proposal: debug/dwarf: define Go-specific attributes

[ajwerner]

Proposal Details

The Go compiler emits dwarf entries with Go-specific attributes. You can find below:

go/src/cmd/internal/dwarf/dwarf.go

Lines 308 to 320 in 8097cf1

	// Go-specific type attributes.
	const (
	DW_AT_go_kind = 0x2900
	DW_AT_go_key = 0x2901
	DW_AT_go_elem = 0x2902
	// Attribute for DW_TAG_member of a struct type.
	// Nonzero value indicates the struct field is an embedded field.
	DW_AT_go_embedded_field = 0x2903
	DW_AT_go_runtime_type = 0x2904
	DW_AT_go_package_name = 0x2905 // Attribute for DW_TAG_compile_unit
	DW_AT_go_dict_index = 0x2906 // Attribute for DW_TAG_typedef_type, index of the dictionary entry describing the real type of this type shape
	DW_AT_go_closure_offset = 0x2907 // Attribute for DW_TAG_variable, offset in the closure struct where this captured variable resides

The Go stdlib also happens to include a library for parsing and analyzing DWARF in debug/dwarf. Unfortunately, the Go-specific attributes are not supported by that library.

This proposal suggests that the debug/dwarf package be aware of these attributes by including them here. Technically this is part of the public API, hence the proposal.

[gabyhelp]

Related Issues

• go/src/debug/dwarf: more DWARF tag and attribute constants #32304 (closed)
• cmd/link: option to omit DWARF vendor attributes #25297 (closed)

Related Code Changes

• debug/dwarf: document DWARF class -> Go type mapping
• cmd/link: add option to omit go DWARF user attributes
• debug/dwarf: add minimal support for C++ reference types
• cmd/link: add support for "minimal" DWARF gen
• debug/dwarf: integrate code to read DWARF call frame information from x/debug/dwarf.
• cmd/internal: add additional DWARF 5 language constants
• debug/dwarf, debug/elf: support DWARF 5

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}