From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 76424 invoked by alias); 29 Jul 2016 16:13:45 -0000 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 Received: (qmail 76412 invoked by uid 89); 29 Jul 2016 16:13:44 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=sp1, 485, UD:n, load_lib X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Fri, 29 Jul 2016 16:13:34 +0000 Received: from svr-orw-fem-03.mgc.mentorg.com ([147.34.97.39]) by relay1.mentorg.com with esmtp id 1bTAPk-0003pq-1D from Don_Breazeal@mentor.com ; Fri, 29 Jul 2016 09:13:32 -0700 Received: from [172.30.4.207] (147.34.91.1) by SVR-ORW-FEM-03.mgc.mentorg.com (147.34.97.39) with Microsoft SMTP Server (TLS) id 14.3.224.2; Fri, 29 Jul 2016 09:13:31 -0700 Subject: [PING^4] [PATCH v2] Fix -var-update for registers in frames 1 and up To: , References: <1465854882-42527-1-git-send-email-donb@codesourcery.com> <57680C62.5060807@codesourcery.com> <5783B1BE.7010206@codesourcery.com> <578FE7E6.5070507@codesourcery.com> <5790FF6C.9040003@codesourcery.com> From: Don Breazeal Message-ID: <579B80A6.7090207@codesourcery.com> Date: Fri, 29 Jul 2016 16:13:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <5790FF6C.9040003@codesourcery.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-07/txt/msg00376.txt.bz2 ping On 7/21/2016 9:59 AM, Don Breazeal wrote: > Hi, see below, > > On 7/20/2016 2:06 PM, Don Breazeal wrote: >> ping >> >> On 7/11/2016 7:48 AM, Don Breazeal wrote: >>> >>> ping >>> >>> On 6/20/2016 8:31 AM, Don Breazeal wrote: >>>> On 6/13/2016 2:54 PM, Don Breazeal wrote: >>>>> This is an updated version of a patch to fix access to registers >>>>> for frames other than the current frame via var-update. The piece >>>>> of the patch affecting GDB proper has been completely re-written. >>>>> It changes the initialization of varobj->root->frame in varobj_create >>>>> so that existing mechanisms (with minimal changes) select the correct >>>>> frame and provide correct register values from -var-update. >>>>> >>>>> In addition, the new test for this functionality has been expanded >>>>> to cover an analogous case using floating variable objects, and >>>>> several tests have been updated to account for the fact that with >>>>> the new initialization, -var-create and -var-list-children now >>>>> provide a thread-id field where previously they didn't. >>>>> >>>>> Thanks >>>>> --Don >>>>> >>>>> ------------ >>>>> This patch fixes a problem with using the MI -var-update command >>>>> to access the values of registers in frames other than the current >>>>> frame. The patch includes a test that demonstrates the problem: >>>>> >>>>> * run so there are several frames on the stack >>>>> * create a fixed varobj for $pc in each frame, #'s 1 and above >>>>> * step one instruction, to modify the value of $pc >>>>> * call -var-update for each of the previously created varobjs >>>>> to verify that they are not reported as having changed. >>>>> >>>>> Without the patch, the -var-update command reported that $pc for all >>>>> frames 1 and above had changed to the value of $pc in frame 0. >>>>> >>>>> When a varobj is created by -var-create, varobj->root->frame should >>>>> be set to specified frame. Then for a subsequent -var-update, >>>>> varobj.c:check_scope can use varobj->root->frame to select the >>>>> right frame based on the type of varobj. >>>>> >>>>> The problem is that for register expressions varobj->root->frame is not >>>>> set correctly. This frame tracking is done using the global >>>>> 'innermost_block' which is set in the various parser files (for example >>>>> c-exp.y). However, this is not set for register expressions. >>>>> >>>>> The fix is to change the initialization of innermost_block in >>>>> varobj_create from NULL to the global block, as returned by >>>>> block_global_block. Then varobj_create sets varobj->root->frame >>>>> for register varobjs, and value_of_root_1 can check for the >>>>> global block when determining whether the variable is in-scope >>>>> and select the frame appropriately. >>>>> >>>>> A side-effect of this change is that for register varobjs and some >>>>> global variable varobjs, the output of -var-create now includes the >>>>> thread-id field. The rationale for this is as follow: if we ask for a >>>>> particular expression in a particular frame, that implies a particular >>>>> thread. Thus including the thread-id is correct behavior, and the >>>>> test results have been updated accordingly. >>>>> >>>>> In addition there is a new test, gdb.mi/mi-frame-regs.exp, which >>>>> performs the test described in the bullet list above as well as a >>>>> similar test using a floating variable object to represent $pc. >>>>> >>>>> We attempted a couple alternative solutions: >>>>> * a special case in varobj_update to select the frame was not ideal >>>>> because it didn't use the existing mechanisms to select the frame. >>>>> * setting innermost_block in write_dollar_variable had side-effects >>>>> in the CLI that would have required special case code. >>>>> >>>>> Tested on x86_64 Linux native, no regressions. >>>>> >>>>> gdb/testsuite/ChangeLog: >>>>> 2016-06-13 Don Breazeal >>>>> >>>>> * gdb.ada/mi_interface.exp: Add thread-id field to expected >>>>> output of -var-create and -var-list-children. >>>>> * gdb.ada/mi_var_array.exp: Add thread-id field to expected >>>>> output of -var-list-children. >>>>> * gdb.mi/mi-break.exp (test_error): Add thread-id field to >>>>> expected output of -var-create. >>>>> * gdb.mi/mi-frame-regs.exp: New test script. >>>>> * gdb.mi/mi-var-cmd.exp: Add thread-id field to expected >>>>> output of -var-create. >>>>> * gdb.mi/mi-var-create-rtti.exp: Likewise. >>>>> >>>>> gdb/ChangeLog: >>>>> 2016-06-13 Don Breazeal >>>>> Andrew Burgess >>>>> >>>>> * varobj.c (varobj_create): Initialize innermost_block to >>>>> the global block instead of NULL. >>>>> (new_root_variable): Initialize the thread_id and next >>>>> fields. >>>>> (value_of_root_1): Set within_scope if the variable's >>>>> valid_block field is the global block. >>>>> >>>>> --- >>>>> gdb/testsuite/gdb.ada/mi_interface.exp | 4 +- >>>>> gdb/testsuite/gdb.ada/mi_var_array.exp | 2 +- >>>>> gdb/testsuite/gdb.mi/mi-break.exp | 2 +- >>>>> gdb/testsuite/gdb.mi/mi-frame-regs.exp | 183 ++++++++++++++++++++++++++++ >>>>> gdb/testsuite/gdb.mi/mi-var-cmd.exp | 4 +- >>>>> gdb/testsuite/gdb.mi/mi-var-create-rtti.exp | 2 +- >>>>> gdb/varobj.c | 8 +- >>>>> 7 files changed, 196 insertions(+), 9 deletions(-) >>>>> >>>>> diff --git a/gdb/testsuite/gdb.ada/mi_interface.exp b/gdb/testsuite/gdb.ada/mi_interface.exp >>>>> index 6000ec8..b948cd5 100644 >>>>> --- a/gdb/testsuite/gdb.ada/mi_interface.exp >>>>> +++ b/gdb/testsuite/gdb.ada/mi_interface.exp >>>>> @@ -44,9 +44,9 @@ mi_continue_to_line \ >>>>> "stop at start of main Ada procedure" >>>>> >>>>> mi_gdb_test "-var-create ggg1 * ggg1" \ >>>>> - "\\^done,name=\"ggg1\",numchild=\"1\",value=\"{...}\",type=\" pck.gadatatype\",has_more=\"0\"" \ >>>>> + "\\^done,name=\"ggg1\",numchild=\"1\",value=\"{...