Commit Graph

4 Commits

Author SHA1 Message Date
Richard Smith 0a088ead85 Improve diagnostics for missing import / #include of module.
Fix a few bugs where we would fail to properly determine header to
module correspondence when determining whether to suggest a #include or
import, and suggest a #include more often in language modes where there
is no import syntax. Generally, if the target is in a header with
include guards or #pragma once, we should suggest either #including or
importing that header, and not importing a module that happens to
textually include it.

In passing, improve the notes we attach to the corresponding
diagnostics: calling an entity that we couldn't see "previous" is
confusing.
2020-04-28 18:41:14 -07:00
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 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 04765ae01e [modules] If we re-enter a submodule from within itself (when submodule
visibility is enabled) or leave and re-enter it, restore the macro and module
visibility state from last time we were in that submodule.

This allows mutually-#including header files to stand a chance at being
modularized with local visibility enabled.

llvm-svn: 237871
2015-05-21 01:20:10 +00:00