1 //===- PostOrderCFGView.cpp - Post order view of CFG blocks ---------------===// 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 implements post order view of the blocks in a CFG. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "clang/Analysis/Analyses/PostOrderCFGView.h" 14 #include "clang/Analysis/AnalysisDeclContext.h" 15 #include "clang/Analysis/CFG.h" 16 17 using namespace clang; 18 19 void PostOrderCFGView::anchor() {} 20 21 PostOrderCFGView::PostOrderCFGView(const CFG *cfg) { 22 Blocks.reserve(cfg->getNumBlockIDs()); 23 CFGBlockSet BSet(cfg); 24 25 for (po_iterator I = po_iterator::begin(cfg, BSet), 26 E = po_iterator::end(cfg, BSet); I != E; ++I) { 27 BlockOrder[*I] = Blocks.size() + 1; 28 Blocks.push_back(*I); 29 } 30 } 31 32 std::unique_ptr<PostOrderCFGView> 33 PostOrderCFGView::create(AnalysisDeclContext &ctx) { 34 const CFG *cfg = ctx.getCFG(); 35 if (!cfg) 36 return nullptr; 37 return std::make_unique<PostOrderCFGView>(cfg); 38 } 39 40 const void *PostOrderCFGView::getTag() { static int x; return &x; } 41 42 bool PostOrderCFGView::BlockOrderCompare::operator()(const CFGBlock *b1, 43 const CFGBlock *b2) const { 44 PostOrderCFGView::BlockOrderTy::const_iterator b1It = POV.BlockOrder.find(b1); 45 PostOrderCFGView::BlockOrderTy::const_iterator b2It = POV.BlockOrder.find(b2); 46 47 unsigned b1V = (b1It == POV.BlockOrder.end()) ? 0 : b1It->second; 48 unsigned b2V = (b2It == POV.BlockOrder.end()) ? 0 : b2It->second; 49 return b1V > b2V; 50 } 51