If an excluded header does not exist, just ignore it

llvm-svn: 168077

clang/lib/Lex/ModuleMap.cpp

@@ -1307,7 +1307,9 @@ void ModuleMapParser::parseHeaderDecl(SourceLocation UmbrellaLoc,
       if (BuiltinFile)
         Map.addHeader(ActiveModule, BuiltinFile, Exclude);
     }
-  } else {
+  } else if (!Exclude) {
+    // Ignore excluded header files. They're optional anyway.
+    
     Diags.Report(FileNameLoc, diag::err_mmap_header_not_found)
       << Umbrella << FileName;
     HadError = true;

clang/test/Modules/Inputs/module.map

@@ -63,6 +63,7 @@ module decldef {
 module redecl_merge_top { 
   header "redecl-merge-top.h"
   explicit module Explicit { header "redecl-merge-top-explicit.h" }
+  exclude header "nonexistent.h"
 }
 module redecl_merge_left { 
   header "redecl-merge-left.h"