1//===- PostOrderCFGView.cpp - Post order view of CFG blocks -------*- C++ --*-//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements post order view of the blocks in a CFG.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Analysis/Analyses/PostOrderCFGView.h"
15
16using namespace clang;
17
18void PostOrderCFGView::anchor() { }
19
20PostOrderCFGView::PostOrderCFGView(const CFG *cfg) {
21  Blocks.reserve(cfg->getNumBlockIDs());
22  CFGBlockSet BSet(cfg);
23
24  for (po_iterator I = po_iterator::begin(cfg, BSet),
25                   E = po_iterator::end(cfg, BSet); I != E; ++I) {
26    BlockOrder[*I] = Blocks.size() + 1;
27    Blocks.push_back(*I);
28  }
29}
30
31PostOrderCFGView *PostOrderCFGView::create(AnalysisDeclContext &ctx) {
32  const CFG *cfg = ctx.getCFG();
33  if (!cfg)
34    return nullptr;
35  return new PostOrderCFGView(cfg);
36}
37
38const void *PostOrderCFGView::getTag() { static int x; return &x; }
39
40bool PostOrderCFGView::BlockOrderCompare::operator()(const CFGBlock *b1,
41                                                     const CFGBlock *b2) const {
42  PostOrderCFGView::BlockOrderTy::const_iterator b1It = POV.BlockOrder.find(b1);
43  PostOrderCFGView::BlockOrderTy::const_iterator b2It = POV.BlockOrder.find(b2);
44
45  unsigned b1V = (b1It == POV.BlockOrder.end()) ? 0 : b1It->second;
46  unsigned b2V = (b2It == POV.BlockOrder.end()) ? 0 : b2It->second;
47  return b1V > b2V;
48}
49
50