Rather than passing two booleans around, which is especially error prone
with them being next to each other, use a struct with named fields
instead.
Differential revision: https://reviews.llvm.org/D107295
Clang adds a Decl in two phases to a DeclContext. First it adds it invisible and
then it makes it visible (which will add it to the lookup data structures). It's
important that we can't do lookups into the DeclContext we are currently adding
the Decl to during this process as once the Decl has been added, any lookup will
automatically build a new lookup map and add the added Decl to it. The second
step would then add the Decl a second time to the lookup which will lead to
weird errors later one. I made adding a Decl twice to a lookup an assertion
error in D84827.
In the first step Clang also does some computations on the added Decl if it's
for example a FieldDecl that is added to a RecordDecl.
One of these computations is checking if the FieldDecl is of a record type
and the record type has a deleted constexpr destructor which will delete
the constexpr destructor of the record that got the FieldDecl.
This can lead to a bug with the way we implement MinimalImport in LLDB
and the following code:
```
struct Outer {
typedef int HookToOuter;
struct NestedClass {
HookToOuter RefToOuter;
} NestedClassMember; // We are adding this.
};
```
1. We just imported `Outer` minimally so far.
2. We are now asked to add `NestedClassMember` as a FieldDecl.
3. We import `NestedClass` minimally.
4. We add `NestedClassMember` and clang does a lookup for a constexpr dtor in
`NestedClass`. `NestedClassMember` hasn't been added to the lookup.
5. The lookup into `NestedClass` will now load the members of `NestedClass`.
6. We try to import the type of `RefToOuter` which will try to import the `HookToOuter` typedef.
7. We import the typedef and while importing we check for conflicts in `Outer` via a lookup.
8. The lookup into `Outer` will cause the invisible `NestedClassMember` to be added to the lookup.
9. We continue normally until we get back to the `addDecl` call in step 2.
10. We now add `NestedClassMember` to the lookup even though we already did that in step 8.
The fix here is disabling the minimal import for RecordTypes from FieldDecls. We
actually already did this, but so far we only force the definition of the type
to be imported *after* we imported the FieldDecl. This just moves that code
*before* we import the FieldDecl so prevent the issue above.
Reviewed By: shafik, aprantl
Differential Revision: https://reviews.llvm.org/D102993
More decoupling of plugins and non-plugins. Target doesn't need to
manage ClangModulesDeclVendor and ClangPersistentVariables is always available
in situations where you need ClangModulesDeclVendor.
Differential Revision: https://reviews.llvm.org/D102811
It looks like a previous change switched these from LLDB_LOGF but did not update the format strings.
Differential Revision: https://reviews.llvm.org/D96550
Replace uses of GetModuleAtIndexUnlocked and
GetModulePointerAtIndexUnlocked with the ModuleIterable and
ModuleIterableNoLocking where applicable.
Differential revision: https://reviews.llvm.org/D94271
Right now we have one large AST for all types in LLDB. All ODR violations in
types we reconstruct are resolved by just letting the ASTImporter handle the
conflicts (either by merging types or somehow trying to introduce a duplicated
declaration in the AST). This works ok for the normal types we build from debug
information as most of them are just simple CXXRecordDecls or empty template
declarations.
However, with a loaded `std` C++ module we have alternative versions of pretty
much all declarations in the `std` namespace that are much more fleshed out than
the debug information declarations. They have all the information that is lost
when converting to DWARF, such as default arguments, template default arguments,
the actual uninstantiated template declarations and so on.
When we merge these C++ module types into the big scratch AST (that might
already contain debug information types) we give the ASTImporter the tricky task
of somehow creating a consistent AST out of all these declarations. Usually this
ends in a messy AST that contains a mostly broken mix of both module and debug
info declarations. The ASTImporter in LLDB is also importing types with the
MinimalImport setting, which usually means the only information we have when
merging two types is often just the name of the declaration and the information
that it contains some child declarations. This makes it pretty much impossible
to even implement a better merging logic (as the names of C++ module
declarations and debug info declarations are identical).
This patch works around this whole merging problem by separating C++ module
types from debug information types. This is done by splitting up the single
scratch AST into two: One default AST for debug information and a dedicated AST
for C++ module types.
