From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id cEeQOr/lBGPmDywAWB0awg (envelope-from ) for ; Tue, 23 Aug 2022 10:35:43 -0400 Received: by simark.ca (Postfix, from userid 112) id ECAA41E4A7; Tue, 23 Aug 2022 10:35:43 -0400 (EDT) Authentication-Results: simark.ca; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.a=rsa-sha256 header.s=default header.b=F3KHqtuR; dkim-atps=neutral X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RDNS_DYNAMIC,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 667641E13B for ; Tue, 23 Aug 2022 10:35:43 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 0B6F43858287 for ; Tue, 23 Aug 2022 14:35:43 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0B6F43858287 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1661265343; bh=hH2b1eDa6uT3XeK1+n2PqdSZkzlAsAnEueLdyKJ30zI=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=F3KHqtuRcn89FeBExTovpXp3EQS8t792kYmyBPxgPBmC4uFXwvLPKwsKEvvOjX+aY WyD7tJtMZ94IOvG2yGAKMZjCrZxX5vNtlV34qDSM+mNDeXS/T9MMEdsOMx79Pahf7D gWwjuExSQwh6VjpMZBghaKcFMH64eKAba/PNjxco= 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 E1B7A3857C68 for ; Tue, 23 Aug 2022 14:35:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E1B7A3857C68 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-86-FmNvVAgHO2m9ziZJ48CnjA-1; Tue, 23 Aug 2022 10:35:02 -0400 X-MC-Unique: FmNvVAgHO2m9ziZJ48CnjA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9482629DD995; Tue, 23 Aug 2022 14:35:01 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.157]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C56641121314; Tue, 23 Aug 2022 14:35:00 +0000 (UTC) To: gdb-patches@sourceware.org Subject: [PATCH v2 2/2] gdb/reverse: Fix stepping over recursive functions Date: Tue, 23 Aug 2022 16:22:05 +0200 Message-Id: <20220823142204.31659-3-blarsen@redhat.com> In-Reply-To: <20220823142204.31659-1-blarsen@redhat.com> References: <20220823142204.31659-1-blarsen@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true 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: , From: Bruno Larsen via Gdb-patches Reply-To: Bruno Larsen Cc: pedro@palves.net Errors-To: gdb-patches-bounces+public-inbox=simark.ca@sourceware.org Sender: "Gdb-patches" Currently, when using GDB to do reverse debugging, if we try to use the command "reverse next" to skip a recursive function, instead of skipping all of the recursive calls and stopping in the previous line, we stop at the second to last recursive call, and need to manually step backwards until we leave the first call. This is well documented in PR gdb/16678. This bug happens because when GDB notices that a reverse step has entered into a function, GDB will add a step_resume_breakpoint at the start of the function, then single step out of the prologue once that breakpoint is hit. The problem was happening because GDB wouldn't give that step_resume_breakpoint a frame-id, so the first time the breakpoint was hit, the inferior would be stopped. This is fixed by giving the current frame-id to the breakpoint. This commit also changes gdb.reverse/step-reverse.c to contain a recursive function and attempt to both, skip it altogether, and to skip the second call from inside the first call, as this setup broke a previous version of the patch. --- gdb/infrun.c | 2 +- gdb/testsuite/gdb.reverse/step-precsave.exp | 6 ++- gdb/testsuite/gdb.reverse/step-reverse.c | 16 +++++- gdb/testsuite/gdb.reverse/step-reverse.exp | 59 +++++++++++++++++++-- 4 files changed, 76 insertions(+), 7 deletions(-) diff --git a/gdb/infrun.c b/gdb/infrun.c index 033699bc3f7..679a0c83ece 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -7133,7 +7133,7 @@ process_event_stop_test (struct execution_control_state *ecs) sr_sal.pc = ecs->stop_func_start; sr_sal.pspace = get_frame_program_space (frame); insert_step_resume_breakpoint_at_sal (gdbarch, - sr_sal, null_frame_id); + sr_sal, get_stack_frame_id (frame)); } } else diff --git a/gdb/testsuite/gdb.reverse/step-precsave.exp b/gdb/testsuite/gdb.reverse/step-precsave.exp index 0836ed2629f..54df9209c96 100644 --- a/gdb/testsuite/gdb.reverse/step-precsave.exp +++ b/gdb/testsuite/gdb.reverse/step-precsave.exp @@ -86,7 +86,8 @@ gdb_test "step 3" ".*STEP TEST 2.*" "step test 2" # step over call -gdb_test "step" ".*NEXT OVER THIS CALL.*" "step up to call" +gdb_test "step" ".*NEXT OVER THIS RECURSION.*" "step up to call" +gdb_test "next" ".*NEXT OVER THIS CALL.*" "skip recursive call" gdb_test "next" ".