From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id YFRBBu0MI2DDbQAAWB0awg (envelope-from ) for ; Tue, 09 Feb 2021 17:30:05 -0500 Received: by simark.ca (Postfix, from userid 112) id 112561EF4F; Tue, 9 Feb 2021 17:30:05 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=0.3 required=5.0 tests=MAILING_LIST_MULTI,RDNS_NONE, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.2 Received: from sourceware.org (unknown [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 778821E590 for ; Tue, 9 Feb 2021 17:30:04 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 1CE53393D00D; Tue, 9 Feb 2021 22:30:04 +0000 (GMT) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 2739B387086B for ; Tue, 9 Feb 2021 22:30:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 2739B387086B Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tdevries@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3A376AD24; Tue, 9 Feb 2021 22:30:00 +0000 (UTC) Subject: Re: [PATCH][gdb/symtab] Fix element type modification in read_array_type To: Tom Tromey References: <20210205122814.GA19232@delia> <87k0rm4gvn.fsf@tromey.com> <8b89b73a-205b-0da0-26fe-8d5e45a10886@suse.de> <87o8gtat0k.fsf@tromey.com> From: Tom de Vries Message-ID: <8d2fb066-e859-3efe-a737-4e28ed1cc554@suse.de> Date: Tue, 9 Feb 2021 23:29:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <87o8gtat0k.fsf@tromey.com> Content-Type: multipart/mixed; boundary="------------7D64FF3AA4D0FA437DE32C3B" Content-Language: en-US X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gdb-patches@sourceware.org Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" This is a multi-part message in MIME format. --------------7D64FF3AA4D0FA437DE32C3B Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 2/9/21 9:24 PM, Tom Tromey wrote: >>>>>> "Tom" == Tom de Vries writes: > > Tom> + { > Tom> + complaint (_("unable to handle array child DIE %s" > Tom> + " - DIE at %s [in module %s]"), > Tom> + dwarf_tag_name (child_die->tag), > Tom> + sect_offset_str (die->sect_off), > Tom> + objfile_name (cu->per_objfile->objfile)); > Tom> + return NULL; > Tom> + } > > This seems a bit too strong to me. A normal DWARF extension mechanism > is to add new "unexpected" children to a DIE. In many (maybe most) > cases, it's fine to just ignore these. > > Maybe another approach would be to bail out if range_types.empty(), > issuing a complaint then. This wouldn't mention > DW_TAG_generic_subrange, but that seems ok to me. Ack, done. > Users don't really read complaints. Maybe even gdb developers don't ;) Heh :) Committed as attached. Thanks, - Tom --------------7D64FF3AA4D0FA437DE32C3B Content-Type: text/x-patch; charset=UTF-8; name="0001-gdb-symtab-Fix-element-type-modification-in-read_array_type.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-gdb-symtab-Fix-element-type-modification-in-read_array_"; filename*1="type.patch" [gdb/symtab] Fix element type modification in read_array_type When running test-case gdb.fortran/function-calls.exp with target board unix/gdb:debug_flags=-gdwarf-5, I run into: ... (gdb) PASS: gdb.fortran/function-calls.exp: \ p derived_types_and_module_calls::pass_cart(c) p derived_types_and_module_calls::pass_cart_nd(c_nd)^M ^M Program received signal SIGSEGV, Segmentation fault.^M 0x0000000000400f73 in derived_types_and_module_calls::pass_cart_nd \ (c=) at \ function-calls.f90:130^M 130 pass_cart_nd = ubound(c%d,1,4)^M The program being debugged was signaled while in a function called from GDB.^M GDB has restored the context to what it was before the call.^M To change this behavior use "set unwindonsignal off".^M Evaluation of the expression containing the function^M (derived_types_and_module_calls::pass_cart_nd) will be abandoned.^M (gdb) FAIL: gdb.fortran/function-calls.exp: p ... The problem originates in read_array_type, when reading a DW_TAG_array_type with a dwarf-5 DW_TAG_generic_subrange child. This is not supported, and the fallout of this is that rather than constructing a new array type, the code proceeds to modify the element type. Fix this conservatively by issuing a complaint and bailing out in read_array_type when not being able to construct an array type, such that we have: ... (gdb) maint expand-symtabs function-calls.f90^M During symbol reading: unable to find array range \ - DIE at 0xe1e [in module function-calls]^M During symbol reading: unable to find array range \ - DIE at 0xe1e [in module function-calls]^M (gdb) KFAIL: gdb.fortran/function-calls.exp: no complaints in srcfile \ (PRMS: symtab/27388) ... Tested on x86_64-linux. gdb/ChangeLog: 2021-02-06 Tom de Vries PR symtab/27341 * dwarf2/read.c (read_array_type): Return NULL when not being able to construct an array type. Add assert to ensure that element_type is not being modified. 