Store a DataLayout in Module.

Now that DataLayout is not a pass, store one in Module.

Since the C API expects to be able to get a char* to the datalayout description,
we have to keep a std::string somewhere. This patch keeps it in Module and also
uses it to represent modules without a DataLayout.

Once DataLayout is mandatory, we should probably move the string to DataLayout
itself since it won't be necessary anymore to represent the special case of a
module without a DataLayout.

llvm-svn: 202190
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index d911c7e..739f888 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -42,8 +42,8 @@
 // Primitive Module methods.
 //
 
-Module::Module(StringRef MID, LLVMContext& C)
-  : Context(C), Materializer(NULL), ModuleID(MID) {
+Module::Module(StringRef MID, LLVMContext &C)
+    : Context(C), Materializer(NULL), ModuleID(MID), DL("") {
   ValSymTab = new ValueSymbolTable();
   NamedMDSymTab = new StringMap<NamedMDNode *>();
   Context.addModule(this);
@@ -338,6 +338,30 @@
   getOrInsertModuleFlagsMetadata()->addOperand(Node);
 }
 
+void Module::setDataLayout(StringRef Desc) {
+  if (Desc.empty()) {
+    DataLayoutStr = "";
+  } else {
+    DL.init(Desc);
+    DataLayoutStr = DL.getStringRepresentation();
+  }
+}
+
+void Module::setDataLayout(const DataLayout *Other) {
+  if (!Other) {
+    DataLayoutStr = "";
+  } else {
+    DL = *Other;
+    DataLayoutStr = DL.getStringRepresentation();
+  }
+}
+
+const DataLayout *Module::getDataLayout() const {
+  if (DataLayoutStr.empty())
+    return 0;
+  return &DL;
+}
+
 //===----------------------------------------------------------------------===//
 // Methods to control the materialization of GlobalValues in the Module.
 //