From 04d0d6ebdc6d08f5a7ec0d4c89eb1835deef54dc Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Sun, 13 Aug 2023 14:08:06 +0200 Subject: [PATCH] [gdb/symtab] Don't deduplicate variables in gdb-index When running test-case gdb.python/py-symbol.exp with target board cc-with-gdb-index, we run into: ... (gdb) python print (len (gdb.lookup_static_symbols ('rr')))^M 1^M (gdb) FAIL: gdb.python/py-symbol.exp: print (len (gdb.lookup_static_symbols ('rr'))) ... [ Note that the test-case contains rr in both py-symtab.c: ... static int __attribute__ ((used)) rr = 42; /* line of rr */ ... and py-symtab-2.c: ... static int __attribute__ ((used)) rr = 99; /* line of other rr */ ... ] This passes with gdb-12-branch, and fails with gdb-13-branch. AFAIU the current code in symtab_index_entry::minimize makes the assumption that it's fine to store only one copy of rr in the gdb-index, because "print rr" will only ever print one, and always the same. But that fails to recognize that gdb supports gdb.lookup_static_symbols, which returns a list of variables rather than the first one. In other words, the current approach breaks feature parity between cooked index and gdb-index. Note btw that also debug-names has both instances: ... [ 5] #00597969 rr: <4> DW_TAG_variable DW_IDX_compile_unit=3 DW_IDX_GNU_internal=1 <4> DW_TAG_variable DW_IDX_compile_unit=4 DW_IDX_GNU_internal=1 ... Fix this in symtab_index_entry::minimize, by not deduplicating variables. Tested on x86_64-linux, with target boards unix and cc-with-gdb-index. Reviewed-by: Kevin Buettner PR symtab/30720 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30720 --- gdb/dwarf2/index-write.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index d10583568c0..ea67f73ac3c 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -294,7 +294,7 @@ symtab_index_entry::minimize () auto from = std::unique (cu_indices.begin (), cu_indices.end ()); cu_indices.erase (from, cu_indices.end ()); - /* We don't want to enter a variable or type more than once, so + /* We don't want to enter a type more than once, so remove any such duplicates from the list as well. When doing this, we want to keep the entry from the first CU -- but this is implicit due to the sort. This choice is done because it's @@ -304,8 +304,7 @@ symtab_index_entry::minimize () [&] (offset_type val) { gdb_index_symbol_kind kind = GDB_INDEX_SYMBOL_KIND_VALUE (val); - if (kind != GDB_INDEX_SYMBOL_KIND_TYPE - && kind != GDB_INDEX_SYMBOL_KIND_VARIABLE) + if (kind != GDB_INDEX_SYMBOL_KIND_TYPE) return false; val &= ~GDB_INDEX_CU_MASK; base-commit: 2521ac7ed0c495b9e804c4356939b9be7166853c -- 2.35.3