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/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index c48214c..d414f76 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1252,8 +1252,9 @@
       M->getModuleIdentifier().find('\n') == std::string::npos)
     Out << "; ModuleID = '" << M->getModuleIdentifier() << "'\n";
 
-  if (!M->getDataLayout().empty())
-    Out << "target datalayout = \"" << M->getDataLayout() << "\"\n";
+  const std::string &DL = M->getDataLayoutStr();
+  if (!DL.empty())
+    Out << "target datalayout = \"" << DL << "\"\n";
   if (!M->getTargetTriple().empty())
     Out << "target triple = \"" << M->getTargetTriple() << "\"\n";
 
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 68bc5c5..b19fbe3 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -107,7 +107,7 @@
 
 /*--.. Data layout .........................................................--*/
 const char * LLVMGetDataLayout(LLVMModuleRef M) {
-  return unwrap(M)->getDataLayout().c_str();
+  return unwrap(M)->getDataLayoutStr().c_str();
 }
 
 void LLVMSetDataLayout(LLVMModuleRef M, const char *Triple) {
diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index 44410ce..d60c79f5 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -344,7 +344,13 @@
   }
 }
 
-DataLayout::DataLayout(const Module *M) { init(M->getDataLayout()); }
+DataLayout::DataLayout(const Module *M) {
+  const DataLayout *Other = M->getDataLayout();
+  if (Other)
+    *this = *Other;
+  else
+    init("");
+}
 
 void
 DataLayout::setAlignment(AlignTypeEnum align_type, unsigned abi_align,
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.
 //