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
Reland 486787210d which broke tests on Arm and Windows.
* Windows -- on Windows const static data members with no out-of-class
definition do have valid addresses, in constract to other platforms
(Linux, macos) where they don't. Adjusted the test to expect success
on Windows and failure on other platforms.
* Arm -- `int128` is not available on 32-bit ARM, so disable the test
for this architecture.
This adds support for using const static integral data members as described by C++11 [class.static.data]p3
to LLDB's expression evaluator.
So far LLDB treated these data members are normal static variables. They already work as intended when they are declared in the class definition and then defined in a namespace scope. However, if they are declared and initialised in the class definition but never defined in a namespace scope, all LLDB expressions that use them will fail to link when LLDB can't find the respective symbol for the variable.
The reason for this is that the data members which are only declared in the class are not emitted into any object file so LLDB can never resolve them. Expressions that use these variables are expected to directly use their constant value if possible. Clang can do this for us during codegen, but it requires that we add the constant value to the VarDecl we generate for these data members.
This patch implements this by:
* parsing the constant values from the debug info and adding it to variable declarations we encounter.
* ensuring that LLDB doesn't implicitly try to take the address of expressions that might be an lvalue that points to such a special data member.
The second change is caused by LLDB's way of storing lvalues in the expression parser. When LLDB parses an expression, it tries to keep the result around via two mechanisms:
1. For lvalues, LLDB generates a static pointer variable and stores the address of the last expression in it: `T *$__lldb_expr_result_ptr = &LastExpression`
2. For everything else, LLDB generates a static variable of the same type as the last expression and then direct initialises that variable: `T $__lldb_expr_result(LastExpression)`
If we try to print a special const static data member via something like `expr Class::Member`, then LLDB will try to take the address of this expression as it's an lvalue. This means LLDB will try to take the address of the variable which causes that Clang can't replace the use with the constant value. There isn't any good way to detect this case (as there a lot of different expressions that could yield an lvalue that points to such a data member), so this patch also changes that we only use the first way of capturing the result if the last expression does not have a type that could potentially indicate it's coming from such a special data member.
This change shouldn't break most workflows for users. The only observable side effect I could find is that the implicit persistent result variables for const int's now have their own memory address:
Before this change:
```
(lldb) p i
(const int) $0 = 123
(lldb) p &$0
(const int *) $1 = 0x00007ffeefbff8e8
(lldb) p &i
(const int *) $2 = 0x00007ffeefbff8e8
```
After this change we capture `i` by value so it has its own value.
```
(lldb) p i
(const int) $0 = 123
(lldb) p &$0
(const int *) $1 = 0x0000000100155320
(lldb) p &i
(const int *) $2 = 0x00007ffeefbff8e8
```
Reviewed By: Michael137
Differential Revision: https://reviews.llvm.org/D81471
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
This adds support for parsing DW_AT_calling_convention in the DWARF parser.
The generic DWARF parsing code already support extracting this attribute from A
DIE and TypeSystemClang already offers a parameter to add a calling convention
to a function type (as the PDB parser supports calling convention parsing), so
this patch just converts the DWARF enum value to the Clang enum value and adds a
few tests.
There are two tests in this patch.:
* A unit test for the added DWARF parsing code that should run on all platforms.
* An API tests that covers the whole expression evaluation machinery by trying
to call functions with non-standard calling conventions. The specific subtests
are target specific as some calling conventions only work on e.g. win32 (or, if
they work on other platforms they only really have observable differences on a
specific target). The tests are also highly compiler-specific, so if GCC or
Clang tell us that they don't support a specific calling convention then we just
skip the test.
