ExternalASTMerger has hitherto relied on being able to look up
any Decl through its named DeclContext chain. This works for
many cases, but causes problems for function-local structs,
which cannot be looked up in their containing FunctionDecl. An
example case is
void f() {
{ struct S { int a; }; }
{ struct S { bool b; }; }
}
It is not possible to lookup either of the two Ses individually
(or even to provide enough information to disambiguate) after
parsing is over; and there is typically no need to, since they
are invisible to the outside world.
However, ExternalASTMerger needs to be able to complete either
S on demand. This led to an XFAIL on test/Import/local-struct,
which this patch removes. The way the patch works is:
It defines a new data structure, ExternalASTMerger::OriginMap,
which clients are expected to maintain (default-constructing
if the origin does not have an ExternalASTMerger servicing it)
As DeclContexts are imported, if they cannot be looked up by
name they are placed in the OriginMap. This allows
ExternalASTMerger to complete them later if necessary.
As DeclContexts are imported from an origin that already has
its own OriginMap, the origins are forwarded – but only for
those DeclContexts that are actually used. This keeps the
amount of stored data minimal.
The patch also applies several improvements from review:
- Thoroughly documents the interface to ExternalASTMerger;
- Adds optional logging to help track what's going on; and
- Cleans up a bunch of braces and dangling elses.
Differential Revision: https://reviews.llvm.org/D38208
llvm-svn: 314336
clang-import-test has until now been only able to report top-level Decls.
This is clearly insufficient; we should be able to look inside structs
and namespaces also. This patch adds new test cases for a variety of
lookups inside existing ASTContexts, and adds the functionality necessar
to make most of these testcases work. (One testcase is known to fail
because of ASTImporter limitations when importing templates; I'll look
into that separately.)
This patch also separates the core functionality out into
ExternalASTMerger, an interface that allows clients like LLDB to make
use of it. clang-import-test now only has the machinery necessary to
set up the tests.
Differential revision: https://reviews.llvm.org/D30435
llvm-svn: 299976
Sean Callanan