}\",type=\" pck.gadatatype\",thread-id=\"1\",has_more=\"0\"" \ >>>>> "Create ggg1 varobj" >>>>> >>>>> mi_gdb_test "-var-list-children 1 ggg1" \ >>>>> - "\\^done,numchild=\"1\",children=\\\[child={name=\"ggg1.i\",exp=\"i\",numchild=\"0\",value=\"42\",type=\"integer\"}\\\],has_more=\"0\"" \ >>>>> + "\\^done,numchild=\"1\",children=\\\[child={name=\"ggg1.i\",exp=\"i\",numchild=\"0\",value=\"42\",type=\"integer\",thread-id=\"1\"}\\\],has_more=\"0\"" \ >>>>> "list ggg1's children" >>>>> diff --git a/gdb/testsuite/gdb.ada/mi_var_array.exp b/gdb/testsuite/gdb.ada/mi_var_array.exp >>>>> index c648e7e..c02d4c9 100644 >>>>> --- a/gdb/testsuite/gdb.ada/mi_var_array.exp >>>>> +++ b/gdb/testsuite/gdb.ada/mi_var_array.exp >>>>> @@ -48,5 +48,5 @@ mi_gdb_test "-var-create vta * vta" \ >>>>> "Create bt varobj" >>>>> >>>>> mi_gdb_test "-var-list-children vta" \ >>>>> - "\\^done,numchild=\"2\",children=\\\[child={name=\"vta.n\",exp=\"n\",numchild=\"0\",type=\"bar\\.int\"},child={name=\"vta.f\",exp=\"f\",numchild=\"0\",type=\"array \\(1 .. n\\) of character\"}\\\],.*" \ >>>>> + "\\^done,numchild=\"2\",children=\\\[child={name=\"vta.n\",exp=\"n\",numchild=\"0\",type=\"bar\\.int\",thread-id=\"1\"},child={name=\"vta.f\",exp=\"f\",numchild=\"0\",type=\"array \\(1 .. n\\) of character\",thread-id=\"1\"}\\\],.*" \ >>>>> "list vta's children" >>>>> diff --git a/gdb/testsuite/gdb.mi/mi-break.exp b/gdb/testsuite/gdb.mi/mi-break.exp >>>>> index 85f328d..bdd43e0 100644 >>>>> --- a/gdb/testsuite/gdb.mi/mi-break.exp >>>>> +++ b/gdb/testsuite/gdb.mi/mi-break.exp >>>>> @@ -213,7 +213,7 @@ proc test_error {} { >>>>> # containing function call, the internal breakpoint created to handle >>>>> # function call would be reported, messing up MI output. >>>>> mi_gdb_test "-var-create V * return_1()" \ >>>>> - "\\^done,name=\"V\",numchild=\"0\",value=\"1\",type=\"int\",has_more=\"0\"" \ >>>>> + "\\^done,name=\"V\",numchild=\"0\",value=\"1\",type=\"int\",thread-id=\"1\",has_more=\"0\"" \ >>>>> "create varobj for function call" >>>>> >>>>> mi_gdb_test "-var-update *" \ >>>>> diff --git a/gdb/testsuite/gdb.mi/mi-frame-regs.exp b/gdb/testsuite/gdb.mi/mi-frame-regs.exp >>>>> new file mode 100644 >>>>> index 0000000..45f81d6 >>>>> --- /dev/null >>>>> +++ b/gdb/testsuite/gdb.mi/mi-frame-regs.exp >>>>> @@ -0,0 +1,183 @@ >>>>> +# Copyright 1999-2016 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 . >>>>> + >>>>> +# Test essential Machine interface (MI) operations >>>>> +# >>>>> +# Verify that -var-update will provide the correct values for floating >>>>> +# and fixed varobjs that represent the pc register. >>>>> +# >>>>> + >>>>> +load_lib mi-support.exp >>>>> +set MIFLAGS "-i=mi" >>>>> + >>>>> +standard_testfile basics.c >>>>> + >>>>> +if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \ >>>>> + executable {debug}] != "" } then { >>>>> + untested mi-frame-regs.exp >>>>> + return -1 >>>>> +} >>>>> + >>>>> +# Return the address of the specified breakpoint. >>>>> + >>>>> +proc breakpoint_address {bpnum} { >>>>> + global hex >>>>> + global expect_out >>>>> + global mi_gdb_prompt >>>>> + >>>>> + send_gdb "info breakpoint $bpnum\n" >>>>> + gdb_expect { >>>>> + -re ".*($hex).*$mi_gdb_prompt$" { >>>>> + return $expect_out(1,string) >>>>> + } >>>>> + -re ".*$mi_gdb_prompt$" { >>>>> + return "" >>>>> + } >>>>> + timeout { >>>>> + return "" >>>>> + } >>>>> + } >>>>> +} >>>>> + >>>>> +# Test that a floating varobj representing $pc will provide the >>>>> +# correct value via -var-update as the program stops at >>>>> +# breakpoints in different functions. >>>>> + >>>>> +proc do_floating_varobj_test {} { >>>>> + global srcfile >>>>> + global hex >>>>> + global expect_out >>>>> + >>>>> + gdb_exit >>>>> + if {[mi_gdb_start]} then { >>>>> + continue >>>>> + } >>>>> + >>>>> + with_test_prefix "floating" { >>>>> + mi_run_to_main >>>>> + >>>>> + # Create a floating varobj for $pc. >>>>> + mi_gdb_test "-var-create --thread 1 --frame 0 - @ \$pc" \ >>>>> + "\\^done,.