Commit Graph

28 Commits

Author SHA1 Message Date
Richard Smith 3cbf3f1f59 Push alias-declarations and alias-template declarations into scope even if
they're redeclarations. This is necessary in order for name lookup to correctly
find the most recent declaration of the name (which affects default template
argument lookup and cross-module merging, among other things).

llvm-svn: 275612
2016-07-15 20:53:25 +00:00
Richard Smith 82b8d4e6fd [modules] Don't try to use the definition of a class if
RequireCompleteType(..., 0) says we're not permitted to do so. The definition
might not be visible, even though we know what it is.

llvm-svn: 256045
2015-12-18 22:19:11 +00:00
Richard Smith 26210db67f [modules] Follow the C++ standard's rule for linkage of enumerators: they have
the linkage of the enumeration. For enumerators of unnamed enumerations, extend
the -Wmodules-ambiguous-internal-linkage extension to allow selecting an
arbitrary enumerator (but only if they all have the same value, otherwise it's
ambiguous).

llvm-svn: 253010
2015-11-13 03:52:13 +00:00
Richard Smith 97135cc94a [modules] Simplify and generalize the existing rule for finding hidden
declarations in redeclaration lookup. A declaration is now visible to
lookup if:

 * It is visible (not in a module, or in an imported module), or
 * We're doing redeclaration lookup and it's externally-visible, or
 * We're doing typo correction and looking for unimported decls.

We now support multiple modules having different internal-linkage or no-linkage
definitions of the same name for all entities, not just for functions,
variables, and some typedefs. As previously, if multiple such entities are
visible, any attempt to use them will result in an ambiguity error.

This patch fixes the linkage calculation for a number of entities where we
previously didn't need to get it right (using-declarations, namespace aliases,
and so on).  It also classifies enumerators as always having no linkage, which
is a slight deviation from the C++ standard's definition, but not an observable
change outside modules (this change is being discussed on the -core reflector
currently).

This also removes the prior special case for tag lookup, which made some cases
of this work, but also led to bizarre, bogus "must use 'struct' to refer to type
'Foo' in this scope" diagnostics in C++.

llvm-svn: 252960
2015-11-12 22:19:45 +00:00
Richard Smith 5e3fb7616d Revert r240335.
This failed to solve the problem it was aimed at, and introduced just as many
issues as it resolved. Realistically, we need to deal with the possibility that
multiple modules might define different internal linkage symbols with the same
name, and this isn't a problem unless two such symbols are simultaneously
visible.

The case where two modules define equivalent internal linkage symbols is
handled by r252063: if lookup finds multiple sufficiently-similar entities from
different modules, we just pick one of them as an extension (but we keep them
separate).

llvm-svn: 252957
2015-11-12 21:55:58 +00:00
Richard Smith 6dc8ae10aa [modules] When parsing the base specifiers of a parse-merged class, the current
context is the class itself but lookups should be performed starting with the
lookup parent of the class (class and base members don't shadow types from the
surrounding context because they have not been declared yet).

llvm-svn: 245236
2015-08-17 20:24:17 +00:00
Richard Smith 8cbd895947 [modules] Make IndirectFieldDecl mergeable to avoid lookup ambiguity when the same anonymous union is defined across multiple modules.
llvm-svn: 243940
2015-08-04 02:05:09 +00:00
Richard Smith b1d8ea4635 [modules] Fix merging support for forward-declared enums with fixed underlying types. A visible declaration is enough to make the type complete, but not enough to make the definition visible.
llvm-svn: 241743
2015-07-08 21:49:31 +00:00
Richard Smith da6c234c39 [modules] Merging support for specializations of a function template. This very
rarely matters, but can affect whether two dependent types are canonically
equivalent.

llvm-svn: 241207
2015-07-01 23:19:58 +00:00
Richard Smith 5327b89001 [modules] Don't make out-of-line member specializations of an instantiated
class template specialization visible just because the class template
specialization's definition is visible.

llvm-svn: 241182
2015-07-01 19:32:54 +00:00
Richard Smith 529ecb237a [modules] Add a flag to disable the feature that permits conflicting redefinitions of internal-linkage symbols that are not visible.
Such conflicts are an accident waiting to happen, and this feature conflicts
with the desire to include existing headers into multiple modules and merge the
results. (In an ideal world, it should not be possible to export internal
linkage symbols from a module, but sadly the glibc and libstdc++ headers
provide 'static inline' functions in a few cases.)

