1//=== Taint.h - Taint tracking and basic propagation rules. --------*- C++ -*-//
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// Defines basic, non-domain-specific mechanisms for tracking tainted values.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_LIB_STATICANALYZER_CHECKERS_TAINT_H
14#define LLVM_CLANG_LIB_STATICANALYZER_CHECKERS_TAINT_H
15
16#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
17#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
18
19namespace clang {
20namespace ento {
21namespace taint {
22
23/// The type of taint, which helps to differentiate between different types of
24/// taint.
25using TaintTagType = unsigned;
26
27static constexpr TaintTagType TaintTagGeneric = 0;
28
29/// Create a new state in which the value of the statement is marked as tainted.
30LLVM_NODISCARD ProgramStateRef addTaint(ProgramStateRef State, const Stmt *S,
31                                        const LocationContext *LCtx,
32                                        TaintTagType Kind = TaintTagGeneric);
33
34/// Create a new state in which the value is marked as tainted.
35LLVM_NODISCARD ProgramStateRef addTaint(ProgramStateRef State, SVal V,
36                                        TaintTagType Kind = TaintTagGeneric);
37
38/// Create a new state in which the symbol is marked as tainted.
39LLVM_NODISCARD ProgramStateRef addTaint(ProgramStateRef State, SymbolRef Sym,
40                                        TaintTagType Kind = TaintTagGeneric);
41
42/// Create a new state in which the pointer represented by the region
43/// is marked as tainted.
44LLVM_NODISCARD ProgramStateRef addTaint(ProgramStateRef State,
45                                        const MemRegion *R,
46                                        TaintTagType Kind = TaintTagGeneric);
47
48LLVM_NODISCARD ProgramStateRef removeTaint(ProgramStateRef State, SVal V);
49
50LLVM_NODISCARD ProgramStateRef removeTaint(ProgramStateRef State,
51                                           const MemRegion *R);
52
53LLVM_NODISCARD ProgramStateRef removeTaint(ProgramStateRef State,
54                                           SymbolRef Sym);
55
56/// Create a new state in a which a sub-region of a given symbol is tainted.
57/// This might be necessary when referring to regions that can not have an
58/// individual symbol, e.g. if they are represented by the default binding of
59/// a LazyCompoundVal.
60LLVM_NODISCARD ProgramStateRef addPartialTaint(
61    ProgramStateRef State, SymbolRef ParentSym, const SubRegion *SubRegion,
62    TaintTagType Kind = TaintTagGeneric);
63
64/// Check if the statement has a tainted value in the given state.
65bool isTainted(ProgramStateRef State, const Stmt *S,
66               const LocationContext *LCtx,
67               TaintTagType Kind = TaintTagGeneric);
68
69/// Check if the value is tainted in the given state.
70bool isTainted(ProgramStateRef State, SVal V,
71               TaintTagType Kind = TaintTagGeneric);
72
73/// Check if the symbol is tainted in the given state.
74bool isTainted(ProgramStateRef State, SymbolRef Sym,
75               TaintTagType Kind = TaintTagGeneric);
76
77/// Check if the pointer represented by the region is tainted in the given
78/// state.
79bool isTainted(ProgramStateRef State, const MemRegion *Reg,
80               TaintTagType Kind = TaintTagGeneric);
81
82void printTaint(ProgramStateRef State, raw_ostream &Out, const char *nl = "\n",
83                const char *sep = "");
84
85LLVM_DUMP_METHOD void dumpTaint(ProgramStateRef State);
86
87/// The bug visitor prints a diagnostic message at the location where a given
88/// variable was tainted.
89class TaintBugVisitor final : public BugReporterVisitor {
90private:
91  const SVal V;
92
93public:
94  TaintBugVisitor(const SVal V) : V(V) {}
95  void Profile(llvm::FoldingSetNodeID &ID) const override { ID.Add(V); }
96
97  PathDiagnosticPieceRef VisitNode(const ExplodedNode *N,
98                                   BugReporterContext &BRC,
99                                   PathSensitiveBugReport &BR) override;
100};
101
102} // namespace taint
103} // namespace ento
104} // namespace clang
105
106#endif
107