Implement parsing, AST, (de-)serialization, and placeholder global

metadata for linking against the libraries/frameworks for imported
modules.

The module map language is extended with a new "link" directive that
specifies what library or framework to link against when a module is
imported, e.g.,

  link "clangAST"

or

  link framework "MyFramework"

Importing the corresponding module (or any of its submodules) will
eventually link against the named library/framework.

For now, I've added some placeholder global metadata that encodes the
imported libraries/frameworks, so that we can test that this
information gets through to the IR. The format of the data is still
under discussion.

llvm-svn: 172437

2 files changed, 33 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 2ed8853bb2a..81d3cea7ba7 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3413,6 +3413,9 @@ bool ASTReader::ReadSubmoduleBlock(ModuleFile &F) {
         DeserializationListener->ModuleRead(GlobalID, CurrentModule);
       
       SubmodulesLoaded[GlobalIndex] = CurrentModule;
+
+      // Clear out link libraries; the module file has them.
+      CurrentModule->LinkLibraries.clear();
       break;
     }
         
@@ -3600,6 +3603,20 @@ bool ASTReader::ReadSubmoduleBlock(ModuleFile &F) {
                                     Context.getTargetInfo());
       break;
     }
+
+    case SUBMODULE_LINK_LIBRARY:
+      if (First) {
+        Error("missing submodule metadata record at beginning of block");
+        return true;
+      }
+
+      if (!CurrentModule)
+        break;
+
+      CurrentModule->LinkLibraries.push_back(
+         Module::LinkLibrary(StringRef(BlobStart, BlobLen),
+         Record[0]));
+      break;
     }
   }
 }
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index fe498bee77f..d4b0367cac6 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -2107,6 +2107,12 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
 
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
+  unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(Abbrev);
+
   // Write the submodule metadata block.
   RecordData Record;
   Record.push_back(getNumberOfModules(WritingModule));
@@ -2209,7 +2215,16 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
       }
       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
     }
-    
+
+    // Emit the link libraries.
+    for (unsigned I = 0, N = Mod->LinkLibraries.size(); I != N; ++I) {
+      Record.clear();
+      Record.push_back(SUBMODULE_LINK_LIBRARY);
+      Record.push_back(Mod->LinkLibraries[I].IsFramework);
+      Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record,
+                                Mod->LinkLibraries[I].Library);
+    }
+
     // Queue up the submodules of this module.
     for (Module::submodule_iterator Sub = Mod->submodule_begin(),
                                  SubEnd = Mod->submodule_end();