clang/lib/CodeGen/Targets/M68k.cpp

   1 //===- M68k.cpp -----------------------------------------------------------===//
   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 #include "ABIInfoImpl.h"
  10 #include "TargetInfo.h"
  11
  12 using namespace clang;
  13 using namespace clang::CodeGen;
  14
  15 //===----------------------------------------------------------------------===//
  16 // M68k ABI Implementation
  17 //===----------------------------------------------------------------------===//
  18
  19 namespace {
  20
  21 class M68kTargetCodeGenInfo : public TargetCodeGenInfo {
  22 public:
  23   M68kTargetCodeGenInfo(CodeGenTypes &CGT)
  24       : TargetCodeGenInfo(std::make_unique<DefaultABIInfo>(CGT)) {}
  25   void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
  26                            CodeGen::CodeGenModule &M) const override;
  27 };
  28
  29 } // namespace
  30
  31 void M68kTargetCodeGenInfo::setTargetAttributes(
  32     const Decl *D, llvm::GlobalValue *GV, CodeGen::CodeGenModule &M) const {
  33   if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D)) {
  34     if (const auto *attr = FD->getAttr<M68kInterruptAttr>()) {
  35       // Handle 'interrupt' attribute:
  36       llvm::Function *F = cast<llvm::Function>(GV);
  37
  38       // Step 1: Set ISR calling convention.
  39       F->setCallingConv(llvm::CallingConv::M68k_INTR);
  40
  41       // Step 2: Add attributes goodness.
  42       F->addFnAttr(llvm::Attribute::NoInline);
  43
  44       // Step 3: Emit ISR vector alias.
  45       unsigned Num = attr->getNumber() / 2;
  46       llvm::GlobalAlias::create(llvm::Function::ExternalLinkage,
  47                                 "__isr_" + Twine(Num), F);
  48     }
  49   }
  50 }
  51
  52 std::unique_ptr<TargetCodeGenInfo>
  53 CodeGen::createM68kTargetCodeGenInfo(CodeGenModule &CGM) {
  54   return std::make_unique<M68kTargetCodeGenInfo>(CGM.getTypes());
  55 }