1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
//==- CheckSecuritySyntaxOnly.cpp - Basic security checks --------*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a set of flow-insensitive security checks.
//
//===----------------------------------------------------------------------===//
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "clang/Analysis/LocalCheckers.h"
#include "clang/AST/StmtVisitor.h"
#include "llvm/Support/Compiler.h"
using namespace clang;
namespace {
class VISIBILITY_HIDDEN WalkAST : public StmtVisitor<WalkAST> {
BugReporter &BR;
public:
WalkAST(BugReporter &br) : BR(br) {}
// Statement visitor methods.
void VisitDoStmt(DoStmt *S);
void VisitWhileStmt(WhileStmt *S);
void VisitForStmt(ForStmt *S);
void VisitChildren(Stmt *S);
void VisitStmt(Stmt *S) { VisitChildren(S); }
// Checker-specific methods.
void CheckLoopConditionForFloat(Stmt *Loop, Expr *Condition);
};
} // end anonymous namespace
//===----------------------------------------------------------------------===//
// AST walking.
//===----------------------------------------------------------------------===//
void WalkAST::VisitChildren(Stmt *S) {
for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
if (Stmt *child = *I)
Visit(child);
}
void WalkAST::VisitDoStmt(DoStmt *S) {
CheckLoopConditionForFloat(S, S->getCond());
VisitChildren(S);
}
void WalkAST::VisitForStmt(ForStmt *S) {
if (Expr *Cond = S->getCond())
CheckLoopConditionForFloat(S, Cond);
VisitChildren(S);
}
void WalkAST::VisitWhileStmt(WhileStmt *S) {
CheckLoopConditionForFloat(S, S->getCond());
VisitChildren(S);
}
//===----------------------------------------------------------------------===//
// Checking logic.
//===----------------------------------------------------------------------===//
static Expr* IsFloatCondition(Expr *Condition) {
while (Condition) {
Condition = Condition->IgnoreParenCasts();
if (Condition->getType()->isFloatingType())
return Condition;
switch (Condition->getStmtClass()) {
case Stmt::BinaryOperatorClass: {
BinaryOperator *B = cast<BinaryOperator>(Condition);
Expr *LHS = B->getLHS();
if (LHS->getType()->isFloatingType())
return LHS;
Expr *RHS = B->getRHS();
if (RHS->getType()->isFloatingType())
return RHS;
return NULL;
}
case Stmt::UnaryOperatorClass: {
UnaryOperator *U = cast<UnaryOperator>(Condition);
if (U->isArithmeticOp()) {
Condition = U->getSubExpr();
continue;
}
return NULL;
}
default:
break;
}
}
return NULL;
}
void WalkAST::CheckLoopConditionForFloat(Stmt *Loop, Expr *Condition) {
if ((Condition = IsFloatCondition(Condition))) {
const char *bugType = "Floating point value used in loop condition";
SourceRange R = Condition->getSourceRange();
BR.EmitBasicReport(bugType, "Security", bugType, Loop->getLocStart(),&R, 1);
}
}
//===----------------------------------------------------------------------===//
// Entry point for check.
//===----------------------------------------------------------------------===//
void clang::CheckSecuritySyntaxOnly(Decl *D, BugReporter &BR) {
WalkAST walker(BR);
walker.Visit(D->getBody());
}
|
