Author: shafik Date: 2020-03-27T11:28:07-07:00 New Revision: 00c8120acbac3430c3594c5b6ca3527ef9c1afca
URL: https://github.com/llvm/llvm-project/commit/00c8120acbac3430c3594c5b6ca3527ef9c1afca DIFF: https://github.com/llvm/llvm-project/commit/00c8120acbac3430c3594c5b6ca3527ef9c1afca.diff LOG: [LLDB] Fix handling of bit-fields when there is a base class when parsing DWARF When parsing DWARF and laying out bit-fields we currently don't take into account whether we have a base class or not. Currently if the first field is a bit-field but the bit offset is due a field we inherit from a base class we currently treat it as an unnamed bit-field and therefore add an extra field. This fix will not check if we have a base class and assume that this offset is due to members we are inheriting from the base. We are currently seeing asserts during codegen when debugging clang::DiagnosticOptions. This assumption will fail in the case where the first field in the derived class in an unnamed bit-field. Fixing the first field being an unnamed bit-field looks like it will require a larger change since we will need a way to track or discover the last field offset of the bases(s). Differential Revision: https://reviews.llvm.org/D76808 Added: Modified: lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py lldb/test/API/lang/cpp/bitfields/main.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp index 8838888b2e23..760933bf898e 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp @@ -2668,9 +2668,19 @@ void DWARFASTParserClang::ParseSingleMember( } // If we have a gap between the last_field_end and the current - // field we have an unnamed bit-field + // field we have an unnamed bit-field. + // If we have a base class, we assume there is no unnamed + // bit-field if this is the first field since the gap can be + // attributed to the members from the base class. This assumption + // is not correct if the first field of the derived class is + // indeed an unnamed bit-field. We currently do not have the + // machinary to track the offset of the last field of classes we + // have seen before, so we are not handling this case. if (this_field_info.bit_offset != last_field_end && - !(this_field_info.bit_offset < last_field_end)) { + this_field_info.bit_offset > last_field_end && + !(last_field_info.bit_offset == 0 && + last_field_info.bit_size == 0 && + layout_info.base_offsets.size() != 0)) { unnamed_field_info = FieldInfo{}; unnamed_field_info->bit_size = this_field_info.bit_offset - last_field_end; diff --git a/lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py b/lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py index 1b362e6b04f9..7320ce2b816e 100644 --- a/lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py +++ b/lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py @@ -103,3 +103,10 @@ def test_and_run_command(self): '(uint64_t:1) k = 1', ]) + self.expect( + "frame variable --show-types derived", + VARIABLES_DISPLAYED_CORRECTLY, + substrs=[ + '(uint32_t) b_a = 2', + '(uint32_t:1) d_a = 1', + ]) diff --git a/lldb/test/API/lang/cpp/bitfields/main.cpp b/lldb/test/API/lang/cpp/bitfields/main.cpp index e43bf8c138e9..986b7cb947ed 100644 --- a/lldb/test/API/lang/cpp/bitfields/main.cpp +++ b/lldb/test/API/lang/cpp/bitfields/main.cpp @@ -60,6 +60,16 @@ int main(int argc, char const *argv[]) { } } clang_example; + class B { + public: + uint32_t b_a; + }; + + class D : public B { + public: + uint32_t d_a : 1; + } derived; + lba.a = 2; lbb.a = 1; @@ -76,6 +86,8 @@ int main(int argc, char const *argv[]) { lbd.arr[2] = '\0'; lbd.a = 5; + derived.b_a = 2; + derived.d_a = 1; return 0; // Set break point at this line. } _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
