libsanitizer/ubsan/ubsan_diag.h

   1 //===-- ubsan_diag.h --------------------------------------------*- C++ -*-===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // Diagnostics emission for Clang's undefined behavior sanitizer.
   9 //
  10 //===----------------------------------------------------------------------===//
  11 #ifndef UBSAN_DIAG_H
  12 #define UBSAN_DIAG_H
  13
  14 #include "ubsan_value.h"
  15 #include "sanitizer_common/sanitizer_stacktrace.h"
  16 #include "sanitizer_common/sanitizer_symbolizer.h"
  17
  18 namespace __ubsan {
  19
  20 class SymbolizedStackHolder {
  21   SymbolizedStack *Stack;
  22
  23   void clear() {
  24     if (Stack)
  25       Stack->ClearAll();
  26   }
  27
  28 public:
  29   explicit SymbolizedStackHolder(SymbolizedStack *Stack = nullptr)
  30       : Stack(Stack) {}
  31   ~SymbolizedStackHolder() { clear(); }
  32   void reset(SymbolizedStack *S) {
  33     if (Stack != S)
  34       clear();
  35     Stack = S;
  36   }
  37   const SymbolizedStack *get() const { return Stack; }
  38 };
  39
  40 SymbolizedStack *getSymbolizedLocation(uptr PC);
  41
  42 inline SymbolizedStack *getCallerLocation(uptr CallerPC) {
  43   CHECK(CallerPC);
  44   uptr PC = StackTrace::GetPreviousInstructionPc(CallerPC);
  45   return getSymbolizedLocation(PC);
  46 }
  47
  48 /// A location of some data within the program's address space.
  49 typedef uptr MemoryLocation;
  50
  51 /// \brief Location at which a diagnostic can be emitted. Either a
  52 /// SourceLocation, a MemoryLocation, or a SymbolizedStack.
  53 class Location {
  54 public:
  55   enum LocationKind { LK_Null, LK_Source, LK_Memory, LK_Symbolized };
  56
  57 private:
  58   LocationKind Kind;
  59   // FIXME: In C++11, wrap these in an anonymous union.
  60   SourceLocation SourceLoc;
  61   MemoryLocation MemoryLoc;
  62   const SymbolizedStack *SymbolizedLoc;  // Not owned.
  63
  64 public:
  65   Location() : Kind(LK_Null) {}
  66   Location(SourceLocation Loc) :
  67     Kind(LK_Source), SourceLoc(Loc) {}
  68   Location(MemoryLocation Loc) :
  69     Kind(LK_Memory), MemoryLoc(Loc) {}
  70   // SymbolizedStackHolder must outlive Location object.
  71   Location(const SymbolizedStackHolder &Stack) :
  72     Kind(LK_Symbolized), SymbolizedLoc(Stack.get()) {}
  73
  74   LocationKind getKind() const { return Kind; }
  75
  76   bool isSourceLocation() const { return Kind == LK_Source; }
  77   bool isMemoryLocation() const { return Kind == LK_Memory; }
  78   bool isSymbolizedStack() const { return Kind == LK_Symbolized; }
  79
  80   SourceLocation getSourceLocation() const {
  81     CHECK(isSourceLocation());
  82     return SourceLoc;
  83   }
  84   MemoryLocation getMemoryLocation() const {
  85     CHECK(isMemoryLocation());
  86     return MemoryLoc;
  87   }
  88   const SymbolizedStack *getSymbolizedStack() const {
  89     CHECK(isSymbolizedStack());
  90     return SymbolizedLoc;
  91   }
  92 };
  93
  94 /// A diagnostic severity level.
  95 enum DiagLevel {
  96   DL_Error, ///< An error.
  97   DL_Note   ///< A note, attached to a prior diagnostic.
  98 };
  99
 100 /// \brief Annotation for a range of locations in a diagnostic.
 101 class Range {
 102   Location Start, End;
 103   const char *Text;
 104
 105 public:
 106   Range() : Start(), End(), Text() {}
 107   Range(MemoryLocation Start, MemoryLocation End, const char *Text)
 108     : Start(Start), End(End), Text(Text) {}
 109   Location getStart() const { return Start; }
 110   Location getEnd() const { return End; }
 111   const char *getText() const { return Text; }
 112 };
 113
 114 /// \brief A C++ type name. Really just a strong typedef for 'const char*'.
 115 class TypeName {
 116   const char *Name;
 117 public:
 118   TypeName(const char *Name) : Name(Name) {}
 119   const char *getName() const { return Name; }
 120 };
 121
 122 /// \brief Representation of an in-flight diagnostic.
 123 ///
 124 /// Temporary \c Diag instances are created by the handler routines to
 125 /// accumulate arguments for a diagnostic. The destructor emits the diagnostic
 126 /// message.
 127 class Diag {
 128   /// The location at which the problem occurred.
