1//===-- ubsan_diag.h --------------------------------------------*- 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// Diagnostics emission for Clang's undefined behavior sanitizer.
11//
12//===----------------------------------------------------------------------===//
13#ifndef UBSAN_DIAG_H
14#define UBSAN_DIAG_H
15
16#include "ubsan_value.h"
17#include "sanitizer_common/sanitizer_stacktrace.h"
18#include "sanitizer_common/sanitizer_symbolizer.h"
19
20namespace __ubsan {
21
22class SymbolizedStackHolder {
23  SymbolizedStack *Stack;
24
25  void clear() {
26    if (Stack)
27      Stack->ClearAll();
28  }
29
30public:
31  explicit SymbolizedStackHolder(SymbolizedStack *Stack = nullptr)
32      : Stack(Stack) {}
33  ~SymbolizedStackHolder() { clear(); }
34  void reset(SymbolizedStack *S) {
35    if (Stack != S)
36      clear();
37    Stack = S;
38  }
39  const SymbolizedStack *get() const { return Stack; }
40};
41
42SymbolizedStack *getSymbolizedLocation(uptr PC);
43
44inline SymbolizedStack *getCallerLocation(uptr CallerPC) {
45  CHECK(CallerPC);
46  uptr PC = StackTrace::GetPreviousInstructionPc(CallerPC);
47  return getSymbolizedLocation(PC);
48}
49
50/// A location of some data within the program's address space.
51typedef uptr MemoryLocation;
52
53/// \brief Location at which a diagnostic can be emitted. Either a
54/// SourceLocation, a MemoryLocation, or a SymbolizedStack.
55class Location {
56public:
57  enum LocationKind { LK_Null, LK_Source, LK_Memory, LK_Symbolized };
58
59private:
60  LocationKind Kind;
61  // FIXME: In C++11, wrap these in an anonymous union.
62  SourceLocation SourceLoc;
63  MemoryLocation MemoryLoc;
64  const SymbolizedStack *SymbolizedLoc;  // Not owned.
65
66public:
67  Location() : Kind(LK_Null) {}
68  Location(SourceLocation Loc) :
69    Kind(LK_Source), SourceLoc(Loc) {}
70  Location(MemoryLocation Loc) :
71    Kind(LK_Memory), MemoryLoc(Loc) {}
72  // SymbolizedStackHolder must outlive Location object.
73  Location(const SymbolizedStackHolder &Stack) :
74    Kind(LK_Symbolized), SymbolizedLoc(Stack.get()) {}
75
76  LocationKind getKind() const { return Kind; }
77
78  bool isSourceLocation() const { return Kind == LK_Source; }
79  bool isMemoryLocation() const { return Kind == LK_Memory; }
80  bool isSymbolizedStack() const { return Kind == LK_Symbolized; }
81
82  SourceLocation getSourceLocation() const {
83    CHECK(isSourceLocation());
84    return SourceLoc;
85  }
86  MemoryLocation getMemoryLocation() const {
87    CHECK(isMemoryLocation());
88    return MemoryLoc;
89  }
90  const SymbolizedStack *getSymbolizedStack() const {
91    CHECK(isSymbolizedStack());
92    return SymbolizedLoc;
93  }
94};
95
96/// A diagnostic severity level.
97enum DiagLevel {
98  DL_Error, ///< An error.
99  DL_Note   ///< A note, attached to a prior diagnostic.
100};
101
102/// \brief Annotation for a range of locations in a diagnostic.
103class Range {
104  Location Start, End;
105  const char *Text;
106
107public:
108  Range() : Start(), End(), Text() {}
109  Range(MemoryLocation Start, MemoryLocation End, const char *Text)
110    : Start(Start), End(End), Text(Text) {}
111  Location getStart() const { return Start; }
112  Location getEnd() const { return End; }
113  const char *getText() const { return Text; }
114};
115
116/// \brief A mangled C++ name. Really just a strong typedef for 'const char*'.
117class MangledName {
118  const char *Name;
119public:
120  MangledName(const char *Name) : Name(Name) {}
121  const char *getName() const { return Name; }
122};
123
124/// \brief Representation of an in-flight diagnostic.
