clang  10.0.0svn
PostOrderCFGView.cpp
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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 
15 #include "clang/Analysis/CFG.h"
16 
17 using namespace clang;
18 
19 void PostOrderCFGView::anchor() {}
20 
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 
33  const CFG *cfg = ctx.getCFG();
34  if (!cfg)
35  return nullptr;
36  return new PostOrderCFGView(cfg);
37 }
38 
39 const void *PostOrderCFGView::getTag() { static int x; return &x; }
40 
42  const CFGBlock *b2) const {
43  PostOrderCFGView::BlockOrderTy::const_iterator b1It = POV.BlockOrder.find(b1);
44  PostOrderCFGView::BlockOrderTy::const_iterator b2It = POV.BlockOrder.find(b2);
45 
46  unsigned b1V = (b1It == POV.BlockOrder.end()) ? 0 : b1It->second;
47  unsigned b2V = (b2It == POV.BlockOrder.end()) ? 0 : b2It->second;
48  return b1V > b2V;
49 }
AnalysisDeclContext contains the context data for the function or method under analysis.
static PostOrderCFGView * create(AnalysisDeclContext &analysisContext)
Implements a set of CFGBlocks using a BitVector.
Represents a single basic block in a source-level CFG.
Definition: CFG.h:576
Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:1225
unsigned getNumBlockIDs() const
Returns the total number of BlockIDs allocated (which start at 0).
Definition: CFG.h:1392
Dataflow Directional Tag Classes.
bool operator()(const CFGBlock *b1, const CFGBlock *b2) const
static const void * getTag()
PostOrderCFGView(const CFG *cfg)