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 the section is implicit, do nothing
44   if (!GV->hasInitializer() || GV->hasImplicitSection())
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->getParent()->getDataLayout(), GV->getInitializer());
53 }
54 
55 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeDirectXAsmPrinter() {
56   RegisterAsmPrinter<DXILAsmPrinter> X(getTheDirectXTarget());
57 }
58