The C++ module AST is implemented as a 'specialised AST' that lives within the
default ScratchTypeSystemClang. When we select the scratch AST we can explicitly
request that we want such a isolated sub-AST of the scratch AST. I kept the
infrastructure more general as we probably can use the same mechanism for other
features that introduce conflicting types (such as programs that are compiled
with a custom -wchar-size= option).
There are just two places where we explicitly have request the C++ module AST:
When we export persistent declarations (`$mytype`) and when we create our
persistent result variable (`$0`, `$1`, ...). There are a few formatters that
were previously assuming that there is only one scratch AST which I cleaned up
in a preparation revision here (D92757).
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D92759
Summary:
The ClangASTSource has a lock that globally disables all lookups into the
external AST source when we explicitly "guarded" copy a type. It's not used for
anything else, so importing declarations or importing types that are
dependencies of a declaration actually won't activate that lock. The lookups it
is supposed to prevent also don't actually happen in our test suite. The check
in `ClangExpressionDeclMap::FindExternalVisibleDecls` is never executed and the
check in the `ClangASTSource::FindExternalVisibleDeclsByName` is only ever
reached by the `Import-std-module` tests (which explicitly do a lookup into the
expression context on purpose).
This lock was added in 6abfabff61 as a replacement
for a list of types we already looked up which appeared to be an optimisation
strategy. I assume back then this lock had a purpose but these days the
ASTImporter and LLDB seem to be smart enough to avoid whatever lookups this
tried to prevent.
I would say we remove it from LLDB. The main reason is that it blocks D81561
(which explicitly does a specific lookup to resolve placeholder types produced
by `-flimit-debug-info`) but it's semantics are also very confusing. The naming
implies it's a flag to indicate when we import something at the moment which is
practically never true as described above. Also the fact that it makes our
ExternalASTSource alternate between doing lookups into the debug info and
pretending it doesn't know any external decls could really break our lookup in
some weird way if Clang decides to cache a fake empty lookup result that was
generated while the lock was active.
Reviewers: labath, shafik, JDevlieghere, aprantl
Reviewed By: labath, JDevlieghere, aprantl
Subscribers: aprantl, abidh
Differential Revision: https://reviews.llvm.org/D81749
Move the part of the code which is responsible for finding a complete
definition of the type into a separate function (FindCompleteType). This
is split off from D81561, as it's a generally useful cleanup.
No functional change.
The indexes need to start at 0 but in D74951 I removed the first parameter
and didn't decrement all the indexes. This patch at least makes sure that
LLDB logging no longer crashes (but it still deadlocks).
This member is for some reason initialized in ClangASTSource::FindExternalVisibleDecls
so all other functions using this member dereference a nullptr unless we
call this function before that. Let's just initialize this in the constructor.
This should be NFC as the only side effect is that we don't reset the namespace map
when calling ClangASTSource::FindExternalVisibleDecls multiple times (and we never
call this function multiple times for one NameSearchContext from what I can see).
The size of NameSearchContext isn't important as we never store it and rarely
allocate more than a few. This way we also don't have to use the memset to
initialize these fields to zero.
Summary:
We have a lot of code in our lookup code to pass around `current_id` counters which end up in our logs like this:
```
AOCTV::FT [234] Found XYZ
```
This patch removes all of this code because:
* I'm splitting up all humongous functions, so I need to write more and more boilerplate to pass around these ids.
* I never saw any similar counters in the LLDB/LLVM code base.
* They're essentially globals and the last thing we need in LLDB is even more global state.
* They're not really useful when readings logs. It doesn't help that there isn't just 1 or 2 counters, but 12 (!) unique counters. I always thought that if I see two identical counter values in those brackets it's the same lookup request, but it seems that's only true by accident (and you can't know which of the 12 counters is actually printed without reading the code). The only time I know I can trust the counters is when it's obvious from the log that it's the same counter like in the log below, but then why have the counters in the first place?
