for a DeclContext, and fix propagation of exception specifications along
redeclaration chains.
This reverts r232905, r232907, and r232907, which reverted r232793, r232853,
and r232853.
One additional change is present here to resolve issues with LLDB: distinguish
between whether lexical decls missing from the lookup table are local or are
provided by the external AST source, and still look in the external source if
that's where they came from.
llvm-svn: 232928
When we need to build the lookup table for a DeclContext, we used to pull in
all lexical declarations for the context; instead, just build a lookup table
for the local lexical declarations. We previously didn't guarantee that the
imported declarations would be in the returned map, but in some cases we'd
happen to put them all in there regardless. Now we're even lazier about this.
This unnecessary work was papering over some other bugs:
- LookupVisibleDecls would use the DC for name lookups in the TU in C, and
this was not guaranteed to find all imported names (generally, the DC for
the TU in C is not a reliable place to perform lookups). We now use an
identifier-based lookup mechanism for this.
- We didn't actually load in the list of eagerly-deserialized declarations
when importing a module (so external definitions in a module wouldn't be
emitted by users of those modules unless they happened to be deserialized
by the user of the module).
llvm-svn: 232793
declaration of that entity in from one of those modules, keep track of the fact
that we've not completed the redeclaration chain yet so that we can pull the
remaining declarations in from the other module if they're needed.
llvm-svn: 209161
ensure that querying the first declaration for its most recent declaration
checks for redeclarations from the imported module.
This works as follows:
* The 'most recent' pointer on a canonical declaration grows a pointer to the
external AST source and a generation number (space- and time-optimized for
the case where there is no external source).
* Each time the 'most recent' pointer is queried, if it has an external source,
we check whether it's up to date, and update it if not.
* The ancillary data stored on the canonical declaration is allocated lazily
to avoid filling it in for declarations that end up being non-canonical.
We'll still perform a redundant (ASTContext) allocation if someone asks for
the most recent declaration from a decl before setPreviousDecl is called,
but such cases are probably all bugs, and are now easy to find.
Some finessing is still in order here -- in particular, we use a very general
mechanism for handling the DefinitionData pointer on CXXRecordData, and a more
targeted approach would be more compact.
Also, the MayHaveOutOfDateDef mechanism should now be expunged, since it was
addressing only a corner of the full problem space here. That's not covered
by this patch.
Early performance benchmarks show that this makes no measurable difference to
Clang performance without modules enabled (and fixes a major correctness issue
with modules enabled). I'll revert if a full performance comparison shows any
problems.
llvm-svn: 209046
Richard Smith