[modules] When building a module, if there are multiple matches for a header

file in the loaded module maps and one of them is from the current module,
that's the right match.

llvm-svn: 240350

1 files changed, 3 insertions, 0 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 075a17f68b1..4ef0674f8d6 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -346,6 +346,9 @@ ModuleMap::KnownHeader ModuleMap::findModuleForHeader(const FileEntry *File) {
     ModuleMap::KnownHeader Result;
     // Iterate over all modules that 'File' is part of to find the best fit.
     for (KnownHeader &H : Known->second) {
+      // Prefer a header from the current module over all others.
+      if (H.getModule() == CompilingModule)
+        return MakeResult(H);
       // Cannot use a module if it is unavailable.
       if (!H.getModule()->isAvailable())
         continue;