From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7850 invoked by alias); 12 Mar 2007 21:36:35 -0000 Received: (qmail 7842 invoked by uid 22791); 12 Mar 2007 21:36:34 -0000 X-Spam-Check-By: sourceware.org Received: from 195.22.55.53.adsl.nextra.cz (HELO host0.dyn.jankratochvil.net) (195.22.55.53) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 12 Mar 2007 21:36:24 +0000 Received: from host0.dyn.jankratochvil.net (localhost [127.0.0.1]) by host0.dyn.jankratochvil.net (8.14.0/8.13.8) with ESMTP id l2CLaDcE013307; Mon, 12 Mar 2007 22:36:14 +0100 Received: (from jkratoch@localhost) by host0.dyn.jankratochvil.net (8.14.0/8.14.0/Submit) id l2CLaDT3013303; Mon, 12 Mar 2007 22:36:13 +0100 Date: Mon, 12 Mar 2007 21:36:00 -0000 From: Jan Kratochvil To: Daniel Jacobowitz Cc: gdb-patches@sourceware.org Subject: Re: [PATCH] Differentiate empty vs. opaque types Message-ID: <20070312213611.GA6633@host0.dyn.jankratochvil.net> References: <20070311225518.GA10039@host0.dyn.jankratochvil.net> <20070312033529.GA1116@caradoc.them.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="s/l3CgOIzMHHjg/5" Content-Disposition: inline In-Reply-To: <20070312033529.GA1116@caradoc.them.org> User-Agent: Mutt/1.5.14 (2007-02-12) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2007-03/txt/msg00129.txt.bz2 --s/l3CgOIzMHHjg/5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-length: 1265 On Mon, 12 Mar 2007 04:35:29 +0100, Daniel Jacobowitz wrote: > On Sun, Mar 11, 2007 at 11:55:19PM +0100, Jan Kratochvil wrote: > > attached testcase targets the difference of `struct x;' vs. `struct {} x;' by checking > > the DWARF flag `DW_AT_declaration': ... > Does this happen in HEAD? Yes. > It sounds just like the problem Joel fixed > for Ada: > > 2007-01-05 Joel Brobecker > > * dwarf2read.c (partial_die_info): Add field has_byte_size. > (add_partial_symbol): Correct identification of external > references. > (process_structure_scope): Likewise. > (read_partial_die): Handle DW_AT_byte_size attribute. > > There's an Ada testcase for this, and it passes now. I was not aware of it, I checked it now, it looks really related. But that patch / testcase is orthogonal to my patch / testcase below. Joel's patch targets DWARF->symbols phase while my patch targets symbols found in different object files (executable vs. shared library). ... > An objfile flag is usually not right - this is per-compilation-unit, > not per objfile. You are right. Updated, as there is no compilation-unit info reachable from `struct type *' I had to use a new flag in each type there. Regards, Jan --s/l3CgOIzMHHjg/5 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="gdb-empty-is-not-opaque-v2.patch" Content-length: 10504 2007-03-12 Jan Kratochvil * gdbtypes.h (TYPE_FLAG_STUB_SUPPORTED, TYPE_STUB_SUPPORTED): New macros. (TYPE_IS_OPAQUE): Empty vs. opaque structures are now distinct on the TYPE_STUB_SUPPORTED debug targets. * dwarf2read.c (read_structure_type): Set TYPE_FLAG_STUB_SUPPORTED. * dwarfread.c (struct_type): New comment on TYPE_FLAG_STUB_SUPPORTED. 