1 //== TraversalChecker.cpp -------------------------------------- -*- 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 // These checkers print various aspects of the ExprEngine's traversal of the CFG
11 // as it builds the ExplodedGraph.
12 //
13 //===----------------------------------------------------------------------===//
14 #include "ClangSACheckers.h"
15 #include "clang/AST/ParentMap.h"
16 #include "clang/AST/StmtObjC.h"
17 #include "clang/StaticAnalyzer/Core/Checker.h"
18 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
19 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
21 #include "llvm/Support/raw_ostream.h"
22 
23 using namespace clang;
24 using namespace ento;
25 
26 namespace {
27 class TraversalDumper : public Checker< check::BranchCondition,
28                                         check::BeginFunction,
29                                         check::EndFunction > {
30 public:
31   void checkBranchCondition(const Stmt *Condition, CheckerContext &C) const;
32   void checkBeginFunction(CheckerContext &C) const;
33   void checkEndFunction(const ReturnStmt *RS, CheckerContext &C) const;
34 };
35 }
36 
37 void TraversalDumper::checkBranchCondition(const Stmt *Condition,
38                                            CheckerContext &C) const {
39   // Special-case Objective-C's for-in loop, which uses the entire loop as its
40   // condition. We just print the collection expression.
41   const Stmt *Parent = dyn_cast<ObjCForCollectionStmt>(Condition);
42   if (!Parent) {
43     const ParentMap &Parents = C.getLocationContext()->getParentMap();
44     Parent = Parents.getParent(Condition);
45   }
46 
47   // It is mildly evil to print directly to llvm::outs() rather than emitting
48   // warnings, but this ensures things do not get filtered out by the rest of
49   // the static analyzer machinery.
50   SourceLocation Loc = Parent->getBeginLoc();
51   llvm::outs() << C.getSourceManager().getSpellingLineNumber(Loc) << " "
52                << Parent->getStmtClassName() << "\n";
53 }
54 
55 void TraversalDumper::checkBeginFunction(CheckerContext &C) const {
56   llvm::outs() << "--BEGIN FUNCTION--\n";
57 }
58 
59 void TraversalDumper::checkEndFunction(const ReturnStmt *RS,
60                                        CheckerContext &C) const {
61   llvm::outs() << "--END FUNCTION--\n";
62 }
63 
64 void ento::registerTraversalDumper(CheckerManager &mgr) {
65   mgr.registerChecker<TraversalDumper>();
66 }
67 
68 //------------------------------------------------------------------------------
69 
70 namespace {
71 class CallDumper : public Checker< check::PreCall,
72                                    check::PostCall > {
73 public:
74   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
75   void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
76 };
77 }
78 
79 void CallDumper::checkPreCall(const CallEvent &Call, CheckerContext &C) const {
80   unsigned Indentation = 0;
81   for (const LocationContext *LC = C.getLocationContext()->getParent();
82        LC != nullptr; LC = LC->getParent())
83     ++Indentation;
84 
85   // It is mildly evil to print directly to llvm::outs() rather than emitting
86   // warnings, but this ensures things do not get filtered out by the rest of
87   // the static analyzer machinery.
88   llvm::outs().indent(Indentation);
89   Call.dump(llvm::outs());
90 }
91 
92 void CallDumper::checkPostCall(const CallEvent &Call, CheckerContext &C) const {
93   const Expr *CallE = Call.getOriginExpr();
94   if (!CallE)
95     return;
96 
97   unsigned Indentation = 0;
98   for (const LocationContext *LC = C.getLocationContext()->getParent();
99        LC != nullptr; LC = LC->getParent())
100     ++Indentation;
101 
102   // It is mildly evil to print directly to llvm::outs() rather than emitting
103   // warnings, but this ensures things do not get filtered out by the rest of
104   // the static analyzer machinery.
105   llvm::outs().indent(Indentation);
106   if (Call.getResultType()->isVoidType())
107     llvm::outs() << "Returning void\n";
108   else
109     llvm::outs() << "Returning " << C.getSVal(CallE) << "\n";
110 }
111 
112 void ento::registerCallDumper(CheckerManager &mgr) {
113   mgr.registerChecker<CallDumper>();
114 }
115