```
LayoutRecordType[28] on (ASTContext*)0x00007FFA1C840200 'scratch ASTContext' for (RecordDecl*)0x00007FFA0AAE8CF0 [name = '__tree']
LRT[28] returned:
LRT[28] Original = (RecordDecl*)%p
LRT[28] Size = %lld
LRT[28] Alignment = %lld
LRT[28] Fields:
LRT[28] (FieldDecl*)0x00007FFA1A13B1D0, Name = '__begin_node_', Offset = 0 bits
LRT[28] (FieldDecl*)0x00007FFA1C08FD30, Name = '__pair1_', Offset = 64 bits
LRT[28] (FieldDecl*)0x00007FFA1C061210, Name = '__pair3_', Offset = 128 bits
LRT[28] Bases:
```
Reviewers: labath, shafik, JDevlieghere
Reviewed By: labath, shafik, JDevlieghere
Subscribers: abidh, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74951
Summary:
All of our lookup APIs either use `CompilerDeclContext &` or `CompilerDeclContext *` semi-randomly it seems.
This leads to us constantly converting between those two types (and doing nullptr checks when going from
pointer to reference). It also leads to the confusing situation where we have two possible ways to express
that we don't have a CompilerDeclContex: either a nullptr or an invalid CompilerDeclContext (aka a default
constructed CompilerDeclContext).
This moves all APIs to use references and gets rid of all the nullptr checks and conversions.
Reviewers: labath, mib, shafik
Reviewed By: labath, shafik
Subscribers: shafik, arphaman, abidh, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74607
Summary:
lldb-forward.h is convenient in many ways, but having clang-based
class forward declarations in there makes it easy to proliferate uses of clang
outside of plugins. Removing them makes you much more conscious of when
you're using something from clang and marks where we're using things
from clang in non-plugins.
Differential Revision: https://reviews.llvm.org/D73935
Summary:
This change represents the move of ClangASTImporter, ClangASTMetadata,
ClangExternalASTSourceCallbacks, ClangUtil, CxxModuleHandler, and
TypeSystemClang from lldbSource to lldbPluginExpressionParserClang.h
This explicitly removes knowledge of clang internals from lldbSymbol,
moving towards a more generic core implementation of lldb.
Reviewers: JDevlieghere, davide, aprantl, teemperor, clayborg, labath, jingham, shafik
Subscribers: emaste, mgorny, arphaman, jfb, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73661
A ClangASTSource always has a ClangASTImporter. Let's remove these sporadic
checks with a single assert during construction. They were added originally
for the modern-type-lookup mode that didn't use a ClangASTImporter in there.
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
Summary:
This is a port of D67803 that was about preventing indirect importing to our scratch context when evaluating expressions.
D67803 already has a pretty long explanation of how this works, but the idea is that instead
of importing declarations indirectly over the expression AST (i.e., Debug info AST -> Expression AST -> scratch AST)
we instead directly import the declaration from the debug info AST to the scratch AST.
The difference from D67803 is that here we have to do this in the ASTImporterDelegate (which is our ASTImporter
subclass we use in LLDB). It has the same information as the ExternalASTMerger in D67803 as it can access the
ClangASTImporter (which also keeps track of where Decls originally came from).
With this patch we can also delete the FieldDecl stealing hack in the ClangASTSource (this was only necessary as the
indirect imports caused the creation of duplicate Record declarations but we needed the fields in the Record decl
we originally found in the scratch ASTContext).
This also fixes the current gmodules failures where we fail to find std::vector fields after an indirect import
over the expression AST (where it seems even our FieldDecl stealing hack can't save us from).
Reviewers: shafik, aprantl
Reviewed By: shafik
Subscribers: JDevlieghere, lldb-commits, mib, labath, friss
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72507
LLDB frequently converts QualType to CompilerType. This is currently done like this:
result = CompilerType(this, qual_type_var.getAsOpaquePtr())
There are a few shortcomings in this current approach:
1. CompilerType's constructor takes a void* pointer so it isn't type safe.
2. We can't add any sanity checks to the CompilerType constructor (e.g. that the type
actually belongs to the passed ClangASTContext) without expanding the TypeSystem API.
3. The logic for converting QualType->CompilerType is spread out over all of LLDB so
changing it is difficult (e.g., what if we want to just pass the type ptr and not the
1type_ptr | qual_flags1 to CompilerType).
This patch adds a `ClangASTContext::GetType` function similar to the other GetTypeForDecl
functions that does this conversion in a type safe way.
It also adds a sanity check for Tag-based types that the type actually belongs to the
current ClangASTContext (Types don't seem to know their ASTContext, so we have to
workaround by looking at the decl for the underlying TagDecl. This doesn't cover all types
we construct but it's better than no sanity check).
