From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 107BA385BF81 for ; Thu, 16 Apr 2020 12:59:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 107BA385BF81 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 [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 991ECAC6D; Thu, 16 Apr 2020 12:59:00 +0000 (UTC) Subject: Re: [PATCH][gdb/symtab] Handle PU without import in "save gdb-index" From: Tom de Vries To: gdb-patches@sourceware.org References: <20200407094642.GA19969@delia> Autocrypt: addr=tdevries@suse.de; keydata= xsBNBF0ltCcBCADDhsUnMMdEXiHFfqJdXeRvgqSEUxLCy/pHek88ALuFnPTICTwkf4g7uSR7 HvOFUoUyu8oP5mNb4VZHy3Xy8KRZGaQuaOHNhZAT1xaVo6kxjswUi3vYgGJhFMiLuIHdApoc u5f7UbV+egYVxmkvVLSqsVD4pUgHeSoAcIlm3blZ1sDKviJCwaHxDQkVmSsGXImaAU+ViJ5l CwkvyiiIifWD2SoOuFexZyZ7RUddLosgsO0npVUYbl6dEMq2a5ijGF6/rBs1m3nAoIgpXk6P TCKlSWVW6OCneTaKM5C387972qREtiArTakRQIpvDJuiR2soGfdeJ6igGA1FZjU+IsM5ABEB AAHNH1RvbSBkZSBWcmllcyA8dGRldnJpZXNAc3VzZS5kZT7CwKsEEwEIAD4WIQSsnSe5hKbL MK1mGmjuhV2rbOJEoAUCXSW0JwIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAh CRDuhV2rbOJEoBYhBKydJ7mEpsswrWYaaO6FXats4kSgc48H/Ra2lq5p3dHsrlQLqM7N68Fo eRDf3PMevXyMlrCYDGLVncQwMw3O/AkousktXKQ42DPJh65zoXB22yUt8m0g12xkLax98KFJ 5NyUloa6HflLl+wQL/uZjIdNUQaHQLw3HKwRMVi4l0/Jh/TygYG1Dtm8I4o708JS4y8GQxoQ UL0z1OM9hyM3gI2WVTTyprsBHy2EjMOu/2Xpod95pF8f90zBLajy6qXEnxlcsqreMaqmkzKn 3KTZpWRxNAS/IH3FbGQ+3RpWkNGSJpwfEMVCeyK5a1n7yt1podd1ajY5mA1jcaUmGppqx827 8TqyteNe1B/pbiUt2L/WhnTgW1NC1QDOwE0EXSW0JwEIAM99H34Bu4MKM7HDJVt864MXbx7B 1M93wVlpJ7Uq+XDFD0A0hIal028j+h6jA6bhzWto4RUfDl/9mn1StngNVFovvwtfzbamp6+W pKHZm9X5YvlIwCx131kTxCNDcF+/adRW4n8CU3pZWYmNVqhMUiPLxElA6QhXTtVBh1RkjCZQ Kmbd1szvcOfaD8s+tJABJzNZsmO2hVuFwkDrRN8Jgrh92a+yHQPd9+RybW2l7sJv26nkUH5Z 5s84P6894ebgimcprJdAkjJTgprl1nhgvptU5M9Uv85Pferoh2groQEAtRPlCGrZ2/2qVNe9 XJfSYbiyedvApWcJs5DOByTaKkcAEQEAAcLAkwQYAQgAJhYhBKydJ7mEpsswrWYaaO6FXats 4kSgBQJdJbQnAhsMBQkDwmcAACEJEO6FXats4kSgFiEErJ0nuYSmyzCtZhpo7oVdq2ziRKD3 twf7BAQBZ8TqR812zKAD7biOnWIJ0McV72PFBxmLIHp24UVe0ZogtYMxSWKLg3csh0yLVwc7 H3vldzJ9AoK3Qxp0Q6K/rDOeUy3HMqewQGcqrsRRh0NXDIQk5CgSrZslPe47qIbe3O7ik/MC q31FNIAQJPmKXX25B115MMzkSKlv4udfx7KdyxHrTSkwWZArLQiEZj5KG4cCKhIoMygPTA3U yGaIvI/BGOtHZ7bEBVUCFDFfOWJ26IOCoPnSVUvKPEOH9dv+sNy7jyBsP5QxeTqwxC/1ZtNS DUCSFQjqA6bEGwM22dP8OUY6SC94x1G81A9/xbtm9LQxKm0EiDH8KBMLfQ== Message-ID: Date: Thu, 16 Apr 2020 14:58:59 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200407094642.GA19969@delia> Content-Type: multipart/mixed; boundary="------------FB85711FB2467FAB81904BD5" Content-Language: en-US X-Spam-Status: No, score=-30.5 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_DMARC_STATUS, KAM_SHORT, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org 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: , X-List-Received-Date: Thu, 16 Apr 2020 12:59:04 -0000 This is a multi-part message in MIME format. --------------FB85711FB2467FAB81904BD5 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 07-04-2020 11:46, Tom de Vries wrote: > Hi, > > Consider the test-case added in this patch, with resulting dwarf: > ... > Compilation Unit @ offset 0xc7: > Length: 0x2c (32-bit) > Version: 4 > Abbrev Offset: 0x64 > Pointer Size: 8 > <0>: Abbrev Number: 2 (DW_TAG_partial_unit) > DW_AT_language : 2 (non-ANSI C) > DW_AT_name : imported_unit.c > <1>: Abbrev Number: 3 (DW_TAG_base_type) > DW_AT_byte_size : 4 > DW_AT_encoding : 5 (signed) > DW_AT_name : int > <1>: Abbrev Number: 4 (DW_TAG_subprogram) > DW_AT_name : main > DW_AT_type : <0xe4> > DW_AT_external : 1 > <1>: Abbrev Number: 0 > Compilation Unit @ offset 0xf7: > Length: 0x2c (32-bit) > Version: 4 > Abbrev Offset: 0x85 > Pointer Size: 8 > <0><102>: Abbrev Number: 2 (DW_TAG_compile_unit) > <103> DW_AT_language : 2 (non-ANSI C) > <104> DW_AT_name : > <1><111>: Abbrev Number: 3 (DW_TAG_subprogram) > <112> DW_AT_abstract_origin: <0xeb> > <116> DW_AT_low_pc : 0x4004a7 > <11e> DW_AT_high_pc : 0x4004b2 > <1><126>: Abbrev Number: 0 > ... > > When run with target board cc-with-gdb-index, we run into: > ... > (gdb) break main > warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.) > > warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) > > Breakpoint 1 at 0x4004ab > (gdb) PASS: gdb.dwarf2/imported-unit-runto-main.exp: setting breakpoint at main > run > Starting program: /data/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.dwarf2/imported-unit-runto-main/imported-unit-runto-main > warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.) > > warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) > > > Breakpoint 1, warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) > warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) > > 0x00000000004004ab in main () > warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) > > (gdb) FAIL: gdb.dwarf2/imported-unit-runto-main.exp: running to main in runto > ... > > Looking at the .gdb_index section contents using objdump --dwarf=gdb_index, we > have: > ... > CU table: > [ 0] 0x0 - 0x2d > [ 1] 0x2e - 0xa4 > [ 2] 0xa5 - 0xc6 > [ 3] 0xf7 - 0x126 > [ 4] 0x127 - 0x2de > [ 5] 0x2df - 0x300 > > Address table: > 00000000004004a7 00000000004004b2 4 > > Symbol table: > [489] main: 4 [global, function] > ... > We see that both the main symbol, and main address range map to CU 4, which has > offset range 0x127 - 0x2de, while main actually is contained in CU 3 at offset > range 0xf7 - 0x126. > > This is caused by this continue in write_gdbindex, which triggers for the PU: > ... > /* CU of a shared file from 'dwz -m' may be unused by this main file. > It may be referenced from a local scope but in such case it does not > need to be present in .gdb_index. */ > if (psymtab == NULL) > continue; > ... > The continue causes the PU to be skipped in the CU table (we can see that the > PU offset range 0xc7-0xf6 is missing) but the references are not taking that > into account. > > I've tried fixing this in the optimal way, by updating the references, but ran > into trouble when follow_die_offset tries to find the CU for the inter-CU > ref. Because the PU is missing from the CU table, > dwarf2_find_containing_comp_unit bisects to the wrong CU. > > Fix this by not skipping the PU in the CU table. > > Build and reg-tested on x86_64-linux, with native and target boards > cc-with-gdb-index, cc-with-dwz and cc-with-dwz-m. > I've updated the test-case to trigger the error condition in a native testrun (before it only triggered with target board cc-with-gdb-index). Committed. Thanks, - Tom --------------FB85711FB2467FAB81904BD5 Content-Type: text/x-patch; charset=UTF-8; name="0001-gdb-symtab-Handle-PU-without-import-in-save-gdb-index.