Note that some calling conventions are supported by Clang but aren't implemented
in LLVM (e.g. `pascal`), so there we just test that if this ever gets
implemented in LLVM that LLDB works too. There are also some more tricky/obscure
conventions that are left out such as the different swift* conventions, some
planned Obj-C conventions (`Preserve*`), AAPCS* conventions (as the DWARF->Clang
conversion is ambiguous for AAPCS and APPCS-VFP) and conventions only used for
OpenCL etc.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D108629
The class only supports a single DWARF unit (needed for my new test), and it
reimplements chunks of object and symbol file classes. We can just make it use
the real thing, save some LOC and get the full feature set.
Differential Revision: https://reviews.llvm.org/D90393
The Length, AbbrOffset and Values fields of the debug_info section are
optional. This patch helps remove them and simplify test cases.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D86857
This patch adds support for emitting multiple abbrev tables. Currently,
compilation units will always reference the first abbrev table.
Reviewed By: jhenderson, labath
Differential Revision: https://reviews.llvm.org/D86194
'InitialLength' is replaced with 'Format' (DWARF32 by default) and 'Length' in this patch.
Besides, test cases for DWARFv4 and DWARFv5, DWARF32 and DWARF64 is
added.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D82622
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
Summary:
This commit renames ClangASTContext to TypeSystemClang to better reflect what this class is actually supposed to do
(implement the TypeSystem interface for Clang). It also gets rid of the very confusing situation that we have both a
`clang::ASTContext` and a `ClangASTContext` in clang (which sometimes causes Clang people to think I'm fiddling
with Clang's ASTContext when I'm actually just doing LLDB work).
I also have plans to potentially have multiple clang::ASTContext instances associated with one ClangASTContext so
the ASTContext naming will then become even more confusing to people.
Reviewers: #lldb, aprantl, shafik, clayborg, labath, JDevlieghere, davide, espindola, jdoerfert, xiaobai
Reviewed By: clayborg, labath, xiaobai
Subscribers: wuzish, emaste, nemanjai, mgorny, kbarton, MaskRay, arphaman, jfb, usaxena95, jingham, xiaobai, abidh, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72684
Summary:
I often struggle to understand what exactly LLDB is doing by looking at our expression evaluation logging as our messages look like this:
```
CompleteTagDecl[2] on (ASTContext*)0x7ff31f01d240 Completing (TagDecl*)0x7ff31f01d568 named DeclName1
```
From the log messages it's unclear what this ASTContext is. Is it the scratch context, the expression context, some decl vendor context or a context from a module?
The pointer value isn't helpful for anyone unless I'm in a debugger where I could inspect the memory at the address. But even with a debugger it's not easy to
figure out what this ASTContext is without having deeper understanding about all the different ASTContext instances in LLDB (e.g., valid SourceLocation
from the file system usually means that this is the Objective-C decl vendor, a file name from multiple expressions is probably the scratch context, etc.).
This patch adds a name field to ClangASTContext instances that we can use to store a name which can be used for logging and debugging. With this
our log messages now look like this:
```
CompleteTagDecl[2] on scratch ASTContext. Completing (TagDecl*)0x7ff31f01d568 named Foo
```
We can now also just print a ClangASTContext from the debugger and see a useful name in the `m_display_name` field, e.g.
```
m_display_name = "AST for /Users/user/test/main.o";
```
Reviewers: shafik, labath, JDevlieghere, mib
Reviewed By: shafik
Subscribers: clayborg, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72391
Creating an ASTContext with an unknown triple is rarely a good idea (as usually
all our ASTs have a valid triple that is either from the host or the target) and the
default argument makes it far to easy to implicitly create such an AST. Let's
remove it and force people to pass a triple.
The only place where we don't pass a triple is a DWARFASTParserClangTests
where we now just pass the host triple instead (the test doesn't depend on any
triple so this shouldn't change anything).
This adds a check that the ClangASTContext actually fits to the
DeclContext that we want to create a CompilerDeclContext for. If
the ClangASTContext (and its associated ASTContext) does not fit
to the DeclContext (that is, the DeclContext wasn't created by the
ASTContext), all computations using this malformed CompilerDeclContext
will yield unpredictable results.
