xref: /openbsd-src/gnu/llvm/clang/lib/Analysis/PostOrderCFGView.cpp (revision ec727ea710c91afd8ce4f788c5aaa8482b7b69b2)
1e5dd7070Spatrick //===- PostOrderCFGView.cpp - Post order view of CFG blocks ---------------===//
2e5dd7070Spatrick //
3e5dd7070Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4e5dd7070Spatrick // See https://llvm.org/LICENSE.txt for license information.
5e5dd7070Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6e5dd7070Spatrick //
7e5dd7070Spatrick //===----------------------------------------------------------------------===//
8e5dd7070Spatrick //
9e5dd7070Spatrick // This file implements post order view of the blocks in a CFG.
10e5dd7070Spatrick //
11e5dd7070Spatrick //===----------------------------------------------------------------------===//
12e5dd7070Spatrick 
13e5dd7070Spatrick #include "clang/Analysis/Analyses/PostOrderCFGView.h"
14e5dd7070Spatrick #include "clang/Analysis/AnalysisDeclContext.h"
15e5dd7070Spatrick #include "clang/Analysis/CFG.h"
16e5dd7070Spatrick 
17e5dd7070Spatrick using namespace clang;
18e5dd7070Spatrick 
anchor()19e5dd7070Spatrick void PostOrderCFGView::anchor() {}
20e5dd7070Spatrick 
PostOrderCFGView(const CFG * cfg)21e5dd7070Spatrick PostOrderCFGView::PostOrderCFGView(const CFG *cfg) {
22e5dd7070Spatrick   Blocks.reserve(cfg->getNumBlockIDs());
23e5dd7070Spatrick   CFGBlockSet BSet(cfg);
24e5dd7070Spatrick 
25e5dd7070Spatrick   for (po_iterator I = po_iterator::begin(cfg, BSet),
26e5dd7070Spatrick                    E = po_iterator::end(cfg, BSet); I != E; ++I) {
27e5dd7070Spatrick     BlockOrder[*I] = Blocks.size() + 1;
28e5dd7070Spatrick     Blocks.push_back(*I);
29e5dd7070Spatrick   }
30e5dd7070Spatrick }
31e5dd7070Spatrick 
32*ec727ea7Spatrick std::unique_ptr<PostOrderCFGView>
create(AnalysisDeclContext & ctx)33*ec727ea7Spatrick PostOrderCFGView::create(AnalysisDeclContext &ctx) {
34e5dd7070Spatrick   const CFG *cfg = ctx.getCFG();
35e5dd7070Spatrick   if (!cfg)
36e5dd7070Spatrick     return nullptr;
37*ec727ea7Spatrick   return std::make_unique<PostOrderCFGView>(cfg);
38e5dd7070Spatrick }
39e5dd7070Spatrick 
getTag()40e5dd7070Spatrick const void *PostOrderCFGView::getTag() { static int x; return &x; }
41e5dd7070Spatrick 
operator ()(const CFGBlock * b1,const CFGBlock * b2) const42e5dd7070Spatrick bool PostOrderCFGView::BlockOrderCompare::operator()(const CFGBlock *b1,
43e5dd7070Spatrick                                                      const CFGBlock *b2) const {
44e5dd7070Spatrick   PostOrderCFGView::BlockOrderTy::const_iterator b1It = POV.BlockOrder.find(b1);
45e5dd7070Spatrick   PostOrderCFGView::BlockOrderTy::const_iterator b2It = POV.BlockOrder.find(b2);
46e5dd7070Spatrick 
47e5dd7070Spatrick   unsigned b1V = (b1It == POV.BlockOrder.end()) ? 0 : b1It->second;
48e5dd7070Spatrick   unsigned b2V = (b2It == POV.BlockOrder.end()) ? 0 : b2It->second;
49e5dd7070Spatrick   return b1V > b2V;
50e5dd7070Spatrick }
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