Implement umbrella directories for modules, which are similar to

umbrella headers in the sense that all of the headers within that
directory (and eventually its subdirectories) are considered to be
part of the module with that umbrella directory. However, unlike
umbrella headers, which are expected to include all of the headers
within their subdirectories, Clang will automatically include all of
the headers it finds in the named subdirectory.

The intent here is to allow a module map to trivially turn a
subdirectory into a module, where the module's structure can mimic the
directory structure.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146165 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 36 insertions, 4 deletions

diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 21be3aa50c..236c2bd1f5 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -3088,7 +3088,7 @@ ASTReader::ASTReadResult ASTReader::ReadSubmoduleBlock(ModuleFile &F) {
       break;
     }
         
-    case SUBMODULE_UMBRELLA: {
+    case SUBMODULE_UMBRELLA_HEADER: {
       if (First) {
         Error("missing submodule metadata record at beginning of block");
         return Failure;
@@ -3129,6 +3129,28 @@ ASTReader::ASTReadResult ASTReader::ReadSubmoduleBlock(ModuleFile &F) {
       break;      
     }
         
+    case SUBMODULE_UMBRELLA_DIR: {
+      if (First) {
+        Error("missing submodule metadata record at beginning of block");
+        return Failure;
+      }
+      
+      if (!CurrentModule)
+        break;
+      
+      StringRef DirName(BlobStart, BlobLen);
+      if (const DirectoryEntry *Umbrella
+                                  = PP.getFileManager().getDirectory(DirName)) {
+        if (!CurrentModule->getUmbrellaDir())
+          ModMap.setUmbrellaDir(CurrentModule, Umbrella);
+        else if (CurrentModule->getUmbrellaDir() != Umbrella) {
+          Error("mismatched umbrella directories in submodule");
+          return Failure;
+        }
+      }
+      break;
+    }
+        
     case SUBMODULE_METADATA: {
       if (!First) {
         Error("submodule metadata record not at beginning of block");
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 1bd9050fe0..83ad885969 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1900,7 +1900,7 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
 
   Abbrev = new BitCodeAbbrev();
-  Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA));
+  Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
 
@@ -1908,7 +1908,12 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
-  
+
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
+  unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
+
   // Write the submodule metadata block.
   RecordData Record;
   Record.push_back(getNumberOfModules(WritingModule));
@@ -1943,9 +1948,14 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
     // Emit the umbrella header, if there is one.
     if (const FileEntry *UmbrellaHeader = Mod->getUmbrellaHeader()) {
       Record.clear();
-      Record.push_back(SUBMODULE_UMBRELLA);
+      Record.push_back(SUBMODULE_UMBRELLA_HEADER);
       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record, 
                                 UmbrellaHeader->getName());
+    } else if (const DirectoryEntry *UmbrellaDir = Mod->getUmbrellaDir()) {
+      Record.clear();
+      Record.push_back(SUBMODULE_UMBRELLA_DIR);
+      Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record, 
+                                UmbrellaDir->getName());      
     }
     
     // Emit the headers.