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Diffstat (limited to 'contrib/llvm/lib/Support/DataExtractor.cpp')
-rw-r--r-- | contrib/llvm/lib/Support/DataExtractor.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/DataExtractor.cpp b/contrib/llvm/lib/Support/DataExtractor.cpp new file mode 100644 index 0000000..b946c1d --- /dev/null +++ b/contrib/llvm/lib/Support/DataExtractor.cpp @@ -0,0 +1,175 @@ +//===-- DataExtractor.cpp -------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Support/DataExtractor.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/Host.h" +#include "llvm/Support/SwapByteOrder.h" +using namespace llvm; + +template <typename T> +static T getU(uint32_t *offset_ptr, const DataExtractor *de, + bool isLittleEndian, const char *Data) { + T val = 0; + uint32_t offset = *offset_ptr; + if (de->isValidOffsetForDataOfSize(offset, sizeof(val))) { + std::memcpy(&val, &Data[offset], sizeof(val)); + if (sys::isLittleEndianHost() != isLittleEndian) + val = sys::SwapByteOrder(val); + + // Advance the offset + *offset_ptr += sizeof(val); + } + return val; +} + +template <typename T> +static T *getUs(uint32_t *offset_ptr, T *dst, uint32_t count, + const DataExtractor *de, bool isLittleEndian, const char *Data){ + uint32_t offset = *offset_ptr; + + if (count > 0 && de->isValidOffsetForDataOfSize(offset, sizeof(*dst)*count)) { + for (T *value_ptr = dst, *end = dst + count; value_ptr != end; + ++value_ptr, offset += sizeof(*dst)) + *value_ptr = getU<T>(offset_ptr, de, isLittleEndian, Data); + // Advance the offset + *offset_ptr = offset; + // Return a non-NULL pointer to the converted data as an indicator of + // success + return dst; + } + return NULL; +} + +uint8_t DataExtractor::getU8(uint32_t *offset_ptr) const { + return getU<uint8_t>(offset_ptr, this, IsLittleEndian, Data.data()); +} + +uint8_t * +DataExtractor::getU8(uint32_t *offset_ptr, uint8_t *dst, uint32_t count) const { + return getUs<uint8_t>(offset_ptr, dst, count, this, IsLittleEndian, + Data.data()); +} + + +uint16_t DataExtractor::getU16(uint32_t *offset_ptr) const { + return getU<uint16_t>(offset_ptr, this, IsLittleEndian, Data.data()); +} + +uint16_t *DataExtractor::getU16(uint32_t *offset_ptr, uint16_t *dst, + uint32_t count) const { + return getUs<uint16_t>(offset_ptr, dst, count, this, IsLittleEndian, + Data.data()); +} + +uint32_t DataExtractor::getU32(uint32_t *offset_ptr) const { + return getU<uint32_t>(offset_ptr, this, IsLittleEndian, Data.data()); +} + +uint32_t *DataExtractor::getU32(uint32_t *offset_ptr, uint32_t *dst, + uint32_t count) const { + return getUs<uint32_t>(offset_ptr, dst, count, this, IsLittleEndian, + Data.data());; +} + +uint64_t DataExtractor::getU64(uint32_t *offset_ptr) const { + return getU<uint64_t>(offset_ptr, this, IsLittleEndian, Data.data()); +} + +uint64_t *DataExtractor::getU64(uint32_t *offset_ptr, uint64_t *dst, + uint32_t count) const { + return getUs<uint64_t>(offset_ptr, dst, count, this, IsLittleEndian, + Data.data()); +} + +uint64_t +DataExtractor::getUnsigned(uint32_t *offset_ptr, uint32_t byte_size) const { + switch (byte_size) { + case 1: + return getU8(offset_ptr); + case 2: + return getU16(offset_ptr); + case 4: + return getU32(offset_ptr); + case 8: + return getU64(offset_ptr); + } + llvm_unreachable("getUnsigned unhandled case!"); +} + +int64_t +DataExtractor::getSigned(uint32_t *offset_ptr, uint32_t byte_size) const { + switch (byte_size) { + case 1: + return (int8_t)getU8(offset_ptr); + case 2: + return (int16_t)getU16(offset_ptr); + case 4: + return (int32_t)getU32(offset_ptr); + case 8: + return (int64_t)getU64(offset_ptr); + } + llvm_unreachable("getSigned unhandled case!"); +} + +const char *DataExtractor::getCStr(uint32_t *offset_ptr) const { + uint32_t offset = *offset_ptr; + StringRef::size_type pos = Data.find('\0', offset); + if (pos != StringRef::npos) { + *offset_ptr = pos + 1; + return Data.data() + offset; + } + return NULL; +} + +uint64_t DataExtractor::getULEB128(uint32_t *offset_ptr) const { + uint64_t result = 0; + if (Data.empty()) + return 0; + + unsigned shift = 0; + uint32_t offset = *offset_ptr; + uint8_t byte = 0; + + while (isValidOffset(offset)) { + byte = Data[offset++]; + result |= (byte & 0x7f) << shift; + shift += 7; + if ((byte & 0x80) == 0) + break; + } + + *offset_ptr = offset; + return result; +} + +int64_t DataExtractor::getSLEB128(uint32_t *offset_ptr) const { + int64_t result = 0; + if (Data.empty()) + return 0; + + unsigned shift = 0; + uint32_t offset = *offset_ptr; + uint8_t byte = 0; + + while (isValidOffset(offset)) { + byte = Data[offset++]; + result |= (byte & 0x7f) << shift; + shift += 7; + if ((byte & 0x80) == 0) + break; + } + + // Sign bit of byte is 2nd high order bit (0x40) + if (shift < 64 && (byte & 0x40)) + result |= -(1 << shift); + + *offset_ptr = offset; + return result; +} |