2007-03-12 Jan Kratochvil * gdb.base/type-opaque-lib.c, gdb.base/type-opaque-main.c, gdb.base/type-opaque.exp: New files. --- gdb/dwarf2read.c 12 Feb 2007 15:19:31 -0000 1.215 +++ gdb/dwarf2read.c 12 Mar 2007 21:33:06 -0000 @@ -3879,6 +3879,7 @@ read_structure_type (struct die_info *di TYPE_LENGTH (type) = 0; } + TYPE_FLAGS (type) |= TYPE_FLAG_STUB_SUPPORTED; if (die_is_declaration (die, cu)) TYPE_FLAGS (type) |= TYPE_FLAG_STUB; --- gdb/dwarfread.c 12 Feb 2007 15:19:31 -0000 1.47 +++ gdb/dwarfread.c 12 Mar 2007 21:33:07 -0000 @@ -1083,7 +1083,10 @@ struct_type (struct dieinfo *dip, char * not even have any fields, if this DIE was generated due to a reference to an anonymous structure or union. In this case, TYPE_FLAG_STUB is set, which clues gdb in to the fact that it needs to search elsewhere - for the full structure definition. */ + for the full structure definition. + As such opaque reference is not distinguishable from an empty STRUCT + definition as DWARF1 is missing DW_AT_declaration we cannot set + TYPE_FLAG_STUB_SUPPORTED here. */ if (nfields == 0) { TYPE_FLAGS (type) |= TYPE_FLAG_STUB; --- gdb/gdbtypes.h 29 Jan 2007 17:31:06 -0000 1.68 +++ gdb/gdbtypes.h 12 Mar 2007 21:33:08 -0000 @@ -319,6 +319,14 @@ enum type_code #define TYPE_FLAG_FIXED_INSTANCE (1 << 15) +/* This debug target supports TYPE_STUB(t). In the unsupported case we have to + rely on NFIELDS to be zero etc., see TYPE_IS_OPAQUE (). + TYPE_STUB(t) with !TYPE_STUB_SUPPORTED(t) may exist if we only guessed + the TYPE_STUB(t) value (see dwarfread.c). */ + +#define TYPE_FLAG_STUB_SUPPORTED (1 << 16) +#define TYPE_STUB_SUPPORTED(t) (TYPE_FLAGS (t) & TYPE_FLAG_STUB_SUPPORTED) + /* Array bound type. */ enum array_bound_type { @@ -969,7 +977,8 @@ extern void allocate_cplus_struct_type ( #define TYPE_IS_OPAQUE(thistype) (((TYPE_CODE (thistype) == TYPE_CODE_STRUCT) || \ (TYPE_CODE (thistype) == TYPE_CODE_UNION)) && \ (TYPE_NFIELDS (thistype) == 0) && \ - (TYPE_CPLUS_SPECIFIC (thistype) && (TYPE_NFN_FIELDS (thistype) == 0))) + (TYPE_CPLUS_SPECIFIC (thistype) && (TYPE_NFN_FIELDS (thistype) == 0)) && \ + (TYPE_STUB (thistype) || !TYPE_STUB_SUPPORTED (thistype))) struct builtin_type { --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb/testsuite/gdb.base/type-opaque-lib.c 12 Mar 2007 21:33:09 -0000 @@ -0,0 +1,56 @@ +/* Test resolving of an opaque type from the loaded shared library. + + Copyright 2007, Free Software Foundation, Inc. + + This file is part of GDB. + + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +struct struct_libtype_opaque +{ + int libfield_opaque; +}; +struct struct_libtype_opaque struct_libtype_opaque_use; + +struct struct_libtype_empty +{ + int libfield_empty; +}; +struct struct_libtype_empty struct_libtype_empty_use; + +struct struct_libtype_filled +{ + int libfield_filled; +}; +struct struct_libtype_filled struct_libtype_filled_use; + +union union_libtype_opaque +{ + int libfield_opaque; +}; +union union_libtype_opaque union_libtype_opaque_use; + +union union_libtype_empty +{ + int libfield_empty; +}; +union union_libtype_empty union_libtype_empty_use; + +union union_libtype_filled +{ + int libfield_filled; +}; +union union_libtype_filled union_libtype_filled_use; --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb/testsuite/gdb.base/type-opaque-main.c 12 Mar 2007 21:33:09 -0000 @@ -0,0 +1,56 @@ +/* Test resolving of an opaque type from the loaded shared library. + + Copyright 2007, Free Software Foundation, Inc. + + This file is part of GDB. + + 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +struct struct_libtype_opaque; + +struct struct_libtype_empty + { + }; + +struct struct_libtype_filled + { + long mainfield_filled; + }; + +union union_libtype_opaque; + +union union_libtype_empty + { + }; + +union union_libtype_filled + { + long mainfield_filled; + }; + +int main (void) +{ + volatile struct struct_libtype_opaque *pointer_struct_opaque = (void *) 0; + volatile struct struct_libtype_empty *pointer_struct_empty = (void *) 0; + volatile struct struct_libtype_filled *pointer_struct_filled = (void *) 0; + volatile union union_libtype_opaque *pointer_union_opaque = (void *) 0; + volatile union union_libtype_empty *pointer_union_empty = (void *) 0; + volatile union union_libtype_filled *pointer_union_filled = (void *) 0; + + return (int) pointer_struct_opaque + (int) pointer_struct_empty + + (int) pointer_struct_filled + (int) pointer_union_opaque + + (int) pointer_union_empty + (int) pointer_union_filled; +} --- /dev/null 1 Jan 1970 00:00:00 -0000 +++ gdb/testsuite/gdb.base/type-opaque.exp 12 Mar 2007 21:33:09 -0000 @@ -0,0 +1,134 @@ +# Copyright 2004, 2007 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 2 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, write to the Free Software +# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +# Please email any bugs, comments, and/or additions to this file to: +# bug-gdb@prep.ai.mit.edu + +# Test resolving of an opaque type from the loaded shared library. + +if $tracelevel then { + strace $tracelevel +} + +set testfile type-opaque-main +set libfile type-opaque-lib +set srcfile ${testfile}.c +set binfile ${objdir}/${subdir}/${testfile} + +set libsrc "${srcdir}/${subdir}/${libfile}.c" +set libobj "${objdir}/${subdir}/${libfile}.so" +set execsrc "${srcdir}/${subdir}/${srcfile}" + +remote_exec build "rm -f ${binfile}" + +# Are we on a target board? No support for downloading shared libraries +# to a target yet. +if ![isnative] then { + return 0 +} + +# get the value of gcc_compiled +if [get_compiler_info ${binfile}] { + return -1 +} + +if { [gdb_compile_shlib $libsrc $libobj {debug}] != "" + || [gdb_compile $execsrc ${binfile} executable \ + [list debug shlib=${libobj}]] != "" } { + return -1 +} + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +if ![runto_main] then { + fail "Can't run to main" + return 0 +} + + +# DWARF3: An incomplete structure, union or class type is represented by +# a structure, union or class entry that does not have a byte size attribute +# and that has a DW_AT_declaration attribute. + + +proc body { struct } { + global gdb_prompt + + + # <1><15f>: Abbrev Number: 8 (DW_TAG_structure_type) + # DW_AT_name : libtype_opaque + # DW_AT_declaration : 1 + + set name "opaque $struct type resolving" + gdb_test_multiple "ptype pointer_${struct}_opaque" $name \ + { + -re "libfield_opaque.*$gdb_prompt $" { + pass $name + } + } + + + # <1><9e>: Abbrev Number: 2 (DW_TAG_structure_type) + # DW_AT_name : libtype_empty + # DW_AT_byte_size : 0 + # DW_AT_decl_file : 1 + # DW_AT_decl_line : 25 + + set name "empty $struct type resolving" + gdb_test_multiple "ptype pointer_${struct}_empty" $name \ + { + -re "\\{\[ \t\r\n\]*\[ \t\r\n\]*\\}.*$gdb_prompt $" { + pass $name + } + -re "libfield_empty.*$gdb_prompt $" { + fail $name + } + } + + + # <1>: Abbrev Number: 3 (DW_TAG_structure_type) + # DW_AT_sibling : + # DW_AT_name : libtype_filled + # DW_AT_byte_size : 4 + # DW_AT_decl_file : 1 + # DW_AT_decl_line : 29 + # <2>: Abbrev Number: 4 (DW_TAG_member) + # DW_AT_name : mainfield_filled + # DW_AT_decl_file : 1 + # DW_AT_decl_line : 30 + # DW_AT_type : + # DW_AT_data_member_location: 2 byte block: 23 0 (DW_OP_plus_uconst: 0) + + set name "filled $struct type resolving" + gdb_test_multiple "ptype pointer_${struct}_filled" $name \ + { + -re "mainfield_filled.*$gdb_prompt $" { + pass $name + } + -re "libfield_filled.*$gdb_prompt $" { + fail $name + } + } + + +} + + +body struct +body union --s/l3CgOIzMHHjg/5--