[WebAssembly] Initial WebAssembly backend

This WebAssembly backend is just a skeleton at this time and is not yet
functional.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241022 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/WebAssembly/WebAssemblyTargetObjectFile.h

@@ -0,0 +1,67 @@
+//===-- WebAssemblyTargetObjectFile.h - WebAssembly Object Info -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file declares the WebAssembly-specific subclass of
+/// TargetLoweringObjectFile.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYTARGETOBJECTFILE_H
+#define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYTARGETOBJECTFILE_H
+
+#include "llvm/Target/TargetLoweringObjectFile.h"
+
+namespace llvm {
+
+class GlobalVariable;
+
+class WebAssemblyTargetObjectFile final : public TargetLoweringObjectFile {
+public:
+  WebAssemblyTargetObjectFile() {
+    TextSection = nullptr;
+    DataSection = nullptr;
+    BSSSection = nullptr;
+    ReadOnlySection = nullptr;
+
+    StaticCtorSection = nullptr;
+    StaticDtorSection = nullptr;
+    LSDASection = nullptr;
+    EHFrameSection = nullptr;
+    DwarfAbbrevSection = nullptr;
+    DwarfInfoSection = nullptr;
+    DwarfLineSection = nullptr;
+    DwarfFrameSection = nullptr;
+    DwarfPubTypesSection = nullptr;
+    DwarfDebugInlineSection = nullptr;
+    DwarfStrSection = nullptr;
+    DwarfLocSection = nullptr;
+    DwarfARangesSection = nullptr;
+    DwarfRangesSection = nullptr;
+  }
+
+  MCSection *getSectionForConstant(SectionKind Kind,
+                                   const Constant *C) const override {
+    return ReadOnlySection;
+  }
+
+  MCSection *getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
+                                      Mangler &Mang,
+                                      const TargetMachine &TM) const override {
+    return DataSection;
+  }
+
+  MCSection *SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
+                                    Mangler &Mang,
+                                    const TargetMachine &TM) const override;
+};
+
+} // end namespace llvm
+
+#endif