thirdparty/scummvm
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COMMON: Restrict use of data access helpers

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The data access helpers as written are effectively little-endian
when reading from spans with value_types larger than the size of
the requested data (e.g. more than 1 byte for getting a char,
more than 2 bytes for getting a uint16, etc.). For now, restrict
use of these methods at compile time until someone actually needs
to read memory that way.
This commit is contained in:
Colin Snover 2017-01-07 15:44:06 -06:00
parent 2558b20cdd
commit b2796e65aa
1 changed files with 14 additions and 2 deletions
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16
common/span.h
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@ -314,62 +314,74 @@ public:
}
inline int8 getInt8At(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) == sizeof(uint8), int8_can_only_be_read_from_byte_or_char_spans);
return (int8)getUint8At(index);
}
inline uint8 getUint8At(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) == sizeof(uint8), uint8_can_only_be_read_from_byte_or_char_spans);
impl().validate(index, sizeof(uint8));
return (uint8)impl().data()[index];
}
inline int16 getInt16BEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint16), int16_can_only_be_read_from_int16_or_smaller_spans);
return (int16)impl().getUint16BEAt(index);
}
inline int16 getInt16LEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint16), int16_can_only_be_read_from_int16_or_smaller_spans);
return (int16)impl().getUint16LEAt(index);
}
inline uint16 getUint16BEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint16), uint16_can_only_be_read_from_int16_or_smaller_spans);
impl().validate(index, sizeof(uint16));
return READ_BE_UINT16(impl().data() + index);
}
inline uint16 getUint16LEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint16), uint16_can_only_be_read_from_int16_or_smaller_spans);
impl().validate(index, sizeof(uint16));
return READ_LE_UINT16(impl().data() + index);
}
inline uint32 getUint24LEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= 3, uint24_can_only_be_read_from_int24_or_smaller_spans);
impl().validate(index, 3);
return READ_LE_UINT24(impl().data() + index);
}
inline uint32 getUint32At(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint32), uint32_can_only_be_read_from_int32_or_smaller_spans);
impl().validate(index, sizeof(uint32));
return READ_UINT32(impl().data() + index);
}
inline int32 getInt32BEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint32), int32_can_only_be_read_from_int32_or_smaller_spans);
return (int32)impl().getUint32BEAt(index);
}
inline int32 getInt32LEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint32), int32_can_only_be_read_from_int32_or_smaller_spans);
return (int32)impl().getUint32LEAt(index);
}
inline uint32 getUint32BEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint32), uint32_can_only_be_read_from_int32_or_smaller_spans);
impl().validate(index, sizeof(uint32));
return READ_BE_UINT32(impl().data() + index);
}
inline uint32 getUint32LEAt(const index_type index) const {
STATIC_ASSERT(sizeof(value_type) <= sizeof(uint32), uint32_can_only_be_read_from_int32_or_smaller_spans);
impl().validate(index, sizeof(uint32));
return READ_LE_UINT32(impl().data() + index);
}
inline String getStringAt(const index_type index, size_type numEntries = kSpanMaxSize) const {
STATIC_ASSERT(sizeof(value_type) == 1, strings_can_only_be_read_from_byte_or_char_arrays);
STATIC_ASSERT(sizeof(value_type) == sizeof(char), strings_can_only_be_read_from_byte_or_char_spans);
const char *string = (const char *)impl().data();
if (numEntries == kSpanMaxSize) {
@ -410,7 +422,7 @@ public:
}
impl().validate(index, numEntries * sizeof(value_type));
return MemoryReadStream(impl().data() + index, numEntries, DisposeAfterUse::NO);
return MemoryReadStream(impl().data() + index, numEntries * sizeof(value_type), DisposeAfterUse::NO);
}
#pragma mark -