From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 53189 invoked by alias); 11 Jul 2016 14:48:49 -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 51796 invoked by uid 89); 11 Jul 2016 14:48:48 -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=Don, substantially, pc, cli 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; Mon, 11 Jul 2016 14:48:38 +0000 Received: from svr-orw-fem-03.mgc.mentorg.com ([147.34.97.39]) by relay1.mentorg.com with esmtp id 1bMcVf-0003Hl-IA from Don_Breazeal@mentor.com ; Mon, 11 Jul 2016 07:48:35 -0700 Received: from [172.30.2.176] (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; Mon, 11 Jul 2016 07:48:35 -0700 Subject: Re: [PING] [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> From: Don Breazeal Message-ID: <5783B1BE.7010206@codesourcery.com> Date: Mon, 11 Jul 2016 14:48:00 -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: <57680C62.5060807@codesourcery.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-07/txt/msg00114.txt.bz2 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) >> { >> >