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//===-- ubsan_value.h -------------------------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// Representation of data which is passed from the compiler-generated calls into
// the ubsan runtime.
// For now, only support Linux, FreeBSD and Darwin. Other platforms should
// be easy to add, and probably work as-is.
#if !defined(__linux__) && !defined(__FreeBSD__) && !defined(__APPLE__)
#error "UBSan not supported for this platform!"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
// FIXME: Move this out to a config header.
#if __SIZEOF_INT128__
__extension__ typedef __int128 s128;
__extension__ typedef unsigned __int128 u128;
#define HAVE_INT128_T 1
#define HAVE_INT128_T 0
namespace __ubsan {
/// \brief Largest integer types we support.
#if HAVE_INT128_T
typedef s128 SIntMax;
typedef u128 UIntMax;
typedef s64 SIntMax;
typedef u64 UIntMax;
/// \brief Largest floating-point type we support.
typedef long double FloatMax;
/// \brief A description of a source location. This corresponds to Clang's
/// \c PresumedLoc type.
class SourceLocation {
const char *Filename;
u32 Line;
u32 Column;
SourceLocation() : Filename(), Line(), Column() {}
SourceLocation(const char *Filename, unsigned Line, unsigned Column)
: Filename(Filename), Line(Line), Column(Column) {}
/// \brief Determine whether the source location is known.
bool isInvalid() const { return !Filename; }
/// \brief Atomically acquire a copy, disabling original in-place.
/// Exactly one call to acquire() returns a copy that isn't disabled.
SourceLocation acquire() {
u32 OldColumn = __sanitizer::atomic_exchange(
(__sanitizer::atomic_uint32_t *)&Column, ~u32(0),
return SourceLocation(Filename, Line, OldColumn);
/// \brief Determine if this Location has been disabled.
/// Disabled SourceLocations are invalid to use.
bool isDisabled() {
return Column == ~u32(0);
/// \brief Get the presumed filename for the source location.
const char *getFilename() const { return Filename; }
/// \brief Get the presumed line number.
unsigned getLine() const { return Line; }
/// \brief Get the column within the presumed line.
unsigned getColumn() const { return Column; }
/// \brief A description of a type.
class TypeDescriptor {
/// A value from the \c Kind enumeration, specifying what flavor of type we
/// have.
u16 TypeKind;
/// A \c Type-specific value providing information which allows us to
/// interpret the meaning of a ValueHandle of this type.
u16 TypeInfo;
/// The name of the type follows, in a format suitable for including in
/// diagnostics.
char TypeName[1];
enum Kind {
/// An integer type. Lowest bit is 1 for a signed value, 0 for an unsigned
/// value. Remaining bits are log_2(bit width). The value representation is
/// the integer itself if it fits into a ValueHandle, and a pointer to the
/// integer otherwise.
TK_Integer = 0x0000,
/// A floating-point type. Low 16 bits are bit width. The value
/// representation is that of bitcasting the floating-point value to an
/// integer type.
TK_Float = 0x0001,
/// Any other type. The value representation is unspecified.
TK_Unknown = 0xffff
const char *getTypeName() const { return TypeName; }
Kind getKind() const {
return static_cast<Kind>(TypeKind);
bool isIntegerTy() const { return getKind() == TK_Integer; }
bool isSignedIntegerTy() const {
return isIntegerTy() && (TypeInfo & 1);
bool isUnsignedIntegerTy() const {
return isIntegerTy() && !(TypeInfo & 1);
unsigned getIntegerBitWidth() const {
return 1 << (TypeInfo >> 1);
bool isFloatTy() const { return getKind() == TK_Float; }
unsigned getFloatBitWidth() const {
return TypeInfo;
/// \brief An opaque handle to a value.
typedef uptr ValueHandle;
/// \brief Representation of an operand value provided by the instrumented code.
/// This is a combination of a TypeDescriptor (which is emitted as constant data
/// as an operand to a handler function) and a ValueHandle (which is passed at
/// runtime when a check failure occurs).
class Value {
/// The type of the value.
const TypeDescriptor &Type;
/// The encoded value itself.
ValueHandle Val;
/// Is \c Val a (zero-extended) integer?
bool isInlineInt() const {
const unsigned InlineBits = sizeof(ValueHandle) * 8;
const unsigned Bits = getType().getIntegerBitWidth();
return Bits <= InlineBits;
/// Is \c Val a (zero-extended) integer representation of a float?
bool isInlineFloat() const {
const unsigned InlineBits = sizeof(ValueHandle) * 8;
const unsigned Bits = getType().getFloatBitWidth();
return Bits <= InlineBits;
Value(const TypeDescriptor &Type, ValueHandle Val) : Type(Type), Val(Val) {}
const TypeDescriptor &getType() const { return Type; }
/// \brief Get this value as a signed integer.
SIntMax getSIntValue() const;
/// \brief Get this value as an unsigned integer.
UIntMax getUIntValue() const;
/// \brief Decode this value, which must be a positive or unsigned integer.
UIntMax getPositiveIntValue() const;
/// Is this an integer with value -1?
bool isMinusOne() const {
return getType().isSignedIntegerTy() && getSIntValue() == -1;
/// Is this a negative integer?
bool isNegative() const {
return getType().isSignedIntegerTy() && getSIntValue() < 0;
/// \brief Get this value as a floating-point quantity.
FloatMax getFloatValue() const;
} // namespace __ubsan
#endif // UBSAN_VALUE_H