nx_dwarf_str_offsets.nx

nx_dwarf_str_offsets.nx -- DWARF v5 .debug_str_offsets builder. DWARF v5 introduced a level of indirection: instead of every DIE attribute storing a direct file offset into .debug_str (form DW_FORM_strp), per-CU strings are referenced by INDEX into a per-CU offset table that lives in .debug_str_offsets (form DW_FORM_strx). Benefits: - Smaller DIEs in 32-bit DWARF (uleb128 index vs 4-byte offset). - All string offsets concentrate in one section -- better compression by gold/lld split-debug toolchains. - Makes incremental linking cheaper (only patch the offset table, not every DIE that referenced a moved string). Per-CU layout (DWARF v5 7.26): length u32 (excludes itself) version u16 = 5 padding u16 = 0 offsets[] u32 each (file offsets into .debug_str) Caller emits one CU contribution per .debug_info CU and writes one u32 per string the CU references. DIE attributes use form DW_FORM_strx (uleb128 index) which the consumer resolves via (cu_str_offsets_base + idx*4) -> file offset into .debug_str. Pairs with nx_dwarf_str (string pool) + nx_dwarf_info (consumer of strx forms).