1//===- Verifier.h - LLVM IR Verifier ----------------------------*- 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// This file defines the function verifier interface, that can be used for some
10// sanity checking of input to the system, and for checking that transformations
11// haven't done something bad.
12//
13// Note that this does not provide full 'java style' security and verifications,
14// instead it just tries to ensure that code is well formed.
15//
16// To see what specifically is checked, look at the top of Verifier.cpp
17//
18//===----------------------------------------------------------------------===//
19
20#ifndef LLVM_IR_VERIFIER_H
21#define LLVM_IR_VERIFIER_H
22
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/IR/PassManager.h"
25#include <utility>
26
27namespace llvm {
28
29class APInt;
30class Function;
31class FunctionPass;
32class Instruction;
33class MDNode;
34class Module;
35class raw_ostream;
36struct VerifierSupport;
37
38/// Verify that the TBAA Metadatas are valid.
39class TBAAVerifier {
40  VerifierSupport *Diagnostic = nullptr;
41
42  /// Helper to diagnose a failure
43  template <typename... Tys> void CheckFailed(Tys &&... Args);
44
45  /// Cache of TBAA base nodes that have already been visited.  This cachce maps
46  /// a node that has been visited to a pair (IsInvalid, BitWidth) where
47  ///
48  ///  \c IsInvalid is true iff the node is invalid.
49  ///  \c BitWidth, if non-zero, is the bitwidth of the integer used to denoting
50  ///    the offset of the access.  If zero, only a zero offset is allowed.
51  ///
52  /// \c BitWidth has no meaning if \c IsInvalid is true.
53  using TBAABaseNodeSummary = std::pair<bool, unsigned>;
54  DenseMap<const MDNode *, TBAABaseNodeSummary> TBAABaseNodes;
55
56  /// Maps an alleged scalar TBAA node to a boolean that is true if the said
57  /// TBAA node is a valid scalar TBAA node or false otherwise.
58  DenseMap<const MDNode *, bool> TBAAScalarNodes;
59
60  /// \name Helper functions used by \c visitTBAAMetadata.
61  /// @{
62  MDNode *getFieldNodeFromTBAABaseNode(Instruction &I, const MDNode *BaseNode,
63                                       APInt &Offset, bool IsNewFormat);
64  TBAAVerifier::TBAABaseNodeSummary verifyTBAABaseNode(Instruction &I,
65                                                       const MDNode *BaseNode,
66                                                       bool IsNewFormat);
67  TBAABaseNodeSummary verifyTBAABaseNodeImpl(Instruction &I,
68                                             const MDNode *BaseNode,
69                                             bool IsNewFormat);
70
71  bool isValidScalarTBAANode(const MDNode *MD);
72  /// @}
73
74public:
75  TBAAVerifier(VerifierSupport *Diagnostic = nullptr)
76      : Diagnostic(Diagnostic) {}
77  /// Visit an instruction and return true if it is valid, return false if an
78  /// invalid TBAA is attached.
79  bool visitTBAAMetadata(Instruction &I, const MDNode *MD);
80};
81
82/// Check a function for errors, useful for use when debugging a
83/// pass.
84///
85/// If there are no errors, the function returns false. If an error is found,
86/// a message describing the error is written to OS (if non-null) and true is
87/// returned.
88bool verifyFunction(const Function &F, raw_ostream *OS = nullptr);
89
90/// Check a module for errors.
91///
92/// If there are no errors, the function returns false. If an error is
93/// found, a message describing the error is written to OS (if
94/// non-null) and true is returned.
95///
96/// \return true if the module is broken. If BrokenDebugInfo is
97/// supplied, DebugInfo verification failures won't be considered as
98/// error and instead *BrokenDebugInfo will be set to true. Debug
99/// info errors can be "recovered" from by stripping the debug info.
100bool verifyModule(const Module &M, raw_ostream *OS = nullptr,
101                  bool *BrokenDebugInfo = nullptr);
102
103FunctionPass *createVerifierPass(bool FatalErrors = true);
104
105/// Check a module for errors, and report separate error states for IR
106/// and debug info errors.
107class VerifierAnalysis : public AnalysisInfoMixin<VerifierAnalysis> {
108  friend AnalysisInfoMixin<VerifierAnalysis>;
109
110  static AnalysisKey Key;
111
112public:
113  struct Result {
114    bool IRBroken, DebugInfoBroken;
115  };
116
117  Result run(Module &M, ModuleAnalysisManager &);
118  Result run(Function &F, FunctionAnalysisManager &);
119};
120
121/// Check a module for errors, but report debug info errors separately.
122/// Otherwise behaves as the normal verifyModule. Debug info errors can be
123/// "recovered" from by stripping the debug info.
124bool verifyModule(bool &BrokenDebugInfo, const Module &M, raw_ostream *OS);
125
126/// Create a verifier pass.
127///
128/// Check a module or function for validity. This is essentially a pass wrapped
129/// around the above verifyFunction and verifyModule routines and
130/// functionality. When the pass detects a verification error it is always
131/// printed to stderr, and by default they are fatal. You can override that by
132/// passing \c false to \p FatalErrors.
133///
134/// Note that this creates a pass suitable for the legacy pass manager. It has
135/// nothing to do with \c VerifierPass.
136class VerifierPass : public PassInfoMixin<VerifierPass> {
137  bool FatalErrors;
138
139public:
140  explicit VerifierPass(bool FatalErrors = true) : FatalErrors(FatalErrors) {}
141
142  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
143  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
144};
145
146} // end namespace llvm
147
148#endif // LLVM_IR_VERIFIER_H
149