No |
| Big | Little | Yes | Yes |
| Little | Big | No | Yes |
| Big | Big | No | No |
Testing was done as follows:
* Little -> Little
* LE AArch64 native debug.
* Big -> Little
* s390x lldb running under QEMU, connected to LE AArch64 target.
* Little -> Big
* LE AArch64 lldb connected to QEMU's GDB stub, which is running
an s390x program.
* Big -> Big
* s390x lldb running under QEMU, connected to another QEMU's GDB
stub, which is running an s390x program.
As we are not allowed to link core code to plugins directly,
I have added a new plugin RegisterTypeBuilder. There is one implementation
of this, RegisterTypeBuilderClang, which uses TypeSystemClang to build
the CompilerType from the register fields.
Reviewed By: jasonmolenda
Differential Revision: https://reviews.llvm.org/D145580
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
Fixes printing of spaces in cases where the following are true:
1. Persistent results are disabled
2. The type has a summary string
As reported by @jgorbe in D146783, two spaces were being printed before the summary
string, and no spaces were printed after.
Differential Revision: https://reviews.llvm.org/D147006
When printing a value, allow the root value's name to be elided, without omiting the
names of child values.
At the API level, this adds `SetHideRootName()`, which joins the existing
`SetHideName()` function.
This functionality is used by `dwim-print` and `expression`.
Fixes an issue identified by @jgorbe in https://reviews.llvm.org/D145609.
Differential Revision: https://reviews.llvm.org/D146783
Non-plugin lldb libraries should generally not be linking against lldb
plugin libraries. Enforce this in CMake.
Differential Revision: https://reviews.llvm.org/D146553
Revert while I investigate two CI bot failures;
the more important is the lldb-arm-ubuntu where
the FixAddress is removing the 0th bit so we're
adding the `actual=` decorator on a string pointer,
```
Got output:
(char *) strptr = 0x00400817 (actual=0x400816) ptr = [{ },{H}]
```
in TestDataFormatterSmartArray.py line 229.
This reverts commit 4d635be2db.
On target where metadata is stored in bits that aren't used for
virtual addressing -- AArch64 Top Byte Ignore and pointer authentication
are two examples -- an SBValue object representing a pointer will
return the address with metadata for SBValue::GetValueAsUnsigned.
Users may want to get the virtual address without the metadata;
this new method gives them a way to do this.
Differential Revision: https://reviews.llvm.org/D142792
hold an error should:
(a) return false for IsValid, since that's the current behavior and is
a convenient way to check "should I get the value for this".
(b) preserve the error when an SBValue is made from it, and print the
error in the ValueObjectPrinter.
Make that happen.
Differential Revision: https://reviews.llvm.org/D144664
Context: The `expression` command uses artificial variables to store the expression
result. This result variable is unconditionally kept around after the expression command
has completed. These variables are known as persistent results. These are the variables
`$0`, `$1`, etc, that are displayed when running `p` or `expression`.
This change allows users to control whether result variables are persisted, by
introducing a `--persistent-result` flag.
This change keeps the current default behavior, persistent results are created by
default. This change gives users the ability to opt-out by re-aliasing `p`. For example:
```
command unalias p
command alias p expression --persistent-result false --
```
For consistency, this flag is also adopted by `dwim-print`. Of note, if asked,
`dwim-print` will create a persistent result even for frame variables.
Differential Revision: https://reviews.llvm.org/D144230
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
