From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 118981 invoked by alias); 20 Jul 2016 21:07:06 -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 118966 invoked by uid 89); 20 Jul 2016 21:07:05 -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=disp, Don, srcdir, 3237 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; Wed, 20 Jul 2016 21:06:54 +0000 Received: from svr-orw-fem-03.mgc.mentorg.com ([147.34.97.39]) by relay1.mentorg.com with esmtp id 1bPyhf-00061M-T9 from Don_Breazeal@mentor.com ; Wed, 20 Jul 2016 14:06:51 -0700 Received: from [172.30.3.32] (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; Wed, 20 Jul 2016 14:06:51 -0700 Subject: [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> <5783B1BE.7010206@codesourcery.com> From: Don Breazeal Message-ID: <578FE7E6.5070507@codesourcery.com> Date: Wed, 20 Jul 2016 21:07:00 -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: <5783B1BE.7010206@codesourcery.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-07/txt/msg00231.txt.bz2 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) >>> { >>> >> >