*STEP INTO THIS CALL.*" "next over call" # step into call @@ -280,9 +281,10 @@ gdb_test_multiple "step" "$test_message" { } } -# next backward over call +# next backward over calls gdb_test "next" ".*NEXT OVER THIS CALL.*" "reverse next over call" +gdb_test "next" ".*NEXT OVER THIS RECURSION.*" "reverse next over recursive call" # step/next backward with count diff --git a/gdb/testsuite/gdb.reverse/step-reverse.c b/gdb/testsuite/gdb.reverse/step-reverse.c index aea2a98541d..a390ac2580c 100644 --- a/gdb/testsuite/gdb.reverse/step-reverse.c +++ b/gdb/testsuite/gdb.reverse/step-reverse.c @@ -26,6 +26,17 @@ int callee() { /* ENTER CALLEE */ return myglob++; /* ARRIVED IN CALLEE */ } /* RETURN FROM CALLEE */ +/* We need to make this function take more than a single instruction + to run, otherwise it could hide PR gdb/16678, as reverse execution can + step over a single-instruction function. */ +int recursive_callee (int val){ + if (val == 0) return 0; + val /= 2; + if (val>1) + val++; + return recursive_callee (val); /* RECURSIVE CALL */ +} /* EXIT RECURSIVE FUNCTION */ + /* A structure which, we hope, will need to be passed using memcpy. */ struct rhomboidal { int rather_large[100]; @@ -51,6 +62,9 @@ int main () { y = y + 4; z = z + 5; /* STEP TEST 2 */ + /* Test that next goes over recursive calls too */ + recursive_callee (32); /* NEXT OVER THIS RECURSION */ + /* Test that "next" goes over a call */ callee(); /* NEXT OVER THIS CALL */ @@ -60,7 +74,7 @@ int main () { /* Test "stepi" */ a[5] = a[3] - a[4]; /* FINISH TEST */ callee(); /* STEPI TEST */ - + /* Test "nexti" */ callee(); /* NEXTI TEST */ diff --git a/gdb/testsuite/gdb.reverse/step-reverse.exp b/gdb/testsuite/gdb.reverse/step-reverse.exp index 997b62604d5..4f56b4785ca 100644 --- a/gdb/testsuite/gdb.reverse/step-reverse.exp +++ b/gdb/testsuite/gdb.reverse/step-reverse.exp @@ -47,9 +47,11 @@ gdb_test "step" ".*STEP TEST 1.*" "step test 1" gdb_test "next 2" ".*NEXT TEST 2.*" "next test 2" gdb_test "step 3" ".*STEP TEST 2.*" "step test 2" +# next through a recursive function call +gdb_test "next 2" "NEXT OVER THIS CALL.*" "next over recursion" + # step over call -gdb_test "step" ".*NEXT OVER THIS CALL.*" "step up to call" gdb_test "next" ".*STEP INTO THIS CALL.*" "next over call" # step into call @@ -118,7 +120,7 @@ gdb_test_multiple "stepi" "$test_message" { set test_message "stepi back from function call" gdb_test_multiple "stepi" "$test_message" { - -re "NEXTI TEST.*$gdb_prompt $" { + -re -wrap "NEXTI TEST.*" { pass "$test_message" } -re "ARRIVED IN CALLEE.*$gdb_prompt $" { @@ -143,7 +145,6 @@ gdb_test_multiple "stepi" "$test_message" { ### # Set reverse execution direction - gdb_test_no_output "set exec-dir reverse" "set reverse execution" # stepi backward thru return and into a function @@ -247,6 +248,58 @@ gdb_test_multiple "step" "$test_message" { gdb_test "next" ".*NEXT OVER THIS CALL.*" "reverse next over call" +# Dont reverse the execution direction yet, as we will need another +# forward step after this test + +set step_out 0 +gdb_test_multiple "next" "reverse next over recursion" { + -re -wrap ".*NEXT OVER THIS RECURSION.*" { + pass "reverse next over recursion" + } + -re -wrap ".*RECURSIVE CALL.*" { + fail "reverse next over recursion" + set step_out 1 + } +} +if { "$step_out" == 1 } { + gdb_test_multiple "next" "stepping out of recursion" { + -re -wrap "NEXT OVER THIS RECURSION.*" { + set step_out 0 + } + -re -wrap ".*" { + send_gdb "reverse-next\n" + exp_continue + } + } +} + +# Step forward over recursion again so we can test stepping over calls +# inside the recursion itself. +gdb_test_no_output "set exec-dir forward" "forward again to test recursion" +gdb_test "next" "NEXT OVER THIS CALL.*" "reverse next over recursion again" +gdb_test_no_output "set exec-dir reverse" "reverse again to test recursion" + +gdb_test "step" ".*EXIT RECURSIVE FUNCTION.*" "enter recursive function" +set step_pass 1 +gdb_test_multiple "next" "step over recursion inside the recursion" { + -re -wrap ".*EXIT RECURSIVE FUNCTION.*" { + set step_pass 0 + send_gdb "next\n" + exp_continue + } + -re -wrap ".*NEXT OVER THIS RECURSION.*" { + if {$step_pass} { + pass "step over recursion inside the recursion" + } else { + fail "step over recursion inside the recursion" + } + } + -re -wrap ".*" { + send_gdb "next\n" + exp_continue + } +} + # step/next backward with count gdb_test "step 3" ".*REVERSE STEP TEST 1.*" "reverse step test 1" -- 2.37.2