*value=\"$hex.*" \ >>>>> + "create varobj for pc in frame 0" >>>>> + >>>>> + set nframes 4 >>>>> + for {set i 1} {$i < $nframes} {incr i} { >>>>> + >>>>> + # Run to a breakpoint in each callee function in succession. >>>>> + # Note that we can't use mi_runto because we need the >>>>> + # breakpoint to be persistent, so we can use its address. >>>>> + set bpnum [expr $i + 1] >>>>> + mi_create_breakpoint \ >>>>> + "basics.c:callee$i" \ >>>>> + "insert breakpoint at basics.c:callee$i" \ >>>>> + -number $bpnum -func callee$i -file ".*basics.c" >>>>> + >>>>> + mi_execute_to "exec-continue" "breakpoint-hit" \ >>>>> + "callee$i" ".*" ".*${srcfile}" ".*" \ >>>>> + { "" "disp=\"keep\"" } "breakpoint hit" >>>>> + >>>>> + # Get the value of $pc from the floating varobj. >>>>> + mi_gdb_test "-var-update 1 var1" \ >>>>> + "\\^done,.*value=\"($hex) .*" \ >>>>> + "-var-update for frame $i" >>>>> + set pcval $expect_out(3,string) >>>>> + >>>>> + # Get the address of the current breakpoint. >>>>> + set bpaddr [breakpoint_address $bpnum] >>>>> + if {$bpaddr == ""} then { >>>>> + unresolved "get address of breakpoint $bpnum" >>>>> + return >>>>> + } >>>>> + >>>>> + # Check that the addresses are the same. >>>>> + if {[expr $bpaddr != $pcval]} then { >>>>> + fail "\$pc does not equal address of breakpoint" >>>>> + } else { >>>>> + pass "\$pc equals address of breakpoint" >>>>> + } >>>>> + } >>>>> + } >>>>> +} >>>>> + >>>>> +# Create a varobj for the pc register in each of the frames other >>>>> +# than frame 0. >>>>> + >>>>> +proc var_create_regs {nframes} { >>>>> + global hex >>>>> + >>>>> + for {set i 1} {$i < $nframes} {incr i} { >>>>> + mi_gdb_test "-var-create --thread 1 --frame $i - \* \$pc" \ >>>>> + "\\^done,.*value=\"$hex.*" \ >>>>> + "create varobj for pc in frame $i" >>>>> + } >>>>> +} >>>>> + >>>>> +# Check that -var-update reports that the value of the pc register >>>>> +# for each of the frames 1 and above is reported as unchanged. >>>>> + >>>>> +proc var_update_regs {nframes} { >>>>> + >>>>> + for {set i 1} {$i < $nframes} {incr i} { >>>>> + mi_gdb_test "-var-update 1 var$i" \ >>>>> + "\\^done,(changelist=\\\[\\\])" \ >>>>> + "pc unchanged in -var-update for frame $i" >>>>> + } >>>>> +} >>>>> + >>>>> +# Test that fixed varobjs representing $pc in different stack frames >>>>> +# will provide the correct value via -var-update after the program >>>>> +# counter changes (without substantially changing the stack). >>>>> + >>>>> +proc do_fixed_varobj_test {} { >>>>> + global srcfile >>>>> + >>>>> + gdb_exit >>>>> + if {[mi_gdb_start]} then { >>>>> + continue >>>>> + } >>>>> + >>>>> + with_test_prefix "fixed" { >>>>> + mi_run_to_main >>>>> + >>>>> + # Run to the function 'callee3' so we have several frames. >>>>> + mi_create_breakpoint "basics.c:callee3" \ >>>>> + "insert breakpoint at basics.c:callee3" \ >>>>> + -number 2 -func callee3 -file ".*basics.c" >>>>> + >>>>> + mi_execute_to "exec-continue" "breakpoint-hit" \ >>>>> + "callee3" ".*" ".*${srcfile}" ".*" \ >>>>> + { "" "disp=\"keep\"" } "breakpoint hit" >>>>> + >>>>> + # At the breakpoint in callee3 there are 4 frames. Create a >>>>> + # varobj for the pc in each of frames 1 and above. >>>>> + set nframes 4 >>>>> + var_create_regs $nframes >>>>> + >>>>> + # Step one instruction to change the program counter. >>>>> + mi_execute_to "exec-next-instruction" "end-stepping-range" \ >>>>> + "callee3" ".*" ".