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/Support/GraphWriter.h"
21
22using namespace llvm;
23
24#define DEBUG_TYPE "dot-machine-cfg"
25
26static cl::opt<std::string>
27 MCFGFuncName("mcfg-func-name", cl::Hidden,
28 cl::desc("The name of a function (or its substring)"
29 " whose CFG is viewed/printed."));
30
31static cl::opt<std::string> MCFGDotFilenamePrefix(
32 "mcfg-dot-filename-prefix", cl::Hidden,
33 cl::desc("The prefix used for the Machine CFG dot file names."));
34
35static cl::opt<bool>
36 CFGOnly("dot-mcfg-only", cl::init(Val: false), cl::Hidden,
37 cl::desc("Print only the CFG without blocks body"));
38
39static void writeMCFGToDotFile(MachineFunction &MF) {
40 std::string Filename =
41 (MCFGDotFilenamePrefix + "." + MF.getName() + ".dot").str();
42 errs() << "Writing '" << Filename << "'...";
43
44 std::error_code EC;
45 raw_fd_ostream File(Filename, EC, sys::fs::OF_Text);
46
47 DOTMachineFuncInfo MCFGInfo(&MF);
48
49 if (!EC)
50 WriteGraph(O&: File, G: &MCFGInfo, ShortNames: CFGOnly);
51 else
52 errs() << " error opening file for writing!";
53 errs() << '\n';
54}
55
56namespace {
57
58class MachineCFGPrinterLegacy : public MachineFunctionPass {
59public:
60 static char ID;
61
62 MachineCFGPrinterLegacy();
63
64 bool runOnMachineFunction(MachineFunction &MF) override;
65
66 void getAnalysisUsage(AnalysisUsage &AU) const override {
67 AU.setPreservesCFG();
68 MachineFunctionPass::getAnalysisUsage(AU);
69 }
70};
71
72} // namespace
73
74char MachineCFGPrinterLegacy::ID = 0;
75
76char &llvm::MachineCFGPrinterID = MachineCFGPrinterLegacy::ID;
77
78INITIALIZE_PASS(MachineCFGPrinterLegacy, DEBUG_TYPE, "Machine CFG Printer Pass",
79 false, true)
80
81/// Default construct and initialize the pass.
82MachineCFGPrinterLegacy::MachineCFGPrinterLegacy() : MachineFunctionPass(ID) {}
83
84bool MachineCFGPrinterLegacy::runOnMachineFunction(MachineFunction &MF) {
85 if (!MCFGFuncName.empty() && !MF.getName().contains(Other: MCFGFuncName))
86 return false;
87 errs() << "Writing Machine CFG for function ";
88 errs().write_escaped(Str: MF.getName()) << '\n';
89
90 writeMCFGToDotFile(MF);
91 return false;
92}
93
94PreservedAnalyses
95MachineCFGPrinterPass::run(MachineFunction &MF,
96 MachineFunctionAnalysisManager &MFAM) {
97 if (!MCFGFuncName.empty() && !MF.getName().contains(Other: MCFGFuncName))
98 return PreservedAnalyses::all();
99 errs() << "Writing Machine CFG for function ";
100 errs().write_escaped(Str: MF.getName()) << '\n';
101
102 writeMCFGToDotFile(MF);
103 return PreservedAnalyses::all();
104}
105