Re: [PATCH 04/12] Delete reinsert breakpoints from forked child

Yao Qi
2016-06-17T09:53:37Z

Pedro Alves <palves@redhat.com> writes:

> I'd suggest reversing the condition logic, making it match the
> comment, like this:
>
> if { $syscall == "vfork"
> && ${follow-fork} == "parent"
> && ${detach-on-fork} == "off" } {
> # Both vforked child process and parent process are
> # under GDB's control, but GDB follows the parent
> # process only, which can't be run until vforked child
> # finishes. Skip the test in this scenario.
> continue
> }
>
> break_cond_on_syscall $syscall ${follow-fork} ${detach-on-fork}

OK, revert the condition logic, and patch below is pushed in.

--
Yao (齐尧)

From 21a770913c24ab085fe66a5274ebe7cf9e031982 Mon Sep 17 00:00:00 2001
From: Yao Qi <yao.qi@linaro.org>
Date: Fri, 17 Jun 2016 10:25:13 +0100
Subject: [PATCH] Extend step-over-syscall.exp with different detach-on-fork
and follow-fork modes

This patch extends step-over-syscall.exp by setting different values to
detach-on-fork and follow-fork.

gdb/testsuite:

2016-06-17 Yao Qi <yao.qi@linaro.org>

* gdb.base/step-over-syscall.exp (break_cond_on_syscall): New
parameters follow_fork and detach_on_fork. Set follow-fork-mode
and detach-on-fork. Adjust tests.
(top level): Invoke break_cond_on_syscall with combinations of
syscall, follow-fork-mode and detach-on-fork.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index fbdcd2b..69aad53 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,13 @@
2016-06-17 Yao Qi <yao.qi@linaro.org>

+ * gdb.base/step-over-syscall.exp (break_cond_on_syscall): New
+ parameters follow_fork and detach_on_fork. Set follow-fork-mode
+ and detach-on-fork. Adjust tests.
+ (top level): Invoke break_cond_on_syscall with combinations of
+ syscall, follow-fork-mode and detach-on-fork.
+
+2016-06-17 Yao Qi <yao.qi@linaro.org>
+
* gdb.base/step-over-exit.c: New.
* gdb.base/step-over-exit.exp: New.

diff --git a/gdb/testsuite/gdb.base/step-over-syscall.exp b/gdb/testsuite/gdb.base/step-over-syscall.exp
index 7e5a719..e1d5ba1 100644
--- a/gdb/testsuite/gdb.base/step-over-syscall.exp
+++ b/gdb/testsuite/gdb.base/step-over-syscall.exp
@@ -176,9 +176,11 @@ proc step_over_syscall { syscall } {

# Set a breakpoint with a condition that evals false on syscall
# instruction. In fact, it tests GDBserver steps over syscall
-# instruction.
+# instruction. SYSCALL is the syscall the program calls.
+# FOLLOW_FORK is either "parent" or "child". DETACH_ON_FORK is
+# "on" or "off".

-proc break_cond_on_syscall { syscall } {
+proc break_cond_on_syscall { syscall follow_fork detach_on_fork } {
with_test_prefix "break cond on target : $syscall" {
set testfile "step-over-$syscall"

@@ -195,6 +197,8 @@ proc break_cond_on_syscall { syscall } {
# Delete breakpoint syscall insns to avoid interference with other syscalls.
delete_breakpoints

+ gdb_test "set follow-fork-mode $follow_fork"
+ gdb_test "set detach-on-fork $detach_on_fork"

# Create a breakpoint with a condition that evals false.
gdb_test "break \*$syscall_insn_addr if main == 0" \
@@ -212,9 +216,27 @@ proc break_cond_on_syscall { syscall } {
gdb_test "break clone_fn if main == 0"
}

- gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
- gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
- "continue to marker ($syscall)"
+ if { $syscall == "clone" } {
+ # follow-fork and detach-on-fork only make sense to
+ # fork and vfork.
+ gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
+ "continue to marker"
+ } else {
+ if { $follow_fork == "child" } {
+ gdb_test "continue" "exited normally.*" "continue to end of inf 2"
+ if { $detach_on_fork == "off" } {
+ gdb_test "inferior 1"
+ gdb_test "break marker" "Breakpoint.*at.*"
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
+ "continue to marker"
+ }
+ } else {
+ gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
+ gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
+ "continue to marker"
+ }
+ }
}
}

@@ -243,7 +265,22 @@ gdb_test_multiple $test $test {
}

if { $cond_bp_target } {
- break_cond_on_syscall "fork"
- break_cond_on_syscall "vfork"
- break_cond_on_syscall "clone"
+
+ foreach_with_prefix detach-on-fork {"on" "off"} {
+ foreach_with_prefix follow-fork {"parent" "child"} {
+ foreach syscall { "fork" "vfork" "clone" } {
+
+ if { $syscall == "vfork"
+ && ${follow-fork} == "parent"
+ && ${detach-on-fork} == "off" } {
+ # Both vforked child process and parent process are
+ # under GDB's control, but GDB follows the parent
+ # process only, which can't be run until vforked child
+ # finishes. Skip the test in this scenario.
+ continue
+ }
+ break_cond_on_syscall $syscall ${follow-fork} ${detach-on-fork}
+ }
+ }
+ }
}