Swift compiler can try to import clang modules which might fail to load.
In this case, the clang diagnostic engine is reset to ignore the errors,
but the hard reset also clears out the states, including the diagnostics
options and current states. This will affect the future clang module
imports and diagnostics. Use a soft reset that only clears the errors
but not the other states.
rdar://139723218
Even though 'ClangDiagnosticConsumer' filters out 'clang::diag::err_module_not_found' from being emitted by the Swift compiler, delegating to Swift's module-loading logic for error-handling, we must also ensure that we reset Clang's 'DiagnosticEngine''s error count. Otherwise, if we do not, final stages of IRGen will query Clang's code-gen to finalize its 'Module', which Clang will not do if its internal DiagnosticEngine contains errors. This will cause Swift's IRGen to fail, even though the only error emitted was one Swift intended to suppress.
Emitting Swift diagnostics in Clang buffers requires making those
buffers valid places to put Swift SourceLocs, which means making a
mirror of those buffers in the Swift SourceManager. This isn't a copy;
instead, any Clang SourceManagers that are involved are kept alive
until the importer is torn down. (There might be more than one because
of diagnostics emitted during module building.)
For a long time we only emitted diagnostics in Clang buffers if the
diagnostics came from Clang, but then we added another case for custom
Swift names that fail to import. I'm about to add another such
diagnostic, so let's formalize this buffer mapping first.
No intended functionality change.
...that Clang didn't catch for us. The Clang side of things is now looser so
that we don't have to mirror our import logic over there, but that means
invalid cases can slip through.
Part of rdar://problem/21091469
Swift SVN r29535
In particular, the fake "<module-includes>" buffers all have that same name.
Use the buffer itself to provide identity. (We are already deliberately
keeping the buffers alive via their source managers.)
rdar://problem/19716081
Swift SVN r25200
This rare crash happens when
1. A diagnostic is reported when building a Clang module.
2. The diagnostic is mapped to a Swift diagnostic by mirroring the Clang
source buffer as a Swift source buffer (via non-owning reference).
3. The Clang CompilerInstance used specifically to build the module is
destroyed.
4. Some /new/ buffer is allocated in the same memory spot as the old buffer.
5. Some new Clang diagnostic occurs in the new buffer.
6. The Swift source manager asserts when trying to set up a virtual name
for the diagnostic in the second imported buffer, because there's already
a name for that region.
The fix, because we don't expect diagnostics from modules to appear very
often, is to keep any clang::SourceManagers alive if diagnostics are emitted
in their buffers. We can revisit this if/when Swift's source manager
(currently built on llvm::SourceMgr) has the ability to remove buffers.
Many thanks to Greg for noticing the problem, tracking it down, and providing
a diff to make it fail reproducibly under GuardMalloc. I've tried to preserve
the spirit of that diff in the new logic in ~SourceManager, which will also
fail reliably with GuardMalloc (and probably ASan).
rdar://problem/18285805
Swift SVN r21958
This is already a fatal error, so it doesn't matter how many diagnostics we
dump after that. It's better not to lie to the rest of the compiler about
whether the load succeeds.
No immediate Radar, but this fixes a crash in the test case I'm about to
commit, and possibly some other mystery "dependency missing" crashes in
XREF resolution.
Swift SVN r20919
If importing a Clang module fails, we should report that at the location of
the import statement. This doesn't do that fully because it isn't transitive
(if Swift module Foo imports Swift module Bar, which fails to import Clang
module Baz, we don't get an error in user source), but it's a step forward
for the simple cases.
Swift SVN r20575
Now that bridging headers from ASTs are always present and bridging headers
from the command line are checked in advance, we no longer need to worry
about the Clang instance failing to find the bridging header. That's good,
because this wasn't implemented correctly anyway: if a bridging header
imported a module, we could get an error.
Swift SVN r20129
...so don't report a second "module missing" error from Swift itself.
We do still treat the Clang module failing to build as a fatal error.
<rdar://problem/16175035>
Swift SVN r18231
We're not mapping source locations over correctly yet, so the file name
where an error occurs gets shoved into the diagnostic text, but that's
fine for now.
This also silences the "module 'Blah' not found" error coming from the
importer whenever Swift itself can be responsible for importing the module.
Still to do: if we can't build a Clang module, we shouldn't report that
error and then say it can't be found.
<rdar://problem/14509389>
Swift SVN r18230
