[clang][modules] Disallow importing private framework in the implementation

Whenever we are compiling implementation of a framework (with the `-fmodule-name=FW` option), we never translate `#import <FW/Header.h>` to an import, regardless of whether "Header.h" belongs to "FW" or "FW_Private". For the same reasons, we also disallow `@import FW`. However, we still allow `@import FW_Private`. This patch disallows that a well, to be consistent with the rest of the rules.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D142167

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index aa82a99..9c4c834 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -148,6 +148,26 @@ bool Module::isUnimportable(const LangOptions &LangOpts,
   llvm_unreachable("could not find a reason why module is unimportable");
 }
 
+// The -fmodule-name option tells the compiler to textually include headers in
+// the specified module, meaning Clang won't build the specified module. This
+// is useful in a number of situations, for instance, when building a library
+// that vends a module map, one might want to avoid hitting intermediate build
+// products containing the module map or avoid finding the system installed
+// modulemap for that library.
+bool Module::isForBuilding(const LangOptions &LangOpts) const {
+  StringRef TopLevelName = getTopLevelModuleName();
+  StringRef CurrentModule = LangOpts.CurrentModule;
+
+  // When building framework Foo, we want to make sure that Foo *and*
+  // Foo_Private are textually included and no modules are built for both.
+  if (getTopLevelModule()->IsFramework &&
+      CurrentModule == LangOpts.ModuleName &&
+      !CurrentModule.endswith("_Private") && TopLevelName.endswith("_Private"))
+    TopLevelName = TopLevelName.drop_back(8);
+
+  return TopLevelName == CurrentModule;
+}
+
 bool Module::isAvailable(const LangOptions &LangOpts, const TargetInfo &Target,
                          Requirement &Req,
                          UnresolvedHeaderDirective &MissingHeader,