ClangASTContext::getASTContext() currently returns a ptr but we have an assert there since a
while that the ASTContext is not a nullptr. This causes that we still have a lot of code
that is doing nullptr checks on the result of getASTContext() which is all unreachable code.
This patch changes the return value to a reference to make it clear this can't be a nullptr
and deletes all the nullptr checks.
Their naming is misleading as they only return the
ClangASTContext-owned variables. For ClangASTContext instances constructed
for a given clang::ASTContext they silently generated duplicated instances
(e.g., a second IdentifierTable) that were essentially unusable.
This removes all these getters as they are anyway not very useful in comparison
to just calling the clang::ASTContext getters. The initialization
code has been moved to the CreateASTContext initialization method so that all
code for making our own clang::ASTContext is in one place.
We already pass a Decl here and the additional ASTContext needs to
match the Decl. We might as well just pass the Decl and then extract
the ASTContext from that.
The ClangExpressionDeclMap should be testable from a unit test. This is currently
impossible as they have both dependencies on Target/ExecutionContext from their
constructor. This patch allows constructing these classes without an active Target
and adds the missing tests for running without a target that we can do at least
a basic lookup test without crashing.
Summary:
As discussed on the mailing list [1] we have to make a decision for how to proceed with the modern-type-lookup.
This patch removes modern-type-lookup from LLDB. This just removes all the code behind the modern-type-lookup
setting but it does *not* remove any code from Clang (i.e., the ExternalASTMerger and the clang-import-test stay around
for now).
The motivation for this is that I don't think that the current approach of implementing modern-type-lookup
will work out. Especially creating a completely new lookup system behind some setting that is never turned on by anyone
and then one day make one big switch to the new system seems wrong. It doesn't fit into the way LLVM is developed and has
so far made the transition work much more complicated than it has to be.
A lot of the benefits that were supposed to come with the modern-type-lookup are related to having a better organization
in the way types move across LLDB and having less dependencies on unrelated LLDB code. By just looking at the current code (mostly
the ClangASTImporter) I think we can reach the same goals by just incrementally cleaning up, documenting, refactoring
and actually testing the existing code we have.
[1] http://lists.llvm.org/pipermail/lldb-dev/2019-December/015831.html
Reviewers: shafik, martong
Subscribers: rnkovacs, christof, arphaman, JDevlieghere, usaxena95, lldb-commits, friss
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71562
The overloads that don't take a CompilerType serve no purpose as we
always have a CompilerType in the scope where we call them. Instead
just call the overload that takes a CompilerType and delete the
now unused other overloaded methods.
Target doesn't really need to know about ClangASTContext more than any
other TypeSystem. We can create a method ClangASTContext::GetScratch for
anything who needs a ClangASTContext specifically instead of just a
generic TypeSystem.
Summary: Not once have I looked at these numbers in a log and considered them useful. Also this should not have been implemented via an unguarded list of globals.
Reviewers: martong, shafik
Reviewed By: shafik
Subscribers: rnkovacs, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71336
ClangASTSource currently takes a clang::ASTContext and keeps that
around, but a lot of LLDB's functionality for doing operations
on a clang::ASTContext is in its ClangASTContext twin class. We
currently constantly recompute the respective ClangASTContext
from the clang::ASTContext while we instead could just pass and
store a ClangASTContext in the ClangASTSource. This also allows
us to get rid of a bunch of unreachable error checking for cases
where recomputation fails for some reason.
Summary:
LLDB's ASTDumper is just a clone of Clang's ASTDumper but with some scary code and
some unrelated functionality (like dumping name/attributes of types). This removes LLDB's ASTDumper
and replaces its uses with the `ClangUtils::DumpDecl` method that just calls Clang's ASTDumper
and returns the result as a string.
The few uses where we just want a textual representation of a type (which will print their name/attributes but not
dump any AST) are now also in ClangUtil under a `ToString` name until we find a better home for them.
Reviewers: labath
Reviewed By: labath
Subscribers: mgorny, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70663
This patch removes the size_t return value and the append parameter
from the remainder of the Find.* functions in LLDB's internal API. As
in the previous patches, this is motivated by the fact that these
parameters aren't really used, and in the case of the append parameter
were frequently implemented incorrectly.
Differential Revision: https://reviews.llvm.org/D69119
llvm-svn: 375160
Shafik Yaghmour