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 A6BCB385DC3E for ; Wed, 8 Apr 2020 10:22:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A6BCB385DC3E 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 24DD8AF0F; Wed, 8 Apr 2020 10:22:46 +0000 (UTC) Subject: Re: [PATCH][gdb/symtab] Don't create duplicate psymtab for forward-imported CU From: Tom de Vries To: gdb-patches@sourceware.org Cc: Tom Tromey References: <20200408101912.GA32538@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: <5fe7340e-b1c0-c7a5-d6a1-5b39b46d0297@suse.de> Date: Wed, 8 Apr 2020 12:22:44 +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: <20200408101912.GA32538@delia> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-31.3 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_DMARC_STATUS, 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: Wed, 08 Apr 2020 10:23:00 -0000 On 08-04-2020 12:19, Tom de Vries wrote: > Hi, > > Consider the executable generated for test-case gdb.dwarf2/imported-unit.exp. > > When loading the executable using various tracing: > ... > $ gdb \ > outputs/gdb.dwarf2/imported-unit/imported-unit \ > -batch \ > -iex "set verbose on" \ > -iex "set debug symtab-create 1" > ... > Created psymtab 0x213f380 for module @0xc7. > Created psymtab 0x20e7b00 for module imported_unit.c. > Created psymtab 0x215da20 for module imported_unit.c. > Created psymtab 0x2133630 for module elf-init.c. > Created psymtab 0x215b910 for module ../sysdeps/x86_64/crtn.S. > ... > we notice that there are two psymtabs generated for imported_unit.c. > > This is due to the following: in dwarf2_build_psymtabs_hard we loop over CUs > and generate partial symtabs for those, and if we encounter an import of > another CU, we also generate a partial symtab for that one, unless already > created. > > This works well with backward import references: > - the imported CU is read > - then the importing CU is read > - the import is encountered, but the imported CU is already read, so > we're done. > > But with forward import references, we have instead: > - the importing CU is read > - the import is encountered, and the imported CU is read > - the imported CU is read once more > > Fix this by skipping already created psymtabs in the loop in > dwarf2_build_psymtabs_hard. > > Build in combination with the tentative fix for PR25718 - "[ada] symbol in > imported unit not found" > ( https://sourceware.org/pipermail/gdb-patches/2020-March/167152.html ) to > prevent this regression: > ... > FAIL: gdb.ada/char_enum.exp: ptype pck.Global_Enum_Type > ... > > Tested on x86_64-linux, with native and target board > unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects. > > This causes this regression with the target board: > ... > FAIL: gdb.ada/dgopt.exp: list x.adb:16, 16 > ... > which I consider a seperate PR, filed as PR25801 - "Filename of shared psymtab > is ignored". > [ Forgot to mention ] Using a 2.8GB libxul.so debug file from opensuse tumbleweed, build with lto, we have: ... $ time.sh gdb -batch -iex "maint set dwarf max-cache-age 1000" -iex "set language c" usr/lib/debug/usr/lib64/firefox/libxul.so-74.0-1.1.x86_64.debug maxmem: 10417196 real: 116.62 user: 114.85 system: 2.37 ... and with this patch: ... $ time.sh gdb -batch -iex "maint set dwarf max-cache-age 1000" -iex "set language c" usr/lib/debug/usr/lib64/firefox/libxul.so-74.0-1.1.x86_64.debug maxmem: 10436372 real: 77.42 user: 75.54 system: 2.46 OK for trunk? Thanks, - Tom > [gdb/symtab] Don't create duplicate psymtab for forward-imported CU > > gdb/ChangeLog: > > 2020-04-08 Tom de Vries > > PR symtab/25700 > * dwarf2/read.c (dwarf2_build_psymtabs_hard): Don't create psymtab for > CU if already created. > > gdb/testsuite/ChangeLog: > > 2020-04-08 Tom de Vries > > PR symtab/25700 > * gdb.dwarf2/imported-unit.exp: Verify that there's only one partial > symtab for imported_unit.c. > > --- > gdb/dwarf2/read.c | 7 ++++++- > gdb/testsuite/gdb.dwarf2/imported-unit.exp | 18 ++++++++++++++++++ > 2 files changed, 24 insertions(+), 1 deletion(-) > > diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c > index c0b5e58b17..8b761e891e 100644 > --- a/gdb/dwarf2/read.c > +++ b/gdb/dwarf2/read.c > @@ -7781,7 +7781,12 @@ dwarf2_build_psymtabs_hard (struct dwarf2_per_objfile *dwarf2_per_objfile) > addrmap_create_mutable (&temp_obstack)); > > for (dwarf2_per_cu_data *per_cu : dwarf2_per_objfile->all_comp_units) > - process_psymtab_comp_unit (per_cu, false, language_minimal); > + { > + if (per_cu->v.psymtab != NULL) > + /* In case a forward DW_TAG_imported_unit has read the CU already. */ > + continue; > + process_psymtab_comp_unit (per_cu, false, language_minimal); > + } > > /* This has to wait until we read the CUs, we need the list of DWOs. */ > process_skeletonless_type_units (dwarf2_per_objfile); > diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit.exp b/gdb/testsuite/gdb.dwarf2/imported-unit.exp > index 41a7505459..d7b3d4c539 100644 > --- a/gdb/testsuite/gdb.dwarf2/imported-unit.exp > +++ b/gdb/testsuite/gdb.dwarf2/imported-unit.exp > @@ -168,6 +168,24 @@ if { $psymtabs_p } { > } else { > unsupported $test > } > + > +# Verify that there's only one partial symtab for imported_unit.c. Test-case > +# for PR25700. > +set test "no duplicate psymtab for imported_unit.c" > +if { $psymtabs_p } { > + set line "Partial symtab for source file imported_unit.c" > + gdb_test_multiple "maint print psymbols" $test { > + -re -wrap "$line.*$line.*" { > + fail $gdb_test_name > + } > + -re -wrap "$line.*" { > + pass $gdb_test_name > + } > + } > +} else { > + unsupported $test > +} > + > # Sanity check > gdb_test "ptype main" "= int \\(void\\)" > >