Add a DIModule metadata node to the IR.

It is meant to be used to record modules @imported by the current
compile unit, so a debugger an import the same modules to replicate this
environment before dropping into the expression evaluator.

DIModule is a sibling to DINamespace and behaves quite similarly.
In addition to the name of the module it also records the module
configuration details that are necessary to uniquely identify the module.
This includes the configuration macros (e.g., -DNDEBUG), the include path
where the module.map file is to be found, and the isysroot.

The idea is that the backend will turn this into a DW_TAG_module.

http://reviews.llvm.org/D9614
rdar://problem/20965932

llvm-svn: 241017

2 files changed, 25 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index c47d193..e224207 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1827,6 +1827,20 @@ std::error_code BitcodeReader::parseMetadata() {
           NextMDValueNo++);
       break;
     }
+
+    case bitc::METADATA_MODULE: {
+      if (Record.size() != 6)
+        return error("Invalid record");
+
+      MDValueList.assignValue(
+          GET_OR_DISTINCT(DIModule, Record[0],
+                          (Context, getMDOrNull(Record[1]),
+                          getMDString(Record[2]), getMDString(Record[3]),
+                          getMDString(Record[4]), getMDString(Record[5]))),
+          NextMDValueNo++);
+      break;
+    }
+
     case bitc::METADATA_FILE: {
       if (Record.size() != 3)
         return error("Invalid record");
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 673d6f1..622f7ea 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1032,6 +1032,17 @@ static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
   Record.clear();
 }
 
+static void WriteDIModule(const DIModule *N, const ValueEnumerator &VE,
+                          BitstreamWriter &Stream,
+                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
+  Record.push_back(N->isDistinct());
+  for (auto &I : N->operands())
+    Record.push_back(VE.getMetadataOrNullID(I));
+
+  Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
+  Record.clear();
+}
+
 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *N,
                                          const ValueEnumerator &VE,
                                          BitstreamWriter &Stream,