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-gdb-symtab-Handle-PU-without-import-in-save-gdb-index.p"; filename*1="atch" [gdb/symtab] Handle PU without import in "save gdb-index" Consider the test-case added in this patch, with resulting dwarf: ... Compilation Unit @ offset 0xc7: Length: 0x2c (32-bit) Version: 4 Abbrev Offset: 0x64 Pointer Size: 8 <0>: Abbrev Number: 2 (DW_TAG_partial_unit) DW_AT_language : 2 (non-ANSI C) DW_AT_name : imported_unit.c <1>: Abbrev Number: 3 (DW_TAG_base_type) DW_AT_byte_size : 4 DW_AT_encoding : 5 (signed) DW_AT_name : int <1>: Abbrev Number: 4 (DW_TAG_subprogram) DW_AT_name : main DW_AT_type : <0xe4> DW_AT_external : 1 <1>: Abbrev Number: 0 Compilation Unit @ offset 0xf7: Length: 0x2c (32-bit) Version: 4 Abbrev Offset: 0x85 Pointer Size: 8 <0><102>: Abbrev Number: 2 (DW_TAG_compile_unit) <103> DW_AT_language : 2 (non-ANSI C) <104> DW_AT_name : <1><111>: Abbrev Number: 3 (DW_TAG_subprogram) <112> DW_AT_abstract_origin: <0xeb> <116> DW_AT_low_pc : 0x4004a7 <11e> DW_AT_high_pc : 0x4004b2 <1><126>: Abbrev Number: 0 ... When run with target board cc-with-gdb-index, we run into: ... (gdb) break main warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.) warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) Breakpoint 1 at 0x4004ab (gdb) PASS: gdb.dwarf2/imported-unit-runto-main.exp: setting breakpoint at main run Starting program: /data/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.dwarf2/imported-unit-runto-main/imported-unit-runto-main warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.) warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) Breakpoint 1, warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) 0x00000000004004ab in main () warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.) (gdb) FAIL: gdb.dwarf2/imported-unit-runto-main.exp: running to main in runto ... Looking at the .gdb_index section contents using objdump --dwarf=gdb_index, we have: ... CU table: [ 0] 0x0 - 0x2d [ 1] 0x2e - 0xa4 [ 2] 0xa5 - 0xc6 [ 3] 0xf7 - 0x126 [ 4] 0x127 - 0x2de [ 5] 0x2df - 0x300 Address table: 00000000004004a7 00000000004004b2 4 Symbol table: [489] main: 4 [global, function] ... We see that both the main symbol, and main address range map to CU 4, which has offset range 0x127 - 0x2de, while main actually is contained in CU 3 at offset range 0xf7 - 0x126. This is caused by this continue in write_gdbindex, which triggers for the PU: ... /* CU of a shared file from 'dwz -m' may be unused by this main file. It may be referenced from a local scope but in such case it does not need to be present in .gdb_index. */ if (psymtab == NULL) continue; ... The continue causes the PU to be skipped in the CU table (we can see that the PU offset range 0xc7-0xf6 is missing) but the references are not taking that into account. I've tried fixing this in the optimal way, by updating the references, but ran into trouble when follow_die_offset tries to find the CU for the inter-CU ref. Because the PU is missing from the CU table, dwarf2_find_containing_comp_unit bisects to the wrong CU. Fix this by not skipping the PU in the CU table. Build and reg-tested on x86_64-linux, with native and target boards cc-with-gdb-index, cc-with-dwz and cc-with-dwz-m. gdb/ChangeLog: 2020-04-07 Tom de Vries PR symtab/25791 * dwarf2/index-write.c (write_gdbindex): Generate CU table entries for CUs without psymtab. gdb/testsuite/ChangeLog: 2020-04-07 Tom de Vries PR symtab/25791 * gdb.dwarf2/gdb-add-index.exp (add_gdb_index): Move ... (ensure_gdb_index): and factor out and move ... * lib/gdb.exp (add_gdb_index, ensure_gdb_index): ... here. * gdb.dwarf2/imported-unit-runto-main.exp: New file. --- gdb/dwarf2/index-write.c | 19 ++--- gdb/testsuite/gdb.dwarf2/gdb-add-index.exp | 40 +--------- .../gdb.dwarf2/imported-unit-runto-main.exp | 92 ++++++++++++++++++++++ gdb/testsuite/lib/gdb.exp | 43 ++++++++++ 4 files changed, 146 insertions(+), 48 deletions(-) diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index 8c933dc63b..b6a13a0ca1 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -1426,18 +1426,15 @@ write_gdbindex (struct dwarf2_per_objfile *dwarf2_per_objfile, FILE *out_file, = dwarf2_per_objfile->all_comp_units[i]; partial_symtab *psymtab = per_cu->v.psymtab; - /* CU of a shared file from 'dwz -m' may be unused by this main file. - It may be referenced from a local scope but in such case it does not - need to be present in .gdb_index. */ - if (psymtab == NULL) - continue; - - if (psymtab->user == NULL) - recursively_write_psymbols (objfile, psymtab, &symtab, - psyms_seen, i); + if (psymtab != NULL) + { + if (psymtab->user == NULL) + recursively_write_psymbols (objfile, psymtab, &symtab, + psyms_seen, i); - const auto insertpair = cu_index_htab.emplace (psymtab, i); - gdb_assert (insertpair.second); + const auto insertpair = cu_index_htab.emplace (psymtab, i); + gdb_assert (insertpair.second); + } /* The all_comp_units list contains CUs read from the objfile as well as from the eventual dwz file. We need to place the entry in the diff --git a/gdb/testsuite/gdb.dwarf2/gdb-add-index.exp b/gdb/testsuite/gdb.dwarf2/gdb-add-index.exp index 32d319f475..708f4b1375 100644 --- a/gdb/testsuite/gdb.dwarf2/gdb-add-index.exp +++ b/gdb/testsuite/gdb.dwarf2/gdb-add-index.exp @@ -27,48 +27,14 @@ if { [prepare_for_testing "failed to prepare" "${testfile}" \ return -1 } -# Add a .gdb_index section to PROGRAM. -# PROGRAM is assumed to be the output of standard_output_file. -# Returns the 0 if there is a failure, otherwise 1. - -proc add_gdb_index { program } { - global srcdir GDB env BUILD_DATA_DIRECTORY - set contrib_dir "$srcdir/../contrib" - set env(GDB) "$GDB --data-directory=$BUILD_DATA_DIRECTORY" - set result [catch "exec $contrib_dir/gdb-add-index.sh $program" output] - if { $result != 0 } { - verbose -log "result is $result" - verbose -log "output is $output" - return 0 - } - - return 1 -} - -# Build a copy of the program with an index (.gdb_index/.debug_names). -# But only if the toolchain didn't already create one: gdb doesn't support -# building an index from a program already using one. - -set test "check if index present" -gdb_test_multiple "mt print objfiles ${testfile}" $test { - -re "gdb_index.*${gdb_prompt} $" { - set binfile_with_index $binfile - } - -re "debug_names.*${gdb_prompt} $" { - set binfile_with_index $binfile - } - -re "Psymtabs.*${gdb_prompt} $" { - if { [add_gdb_index $binfile] != "1" } { - return -1 - } - set binfile_with_index $binfile - } +if { [ensure_gdb_index $binfile] == -1 } { + return -1 } # Ok, we have a copy of $binfile with an index. # Restart gdb and verify the index was used. -clean_restart ${binfile_with_index} +clean_restart ${binfile} gdb_test "mt print objfiles ${testfile}" \ "(gdb_index|debug_names).