Introduce a cc1-level option to provide the path to the module cache,
where the compiler will look for module files. Eliminates the
egregious hack where we looked into the header search paths for
modules.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139538 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 7ea3161..e7b8854 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -576,6 +576,10 @@
     Res.push_back("-resource-dir");
     Res.push_back(Opts.ResourceDir);
   }
+  if (!Opts.ModuleCachePath.empty()) {
+    Res.push_back("-fmodule-cache-path");
+    Res.push_back(Opts.ModuleCachePath);
+  }
   if (!Opts.UseStandardIncludes)
     Res.push_back("-nostdinc");
   if (!Opts.UseStandardCXXIncludes)
@@ -1378,7 +1382,8 @@
   if (const Arg *A = Args.getLastArg(OPT_stdlib_EQ))
     Opts.UseLibcxx = (strcmp(A->getValue(Args), "libc++") == 0);
   Opts.ResourceDir = Args.getLastArgValue(OPT_resource_dir);
-
+  Opts.ModuleCachePath = Args.getLastArgValue(OPT_fmodule_cache_path);
+  
   // Add -I..., -F..., and -index-header-map options in order.
   bool IsIndexHeaderMap = false;
   for (arg_iterator it = Args.filtered_begin(OPT_I, OPT_F, 
@@ -1426,7 +1431,7 @@
                  ((*it)->getOption().matches(OPT_cxx_isystem) ?
                    frontend::CXXSystem : frontend::System),
                  true, false, !(*it)->getOption().matches(OPT_iwithsysroot));
-
+  
   // FIXME: Need options for the various environment variables!
 }