From patchwork Mon Mar 28 21:33:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Don Breazeal X-Patchwork-Id: 11542 Received: (qmail 107437 invoked by alias); 28 Mar 2016 21:34:18 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 107420 invoked by uid 89); 28 Mar 2016 21:34:17 -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=luis, Luis, thrown, trial 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, 28 Mar 2016 21:34:07 +0000 Received: from svr-orw-fem-06.mgc.mentorg.com ([147.34.97.120]) by relay1.mentorg.com with esmtp id 1akenV-0005da-DP from Don_Breazeal@mentor.com ; Mon, 28 Mar 2016 14:34:05 -0700 Received: from build4-lucid-cs (147.34.91.1) by SVR-ORW-FEM-06.mgc.mentorg.com (147.34.97.120) with Microsoft SMTP Server id 14.3.224.2; Mon, 28 Mar 2016 14:34:05 -0700 Received: by build4-lucid-cs (Postfix, from userid 1905) id EC65541294; Mon, 28 Mar 2016 14:34:04 -0700 (PDT) From: Don Breazeal To: , , Subject: [PATCH v2 1/2] Optzd-out ptr: New test for error handling Date: Mon, 28 Mar 2016 14:33:39 -0700 Message-ID: <1459200820-24735-2-git-send-email-donb@codesourcery.com> In-Reply-To: <1459200820-24735-1-git-send-email-donb@codesourcery.com> References: <56CEF1F5.7060307@redhat.com> <1459200820-24735-1-git-send-email-donb@codesourcery.com> MIME-Version: 1.0 X-IsSubscribed: yes The previous version of this patch was a single patch rather than a patchset, and lacked any test case. This patch adds a new test to address Luis' and Pedro's comments on the original patch: On 2/23/2016 5:14 PM, Gustavo, Luis wrote: > On 02/23/2016 09:19 PM, Don Breazeal wrote: >> Testing: >> I looked at creating a test case for this, but so far haven't been >> able to create anything general enough to include in the test suite. > As for the testcase, how about one that creates a few pointer variables > (to basic types, structures, arrays and other meaningful ones) and tries > to print their original values with the "print object" enabled. This > would be in MI mode, of course. > > I'd expect the error to be thrown in an unpatched gdb and a out> string for the patched debugger. On 2/25/2016 4:22 AM, Pedro Alves wrote: > On 02/24/2016 04:31 PM, Don Breazeal wrote: >> The main problem so far has been to get the compiler to optimize out the >> variables that I want it to optimize out, with a target that is generic >> enough that I can generate some assembly code that will run on something >> other than a specific version of a CPU. Trial and error. > > Sounds like a job for the testsuite's dwarf assembler? ------- This patch implements a test that ensures that with "set print object on", -var-create returns "" for an optimized out pointer to structure, rather than throwing an error, while also ensuring that any attempt to dereference the pointer *will* throw an error. It uses the dwarf assembler to construct the appropriate debug info to represent a pointer-to-struct in the program as optimized out, and then accesses that pointer in various ways. The test uses both the console interpreter and the MI interpreter. Tested on native Linux x86_64. WDYT? thanks --Don 2016-03-28 Don Breazeal * gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.c: New test program. * gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.exp: New test script. --- gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.c | 50 +++++ gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.exp | 255 +++++++++++++++++++++++++ 2 files changed, 305 insertions(+) diff --git a/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.c b/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.c new file mode 100644 index 0000000..003fdc0 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.c @@ -0,0 +1,50 @@ +/* Copyright 2016 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 . */ + +struct foo +{ + int a; + int x[5]; + struct foo *y; +}; + +asm (".section \".text\""); +asm (".balign 8"); +asm ("func01_start: .globl func01_start"); + +int +func01 (void) +{ + struct foo *ptr; + + ptr = (struct foo *) 0x0; + return 0; +} + +asm ("func01_end: .globl func01_end"); + +asm ("main_start: .globl main_start"); +int +main () +{ + int i; + + i = func01 (); + return 0; +} + +asm ("main_end: .globl main_end"); diff --git a/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.exp b/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.exp new file mode 100644 index 0000000..51fdb14 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-opt-structptr.exp @@ -0,0 +1,255 @@ +# Copyright 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 . + +# This test ensures that with "set print object on", -var-create will +# return "" for an optimized out pointer to structure, +# rather than attempting to dereference the pointer to determine its +# actual type (instead of its declared type). We want to test that GDB +# can display such a pointer without throwing an error, while also +# ensuring that any attempt to dereference the pointer *will* throw an +# error. + +load_lib dwarf.exp + +# This test can only be run on targets which support DWARF-2 and use gas. +if {![dwarf2_support]} { + return 0 +} + +standard_testfile dw2-opt-structptr.c dw2-opt-structptr-dw.S + +# Generate a test program with dwarf information showing