Author: Jonas Devlieghere Date: 2022-02-15T20:38:25-08:00 New Revision: 920146316da1e55017d46cfd62be783419da03d5
URL: https://github.com/llvm/llvm-project/commit/920146316da1e55017d46cfd62be783419da03d5 DIFF: https://github.com/llvm/llvm-project/commit/920146316da1e55017d46cfd62be783419da03d5.diff LOG: [lldb] Don't rely on wrapping in PutRawBytes/PutBytesAsRawHex8 I was looking at Stream::PutRawBytes and thought I spotted a bug because both loops are using `i < src_len` as the loop condition despite them iterating in opposite directions. On closer inspection, the existing code is correct, because it relies on well-defined unsigned integer wrapping. Correct doesn't mean readable, so this patch changes the loop condition to compare against 0 when decrementing i while still covering the edge case of src_len potentially being 0 itself. Differential revision: https://reviews.llvm.org/D119857 Added: Modified: lldb/source/Utility/Stream.cpp lldb/unittests/Utility/StreamTest.cpp Removed: ################################################################################ diff --git a/lldb/source/Utility/Stream.cpp b/lldb/source/Utility/Stream.cpp index a1e2de9da4d98..b0f085418023f 100644 --- a/lldb/source/Utility/Stream.cpp +++ b/lldb/source/Utility/Stream.cpp @@ -344,8 +344,8 @@ size_t Stream::PutRawBytes(const void *s, size_t src_len, for (size_t i = 0; i < src_len; ++i) _PutHex8(src[i], false); } else { - for (size_t i = src_len - 1; i < src_len; --i) - _PutHex8(src[i], false); + for (size_t i = src_len; i > 0; --i) + _PutHex8(src[i - 1], false); } if (!binary_was_set) m_flags.Clear(eBinary); @@ -357,6 +357,7 @@ size_t Stream::PutBytesAsRawHex8(const void *s, size_t src_len, ByteOrder src_byte_order, ByteOrder dst_byte_order) { ByteDelta delta(*this); + if (src_byte_order == eByteOrderInvalid) src_byte_order = m_byte_order; @@ -370,8 +371,8 @@ size_t Stream::PutBytesAsRawHex8(const void *s, size_t src_len, for (size_t i = 0; i < src_len; ++i) _PutHex8(src[i], false); } else { - for (size_t i = src_len - 1; i < src_len; --i) - _PutHex8(src[i], false); + for (size_t i = src_len; i > 0; --i) + _PutHex8(src[i - 1], false); } if (binary_is_set) m_flags.Set(eBinary); diff --git a/lldb/unittests/Utility/StreamTest.cpp b/lldb/unittests/Utility/StreamTest.cpp index 940d49fdfdb7d..959097dc52f98 100644 --- a/lldb/unittests/Utility/StreamTest.cpp +++ b/lldb/unittests/Utility/StreamTest.cpp @@ -504,6 +504,30 @@ TEST_F(StreamTest, PutRawBytesToMixedEndian) { #endif } +TEST_F(StreamTest, PutRawBytesZeroLenght) { + uint32_t value = 0x12345678; + + s.PutRawBytes(static_cast<void *>(&value), 0, hostByteOrder, + lldb::eByteOrderLittle); + EXPECT_EQ(0U, s.GetWrittenBytes()); + + s.PutRawBytes(static_cast<void *>(&value), 0, hostByteOrder, + lldb::eByteOrderBig); + EXPECT_EQ(0U, s.GetWrittenBytes()); +} + +TEST_F(StreamTest, PutBytesAsRawHex8ZeroLenght) { + uint32_t value = 0x12345678; + + s.PutBytesAsRawHex8(static_cast<void *>(&value), 0, hostByteOrder, + lldb::eByteOrderLittle); + EXPECT_EQ(0U, s.GetWrittenBytes()); + + s.PutBytesAsRawHex8(static_cast<void *>(&value), 0, hostByteOrder, + lldb::eByteOrderBig); + EXPECT_EQ(0U, s.GetWrittenBytes()); +} + // ULEB128 support for binary streams. TEST_F(BinaryStreamTest, PutULEB128OneByte) { _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
