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      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 
     18 namespace __ubsan {
     19 
     20 /// \brief A location within a loaded module in the program. These are used when
     21 /// the location can't be resolved to a SourceLocation.
     22 class ModuleLocation {
     23   const char *ModuleName;
     24   uptr Offset;
     25 
     26 public:
     27   ModuleLocation() : ModuleName(0), Offset(0) {}
     28   ModuleLocation(const char *ModuleName, uptr Offset)
     29     : ModuleName(ModuleName), Offset(Offset) {}
     30   const char *getModuleName() const { return ModuleName; }
     31   uptr getOffset() const { return Offset; }
     32 };
     33 
     34 /// A location of some data within the program's address space.
     35 typedef uptr MemoryLocation;
     36 
     37 /// \brief Location at which a diagnostic can be emitted. Either a
     38 /// SourceLocation, a ModuleLocation, or a MemoryLocation.
     39 class Location {
     40 public:
     41   enum LocationKind { LK_Null, LK_Source, LK_Module, LK_Memory };
     42 
     43 private:
     44   LocationKind Kind;
     45   // FIXME: In C++11, wrap these in an anonymous union.
     46   SourceLocation SourceLoc;
     47   ModuleLocation ModuleLoc;
     48   MemoryLocation MemoryLoc;
     49 
     50 public:
     51   Location() : Kind(LK_Null) {}
     52   Location(SourceLocation Loc) :
     53     Kind(LK_Source), SourceLoc(Loc) {}
     54   Location(ModuleLocation Loc) :
     55     Kind(LK_Module), ModuleLoc(Loc) {}
     56   Location(MemoryLocation Loc) :
     57     Kind(LK_Memory), MemoryLoc(Loc) {}
     58 
     59   LocationKind getKind() const { return Kind; }
     60 
     61   bool isSourceLocation() const { return Kind == LK_Source; }
     62   bool isModuleLocation() const { return Kind == LK_Module; }
     63   bool isMemoryLocation() const { return Kind == LK_Memory; }
     64 
     65   SourceLocation getSourceLocation() const {
     66     CHECK(isSourceLocation());
     67     return SourceLoc;
     68   }
     69   ModuleLocation getModuleLocation() const {
     70     CHECK(isModuleLocation());
     71     return ModuleLoc;
     72   }
     73   MemoryLocation getMemoryLocation() const {
     74     CHECK(isMemoryLocation());
     75     return MemoryLoc;
     76   }
     77 };
     78 
     79 /// Try to obtain a location for the caller. This might fail, and produce either
     80 /// an invalid location or a module location for the caller.
     81 Location getCallerLocation(uptr CallerLoc = GET_CALLER_PC());
     82 
     83 /// A diagnostic severity level.
     84 enum DiagLevel {
     85   DL_Error, ///< An error.
     86   DL_Note   ///< A note, attached to a prior diagnostic.
     87 };
     88 
     89 /// \brief Annotation for a range of locations in a diagnostic.
     90 class Range {
     91   Location Start, End;
     92   const char *Text;
     93 
     94 public:
     95   Range() : Start(), End(), Text() {}
     96   Range(MemoryLocation Start, MemoryLocation End, const char *Text)
     97     : Start(Start), End(End), Text(Text) {}
     98   Location getStart() const { return Start; }
     99   Location getEnd() const { return End; }
    100   const char *getText() const { return Text; }
    101 };
    102 
    103 /// \brief A mangled C++ name. Really just a strong typedef for 'const char*'.
    104 class MangledName {
    105   const char *Name;
    106 public:
    107   MangledName(const char *Name) : Name(Name) {}
    108   const char *getName() const { return Name; }
    109 };
    110 
    111 /// \brief Representation of an in-flight diagnostic.
    112 ///
    113 /// Temporary \c Diag instances are created by the handler routines to
    114 /// accumulate arguments for a diagnostic. The destructor emits the diagnostic
    115 /// message.
    116 class Diag {
    117   /// The location at which the problem occurred.
    118   Location Loc;
    119 
    120   /// The diagnostic level.
    121   DiagLevel Level;
    122 
    123   /// The message which will be emitted, with %0, %1, ... placeholders for
    124   /// arguments.
    125   const char *Message;
    126 
    127 public:
    128   /// Kinds of arguments, corresponding to members of \c Arg's union.
    129   enum ArgKind {
    130     AK_String, ///< A string argument, displayed as-is.
    131     AK_Mangled,///< A C++ mangled name, demangled before display.
    132     AK_UInt,   ///< An unsigned integer argument.
    133     AK_SInt,   ///< A signed integer argument.
    134     AK_Float,  ///< A floating-point argument.
    135     AK_Pointer ///< A pointer argument, displayed in hexadecimal.
    136   };
    137 
    138   /// An individual diagnostic message argument.
    139   struct Arg {
    140     Arg() {}
    141     Arg(const char *String) : Kind(AK_String), String(String) {}
    142     Arg(MangledName MN) : Kind(AK_Mangled), String(MN.getName()) {}
    143     Arg(UIntMax UInt) : Kind(AK_UInt), UInt(UInt) {}
    144     Arg(SIntMax SInt) : Kind(AK_SInt), SInt(SInt) {}
    145     Arg(FloatMax Float) : Kind(AK_Float), Float(Float) {}
    146     Arg(const void *Pointer) : Kind(AK_Pointer), Pointer(Pointer) {}
    147 
    148     ArgKind Kind;
    149     union {
    150       const char *String;
    151       UIntMax UInt;
    152       SIntMax SInt;
    153       FloatMax Float;
    154       const void *Pointer;
    155     };
    156   };
    157 
    158 private:
    159   static const unsigned MaxArgs = 5;
    160   static const unsigned MaxRanges = 1;
    161 
    162   /// The arguments which have been added to this diagnostic so far.
    163   Arg Args[MaxArgs];
    164   unsigned NumArgs;
    165 
    166   /// The ranges which have been added to this diagnostic so far.
    167   Range Ranges[MaxRanges];
    168   unsigned NumRanges;
    169 
    170   Diag &AddArg(Arg A) {
    171     CHECK(NumArgs != MaxArgs);
    172     Args[NumArgs++] = A;
    173     return *this;
    174   }
    175 
    176   Diag &AddRange(Range A) {
    177     CHECK(NumRanges != MaxRanges);
    178     Ranges[NumRanges++] = A;
    179     return *this;
    180   }
    181 
    182   /// \c Diag objects are not copyable.
    183   Diag(const Diag &); // NOT IMPLEMENTED
    184   Diag &operator=(const Diag &);
    185 
    186 public:
    187   Diag(Location Loc, DiagLevel Level, const char *Message)
    188     : Loc(Loc), Level(Level), Message(Message), NumArgs(0), NumRanges(0) {}
    189   ~Diag();
    190 
    191   Diag &operator<<(const char *Str) { return AddArg(Str); }
    192   Diag &operator<<(MangledName MN) { return AddArg(MN); }
    193   Diag &operator<<(unsigned long long V) { return AddArg(UIntMax(V)); }
    194   Diag &operator<<(const void *V) { return AddArg(V); }
    195   Diag &operator<<(const TypeDescriptor &V);
    196   Diag &operator<<(const Value &V);
    197   Diag &operator<<(const Range &R) { return AddRange(R); }
    198 };
    199 
    200 } // namespace __ubsan
    201 
    202 #endif // UBSAN_DIAG_H
    203