125///
126/// Temporary \c Diag instances are created by the handler routines to
127/// accumulate arguments for a diagnostic. The destructor emits the diagnostic
128/// message.
129class Diag {
130  /// The location at which the problem occurred.
131  Location Loc;
132
133  /// The diagnostic level.
134  DiagLevel Level;
135
136  /// The message which will be emitted, with %0, %1, ... placeholders for
137  /// arguments.
138  const char *Message;
139
140public:
141  /// Kinds of arguments, corresponding to members of \c Arg's union.
142  enum ArgKind {
143    AK_String, ///< A string argument, displayed as-is.
144    AK_Mangled,///< A C++ mangled name, demangled before display.
145    AK_UInt,   ///< An unsigned integer argument.
146    AK_SInt,   ///< A signed integer argument.
147    AK_Float,  ///< A floating-point argument.
148    AK_Pointer ///< A pointer argument, displayed in hexadecimal.
149  };
150
151  /// An individual diagnostic message argument.
152  struct Arg {
153    Arg() {}
154    Arg(const char *String) : Kind(AK_String), String(String) {}
155    Arg(MangledName MN) : Kind(AK_Mangled), String(MN.getName()) {}
156    Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}
157    Arg(SIntMax SInt) : Kind(AK_SInt), SInt(SInt) {}
158    Arg(FloatMax Float) : Kind(AK_Float), Float(Float) {}
159    Arg(const void *Pointer) : Kind(AK_Pointer), Pointer(Pointer) {}
160
161    ArgKind Kind;
162    union {
163      const char *String;
164      UIntMax UInt;
165      SIntMax SInt;
166      FloatMax Float;
167      const void *Pointer;
168    };
169  };
170
171private:
172  static const unsigned MaxArgs = 5;
173  static const unsigned MaxRanges = 1;
174
175  /// The arguments which have been added to this diagnostic so far.
176  Arg Args[MaxArgs];
177  unsigned NumArgs;
178
179  /// The ranges which have been added to this diagnostic so far.
180  Range Ranges[MaxRanges];
181  unsigned NumRanges;
182
183  Diag &AddArg(Arg A) {
184    CHECK(NumArgs != MaxArgs);
185    Args[NumArgs++] = A;
186    return *this;
187  }
188
189  Diag &AddRange(Range A) {
190    CHECK(NumRanges != MaxRanges);
191    Ranges[NumRanges++] = A;
192    return *this;
193  }
194
195  /// \c Diag objects are not copyable.
196  Diag(const Diag &); // NOT IMPLEMENTED
197  Diag &operator=(const Diag &);
198
199public:
200  Diag(Location Loc, DiagLevel Level, const char *Message)
201    : Loc(Loc), Level(Level), Message(Message), NumArgs(0), NumRanges(0) {}
202  ~Diag();
203
204  Diag &operator<<(const char *Str) { return AddArg(Str); }
205  Diag &operator<<(MangledName MN) { return AddArg(MN); }
206  Diag &operator<<(unsigned long long V) { return AddArg(UIntMax(V)); }
207  Diag &operator<<(const void *V) { return AddArg(V); }
208  Diag &operator<<(const TypeDescriptor &V);
209  Diag &operator<<(const Value &V);
210  Diag &operator<<(const Range &R) { return AddRange(R); }
211};
212
213struct ReportOptions {
214  /// If DieAfterReport is specified, UBSan will terminate the program after the
215  /// report is printed.
216  bool DieAfterReport;
217  /// pc/bp are used to unwind the stack trace.
218  uptr pc;
219  uptr bp;
220};
221
222#define GET_REPORT_OPTIONS(die_after_report) \
223    GET_CALLER_PC_BP; \
224    ReportOptions Opts = {die_after_report, pc, bp}
225
226/// \brief Instantiate this class before printing diagnostics in the error
227/// report. This class ensures that reports from different threads and from
228/// different sanitizers won't be mixed.
229class ScopedReport {
230  ReportOptions Opts;
231  Location SummaryLoc;
232
233public:
234  ScopedReport(ReportOptions Opts, Location SummaryLoc);
235  ~ScopedReport();
236};
237
238void InitializeSuppressions();
239bool IsVptrCheckSuppressed(const char *TypeName);
240
241} // namespace __ubsan
242
243#endif // UBSAN_DIAG_H
244