Author: Raphael Isemann Date: 2021-05-19T21:37:10+02:00 New Revision: 4b074b49be206306330076b9fa40632ef1960823
URL: https://github.com/llvm/llvm-project/commit/4b074b49be206306330076b9fa40632ef1960823 DIFF: https://github.com/llvm/llvm-project/commit/4b074b49be206306330076b9fa40632ef1960823.diff LOG: [lldb] Fix UB in half2float and add some more tests. The added DumpDataExtractorTest uncovered that this is lshifting a negative integer which upsets ubsan and breaks the sanitizer bot. This patch just changes the variable we shift to be unsigned and adds a bunch of tests to make sure this function does what it promises. Added: Modified: lldb/source/Core/DumpDataExtractor.cpp lldb/unittests/Core/DumpDataExtractorTest.cpp Removed: ################################################################################ diff --git a/lldb/source/Core/DumpDataExtractor.cpp b/lldb/source/Core/DumpDataExtractor.cpp index ec44e3481c1e5..34c9353c9feaa 100644 --- a/lldb/source/Core/DumpDataExtractor.cpp +++ b/lldb/source/Core/DumpDataExtractor.cpp @@ -52,7 +52,9 @@ static float half2float(uint16_t half) { float f; uint32_t u; } u; - int32_t v = (int16_t)half; + // Sign extend to 4 byte. + int32_t sign_extended = static_cast<int16_t>(half); + uint32_t v = static_cast<uint32_t>(sign_extended); if (0 == (v & 0x7c00)) { u.u = v & 0x80007FFFU; diff --git a/lldb/unittests/Core/DumpDataExtractorTest.cpp b/lldb/unittests/Core/DumpDataExtractorTest.cpp index c4ec5f2e9a35b..05cd13add1e99 100644 --- a/lldb/unittests/Core/DumpDataExtractorTest.cpp +++ b/lldb/unittests/Core/DumpDataExtractorTest.cpp @@ -174,8 +174,30 @@ TEST(DumpDataExtractorTest, Formats) { "{0x0000000000000000 0xaaaabbbbccccdddd}"); // See half2float for format details. + // Test zeroes. + TestDump(std::vector<uint16_t>{0x0000, 0x8000}, + lldb::Format::eFormatVectorOfFloat16, "{0 -0}"); + // Some subnormal numbers. + TestDump(std::vector<uint16_t>{0x0001, 0x8001}, + lldb::Format::eFormatVectorOfFloat16, "{5.96046e-08 -5.96046e-08}"); + // A full mantisse and empty expontent. + TestDump(std::vector<uint16_t>{0x83ff, 0x03ff}, + lldb::Format::eFormatVectorOfFloat16, "{-6.09756e-05 6.09756e-05}"); + // Some normal numbers. + TestDump(std::vector<uint16_t>{0b0100001001001000}, + lldb::Format::eFormatVectorOfFloat16, "{3.14062}"); TestDump(std::vector<uint16_t>{0xabcd, 0x1234}, lldb::Format::eFormatVectorOfFloat16, "{-0.0609436 0.000757217}"); + // Largest and smallest normal number. + TestDump(std::vector<uint16_t>{0x0400, 0x7bff}, + lldb::Format::eFormatVectorOfFloat16, "{6.10352e-05 65504}"); + // quiet/signaling NaNs. + TestDump(std::vector<uint16_t>{0xffff, 0xffc0, 0x7fff, 0x7fc0}, + lldb::Format::eFormatVectorOfFloat16, "{nan nan nan nan}"); + // +/-Inf. + TestDump(std::vector<uint16_t>{0xfc00, 0x7c00}, + lldb::Format::eFormatVectorOfFloat16, "{-inf inf}"); + TestDump(std::vector<float>{std::numeric_limits<float>::min(), std::numeric_limits<float>::max()}, lldb::Format::eFormatVectorOfFloat32, "{1.17549e-38 3.40282e+38}"); _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