*${srcfile}" ".*" "" \ >>>>> + "next instruction in callee3" >>>>> + >>>>> + # Check that -var-update reports that the values are unchanged. >>>>> + var_update_regs $nframes >>>>> + } >>>>> +} >>>>> + >>>>> +do_fixed_varobj_test >>>>> +do_floating_varobj_test >>>>> + >>>>> +mi_gdb_exit >>>>> +return 0 >>>>> diff --git a/gdb/testsuite/gdb.mi/mi-var-cmd.exp b/gdb/testsuite/gdb.mi/mi-var-cmd.exp >>>>> index 558cd6c..68e3cf8 100644 >>>>> --- a/gdb/testsuite/gdb.mi/mi-var-cmd.exp >>>>> +++ b/gdb/testsuite/gdb.mi/mi-var-cmd.exp >>>>> @@ -381,7 +381,7 @@ mi_gdb_test "-var-update *" \ >>>>> "assign same value to func (update)" >>>>> >>>>> mi_gdb_test "-var-create array_ptr * array_ptr" \ >>>>> - "\\^done,name=\"array_ptr\",numchild=\"1\",value=\"$hex \",type=\"int \\*\",has_more=\"0\"" \ >>>>> + "\\^done,name=\"array_ptr\",numchild=\"1\",value=\"$hex \",type=\"int \\*\",thread-id=\"1\",has_more=\"0\"" \ >>>>> "create global variable array_ptr" >>>>> >>>>> mi_gdb_test "-var-assign array_ptr array2" \ >>>>> @@ -608,7 +608,7 @@ mi_check_varobj_value F 7 "check F inside callee" >>>>> # A varobj we fail to read during -var-update should be considered >>>>> # out of scope. >>>>> mi_gdb_test "-var-create null_ptr * **0" \ >>>>> - {\^done,name="null_ptr",numchild="0",value=".*",type="int",has_more="0"} \ >>>>> + {\^done,name="null_ptr",numchild="0",value=".*",type="int",thread-id="1"has_more="0"} \ >>>>> "create null_ptr" >>>>> >>>>> # Allow this to succeed, if address zero is readable, although it >>>>> diff --git a/gdb/testsuite/gdb.mi/mi-var-create-rtti.exp b/gdb/testsuite/gdb.mi/mi-var-create-rtti.exp >>>>> index 3bcb36c..a8cc76f 100644 >>>>> --- a/gdb/testsuite/gdb.mi/mi-var-create-rtti.exp >>>>> +++ b/gdb/testsuite/gdb.mi/mi-var-create-rtti.exp >>>>> @@ -49,6 +49,6 @@ mi_gdb_test "-gdb-set print object on" ".*" >>>>> # We use a explicit cast to (void *) as that is the >>>>> # type that caused the bug this testcase is testing for. >>>>> mi_gdb_test "-var-create sp1 * ((void*)\$sp)" \ >>>>> - "\\^done,name=\"sp1\",numchild=\"0\",value=\"$hex\",type=\"void \\*\",has_more=\"0\"" \ >>>>> + "\\^done,name=\"sp1\",numchild=\"0\",value=\"$hex\",type=\"void \\*\",thread-id=\"1\",has_more=\"0\"" \ >>>>> "-var-create sp1 * \$sp" >>>>> gdb_exit >>>>> diff --git a/gdb/varobj.c b/gdb/varobj.c >>>>> index 6f56cba..1e3f192 100644 >>>>> --- a/gdb/varobj.c >>>>> +++ b/gdb/varobj.c >>>>> @@ -323,7 +323,7 @@ varobj_create (char *objname, >>>>> } >>>>> >>>>> p = expression; >>>>> - innermost_block = NULL; >>>>> + innermost_block = block_global_block (block); >>>>> /* Wrap the call to parse expression, so we can >>>>> return a sensible error. */ >>>>> TRY >>>>> @@ -2103,6 +2103,8 @@ new_root_variable (void) >>>>> var->root->floating = 0; >>>>> var->root->rootvar = NULL; >>>>> var->root->is_valid = 1; >>>>> + var->root->thread_id = 0; >>>>> + var->root->next = NULL; >>>>> >>>>> return var; >>>>> } >>>>> @@ -2268,7 +2270,9 @@ value_of_root_1 (struct varobj **var_handle) >>>>> back_to = make_cleanup_restore_current_thread (); >>>>> >>>>> /* Determine whether the variable is still around. */ >>>>> - if (var->root->valid_block == NULL || var->root->floating) >>>>> + if (var->root->valid_block == NULL >>>>> + || BLOCK_SUPERBLOCK (var->root->valid_block) == NULL >>>>> + || var->root->floating) >>>>> within_scope = 1; >>>>> else if (var->root->thread_id == 0) >>>>> { >>>>> >>>> >>> >> > I've created PR mi/20395 for this issue and marked it with the Target > Milestone 7.12. Since it's an issue of returning incorrect data I'm > proposing that it's a blocker. > thanks > --Don >