[PATCH] D48367: [modules] Fix 37878; Autoload subdirectory modulemaps with specific LangOpts

[Bruno Cardoso Lopes via Phabricator via cfe-commits]

bruno added inline comments.


================
Comment at: clang/lib/Lex/HeaderSearch.cpp:285
     // directory.
-    loadSubdirectoryModuleMaps(SearchDirs[Idx]);
+    if (ModMap.getLangOpts().ObjC1 || ModMap.getLangOpts().ObjC2)
+      loadSubdirectoryModuleMaps(SearchDirs[Idx]);
----------------
yamaguchi wrote:
> bruno wrote:
> > aprantl wrote:
> > > Are these flags also enabled in Objective-C++ mode?
> > Looks like all this logic was introduced in r177621 to allow the names of modules to differ from the name of their subdirectory in the include path.
> > 
> > Instead of having this to be based on the language, it's probably better if we have it based on @import name lookup, which is the scenario where we actually currently look more aggressively, did you try that path?
> > 
> > This is also lacking a testcase, can you create one?
> > Are these flags also enabled in Objective-C++ mode?
> I think so from FrontendOptions.h:190
> `bool isObjectiveC() const { return Lang == ObjC || Lang == ObjCXX; }`
> 
> > it's probably better if we have it based on @import name lookup
> I don't think I understood what you're saying, could you explain a bit more?
> 
> > This is also lacking a testcase, can you create one?
> Sure!
> I don't think I understood what you're saying, could you explain a bit more?

This extra call to `loadSubdirectoryModuleMaps` was introduced in r177621 to allow `@import SomeName` to work even if `SomeName` doesn't match a subdirectory name. See the original commit for more details.

This means that it was never supposed to be called when the module is built via `#include` or `#import`, which is what you are getting. That said, I believe it's better if the condition for calling `loadSubdirectoryModuleMaps` checks somehow if the lookup is coming from of an `@import` instead of checking the language (we too don't want it to be called for ObjC when `#include` or `#import` are used).


================
Comment at: clang/test/Modules/autoload-subdirectory.cpp:1
+// RUN: %clang -fmodules -fmodule-name=Foo -I %S/Inputs/autoload-subdirectory/ %s
+
----------------
Instead of `%clang`, please use `%clang_cc1` and `-verify` here.


https://reviews.llvm.org/D48367