From 4330d61dfb05d77fd925efdca45091f12e3a6266 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 29 May 2019 09:34:50 -0600 Subject: [PATCH] Fix crash in cp_print_value_fields PR c++/20020 concerns a crash in cp_print_value_fields. The immediate cause is that cp_print_value_fields does not handle the case where value_static_field fails. This is fixed in this patch by calling cp_print_static_field from the "try" block. Digging a bit deeper, the error occurs because GCC does not emit a DW_AT_const_value for a static constexpr member appearing in a template class. I've filed a GCC bug for this. Tested on x86-64 Fedora 29. gdb/ChangeLog 2019-05-29 Tom Tromey PR c++/20020: * cp-valprint.c (cp_print_value_fields): Call cp_print_static_field inside "try". gdb/testsuite/ChangeLog 2019-05-29 Tom Tromey PR c++/20020: * gdb.cp/constexpr-field.exp: New file. * gdb.cp/constexpr-field.cc: New file. --- gdb/ChangeLog | 6 ++++++ gdb/cp-valprint.c | 12 +++++------ gdb/testsuite/ChangeLog | 6 ++++++ gdb/testsuite/gdb.cp/constexpr-field.cc | 37 ++++++++++++++++++++++++++++++++ gdb/testsuite/gdb.cp/constexpr-field.exp | 36 +++++++++++++++++++++++++++++++ 5 files changed, 90 insertions(+), 7 deletions(-) create mode 100644 gdb/testsuite/gdb.cp/constexpr-field.cc create mode 100644 gdb/testsuite/gdb.cp/constexpr-field.exp diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c105fb7..82655ea 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,11 @@ 2019-05-29 Tom Tromey + PR c++/20020: + * cp-valprint.c (cp_print_value_fields): Call + cp_print_static_field inside "try". + +2019-05-29 Tom Tromey + * inflow.c (struct terminal_info): Add default operator=. * configure: Rebuild. * warning.m4 (AM_GDB_WARNINGS): Add -Wdeprecated-copy, diff --git a/gdb/cp-valprint.c b/gdb/cp-valprint.c index ff860df..d8d5c06 100644 --- a/gdb/cp-valprint.c +++ b/gdb/cp-valprint.c @@ -329,22 +329,20 @@ cp_print_value_fields (struct type *type, struct type *real_type, } else if (field_is_static (&TYPE_FIELD (type, i))) { - struct value *v = NULL; - try { - v = value_static_field (type, i); - } + struct value *v = value_static_field (type, i); + cp_print_static_field (TYPE_FIELD_TYPE (type, i), + v, stream, recurse + 1, + options); + } catch (const gdb_exception_error &ex) { fprintf_filtered (stream, _(""), ex.what ()); } - - cp_print_static_field (TYPE_FIELD_TYPE (type, i), - v, stream, recurse + 1, opts); } else if (i == vptr_fieldno && type == vptr_basetype) { diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index f795ba0..ddcb834 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,5 +1,11 @@ 2019-05-29 Tom Tromey + PR c++/20020: + * gdb.cp/constexpr-field.exp: New file. + * gdb.cp/constexpr-field.cc: New file. + +2019-05-29 Tom Tromey + * gdb.base/finish.exp (finish_no_print): New proc. (finish_tests): Call it. diff --git a/gdb/testsuite/gdb.cp/constexpr-field.cc b/gdb/testsuite/gdb.cp/constexpr-field.cc new file mode 100644 index 0000000..ac2e514 --- /dev/null +++ b/gdb/testsuite/gdb.cp/constexpr-field.cc @@ -0,0 +1,37 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2019 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +template +struct X +{ + static constexpr bool f = true; +}; + +X x; + +struct Y +{ + static constexpr bool f = true; +}; + +Y y; + +int +main (void) +{ + return 0; +} diff --git a/gdb/testsuite/gdb.cp/constexpr-field.exp b/gdb/testsuite/gdb.cp/constexpr-field.exp new file mode 100644 index 0000000..e4849ef --- /dev/null +++ b/gdb/testsuite/gdb.cp/constexpr-field.exp @@ -0,0 +1,36 @@ +# Copyright 2019 Free Software Foundation, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# This file is part of the gdb testsuite. + +if {[skip_cplus_tests]} { continue } + +standard_testfile .cc + +if {[prepare_for_testing "failed to prepare" $testfile $srcfile \ + {c++ debug additional_flags=-std=c++17}]} { + return -1 +} + +if {![runto_main]} { + perror "couldn't run to breakpoint" + continue +} + +# "x" sometimes isn't available due to +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90526 +gdb_test "print x" " = {static f = .*}" + +gdb_test "print y" " = {static f = true}" -- 2.7.4