From 800c393f89a94f49b01dff99f693cb13c5e28116 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 28 Aug 2023 16:27:58 +0200 Subject: [PATCH 2/2] [gdb/symtab] Handle self-reference in inherit_abstract_dies Building gdb with gcc 7.5.0 and -flto -O2 -flto-partition=one generates a self-referencing DIE: ... <2><91dace>: Abbrev Number: 405 (DW_TAG_label) <91dad0> DW_AT_abstract_origin: <0x91dace> ... When encountering the self-reference DIE in inherit_abstract_dies we loop following the abstract origin, effectively hanging gdb. Fix this by handling self-referencing DIEs in the loop in inherit_abstract_dies. Tested on x86_64-linux. Approved-By: Tom Tromey PR symtab/30799 https://sourceware.org/bugzilla/show_bug.cgi?id=30799 --- gdb/dwarf2/read.c | 7 +++++++ gdb/testsuite/gdb.dwarf2/self-spec.exp | 16 +++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 1be5f381432..970dd54c7a5 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -11938,8 +11938,15 @@ inherit_abstract_dies (struct die_info *die, struct dwarf2_cu *cu) if (attr == nullptr) break; + die_info *prev_child_origin_die = child_origin_die; child_origin_die = follow_die_ref (child_origin_die, attr, &child_origin_cu); + + if (prev_child_origin_die == child_origin_die) + { + /* Handle DIE with self-reference. */ + break; + } } /* If missing DW_AT_abstract_origin, try the corresponding child diff --git a/gdb/testsuite/gdb.dwarf2/self-spec.exp b/gdb/testsuite/gdb.dwarf2/self-spec.exp index 77e92549fd1..f04ff6da42e 100644 --- a/gdb/testsuite/gdb.dwarf2/self-spec.exp +++ b/gdb/testsuite/gdb.dwarf2/self-spec.exp @@ -14,7 +14,7 @@ # along with this program. If not, see . # Check that gdb doesn't hang or segfault on reading a DIE with a -# specification reference to itself. +# specification/abstract_origin reference to itself. load_lib dwarf.exp @@ -29,11 +29,25 @@ set asm_file [standard_output_file $srcfile2] Dwarf::assemble $asm_file { cu {} { compile_unit {{language @DW_LANG_C_plus_plus}} { + # Check handling of self-referencing DIE. declare_labels c1 c1: class_type { {name c1} {specification :$c1} } + + # Check handling of self-referencing child DIE. Regression test + # for PR30799. + declare_labels f1 abstract_f1 f1_l + abstract_f1: subprogram {} + f1: subprogram { + {MACRO_AT_func {main}} + {abstract_origin :$abstract_f1} + } { + f1_l: label { + {abstract_origin :$f1_l} + } + } } } } -- 2.35.3