 129   Location Loc;
 130
 131   /// The diagnostic level.
 132   DiagLevel Level;
 133
 134   /// The message which will be emitted, with %0, %1, ... placeholders for
 135   /// arguments.
 136   const char *Message;
 137
 138 public:
 139   /// Kinds of arguments, corresponding to members of \c Arg's union.
 140   enum ArgKind {
 141     AK_String, ///< A string argument, displayed as-is.
 142     AK_TypeName,///< A C++ type name, possibly demangled before display.
 143     AK_UInt,   ///< An unsigned integer argument.
 144     AK_SInt,   ///< A signed integer argument.
 145     AK_Float,  ///< A floating-point argument.
 146     AK_Pointer ///< A pointer argument, displayed in hexadecimal.
 147   };
 148
 149   /// An individual diagnostic message argument.
 150   struct Arg {
 151     Arg() {}
 152     Arg(const char *String) : Kind(AK_String), String(String) {}
 153     Arg(TypeName TN) : Kind(AK_TypeName), String(TN.getName()) {}
 154     Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}
 155     Arg(SIntMax SInt) : Kind(AK_SInt), SInt(SInt) {}
 156     Arg(FloatMax Float) : Kind(AK_Float), Float(Float) {}
 157     Arg(const void *Pointer) : Kind(AK_Pointer), Pointer(Pointer) {}
 158
 159     ArgKind Kind;
 160     union {
 161       const char *String;
 162       UIntMax UInt;
 163       SIntMax SInt;
 164       FloatMax Float;
 165       const void *Pointer;
 166     };
 167   };
 168
 169 private:
 170   static const unsigned MaxArgs = 5;
 171   static const unsigned MaxRanges = 1;
 172
 173   /// The arguments which have been added to this diagnostic so far.
 174   Arg Args[MaxArgs];
 175   unsigned NumArgs;
 176
 177   /// The ranges which have been added to this diagnostic so far.
 178   Range Ranges[MaxRanges];
 179   unsigned NumRanges;
 180
 181   Diag &AddArg(Arg A) {
 182     CHECK(NumArgs != MaxArgs);
 183     Args[NumArgs++] = A;
 184     return *this;
 185   }
 186
 187   Diag &AddRange(Range A) {
 188     CHECK(NumRanges != MaxRanges);
 189     Ranges[NumRanges++] = A;
 190     return *this;
 191   }
 192
 193   /// \c Diag objects are not copyable.
 194   Diag(const Diag &); // NOT IMPLEMENTED
 195   Diag &operator=(const Diag &);
 196
 197 public:
 198   Diag(Location Loc, DiagLevel Level, const char *Message)
 199     : Loc(Loc), Level(Level), Message(Message), NumArgs(0), NumRanges(0) {}
 200   ~Diag();
 201
 202   Diag &operator<<(const char *Str) { return AddArg(Str); }
 203   Diag &operator<<(TypeName TN) { return AddArg(TN); }
 204   Diag &operator<<(unsigned long long V) { return AddArg(UIntMax(V)); }
 205   Diag &operator<<(const void *V) { return AddArg(V); }
 206   Diag &operator<<(const TypeDescriptor &V);
 207   Diag &operator<<(const Value &V);
 208   Diag &operator<<(const Range &R) { return AddRange(R); }
 209 };
 210
 211 struct ReportOptions {
 212   /// If DieAfterReport is specified, UBSan will terminate the program after the
 213   /// report is printed.
 214   bool DieAfterReport;
 215   /// pc/bp are used to unwind the stack trace.
 216   uptr pc;
 217   uptr bp;
 218 };
 219
 220 enum class ErrorType {
 221 #define UBSAN_CHECK(Name, SummaryKind, FlagName) Name,
 222 #include "ubsan_checks.inc"
 223 #undef UBSAN_CHECK
 224 };
 225
 226 #define GET_REPORT_OPTIONS(die_after_report) \
 227     GET_CALLER_PC_BP; \
 228     ReportOptions Opts = {die_after_report, pc, bp}
 229
 230 /// \brief Instantiate this class before printing diagnostics in the error
 231 /// report. This class ensures that reports from different threads and from
 232 /// different sanitizers won't be mixed.
 233 class ScopedReport {
 234   ReportOptions Opts;
 235   Location SummaryLoc;
 236   ErrorType Type;
 237
 238 public:
 239   ScopedReport(ReportOptions Opts, Location SummaryLoc,
 240                ErrorType Type = ErrorType::GenericUB);
 241   void setErrorType(ErrorType T) { Type = T; }
 242   ~ScopedReport();
 243 };
 244
 245 void InitializeSuppressions();
 246 bool IsVptrCheckSuppressed(const char *TypeName);
 247
 248 } // namespace __ubsan
 249
 250 #endif // UBSAN_DIAG_H