2021-02-06 Tom de Vries PR symtab/27341 * lib/gdb.exp (with_complaints): New proc, factored out of ... (gdb_load_no_complaints): ... here. * gdb.fortran/function-calls.exp: Add test-case. --- gdb/dwarf2/read.c | 10 +++++++ gdb/testsuite/gdb.fortran/function-calls.exp | 15 ++++++++++ gdb/testsuite/lib/gdb.exp | 43 +++++++++++++++++++++------- 3 files changed, 58 insertions(+), 10 deletions(-) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 3f60ce6a4f1..4b901c565f8 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -17217,6 +17217,14 @@ read_array_type (struct die_info *die, struct dwarf2_cu *cu) child_die = child_die->sibling; } + if (range_types.empty ()) + { + complaint (_("unable to find array range - DIE at %s [in module %s]"), + sect_offset_str (die->sect_off), + objfile_name (cu->per_objfile->objfile)); + return NULL; + } + /* Dwarf2 dimensions are output from left to right, create the necessary array types in backwards order. */ @@ -17246,6 +17254,8 @@ read_array_type (struct die_info *die, struct dwarf2_cu *cu) } } + gdb_assert (type != element_type); + /* Understand Dwarf2 support for vector types (like they occur on the PowerPC w/ AltiVec). Gcc just adds another attribute to the array type. This is not part of the Dwarf2/3 standard yet, but a diff --git a/gdb/testsuite/gdb.fortran/function-calls.exp b/gdb/testsuite/gdb.fortran/function-calls.exp index a14cfaeb08a..00036d96c7c 100644 --- a/gdb/testsuite/gdb.fortran/function-calls.exp +++ b/gdb/testsuite/gdb.fortran/function-calls.exp @@ -24,6 +24,21 @@ if {[prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {debug f90}]} { return -1 } +with_complaints 5 { + set cmd "maint expand-symtabs $srcfile" + set cmd_regexp [string_to_regexp $cmd] + set re_kfail [concat "During symbol reading:" \ + " unable to find array range"] + gdb_test_multiple $cmd "no complaints in srcfile" { + -re -wrap "$re_kfail.*" { + kfail symtab/27388 $gdb_test_name + } + -re "^$cmd_regexp\r\n$gdb_prompt $" { + pass $gdb_test_name + } + } +} + if {![runto [gdb_get_line_number "post_init"]]} then { perror "couldn't run to breakpoint post_init" continue diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp index 53ac9f1408c..1406b917151 100644 --- a/gdb/testsuite/lib/gdb.exp +++ b/gdb/testsuite/lib/gdb.exp @@ -5096,11 +5096,11 @@ proc gdb_load { arg } { } # -# gdb_load_no_complaints -- As gdb_load, but in addition verifies that -# loading caused no symbol reading complaints. +# with_complaints -- Execute BODY and set complaints temporary to N for the +# duration. # -proc gdb_load_no_complaints { arg } { - global gdb_prompt gdb_file_cmd_msg decimal +proc with_complaints { n body } { + global decimal # Save current setting of complaints. set save "" @@ -5112,16 +5112,39 @@ proc gdb_load_no_complaints { arg } { } } - # Fall back to regular gdb_load if we couldn't get the current setting - # of complaints. if { $save == "" } { - return gdb_load $arg + perror "Did not manage to set complaints" + } else { + # Set complaints. + gdb_test_no_output "set complaints $n" "" } - # Temporarily set complaint to a small non-zero number. - gdb_test_no_output "set complaints 5" "" + set code [catch {uplevel 1 $body} result] + + # Restore saved setting of complaints. + if { $save != "" } { + gdb_test_no_output "set complaints $save" "" + } + + if {$code == 1} { + global errorInfo errorCode + return -code $code -errorinfo $errorInfo -errorcode $errorCode $result + } else { + return -code $code $result + } +} + +# +# gdb_load_no_complaints -- As gdb_load, but in addition verifies that +# loading caused no symbol reading complaints. +# +proc gdb_load_no_complaints { arg } { + global gdb_prompt gdb_file_cmd_msg decimal - gdb_load $arg + # Temporarily set complaint to a small non-zero number. + with_complaints 5 { + gdb_load $arg + } # Verify that there were no complaints. set re "^Reading symbols from \[^\r\n\]*\r\n$gdb_prompt $" --------------7D64FF3AA4D0FA437DE32C3B--