1//===-- ubsan_diag.h --------------------------------------------*- 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// Diagnostics emission for Clang's undefined behavior sanitizer.
10//
11//===----------------------------------------------------------------------===//
12#ifndef UBSAN_DIAG_H
13#define UBSAN_DIAG_H
14
15#include "ubsan_value.h"
16#include "sanitizer_common/sanitizer_stacktrace.h"
17#include "sanitizer_common/sanitizer_symbolizer.h"
18
19namespace __ubsan {
20
21SymbolizedStack *getSymbolizedLocation(uptr PC);
22
23inline SymbolizedStack *getCallerLocation(uptr CallerPC) {
24  CHECK(CallerPC);
25  uptr PC = StackTrace::GetPreviousInstructionPc(CallerPC);
26  return getSymbolizedLocation(PC);
27}
28
29/// A location of some data within the program's address space.
30typedef uptr MemoryLocation;
31
32/// \brief Location at which a diagnostic can be emitted. Either a
33/// SourceLocation, a MemoryLocation, or a SymbolizedStack.
34class Location {
35public:
36  enum LocationKind { LK_Null, LK_Source, LK_Memory, LK_Symbolized };
37
38private:
39  LocationKind Kind;
40  // FIXME: In C++11, wrap these in an anonymous union.
41  SourceLocation SourceLoc;
42  MemoryLocation MemoryLoc;
43  const SymbolizedStack *SymbolizedLoc;  // Not owned.
44
45public:
46  Location() : Kind(LK_Null) {}
47  Location(SourceLocation Loc) :
48    Kind(LK_Source), SourceLoc(Loc) {}
49  Location(MemoryLocation Loc) :
50    Kind(LK_Memory), MemoryLoc(Loc) {}
51  // SymbolizedStackHolder must outlive Location object.
52  Location(const SymbolizedStackHolder &Stack) :
53    Kind(LK_Symbolized), SymbolizedLoc(Stack.get()) {}
54
55  LocationKind getKind() const { return Kind; }
56
57  bool isSourceLocation() const { return Kind == LK_Source; }
58  bool isMemoryLocation() const { return Kind == LK_Memory; }
59  bool isSymbolizedStack() const { return Kind == LK_Symbolized; }
60
61  SourceLocation getSourceLocation() const {
62    CHECK(isSourceLocation());
63    return SourceLoc;
64  }
65  MemoryLocation getMemoryLocation() const {
66    CHECK(isMemoryLocation());
67    return MemoryLoc;
68  }
69  const SymbolizedStack *getSymbolizedStack() const {
70    CHECK(isSymbolizedStack());
71    return SymbolizedLoc;
72  }
73};
74
75/// A diagnostic severity level.
76enum DiagLevel {
77  DL_Error, ///< An error.
78  DL_Note   ///< A note, attached to a prior diagnostic.
79};
80
81/// \brief Annotation for a range of locations in a diagnostic.
82class Range {
83  Location Start, End;
84  const char *Text;
85
86public:
87  Range() : Start(), End(), Text() {}
88  Range(MemoryLocation Start, MemoryLocation End, const char *Text)
89    : Start(Start), End(End), Text(Text) {}
90  Location getStart() const { return Start; }
91  Location getEnd() const { return End; }
92  const char *getText() const { return Text; }
93};
94
95/// \brief A C++ type name. Really just a strong typedef for 'const char*'.
96class TypeName {
97  const char *Name;
98public:
99  TypeName(const char *Name) : Name(Name) {}
100  const char *getName() const { return Name; }
101};
102
103enum class ErrorType {
104#define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) Name,
105#include "ubsan_checks.inc"
106#undef UBSAN_CHECK
107};
108
109/// \brief Representation of an in-flight diagnostic.
110///
111/// Temporary \c Diag instances are created by the handler routines to
112/// accumulate arguments for a diagnostic. The destructor emits the diagnostic
113/// message.
114class Diag {
115  /// The location at which the problem occurred.
116  Location Loc;
117
118  /// The diagnostic level.
119  DiagLevel Level;
120
121  /// The error type.
122  ErrorType ET;
123
124  /// The message which will be emitted, with %0, %1, ... placeholders for
125  /// arguments.
126  const char *Message;
127
128public:
129  /// Kinds of arguments, corresponding to members of \c Arg's union.