llvm-svn: 240335
2015-06-22 21:15:01 +00:00
Richard Smith 75ea855fd7 [modules] Ensure that if we merge the definitions of two enumerations, that
making either of them visible makes the merged definition visible.

llvm-svn: 239969
2015-06-17 23:07:50 +00:00
Richard Smith afe800c456 [modules] Fix typo in default argument merging.
llvm-svn: 239954
2015-06-17 22:13:23 +00:00
Richard Smith 63e09bf70b [modules] If we merge a template, also track that its parameters are merged so
that we know when its default arguments should be visible.

llvm-svn: 239936
2015-06-17 20:39:41 +00:00
Richard Smith 35c1df5cb6 [modules] Improve diagnostic for a template-id that's invalid because a default
argument is not visible.

llvm-svn: 239934
2015-06-17 20:16:32 +00:00
Richard Smith 5293379374 [modules] Fix merging of default template arguments onto friend templates.
Previously we'd complain about redefinition of default arguments when we
instantiated a class with a friend template that inherits its default argument,
because we propagate the default template arguemnt onto the friend when we
reload the AST.

llvm-svn: 239857
2015-06-16 21:57:05 +00:00
Richard Smith 47972afd10 [modules] Simplify -cc1 interface for enabling implicit module maps.
We used to have a flag to enable module maps, and two more flags to enable
implicit module maps. This is all redundant; we don't need any flag for
enabling module maps in the abstract, and we don't usually have -fno- flags for
-cc1. We now have just a single flag, -fimplicit-module-maps, that enables
implicitly searching the file system for module map files and loading them.

The driver interface is unchanged for now. We should probably rename
-fmodule-maps to -fimplicit-module-maps at some point.

llvm-svn: 239789
2015-06-16 00:08:24 +00:00
Richard Smith f2b1eb9eb2 [modules] Better support for redefinitions of an entity from the same module.
Support this across module save/reload and extend the 'missing import'
diagnostics with a list of providing modules.

llvm-svn: 239750
2015-06-15 20:15:48 +00:00
Richard Smith a1431077de [modules] Apply name visibility rules to names found by ADL.
llvm-svn: 239578
2015-06-12 01:32:13 +00:00
Richard Smith c785276b92 [modules] Fix crash with multiple levels of default template argument merging.
llvm-svn: 239575
2015-06-11 23:46:11 +00:00
Richard Smith 00be6d0ff8 [modules] Fix a few places where merging wasn't performed if modules was disabled but local module visibilty was enabled.
llvm-svn: 239504
2015-06-11 03:05:39 +00:00
Richard Smith 4241314164 [modules] Add local submodule visibility support for declarations.
With this change, enabling -fmodules-local-submodule-visibility results in name
visibility rules being applied to submodules of the current module in addition
to imported modules (that is, names no longer "leak" between submodules of the
same top-level module). This also makes it much safer to textually include a
non-modular library into a module: each submodule that textually includes that
library will get its own "copy" of that library, and so the library becomes
visible no matter which including submodule you import.

llvm-svn: 237473
2015-05-15 20:05:43 +00:00
Richard Smith d6aab59ad1 [modules] Allow a function template definition if we have a pre-existing but not visible definition of the same template.
llvm-svn: 233430
2015-03-27 21:57:41 +00:00
Richard Smith 0279375836 [modules] When merging class definitions, make the retained definition visible
if the merged definition is visible, and perform lookups into all merged copies
of the definition (not just for special members) so that we can complete the
redecl chains for members of the class.

llvm-svn: 233420
2015-03-27 21:16:39 +00:00
Richard Smith 9a71c99844 [modules] Allow a function to be redefined if the old definition is not visible.
llvm-svn: 233407
2015-03-27 20:16:58 +00:00
Richard Smith a523022b53 [modules] Handle defining a tag with a typedef name for linkage purposes on top of an existing imported-but-not-visible definition.
llvm-svn: 233345
2015-03-27 01:37:43 +00:00
Richard Smith be3980b73c [modules] Handle defining a class template on top of an existing imported-but-not-visible definition.
llvm-svn: 233341
2015-03-27 00:41:57 +00:00
Richard Smith 65ebb4ac8a [modules] If we reach a definition of a class for which we already have a
non-visible definition, skip the new definition and make the old one visible
instead of trying to parse it again and failing horribly. C++'s ODR allows
us to assume that the two definitions are identical.

llvm-svn: 233250
2015-03-26 04:09:53 +00:00