{"record":{"id":"022ce6fac63cd742","repo":"go-delve/delve","slug":"member-data-has-no-data-member-location-attribute","errorCode":null,"errorMessage":"member data has no data member location attribute","messagePattern":"member data has no data member location attribute","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/dwarf/reader/reader.go","lineNumber":199,"sourceCode":"\t}\n\tvar attr dwarf.Attr\n\tif member {\n\t\tattr = dwarf.AttrDataMemberLoc\n\t} else {\n\t\tattr = dwarf.AttrLocation\n\t}\n\tinstr, ok := entry.Val(attr).([]byte)\n\tif !ok {\n\t\treturn nil, errors.New(\"invalid typecast for Dwarf instructions\")\n\t}\n\treturn instr, nil\n}\n\nfunc (reader *Reader) InstructionsForEntry(entry *dwarf.Entry) ([]byte, error) {\n\tif entry.Tag == dwarf.TagMember {\n\t\tinstructions, ok := entry.Val(dwarf.AttrDataMemberLoc).([]byte)\n\t\tif !ok {\n\t\t\treturn nil, errors.New(\"member data has no data member location attribute\")\n\t\t}\n\t\t// clone slice to prevent stomping on the dwarf data\n\t\treturn append([]byte{}, instructions...), nil\n\t}\n\n\t// non-member\n\tinstructions, ok := entry.Val(dwarf.AttrLocation).([]byte)\n\tif !ok {\n\t\treturn nil, errors.New(\"entry has no location attribute\")\n\t}\n\n\t// clone slice to prevent stomping on the dwarf data\n\treturn append([]byte{}, instructions...), nil\n}\n\n// NextMemberVariable moves the reader to the next debug entry that describes a member variable and returns the entry.\nfunc (reader *Reader) NextMemberVariable() (*dwarf.Entry, error) {\n\tfor {","sourceCodeStart":181,"sourceCodeEnd":217,"githubUrl":"https://github.com/go-delve/delve/blob/a23773e6c31361e43246bc43a424ee009679b174/pkg/dwarf/reader/reader.go#L181-L217","documentation":"Returned by Reader.InstructionsForEntry when the entry is a member (TagMember) but its DW_AT_data_member_location attribute is not a []byte expression. Member location is sometimes a plain integer offset; in that case this error is raised instead of returning instructions.","triggerScenarios":"InstructionsForEntry on a struct member whose AttrDataMemberLoc is missing or is an int offset rather than a DWARF expression byte slice.","commonSituations":"Members of C-like/aligned structs where the producer emits a constant offset, hand-built dwarf.Entry values in tests, or older DWARF forms encoding member offset as a constant.","solutions":["If the attribute is an integer constant, compute the offset directly instead of asking for instructions","Verify the member entry with a DWARF dumper to see the attribute's actual form","Regenerate debug info with a toolchain that emits expression-form member locations if expression evaluation is required"],"exampleFix":"// before\ninstr, err := reader.InstructionsForEntry(memberEntry)\n// after\noff, ok := memberEntry.Val(dwarf.AttrDataMemberLoc).(int64)\nif ok {\n    return off // constant offset, no DWARF program\n}\ninstr, err := reader.InstructionsForEntry(memberEntry)","handlingStrategy":"type-guard","validationCode":null,"typeGuard":"func memberOffset(e *dwarf.Entry) (int64, []byte, bool) {\n    switch v := e.Val(dwarf.AttrDataMemberLoc).(type) {\n    case int64:\n        return v, nil, true\n    case []byte:\n        return 0, v, true\n    }\n    return 0, nil, false\n}","tryCatchPattern":null,"preventionTips":["Inspect member attribute form first; constant offsets are common","Fall back to manual offset computation when no expression exists"],"tags":["dwarf","member-location","missing-attribute"],"backgroundTag":"dwarf-attribute-type-mismatch","analyzedSha":"a23773e6c31361e43246bc43a424ee009679b174","analyzedAt":"2026-08-31T15:12:45.221Z","schemaVersion":2},"datasetVersion":"2026-08-31T19:17:28.585Z"}