*" \ "index used" diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit-runto-main.exp b/gdb/testsuite/gdb.dwarf2/imported-unit-runto-main.exp new file mode 100644 index 0000000000..2794684053 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/imported-unit-runto-main.exp @@ -0,0 +1,92 @@ +# Copyright 2020 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 . + +load_lib dwarf.exp + +# This test can only be run on targets which support DWARF-2 and use gas. +if {![dwarf2_support]} { + return 0 +}; + +standard_testfile main.c .S + +set executable ${testfile} +set asm_file [standard_output_file ${srcfile2}] + +# We need to know the size of integer types in order to write some of the +# debugging info we'd like to generate. +if [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] { + return -1 +} + +# Create the DWARF. +Dwarf::assemble $asm_file { + declare_labels cu_label main_label int_label + declare_labels aaa_label + set int_size [get_sizeof "int" 4] + + global srcdir subdir srcfile + + extern main + + set main_range [function_range main ${srcdir}/${subdir}/${srcfile}] + set main_start [lindex $main_range 0] + set main_length [lindex $main_range 1] + + cu {} { + cu_label: partial_unit { + {language @DW_LANG_C} + {name "imported_unit.c"} + } { + int_label: base_type { + {byte_size $int_size sdata} + {encoding @DW_ATE_signed} + {name int} + } + + main_label: subprogram { + {name main} + {type :$int_label} + {external 1 flag} + } + } + } + + cu {} { + compile_unit { + {language @DW_LANG_C} + {name ""} + } { + subprogram { + {abstract_origin %$main_label} + {low_pc $main_start addr} + {high_pc "$main_start + $main_length" addr} + } + } + } +} + +if { [prepare_for_testing "failed to prepare" ${testfile} \ + [list $srcfile $asm_file] {nodebug}] } { + return -1 +} + +if { [ensure_gdb_index $binfile] == -1 } { + return -1 +} + +clean_restart ${binfile} + +runto main message diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp index 52687ad89a..8418c3d875 100644 --- a/gdb/testsuite/lib/gdb.exp +++ b/gdb/testsuite/lib/gdb.exp @@ -7038,5 +7038,48 @@ proc verify_psymtab_expanded { filename readin } { } } +# Add a .gdb_index section to PROGRAM. +# PROGRAM is assumed to be the output of standard_output_file. +# Returns the 0 if there is a failure, otherwise 1. + +proc add_gdb_index { program } { + global srcdir GDB env BUILD_DATA_DIRECTORY + set contrib_dir "$srcdir/../contrib" + set env(GDB) "$GDB --data-directory=$BUILD_DATA_DIRECTORY" + set result [catch "exec $contrib_dir/gdb-add-index.sh $program" output] + if { $result != 0 } { + verbose -log "result is $result" + verbose -log "output is $output" + return 0 + } + + return 1 +} + +# Add a .gdb_index section to PROGRAM, unless it alread has an index +# (.gdb_index/.debug_names). Gdb doesn't support building an index from a +# program already using one. Return 1 if a .gdb_index was added, return 0 +# if it already contained an index, and -1 if an error occurred. + +proc ensure_gdb_index { binfile } { + set testfile [file tail $binfile] + set test "check if index present" + gdb_test_multiple "mt print objfiles ${testfile}" $test { + -re -wrap "gdb_index.*" { + return 0 + } + -re -wrap "debug_names.*" { + return 0 + } + -re -wrap "Psymtabs.*" { + if { [add_gdb_index $binfile] != "1" } { + return -1 + } + return 1 + } + } + return -1 +} + # Always load compatibility stuff. load_lib future.exp --------------FB85711FB2467FAB81904BD5--