https://github.com/satyajanga updated https://github.com/llvm/llvm-project/pull/150149
>From 0431e9a3404b45e95e737ecbcf92f222527a51cc Mon Sep 17 00:00:00 2001 From: satya janga <satyaja...@fb.com> Date: Tue, 22 Jul 2025 17:57:30 -0700 Subject: [PATCH] Zero extend APInt when piece size is bigger than the bitwidth Summary: Test Plan: Reviewers: Subscribers: Tasks: Tags: Differential Revision: https://phabricator.intern.facebook.com/D78791142 --- lldb/source/Expression/DWARFExpression.cpp | 7 ++++++- .../Expression/DWARFExpressionTest.cpp | 20 +++++++++++++++++++ 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp index 52891fcefd68b..c00795b97467b 100644 --- a/lldb/source/Expression/DWARFExpression.cpp +++ b/lldb/source/Expression/DWARFExpression.cpp @@ -1978,7 +1978,12 @@ llvm::Expected<Value> DWARFExpression::Evaluate( // grows to the nearest host integer type. llvm::APInt fail_value(1, 0, false); llvm::APInt ap_int = scalar.UInt128(fail_value); - assert(ap_int.getBitWidth() >= bit_size); + // We have seen a case where we have expression like: + // DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x28 + // here we are assuming the compiler was trying to zero + // extend the value that we should append to the buffer. + if (ap_int.getBitWidth() < bit_size) + ap_int = ap_int.zext(bit_size); llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(), ap_int.getNumWords()}; curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf)); diff --git a/lldb/unittests/Expression/DWARFExpressionTest.cpp b/lldb/unittests/Expression/DWARFExpressionTest.cpp index fdc9bfae1876c..b2bafca5dd25b 100644 --- a/lldb/unittests/Expression/DWARFExpressionTest.cpp +++ b/lldb/unittests/Expression/DWARFExpressionTest.cpp @@ -358,6 +358,26 @@ TEST(DWARFExpression, DW_OP_piece) { llvm::HasValue(GetScalar(16, 0xff00, true))); } +TEST(DWARFExpression, DW_OP_piece_host_address) { + llvm::ArrayRef<uint8_t> expr = {DW_OP_lit2, DW_OP_stack_value, DW_OP_piece, + 40}; + DataExtractor extractor(expr.data(), expr.size(), lldb::eByteOrderLittle, 4); + + // This tests if ap_int is extended to the right width. + // expect 40*8 = 320 bits size. + llvm::Expected<Value> result = + DWARFExpression::Evaluate(nullptr, nullptr, nullptr, extractor, nullptr, + lldb::eRegisterKindLLDB, nullptr, nullptr); + ASSERT_THAT_EXPECTED(result, llvm::Succeeded()); + ASSERT_EQ(result->GetValueType(), Value::ValueType::HostAddress); + ASSERT_EQ(result->GetBuffer().GetByteSize(), 40); + const uint8_t *data = result->GetBuffer().GetBytes(); + ASSERT_EQ(data[0], 2); + for (int i = 1; i < 40; i++) { + ASSERT_EQ(data[i], 0); + } +} + TEST(DWARFExpression, DW_OP_implicit_value) { unsigned char bytes = 4; _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
