https://github.com/firmiana402 updated https://github.com/llvm/llvm-project/pull/208478
>From d3f86e442eb12729e07a25ea9aa5d6e4ab34a90c Mon Sep 17 00:00:00 2001 From: firmiana402 <[email protected]> Date: Thu, 9 Jul 2026 22:36:44 +0800 Subject: [PATCH] [lldb] Prefer DW_AT_bit_size for DW_OP_convert type width --- .../Plugins/SymbolFile/DWARF/DWARFUnit.cpp | 4 +-- .../Expression/DWARFExpressionTest.cpp | 29 +++++++++++++++++++ 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp index aea2267277656..3fe8bbb8fdf56 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp @@ -729,9 +729,9 @@ DWARFUnit::GetDIEBitSizeAndSign(uint64_t relative_die_offset) const { "DW_OP_convert type DIE is not a DW_TAG_base_type"); uint64_t encoding = die.GetAttributeValueAsUnsigned(DW_AT_encoding, DW_ATE_hi_user); - uint64_t bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8; + uint64_t bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0); if (!bit_size) - bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0); + bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8; if (!bit_size) return llvm::createStringError("unsupported type size"); bool sign; diff --git a/lldb/unittests/Expression/DWARFExpressionTest.cpp b/lldb/unittests/Expression/DWARFExpressionTest.cpp index f552f42dcba5c..3b4d141965611 100644 --- a/lldb/unittests/Expression/DWARFExpressionTest.cpp +++ b/lldb/unittests/Expression/DWARFExpressionTest.cpp @@ -453,6 +453,16 @@ TEST(DWARFExpression, DW_OP_convert) { Form: DW_FORM_data1 - Attribute: DW_AT_byte_size Form: DW_FORM_data1 + - Code: 0x00000004 + Tag: DW_TAG_base_type + Children: DW_CHILDREN_no + Attributes: + - Attribute: DW_AT_encoding + Form: DW_FORM_data1 + - Attribute: DW_AT_byte_size + Form: DW_FORM_data1 + - Attribute: DW_AT_bit_size + Form: DW_FORM_data1 debug_info: - Version: 4 AddrSize: 8 @@ -506,6 +516,12 @@ TEST(DWARFExpression, DW_OP_convert) { Values: - Value: 0x0000000000000007 # DW_ATE_unsigned - Value: 0x0000000000000004 + # 0x00000023: + - AbbrCode: 0x00000004 + Values: + - Value: 0x0000000000000005 # DW_ATE_signed + - Value: 0x0000000000000004 + - Value: 0x000000000000001f - AbbrCode: 0x00000000 )"; @@ -516,6 +532,7 @@ TEST(DWARFExpression, DW_OP_convert) { uint8_t offs_uchar = 0x00000017; uint8_t offs_schar = 0x0000001a; uint8_t offs_enum = 0x00000020; + uint8_t offs_sint31_t = 0x00000023; DWARFExpressionTester t(yamldata, /*cu_index=*/1); ASSERT_TRUE((bool)t.GetDwarfUnit()); @@ -569,6 +586,18 @@ TEST(DWARFExpression, DW_OP_convert) { offs_schar, DW_OP_stack_value}), ExpectScalar(8, 'A', is_signed)); + // Prefer DW_AT_bit_size over DW_AT_byte_size when both are present. + EXPECT_THAT_EXPECTED( + t.Eval({DW_OP_const4u, 0x00, 0x00, 0x00, 0x40, DW_OP_convert, + offs_sint31_t, DW_OP_stack_value}), + ExpectScalar(31, 0x40000000, is_signed)); + + // Truncate the high bit when the value crosses the 31-bit boundary. + EXPECT_THAT_EXPECTED( + t.Eval({DW_OP_const4u, 0x00, 0x00, 0x00, 0xc0, DW_OP_convert, + offs_sint31_t, DW_OP_stack_value}), + ExpectScalar(31, 0x40000000, is_signed)); + // // Errors. // _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
