Commit Graph

5 Commits

Author SHA1 Message Date
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 e156254d4c During typo correction, check for an exact match in an unimported module. If we
find one, then report the error as a missing import instead of as a typo.

llvm-svn: 188821
2013-08-20 20:35:18 +00:00
Andy Gibbs fcc699aee8 Extended VerifyDiagnosticConsumer to also verify source file for diagnostic.
VerifyDiagnosticConsumer previously would not check that the diagnostic and
its matching directive referenced the same source file.  Common practice was
to create directives that referenced other files but only by line number,
and this led to problems such as when the file containing the directive
didn't have enough lines to match the location of the diagnostic in the
other file, leading to bizarre file formatting and other oddities.

This patch causes VerifyDiagnosticConsumer to match source files as well as
line numbers.  Therefore, a new syntax is made available for directives, for
example:

// expected-error@file:line {{diagnostic message}}

This extends the @line feature where "file" is the file where the diagnostic
is generated.  The @line syntax is still available and uses the current file
for the diagnostic.  "file" can be specified either as a relative or absolute
path - although the latter has less usefulness, I think!  The #include search
paths will be used to locate the file and if it is not found an error will be
generated.

The new check is not optional: if the directive is in a different file to the
diagnostic, the file must be specified.  Therefore, a number of test-cases
have been updated with regard to this.

This closes out PR15613.

llvm-svn: 179677
2013-04-17 08:06:46 +00:00
Douglas Gregor 7dab26b87c Ensure that type definitions present in just-loaded modules are
visible.

The basic problem here is that a given translation unit can use
forward declarations to form pointers to a given type, say,

  class X;
  X *x;

and then import a module that includes a definition of X:

  import XDef;

We will then fail when attempting to access a member of X, e.g., 

  x->method()

because the AST reader did not know to look for a default of a class
named X within the new module.

This implementation is a bit of a C-centric hack, because the only
definitions that can have this property are enums, structs, unions,
Objective-C classes, and Objective-C protocols, and all of those are
either visible at the top-level or can't be defined later. Hence, we
can use the out-of-date-ness of the name and the identifier-update
mechanism to force the update.

In C++, we will not be so lucky, and will need a more advanced
solution, because the definitions could be in namespaces defined in
two different modules, e.g.,

  // module 1
  namespace N { struct X; }

  // module 2
  namespace N { struct X { /* ... */ }; }

One possible implementation here is for C++ to extend the information
associated with each identifier table to include the declaration IDs
of any definitions associated with that name, regardless of
context. We would have to eagerly load those definitions.

llvm-svn: 174794
2013-02-09 01:35:03 +00:00