From 34daac4b169da3cb9df3e8bac6347cae630a99dd Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Fri, 27 Aug 2021 17:14:49 +0200 Subject: [PATCH] [gdb/symtab] Don't write .gdb_index symbol table with empty entries When comparing the sizes of the index files generated for shlib outputs/gdb.dwarf2/dw2-zero-range/shr1.sl, I noticed a large difference between .debug_names: ... $ gdb -q -batch $shlib -ex "save gdb-index -dwarf-5 ." $ du -b -h shr1.sl.debug_names shr1.sl.debug_str 61 shr1.sl.debug_names 0 shr1.sl.debug_str ... and .gdb_index: ... $ gdb -q -batch $shlib -ex "save gdb-index ." $ du -b -h shr1.sl.gdb-index 8.2K shr1.sl.gdb-index ... The problem is that the .gdb_index contains a non-empty symbol table with only empty entries. Fix this by making the symbol table empty, such that we have instead: ... $ du -b -h shr1.sl.gdb-index 184 shr1.sl.gdb-index ... Tested on x86_64-linux. --- gdb/dwarf2/index-write.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index 4e00c716d91..5de07a6c07b 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -1385,6 +1385,9 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file, uniquify_cu_indices (&symtab); data_buf symtab_vec, constant_pool; + if (symtab.n_elements == 0) + symtab.data.resize (0); + write_hash_table (&symtab, symtab_vec, constant_pool); write_gdbindex_1(out_file, objfile_cu_list, types_cu_list, addr_vec, -- 2.30.2