[LLDB] Replacing use of ul suffix in GetMaxU64Bitfield since it not guarenteed to be 64 bit

GetMaxU64Bitfield(...) uses the ul suffix but we require a 64 bit unsigned integer and ul could be 32 bit. So this replacing it with a explicit cast and refactors the code around it to use an early exit.

Differential Revision: https://reviews.llvm.org/D70992
This commit is contained in:
shafik 2019-12-05 09:28:08 -08:00
parent ef7267def6
commit fffd70291e
2 changed files with 31 additions and 12 deletions

View File

@ -577,18 +577,28 @@ int64_t DataExtractor::GetMaxS64(offset_t *offset_ptr, size_t byte_size) const {
uint64_t DataExtractor::GetMaxU64Bitfield(offset_t *offset_ptr, size_t size,
uint32_t bitfield_bit_size,
uint32_t bitfield_bit_offset) const {
assert(bitfield_bit_size <= 64);
uint64_t uval64 = GetMaxU64(offset_ptr, size);
if (bitfield_bit_size > 0) {
if (bitfield_bit_size == 0)
return uval64;
int32_t lsbcount = bitfield_bit_offset;
if (m_byte_order == eByteOrderBig)
lsbcount = size * 8 - bitfield_bit_offset - bitfield_bit_size;
if (lsbcount > 0)
uval64 >>= lsbcount;
uint64_t bitfield_mask = ((1ul << bitfield_bit_size) - 1);
uint64_t bitfield_mask =
(bitfield_bit_size == 64
? std::numeric_limits<uint64_t>::max()
: ((static_cast<uint64_t>(1) << bitfield_bit_size) - 1));
if (!bitfield_mask && bitfield_bit_offset == 0 && bitfield_bit_size == 64)
return uval64;
uval64 &= bitfield_mask;
}
return uval64;
}

View File

@ -13,7 +13,7 @@
using namespace lldb_private;
TEST(DataExtractorTest, GetBitfield) {
uint8_t buffer[] = {0x01, 0x23, 0x45, 0x67};
uint8_t buffer[] = {0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF};
DataExtractor LE(buffer, sizeof(buffer), lldb::eByteOrderLittle,
sizeof(void *));
DataExtractor BE(buffer, sizeof(buffer), lldb::eByteOrderBig, sizeof(void *));
@ -24,6 +24,15 @@ TEST(DataExtractorTest, GetBitfield) {
ASSERT_EQ(buffer[1], LE.GetMaxU64Bitfield(&offset, sizeof(buffer), 8, 8));
offset = 0;
ASSERT_EQ(buffer[1], BE.GetMaxU64Bitfield(&offset, sizeof(buffer), 8, 8));
offset = 0;
ASSERT_EQ(static_cast<uint64_t>(0x0123456789ABCDEF),
BE.GetMaxU64Bitfield(&offset, sizeof(buffer), 64, 0));
offset = 0;
ASSERT_EQ(static_cast<uint64_t>(0x01234567),
BE.GetMaxU64Bitfield(&offset, sizeof(buffer), 32, 0));
offset = 0;
ASSERT_EQ(static_cast<uint64_t>(0x012345678),
BE.GetMaxU64Bitfield(&offset, sizeof(buffer), 36, 0));
offset = 0;
ASSERT_EQ(int8_t(buffer[1]),