llvm/lib/Target/DirectX/DirectXAsmPrinter.cpp

   1 //===-- DirectXAsmPrinter.cpp - DirectX assembly writer --------*- C++ -*--===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains AsmPrinters for the DirectX backend.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "TargetInfo/DirectXTargetInfo.h"
  14 #include "llvm/CodeGen/AsmPrinter.h"
  15 #include "llvm/IR/GlobalVariable.h"
  16 #include "llvm/IR/Module.h"
  17 #include "llvm/MC/MCStreamer.h"
  18 #include "llvm/MC/SectionKind.h"
  19 #include "llvm/MC/TargetRegistry.h"
  20 #include "llvm/Target/TargetLoweringObjectFile.h"
  21
  22 using namespace llvm;
  23
  24 #define DEBUG_TYPE "asm-printer"
  25
  26 namespace {
  27
  28 // The DXILAsmPrinter is mostly a stub because DXIL is just LLVM bitcode which
  29 // gets embedded into a DXContainer file.
  30 class DXILAsmPrinter : public AsmPrinter {
  31 public:
  32   explicit DXILAsmPrinter(TargetMachine &TM,
  33                           std::unique_ptr<MCStreamer> Streamer)
  34       : AsmPrinter(TM, std::move(Streamer)) {}
  35
  36   StringRef getPassName() const override { return "DXIL Assembly Printer"; }
  37   void emitGlobalVariable(const GlobalVariable *GV) override;
  38   bool runOnMachineFunction(MachineFunction &MF) override { return false; }
  39 };
  40 } // namespace
  41
  42 void DXILAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
  43   // If there is no initializer, or no explicit section do nothing
  44   if (!GV->hasInitializer() || GV->hasImplicitSection() || !GV->hasSection())
  45     return;
  46   // Skip the LLVM metadata
  47   if (GV->getSection() == "llvm.metadata")
  48     return;
  49   SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
  50   MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
  51   OutStreamer->switchSection(TheSection);
  52   emitGlobalConstant(GV->getDataLayout(), GV->getInitializer());
  53 }
  54
  55 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeDirectXAsmPrinter() {
  56   RegisterAsmPrinter<DXILAsmPrinter> X(getTheDirectXTarget());
  57 }