From e1782d8ad10dc6b556e118fd25fdaff04ce54dde Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Wed, 10 Feb 2021 07:54:30 +0100 Subject: [PATCH] dwarf2out: Don't prune static data members initialized with constants with -gdwarf-5 [PR98755] In DWARF4 and earlier, static data members were represented as DW_TAG_member and the pruning code wouldn't prune those, but in DWARF5 they are represented as DW_TAG_variable with the class parent and the pruning code prunes those by default unless they are referenced from a separate definition without the class parent (out of class definition). C++17 inline vars have the definitions in the class though and even before if the static data member isn't ODR used, it doesn't need to be defined, so we could just never describe those static data members in the debug info. This change stops the pruning of DW_TAG_variable with DW_AT_const_value attribute with a class parent for -gdwarf-5 and later. This fixes -FAIL: g++.dg/debug/dwarf2/constexpr-var-1.C scan-assembler-times DW_AT_const_expr 2 -FAIL: libstdc++-prettyprinters/80276.cc whatis p4 -FAIL: libstdc++-prettyprinters/80276.cc whatis p4 -FAIL: libstdc++-prettyprinters/libfundts.cc print as -FAIL: libstdc++-prettyprinters/libfundts.cc print as -FAIL: libstdc++-prettyprinters/libfundts.cc print os -FAIL: libstdc++-prettyprinters/libfundts.cc print os 2021-02-10 Jakub Jelinek PR debug/98755 * dwarf2out.c (prune_unused_types_walk): Mark DW_TAG_variable DIEs at class scope for DWARF5+. --- gcc/dwarf2out.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c index 0a61d148c8a..d6ad40a580f 100644 --- a/gcc/dwarf2out.c +++ b/gcc/dwarf2out.c @@ -29475,6 +29475,16 @@ prune_unused_types_walk (dw_die_ref die) if (die->die_perennial_p) break; + /* For static data members, the declaration in the class is supposed + to have DW_TAG_member tag in DWARF{3,4} but DW_TAG_variable in + DWARF5. DW_TAG_member will be marked, so mark even such + DW_TAG_variables in DWARF5, as long as it has DW_AT_const_value + attribute. */ + if (dwarf_version >= 5 + && class_scope_p (die->die_parent) + && get_AT (die, DW_AT_const_value)) + break; + /* premark_used_variables marks external variables --- don't mark them here. But function-local externals are always considered used. */ -- 2.30.2