65 lines
1.9 KiB
C++
65 lines
1.9 KiB
C++
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//===- Hello.cpp - Example code from "Writing an LLVM Pass" ---------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements two versions of the LLVM "Hello World" pass described
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// in docs/WritingAnLLVMPass.html
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/Statistic.h"
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#include "llvm/IR/Function.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace llvm;
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#define DEBUG_TYPE "hello"
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STATISTIC(HelloCounter, "Counts number of functions greeted");
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namespace {
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// Hello - The first implementation, without getAnalysisUsage.
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struct Hello : public FunctionPass {
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static char ID; // Pass identification, replacement for typeid
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Hello() : FunctionPass(ID) {}
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bool runOnFunction(Function &F) override {
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++HelloCounter;
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errs() << "Hello: ";
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errs().write_escaped(F.getName()) << '\n';
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return false;
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}
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};
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}
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char Hello::ID = 0;
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static RegisterPass<Hello> X("hello", "Hello World Pass");
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namespace {
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// Hello2 - The second implementation with getAnalysisUsage implemented.
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struct Hello2 : public FunctionPass {
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static char ID; // Pass identification, replacement for typeid
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Hello2() : FunctionPass(ID) {}
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bool runOnFunction(Function &F) override {
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++HelloCounter;
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errs() << "Hello: ";
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errs().write_escaped(F.getName()) << '\n';
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return false;
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}
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// We don't modify the program, so we preserve all analyses.
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.setPreservesAll();
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}
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};
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}
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char Hello2::ID = 0;
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static RegisterPass<Hello2>
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Y("hello2", "Hello World Pass (with getAnalysisUsage implemented)");
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