From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id C6AFF385841D for ; Mon, 7 Mar 2022 20:40:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C6AFF385841D Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-582-JzKH37fOMYytyP2KE18ctQ-1; Mon, 07 Mar 2022 15:40:01 -0500 X-MC-Unique: JzKH37fOMYytyP2KE18ctQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 966F71854E26; Mon, 7 Mar 2022 20:40:00 +0000 (UTC) Received: from [10.97.116.31] (ovpn-116-31.gru2.redhat.com [10.97.116.31]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E98CC61064; Mon, 7 Mar 2022 20:39:58 +0000 (UTC) Message-ID: Date: Mon, 7 Mar 2022 17:39:55 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: [PATCH 07/11] fix gdb.base/call-ar-st to work with clang To: Pedro Alves , gdb-patches@sourceware.org References: <20220126195053.69559-1-blarsen@redhat.com> <20220126195053.69559-8-blarsen@redhat.com> From: Bruno Larsen In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-13.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Mon, 07 Mar 2022 20:40:05 -0000 On 3/2/22 15:59, Pedro Alves wrote: > On 2022-01-26 19:50, Bruno Larsen via Gdb-patches wrote: >> When running this test with clang-compiled code, this test was failing >> by producing an output like >> array_i=, ... >> >> instead of >> >> array_i = , ... >> >> This commit changes the testcase to accept both outputs, as they are >> functionally identical. > > It would be useful to explain that the symbols in question are local static variables. > "main" is the name of the function they are defined in, and Clang puts that in the elf/linkage name. > GCC instead appends a sequence number to the linkage name: > > $ nm -A call-ar-st.gcc | grep integer_ > call-ar-st/call-ar-st:00000000000061a0 b integer_array.3968 > > $ nm -A call-ar-st.clang | grep integer_ > call-ar-st:00000000004061a0 b main.integer_array > > Note that for GCC, even though the ELF symbol is called "integer_array.3968", GDB still > prints "integer_array", without the suffix. I wonder how that happens? Anyone knows offhand? > It kind of looks like the testcase was expecting that the ".3968" suffix could appear in > the output, given that it expects "array_i=" instead of "array_i=" ? I tried to dig around for a bit, but couldn't find any obvious location. I can look some more if we ultimately decide it is a good idea to remove it, but personally, I think that knowing where the variable was declared could be helpful for debugging. Meanwhile, your patch looks good, I can add it to my tree for pushing at the end. > >> --- >> gdb/testsuite/gdb.base/call-ar-st.exp | 13 ++++++++++--- >> 1 file changed, 10 insertions(+), 3 deletions(-) >> >> diff --git a/gdb/testsuite/gdb.base/call-ar-st.exp b/gdb/testsuite/gdb.base/call-ar-st.exp >> index d1fb3ac9ec1..e447d3e231d 100644 >> --- a/gdb/testsuite/gdb.base/call-ar-st.exp >> +++ b/gdb/testsuite/gdb.base/call-ar-st.exp >> @@ -153,9 +153,16 @@ if {!$skip_float_test && \ >> >> #step >> set stop_line [gdb_get_line_number "-step1-"] >> -gdb_test "step" \ >> - "print_all_arrays \\(array_i=, array_c= .ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa., array_f=, array_d=\\) at .*$srcfile:$stop_line\[ \t\r\n\]+$stop_line.*print_int_array\\(array_i\\);.*" \ >> - "step inside print_all_arrays" >> + >> +gdb_test_multiple "step" "" { >> + >> + -re "print_all_arrays \\(array_i=, array_c= .ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa., array_f=, array_d=\\) at .*$srcfile:$stop_line\[ \t\r\n\]+$stop_line.*print_int_array\\(array_i\\);.*" { >> + pass "step inside print_all_arrays" >> + } >> + -re "print_all_arrays \\(array_i=, array_c= .ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa., array_f=, array_d=\\) at .*$srcfile:$stop_line\[ \t\r\n\]+$stop_line.*print_int_array\\(array_i\\);.*" { >> + pass "step inside print_all_arrays (clang)" >> + } >> +} >> > > If we end up taking the approach of accepting the current GDB output, then it would seem better > to me to continue having a single expression. Something like this: > > From d024950e743df1712f9adda759023e5ba07ee6e1 Mon Sep 17 00:00:00 2001 > From: Bruno Larsen > Date: Wed, 2 Mar 2022 18:09:31 +0000 > Subject: [PATCH] Fix gdb.base/call-ar-st to work with Clang > > When running gdb.base/call-ar-st.exp against Clang, we see one FAIL, > like so: > > print_all_arrays (array_i=, array_c= "ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa > ZaZaZaZaZaZaZaZaZaZaZaZa", array_f=, array_d=) at ../../../src/gdb/testsuite/gdb.base/call-ar-st.c:274 > 274 print_int_array(array_i); /* -step1- */ > (gdb) FAIL: gdb.base/call-ar-st.exp: step inside print_all_arrays > > With GCC we instead see: > > print_all_arrays (array_i=, array_c= "ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa", array_f=, array_d=) at /home/pedro/gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/call-ar-st.c:274 > 274 print_int_array(array_i); /* -step1- */ > (gdb) PASS: gdb.base/call-ar-st.exp: step inside print_all_arrays > > The difference is that with Clang we get: > > array_i=, ... > > instead of > > array_i = , ... > > These symbols are local static variables, and "main" is the name of > the function they are defined in. GCC instead appends a sequence > number to the linkage name: > > $ nm -A call-ar-st.gcc | grep integer_ > call-ar-st/call-ar-st:00000000000061a0 b integer_array.3968 > > $ nm -A call-ar-st.clang | grep integer_ > call-ar-st:00000000004061a0 b main.integer_array > > This commit changes the testcase to accept both outputs, as they are > functionally identical. > > Co-Authored-By: Pedro Alves > Change-Id: Iaf2ccdb9d5996e0268ed12f595a6e04b368bfcb4 > --- > gdb/testsuite/gdb.base/call-ar-st.exp | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/gdb/testsuite/gdb.base/call-ar-st.exp b/gdb/testsuite/gdb.base/call-ar-st.exp > index d1fb3ac9ec1..43fd6ff9f40 100644 > --- a/gdb/testsuite/gdb.base/call-ar-st.exp > +++ b/gdb/testsuite/gdb.base/call-ar-st.exp > @@ -151,10 +151,21 @@ if {!$skip_float_test && \ > gdb_test "continue" ".*" "" > } > > +# Return a regexp that matches the linkage name of SYM, assuming SYM > +# is a local static variable inside the main function. > +proc main_static_local_re {sym} { > + # Clang prepends the function name + '.'. > + return "(main\\.)?${sym}" > +} > + > #step > set stop_line [gdb_get_line_number "-step1-"] > gdb_test "step" \ > - "print_all_arrays \\(array_i=, array_c= .ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa., array_f=, array_d=\\) at .*$srcfile:$stop_line\[ \t\r\n\]+$stop_line.*print_int_array\\(array_i\\);.*" \ > + "print_all_arrays \\(array_i=<[main_static_local_re integer_array]>,\ > + array_c=<[main_static_local_re char_array]> .ZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZaZa.,\ > + array_f=<[main_static_local_re float_array]>,\ > + array_d=<[main_static_local_re double_array]>\\)\ > + at .*$srcfile:$stop_line\[ \t\r\n\]+$stop_line.*print_int_array\\(array_i\\);.*" \ > "step inside print_all_arrays" > > #step -over > -- Cheers! Bruno Larsen