[Modules] Change private modules rules and warnings
We used to advertise private modules to be declared as submodules
(Foo.Private). This has proven to not scale well since private headers
might carry several dependencies, introducing unwanted content into the
main module and often causing dep cycles.
Change the canonical way to name it to Foo_Private, forcing private
modules as top level ones, and provide warnings under -Wprivate-module
to suggest fixes for other private naming. Update documentation to
reflect that.
rdar://problem/31173501
llvm-svn: 321337
diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index aa25886..6976294 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -209,11 +209,14 @@
// The facility for "private modules" -- adjacent, optional module maps named
// module.private.modulemap that are supposed to define private submodules --
- // is sometimes misused by frameworks that name their associated private
- // module FooPrivate, rather than as a submodule named Foo.Private as
- // intended. Here we compensate for such cases by looking in directories named
- // Foo.framework, when we previously looked and failed to find a
- // FooPrivate.framework.
+ // may have different flavors of names: FooPrivate, Foo_Private and Foo.Private.
+ //
+ // Foo.Private is now depracated in favor of Foo_Private. Users of FooPrivate
+ // should also rename to Foo_Private. Representing private as submodules
+ // could force building unwanted dependencies into the parent module and cause
+ // dependency cycles.
+ if (!Module && SearchName.consume_back("_Private"))
+ Module = lookupModule(ModuleName, SearchName);
if (!Module && SearchName.consume_back("Private"))
Module = lookupModule(ModuleName, SearchName);
return Module;