130  enum ArgKind {
131    AK_String, ///< A string argument, displayed as-is.
132    AK_TypeName,///< A C++ type name, possibly demangled before display.
133    AK_UInt,   ///< An unsigned integer argument.
134    AK_SInt,   ///< A signed integer argument.
135    AK_Float,  ///< A floating-point argument.
136    AK_Pointer ///< A pointer argument, displayed in hexadecimal.
137  };
138
139  /// An individual diagnostic message argument.
140  struct Arg {
141    Arg() {}
142    Arg(const char *String) : Kind(AK_String), String(String) {}
143    Arg(TypeName TN) : Kind(AK_TypeName), String(TN.getName()) {}
144    Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}
145    Arg(SIntMax SInt) : Kind(AK_SInt), SInt(SInt) {}
146    Arg(FloatMax Float) : Kind(AK_Float), Float(Float) {}
147    Arg(const void *Pointer) : Kind(AK_Pointer), Pointer(Pointer) {}
148
149    ArgKind Kind;
150    union {
151      const char *String;
152      UIntMax UInt;
153      SIntMax SInt;
154      FloatMax Float;
155      const void *Pointer;
156    };
157  };
158
159private:
160  static const unsigned MaxArgs = 8;
161  static const unsigned MaxRanges = 1;
162
163  /// The arguments which have been added to this diagnostic so far.
164  Arg Args[MaxArgs];
165  unsigned NumArgs;
166
167  /// The ranges which have been added to this diagnostic so far.
168  Range Ranges[MaxRanges];
169  unsigned NumRanges;
170
171  Diag &AddArg(Arg A) {
172    CHECK(NumArgs != MaxArgs);
173    Args[NumArgs++] = A;
174    return *this;
175  }
176
177  Diag &AddRange(Range A) {
178    CHECK(NumRanges != MaxRanges);
179    Ranges[NumRanges++] = A;
180    return *this;
181  }
182
183  /// \c Diag objects are not copyable.
184  Diag(const Diag &); // NOT IMPLEMENTED
185  Diag &operator=(const Diag &);
186
187public:
188  Diag(Location Loc, DiagLevel Level, ErrorType ET, const char *Message)
189      : Loc(Loc), Level(Level), ET(ET), Message(Message), NumArgs(0),
190        NumRanges(0) {}
191  ~Diag();
192
193  Diag &operator<<(const char *Str) { return AddArg(Str); }
194  Diag &operator<<(TypeName TN) { return AddArg(TN); }
195  Diag &operator<<(unsigned long long V) { return AddArg(UIntMax(V)); }
196  Diag &operator<<(const void *V) { return AddArg(V); }
197  Diag &operator<<(const TypeDescriptor &V);
198  Diag &operator<<(const Value &V);
199  Diag &operator<<(const Range &R) { return AddRange(R); }
200};
201
202struct ReportOptions {
203  // If FromUnrecoverableHandler is specified, UBSan runtime handler is not
204  // expected to return.
205  bool FromUnrecoverableHandler;
206  /// pc/bp are used to unwind the stack trace.
207  uptr pc;
208  uptr bp;
209};
210
211bool ignoreReport(SourceLocation SLoc, ReportOptions Opts, ErrorType ET);
212
213#define GET_REPORT_OPTIONS(unrecoverable_handler) \
214    GET_CALLER_PC_BP; \
215    ReportOptions Opts = {unrecoverable_handler, pc, bp}
216
217/// \brief Instantiate this class before printing diagnostics in the error
218/// report. This class ensures that reports from different threads and from
219/// different sanitizers won't be mixed.
220class ScopedReport {
221  struct Initializer {
222    Initializer();
223  };
224  Initializer initializer_;
225  ScopedErrorReportLock report_lock_;
226
227  ReportOptions Opts;
228  Location SummaryLoc;
229  ErrorType Type;
230
231public:
232  ScopedReport(ReportOptions Opts, Location SummaryLoc, ErrorType Type);
233  ~ScopedReport();
234
235  static void CheckLocked() { ScopedErrorReportLock::CheckLocked(); }
236};
237
238void InitializeSuppressions();
239bool IsVptrCheckSuppressed(const char *TypeName);
240// Sometimes UBSan runtime can know filename from handlers arguments, even if
241// debug info is missing.
242bool IsPCSuppressed(ErrorType ET, uptr PC, const char *Filename);
243
244} // namespace __ubsan
245
246#endif // UBSAN_DIAG_H
247