Move the DataLayout to the generic TargetMachine, making it mandatory.

Summary:
I don't know why every singled backend had to redeclare its own DataLayout.
There was a virtual getDataLayout() on the common base TargetMachine, the
default implementation returned nullptr. It was not clear from this that
we could assume at call site that a DataLayout will be available with
each Target.

Now getDataLayout() is no longer virtual and return a pointer to the
DataLayout member of the common base TargetMachine. I plan to turn it into
a reference in a future patch.

The only backend that didn't have a DataLayout previsouly was the CPPBackend.
It now initializes the default DataLayout. This commit is NFC for all the
other backends.

Test Plan: clang+llvm ninja check-all

Reviewers: echristo

Subscribers: jfb, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8243

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231987

1 files changed, 17 insertions, 9 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 4389cfad80d..8bf62882edd 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -104,6 +104,16 @@ static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
   return make_unique<AArch64_ELFTargetObjectFile>();
 }
 
+// Helper function to build a DataLayout string
+static std::string computeDataLayout(StringRef TT, bool LittleEndian) {
+  Triple Triple(TT);
+  if (Triple.isOSBinFormatMachO())
+    return "e-m:o-i64:64-i128:128-n32:64-S128";
+  if (LittleEndian)
+    return "e-m:e-i64:64-i128:128-n32:64-S128";
+  return "E-m:e-i64:64-i128:128-n32:64-S128";
+}
+
 /// TargetMachine ctor - Create an AArch64 architecture model.
 ///
 AArch64TargetMachine::AArch64TargetMachine(const Target &T, StringRef TT,
@@ -112,16 +122,14 @@ AArch64TargetMachine::AArch64TargetMachine(const Target &T, StringRef TT,
                                            Reloc::Model RM, CodeModel::Model CM,
                                            CodeGenOpt::Level OL,
                                            bool LittleEndian)
-    : LLVMTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL),
-      // This nested ternary is horrible, but DL needs to be properly
-      // initialized
-      // before TLInfo is constructed.
-      DL(Triple(TT).isOSBinFormatMachO()
-             ? "e-m:o-i64:64-i128:128-n32:64-S128"
-             : (LittleEndian ? "e-m:e-i64:64-i128:128-n32:64-S128"
-                             : "E-m:e-i64:64-i128:128-n32:64-S128")),
+    // This nested ternary is horrible, but DL needs to be properly
+    // initialized
+    // before TLInfo is constructed.
+    : LLVMTargetMachine(T, computeDataLayout(TT, LittleEndian), TT, CPU, FS,
+                        Options, RM, CM, OL),
       TLOF(createTLOF(Triple(getTargetTriple()))),
-      Subtarget(TT, CPU, FS, *this, LittleEndian), isLittle(LittleEndian) {
+      Subtarget(TT, CPU, FS, *this, LittleEndian),
+      isLittle(LittleEndian) {
   initAsmInfo();
 }