clang  6.0.0svn
CFGStmtMap.cpp
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1 //===--- CFGStmtMap.h - Map from Stmt* to CFGBlock* -----------*- 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 defines the CFGStmtMap class, which defines a mapping from
11 // Stmt* to CFGBlock*
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/ADT/DenseMap.h"
16 #include "clang/AST/ParentMap.h"
17 #include "clang/Analysis/CFG.h"
19 
20 using namespace clang;
21 
22 typedef llvm::DenseMap<const Stmt*, CFGBlock*> SMap;
23 static SMap *AsMap(void *m) { return (SMap*) m; }
24 
26 
28  SMap *SM = AsMap(M);
29  Stmt *X = S;
30 
31  // If 'S' isn't in the map, walk the ParentMap to see if one of its ancestors
32  // is in the map.
33  while (X) {
34  SMap::iterator I = SM->find(X);
35  if (I != SM->end()) {
36  CFGBlock *B = I->second;
37  // Memoize this lookup.
38  if (X != S)
39  (*SM)[X] = B;
40  return B;
41  }
42 
43  X = PM->getParentIgnoreParens(X);
44  }
45 
46  return nullptr;
47 }
48 
49 static void Accumulate(SMap &SM, CFGBlock *B) {
50  // First walk the block-level expressions.
51  for (CFGBlock::iterator I = B->begin(), E = B->end(); I != E; ++I) {
52  const CFGElement &CE = *I;
53  Optional<CFGStmt> CS = CE.getAs<CFGStmt>();
54  if (!CS)
55  continue;
56 
57  CFGBlock *&Entry = SM[CS->getStmt()];
58  // If 'Entry' is already initialized (e.g., a terminator was already),
59  // skip.
60  if (Entry)
61  continue;
62 
63  Entry = B;
64 
65  }
66 
67  // Look at the label of the block.
68  if (Stmt *Label = B->getLabel())
69  SM[Label] = B;
70 
71  // Finally, look at the terminator. If the terminator was already added
72  // because it is a block-level expression in another block, overwrite
73  // that mapping.
74  if (Stmt *Term = B->getTerminator())
75  SM[Term] = B;
76 }
77 
79  if (!C || !PM)
80  return nullptr;
81 
82  SMap *SM = new SMap();
83 
84  // Walk all blocks, accumulating the block-level expressions, labels,
85  // and terminators.
86  for (CFG::iterator I = C->begin(), E = C->end(); I != E; ++I)
87  Accumulate(*SM, *I);
88 
89  return new CFGStmtMap(PM, SM);
90 }
91 
Stmt - This represents one statement.
Definition: Stmt.h:60
static void Accumulate(SMap &SM, CFGBlock *B)
Definition: CFGStmtMap.cpp:49
CFGBlockListTy::iterator iterator
Definition: CFG.h:877
iterator begin()
Definition: CFG.h:553
iterator end()
Definition: CFG.h:886
CFGBlock - Represents a single basic block in a source-level CFG.
Definition: CFG.h:401
std::string Label
CFG - Represents a source-level, intra-procedural CFG that represents the control-flow of a Stmt...
Definition: CFG.h:808
CFGBlock * getBlock(Stmt *S)
Returns the CFGBlock the specified Stmt* appears in.
Definition: CFGStmtMap.cpp:27
const SourceManager & SM
Definition: Format.cpp:1308
ElementList::iterator iterator
Definition: CFG.h:545
CFGTerminator getTerminator()
Definition: CFG.h:688
Stmt * getLabel()
Definition: CFG.h:699
Stmt * getParentIgnoreParens(Stmt *) const
Definition: ParentMap.cpp:128
iterator begin()
Definition: CFG.h:885
Optional< T > getAs() const
Convert to the specified CFGElement type, returning None if this CFGElement is not of the desired typ...
Definition: CFG.h:101
Dataflow Directional Tag Classes.
static CFGStmtMap * Build(CFG *C, ParentMap *PM)
Returns a new CFGMap for the given CFG.
Definition: CFGStmtMap.cpp:78
static SMap * AsMap(void *m)
Definition: CFGStmtMap.cpp:23
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13161
CFGElement - Represents a top-level expression in a basic block.
Definition: CFG.h:54
iterator end()
Definition: CFG.h:554
llvm::DenseMap< const Stmt *, CFGBlock * > SMap
Definition: CFGStmtMap.cpp:22