Fix corner case in module-based layering warning.

Before, there SourceManager would not return a FileEntry for a
SourceLocation of a macro expansion (if the header name itself is
defined in a macro). We'd then fallback to assume that the module
currently being built is the including module. However, in this case we
are actually interested in the spelling location of the filename loc in
order to derive the including module.

llvm-svn: 196311

2 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 224508637f0..446eac36418 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -540,7 +540,8 @@ Module *Preprocessor::getModuleForLocation(SourceLocation FilenameLoc) {
     return HeaderInfo.getModuleMap().SourceModule; // Compiling a source.
   }
   // Try to determine the module of the include directive.
-  FileID IDOfIncl = SourceMgr.getFileID(FilenameLoc);
+  // FIXME: Look into directly passing the FileEntry from LookupFile instead.
+  FileID IDOfIncl = SourceMgr.getFileID(SourceMgr.getSpellingLoc(FilenameLoc));
   if (const FileEntry *EntryOfIncl = SourceMgr.getFileEntryForID(IDOfIncl)) {
     // The include comes from a file.
     return ModMap.findModuleForHeader(EntryOfIncl).getModule();
diff --git a/clang/test/Modules/Inputs/declare-use/e.h b/clang/test/Modules/Inputs/declare-use/e.h
index ed8d843f9a8..31247f7f9c7 100644
--- a/clang/test/Modules/Inputs/declare-use/e.h
+++ b/clang/test/Modules/Inputs/declare-use/e.h
@@ -1,6 +1,7 @@
 #ifndef E_H
 #define E_H
-#include "a.h"
+#define HEADER "a.h"
+#include HEADER
 #include "b.h"
 const int e = a*b;
 #endif