1 //===- MachineCFGPrinter.cpp - DOT Printer for Machine Functions ----------===// 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 // 10 // This file defines the `-dot-machine-cfg` analysis pass, which emits 11 // Machine Function in DOT format in file titled `<prefix>.<function-name>.dot. 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/MachineCFGPrinter.h" 15 #include "llvm/CodeGen/MachineBasicBlock.h" 16 #include "llvm/CodeGen/MachineFunctionPass.h" 17 #include "llvm/CodeGen/TargetSubtargetInfo.h" 18 #include "llvm/InitializePasses.h" 19 #include "llvm/Pass.h" 20 #include "llvm/PassRegistry.h" 21 #include "llvm/Support/GraphWriter.h" 22 23 using namespace llvm; 24 25 #define DEBUG_TYPE "dot-machine-cfg" 26 27 static cl::opt<std::string> 28 MCFGFuncName("mcfg-func-name", cl::Hidden, 29 cl::desc("The name of a function (or its substring)" 30 " whose CFG is viewed/printed.")); 31 32 static cl::opt<std::string> MCFGDotFilenamePrefix( 33 "mcfg-dot-filename-prefix", cl::Hidden, 34 cl::desc("The prefix used for the Machine CFG dot file names.")); 35 36 static cl::opt<bool> 37 CFGOnly("dot-mcfg-only", cl::init(false), cl::Hidden, 38 cl::desc("Print only the CFG without blocks body")); 39 40 static void writeMCFGToDotFile(MachineFunction &MF) { 41 std::string Filename = 42 (MCFGDotFilenamePrefix + "." + MF.getName() + ".dot").str(); 43 errs() << "Writing '" << Filename << "'..."; 44 45 std::error_code EC; 46 raw_fd_ostream File(Filename, EC, sys::fs::OF_Text); 47 48 DOTMachineFuncInfo MCFGInfo(&MF); 49 50 if (!EC) 51 WriteGraph(File, &MCFGInfo, CFGOnly); 52 else 53 errs() << " error opening file for writing!"; 54 errs() << '\n'; 55 } 56 57 namespace { 58 59 class MachineCFGPrinter : public MachineFunctionPass { 60 public: 61 static char ID; 62 63 MachineCFGPrinter(); 64 65 bool runOnMachineFunction(MachineFunction &MF) override; 66 67 void getAnalysisUsage(AnalysisUsage &AU) const override { 68 AU.setPreservesCFG(); 69 MachineFunctionPass::getAnalysisUsage(AU); 70 } 71 }; 72 73 } // namespace 74 75 char MachineCFGPrinter::ID = 0; 76 77 char &llvm::MachineCFGPrinterID = MachineCFGPrinter::ID; 78 79 INITIALIZE_PASS(MachineCFGPrinter, DEBUG_TYPE, "Machine CFG Printer Pass", 80 false, true) 81 82 /// Default construct and initialize the pass. 83 MachineCFGPrinter::MachineCFGPrinter() : MachineFunctionPass(ID) { 84 initializeMachineCFGPrinterPass(*PassRegistry::getPassRegistry()); 85 } 86 87 bool MachineCFGPrinter::runOnMachineFunction(MachineFunction &MF) { 88 if (!MCFGFuncName.empty() && !MF.getName().contains(MCFGFuncName)) 89 return false; 90 errs() << "Writing Machine CFG for function "; 91 errs().write_escaped(MF.getName()) << '\n'; 92 93 writeMCFGToDotFile(MF); 94 return false; 95 } 96