1 //===-- ubsan_value.cc ----------------------------------------------------===// 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 // Representation of a runtime value, as marshaled from the generated code to 11 // the ubsan runtime. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #include "ubsan_value.h" 16 #include "sanitizer_common/sanitizer_common.h" 17 #include "sanitizer_common/sanitizer_libc.h" 18 19 using namespace __ubsan; 20 getSIntValue() const21SIntMax Value::getSIntValue() const { 22 CHECK(getType().isSignedIntegerTy()); 23 if (isInlineInt()) { 24 // Val was zero-extended to ValueHandle. Sign-extend from original width 25 // to SIntMax. 26 const unsigned ExtraBits = 27 sizeof(SIntMax) * 8 - getType().getIntegerBitWidth(); 28 return SIntMax(Val) << ExtraBits >> ExtraBits; 29 } 30 if (getType().getIntegerBitWidth() == 64) 31 return *reinterpret_cast<s64*>(Val); 32 #if HAVE_INT128_T 33 if (getType().getIntegerBitWidth() == 128) 34 return *reinterpret_cast<s128*>(Val); 35 #else 36 if (getType().getIntegerBitWidth() == 128) 37 UNREACHABLE("libclang_rt.ubsan was built without __int128 support"); 38 #endif 39 UNREACHABLE("unexpected bit width"); 40 } 41 getUIntValue() const42UIntMax Value::getUIntValue() const { 43 CHECK(getType().isUnsignedIntegerTy()); 44 if (isInlineInt()) 45 return Val; 46 if (getType().getIntegerBitWidth() == 64) 47 return *reinterpret_cast<u64*>(Val); 48 #if HAVE_INT128_T 49 if (getType().getIntegerBitWidth() == 128) 50 return *reinterpret_cast<u128*>(Val); 51 #else 52 if (getType().getIntegerBitWidth() == 128) 53 UNREACHABLE("libclang_rt.ubsan was built without __int128 support"); 54 #endif 55 UNREACHABLE("unexpected bit width"); 56 } 57 getPositiveIntValue() const58UIntMax Value::getPositiveIntValue() const { 59 if (getType().isUnsignedIntegerTy()) 60 return getUIntValue(); 61 SIntMax Val = getSIntValue(); 62 CHECK(Val >= 0); 63 return Val; 64 } 65 66 /// Get the floating-point value of this object, extended to a long double. 67 /// These are always passed by address (our calling convention doesn't allow 68 /// them to be passed in floating-point registers, so this has little cost). getFloatValue() const69FloatMax Value::getFloatValue() const { 70 CHECK(getType().isFloatTy()); 71 if (isInlineFloat()) { 72 switch (getType().getFloatBitWidth()) { 73 #if 0 74 // FIXME: OpenCL / NEON 'half' type. LLVM can't lower the conversion 75 // from '__fp16' to 'long double'. 76 case 16: { 77 __fp16 Value; 78 internal_memcpy(&Value, &Val, 4); 79 return Value; 80 } 81 #endif 82 case 32: { 83 float Value; 84 internal_memcpy(&Value, &Val, 4); 85 return Value; 86 } 87 case 64: { 88 double Value; 89 internal_memcpy(&Value, &Val, 8); 90 return Value; 91 } 92 } 93 } else { 94 switch (getType().getFloatBitWidth()) { 95 case 64: return *reinterpret_cast<double*>(Val); 96 case 80: return *reinterpret_cast<long double*>(Val); 97 case 96: return *reinterpret_cast<long double*>(Val); 98 case 128: return *reinterpret_cast<long double*>(Val); 99 } 100 } 101 UNREACHABLE("unexpected floating point bit width"); 102 } 103