the variable +# 'ptr', a pointer-to-struct, as optimized out. The dwarf will also +# describe the structure as have a scalar, array, and pointer-to-struct +# members. + +proc build_test_program {} { + global testfile + global srcfile + global srcfile2 + + # Make some DWARF for the test. + set asm_file [standard_output_file $srcfile2] + Dwarf::assemble $asm_file { + # Creating a CU with 4-byte addresses lets this test link on + # both 32- and 64-bit machines. + cu { addr_size 4 } { + extern func01_start func01_end main_start main_end + + DW_TAG_compile_unit { + {DW_AT_language @DW_LANG_C99} + {DW_AT_name dw2-opt-structptr.c} + {DW_AT_comp_dir /tmp} + {low_pc func01_start addr} + {high_pc main_end addr} + } { + declare_labels int_label struct_label pointer_label \ + array_label + + int_label: DW_TAG_base_type { + {DW_AT_byte_size 4 DW_FORM_sdata} + {DW_AT_encoding @DW_ATE_signed} + {DW_AT_name integer} + } + + array_label: DW_TAG_array_type { + {DW_AT_name foo__array_type} + {DW_AT_type :$int_label} + } { + DW_TAG_subrange_type { + {DW_AT_type :$int_label} + {DW_AT_lower_bound 0 DW_FORM_data1} + {DW_AT_upper_bound 127 DW_FORM_data1} + } + } + + struct_label: DW_TAG_structure_type { + {DW_AT_name "foo"} + {DW_AT_byte_size 12 DW_FORM_sdata} + } { + member { + {name a} + {type :$int_label} + {data_member_location 0 data1} + } + member { + {name x} + {type :$array_label} + {data_member_location 4 data1} + } + member { + {name y} + {type :$pointer_label} + {data_member_location 8 data1} + } + } + + pointer_label: DW_TAG_pointer_type { + {DW_AT_byte_size 4 DW_FORM_sdata} + {DW_AT_type :$struct_label} + } + + DW_TAG_subprogram { + {DW_AT_name func01} + {DW_AT_type :$int_label} + {external 1 flag} + {low_pc func01_start addr} + {high_pc func01_end addr} + } { + DW_TAG_variable { + {DW_AT_name ptr} + {DW_AT_type :$pointer_label} + {DW_AT_location {} DW_FORM_block1} + } + } + + DW_TAG_subprogram { + {DW_AT_name main} + {DW_AT_type :$int_label} + {external 1 flag} + {low_pc main_start addr} + {high_pc main_end addr} + } { + } + } + } + } + + set sources "$srcfile $asm_file" + if {[build_executable $testfile.exp $testfile $sources {nodebug}]} { + untested $testfile.exp + return -1 + } +} + +# Test access to an optimized-out pointer-to-struct using the +# console interpreter. + +proc do_console_test {} { + global binfile + + clean_restart $binfile + + with_test_prefix "console" { + gdb_test_no_output "set print object on" + + if {![runto_main]} { + return -1 + } + + if {![runto func01]} { + return -1 + } + + gdb_test "info addr ptr" "Symbol \"ptr\" is optimized out." + + gdb_test "print ptr" "" + + gdb_test "print *ptr" "value has been optimized out" + + gdb_test "print ptr->a" "value has been optimized out" + + gdb_test "print ptr->x" "value has been optimized out" + + gdb_test "print ptr->y" "value has been optimized out" + } +} + +# Test access to an optimized-out pointer-to-struct using the +# MI interpreter. + +proc do_mi_test {} { + + load_lib mi-support.exp + set MIFLAGS "-i=mi" + + global mi_gdb_prompt + global srcdir + global subdir + global binfile + + with_test_prefix "mi" { + gdb_exit + if {[mi_gdb_start]} { + return -1 + } + + mi_delete_breakpoints + mi_gdb_reinitialize_dir $srcdir/$subdir + mi_gdb_load $binfile + + # This causes GDB to dereference a pointer-to-structure when doing + # -var-create. + mi_gdb_test "-gdb-set print object on" ".*" "set print object on" + + mi_gdb_test "-break-insert main" ".*" "insert breakpoint main" + mi_gdb_test "-break-insert func01" ".*" "insert breakpoint func01" + + # Run to main. Use an explicit expect here since the limited + # debug info will result in output that isn't handled by the + # MI test utilities. + set test "run to main" + mi_run_cmd + gdb_expect { + -re "\\*stopped,reason=\"breakpoint-hit\".*func=\"main\".*$mi_gdb_prompt$" { + pass "$test" + } + timeout { + fail "$test (timeout)" + } + } + + # Run to func01. Use an explicit expect here as above. + set test "continue to func01" + mi_send_resuming_command "exec-continue" "$test" + gdb_expect { + -re "\\*stopped,reason=\"breakpoint-hit\".*func=\"func01\".*$mi_gdb_prompt$" { + pass "$test" + } + timeout { + fail "$test (timeout)" + } + } + + # Test that -var-create for 'ptr' is successful. + mi_create_varobj "var1" "ptr" "create varobj for ptr" + + # Test that -var-list-children of 'ptr' is successful. + mi_list_varobj_children "var1" { \ + {var1.a a 0 integer} \ + {var1.x x 128 foo__array_type} \ + {var1.y y 3 "struct foo \\*"} \ + } "get children of var1 (ptr)" + + # Test that dereferencing 'ptr' will throw an error. + mi_gdb_test "-var-create var2 * &((ptr)->a)" \ + "\\^error,msg=\"value has been optimized out\"" \ + "throw error, dereference ptr to access integer member " + + # Test that dereferencing 'ptr' will throw an error. + mi_gdb_test "-var-create var3 * &((ptr)->x)" \ + "\\^error,msg=\"value has been optimized out\"" \ + "throw error, dereference ptr to access array member " + + # Test that dereferencing 'ptr' will throw an error. + mi_gdb_test "-var-create var4 * &((ptr)->y)" \ + "\\^error,msg=\"value has been optimized out\"" \ + "throw error, dereference ptr to access pointer member " + } +} + +build_test_program +do_console_test +do_mi_test