Also fixes the only place that actually hits this assert which is the
construction of a CompilerDeclContext in ClangExpressionDeclMap
where we pass an unrelated ASTContext instead of the ASTContext
of the current expression.
I had to revert my previous change to DWARFASTParserClangTests.cpp
back to using the unsafe direct construction of CompilerDeclContext
as this assert won't work if the DeclContext we pass isn't a valid
DeclContext in the first place.
Summary:
Many of our tests need to initialize certain subsystems/plugins of LLDB such as
`FileSystem` or `HostInfo` by calling their static `Initialize` functions before the
test starts and then calling `::Terminate` after the test is done (in reverse order).
This adds a lot of error-prone boilerplate code to our testing code.
This patch adds a RAII called SubsystemRAII that ensures that we always call
::Initialize and then call ::Terminate after the test is done (and that the Terminate
calls are always in the reverse order of the ::Initialize calls). It also gets rid of
all of the boilerplate that we had for these calls.
Per-fixture initialization is still not very nice with this approach as it would
require some kind of static unique_ptr that gets manually assigned/reseted
from the gtest SetUpTestCase/TearDownTestCase functions. Because of that
I changed all per-fixture setup to now do per-test setup which can be done
by just having the SubsystemRAII as a member of the test fixture. This change doesn't
influence our normal test runtime as LIT anyway runs each test case separately
(and the Initialize/Terminate calls are anyway not very expensive). It will however
make running all tests in a single executable slightly slower.
Reviewers: labath, JDevlieghere, martong, espindola, shafik
Reviewed By: labath
Subscribers: mgorny, rnkovacs, emaste, MaskRay, abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71630
The CompilerDeclContext constructor takes a void* pointer which
means that all callers of this constructor need to first explicitly
convert all pointers to clang::DeclContext*. This causes that we
for example can't just pass a TranslationUnitDecl* to the constructor without
first casting it to its parent class (as it inherits from both
Decl and DeclContext so the void* pointer is actually a Decl*).
This patch introduces a utility function in the ClangASTContext
which gets rid of the requirement to cast all pointers to
clang::DeclContext. Also moves all constructor calls to use this
function instead which is NFC (beside the change in
DWARFASTParserClangTests.cpp).
Reason for this patch is the Ssame reason as for the previous patches:
Having a ClangASTContext and being able to switch the associated ASTContext isn't
a use case we have (or should have), so let's simplify all this code.
This way it becomes clearer in what order we initialize data structures.
The DWARFASTParserClangTests changes are necessary as the test is using
a ClangASTContext but relied on the fact that no called function ever calls
getASTContext() on our ClangASTContext (as that would create the ASTContext).
As we now always create the ASTContext the fact that we had an uninitialized
FileSystem made the test crash.
llvm-svn: 373457
This implements
DWARFASTParserClang::EnsureAllDIEsInDeclContextHaveBeenParsed so as to
provide a faster way to ensure all DIEs linked to a certain declaration
context have been parsed.
Currently, we rely on SymbolFileDWARF::ParseDeclsForContext calling
DWARFASTParserClang::GetDIEForDeclContext, and only then
DWARFASTParserClang::GetDeclForUIDFromDWARF. This change shortcuts that
logic and removes redundant calls to DWARFASTParserClang::
GetClangDeclForDIE by deleting DIEs from the m_decl_ctx_to_die map once
they have been parsed.
Differential Revision: https://reviews.llvm.org/D67760
Patch by Guilherme Andrade <guiandrade@google.com>.
llvm-svn: 372744
Currently, we return all the entries such that their decl_ctx pointer >= decl_ctx provided.
Instead, we should return only the ones that decl_ctx pointer == decl_ctx provided.
Differential Revision: https://reviews.llvm.org/D66357
Patch by Guilherme Andrade <guiandrade@google.com>.
llvm-svn: 370374
