[PATCH 02/10] Refactor follow-fork message printing

Don Breazeal
2014-08-07T18:00:26Z

This patch refactors the code that prints messages related to follow-fork into functions, and adds a call so that a message is now printed when the parent process is detached. Previously in this case the only message was notification of attaching to the child. We still do not print any messages when following the parent and detaching the child (the default). My rationale for this is that from the user's perspective the new child was never attached.

Note that all of these messages are only printed when 'verbose' is set or when debugging is turned on.

This is preparatory work for follow-fork and detach-on-fork on extended-remote linux targets.

The test gdb.base/foll-fork.exp was modified to check for the new message.

Tested on x64 Ubuntu Lucid, native only.

Thanks
--Don

gdb/
2014-08-06 Don Breazeal <donb@codesourcery.com>

* infrun.c (print_fork_attach): New function.
(print_fork_detach): New function.
(follow_fork_inferior): Call print_fork_attach and print_fork_detach.
(handle_vfork_child_exec_or_exit): Ditto.

gdb/testsuite/
2014-08-06 Don Breazeal <donb@codesourcery.com>
* gdb.base/foll-fork.exp (test_follow_fork): Add check for new
detach message.
(catch_fork_child_follow): Ditto.
* gdb.base/foll-vfork.exp (vfork_parent_follow_through_step):
Modify to check for "vfork" instead of "fork".
(vfork_parent_follow_to_bp): Ditto.
(vfork_and_exec_child_follow_through_step): Ditto.
(vfork_and_exec_child_follow_to_main_bp): Ditto, plus add check
for new detach message.

---
gdb/infrun.c | 94 +++++++++++++++++++-------------
gdb/testsuite/gdb.base/foll-fork.exp | 12 +++--
gdb/testsuite/gdb.base/foll-vfork.exp | 8 ++--
3 files changed, 68 insertions(+), 46 deletions(-)

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 1de14ed..482fa68 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -569,6 +569,49 @@ follow_fork (void)
return should_resume;
}

+/* Print details about attaching to a process after a fork call. */
+
+static void
+print_fork_attach (pid_t child_pid, pid_t parent_pid, int is_vfork)
+{
+ if (info_verbose || debug_infrun)
+ {
+ target_terminal_ours ();
+ fprintf_filtered (gdb_stdlog,
+ _("Attaching after process %d "
+ "%s to child process %d.\n"),
+ parent_pid, is_vfork?"vfork":"fork", child_pid);
+ }
+}
+
+/* Print details about detaching from a process after a fork call. */
+
+static void
+print_fork_detach (pid_t pid, int is_parent, int is_vfork, char *vfork_action)
+{
+ if (info_verbose || debug_infrun)
+ {
+ target_terminal_ours ();
+
+ if (is_parent && is_vfork)
+ {
+ /* Detaching a vfork parent, so print what the child did
+ that allows the parent to resume. */
+ gdb_assert (vfork_action != NULL && strlen (vfork_action) > 0);
+ fprintf_filtered (gdb_stdlog,
+ "Detaching vfork parent process %d after"
+ " child %s.\n", pid, vfork_action);
+ }
+ else
+ {
+ fprintf_filtered (gdb_stdlog,
+ _("Detaching after %s from %s process %d.\n"),
+ is_vfork?"vfork":"fork",
+ is_parent?"parent":"child", pid);
+ }
+ }
+}
+
/* Handle changes to the inferior list based on the type of fork,
which process is being followed, and whether the other process
should be detached. */
@@ -625,14 +668,7 @@ holding the child stopped. Try \"set detach-on-fork\" or \
remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
}

- if (info_verbose || debug_infrun)
- {
- target_terminal_ours ();
- fprintf_filtered (gdb_stdlog,
- "Detaching after fork from "
- "child process %d.\n",
- child_pid);
- }
+ print_fork_detach (child_pid, follow_child, has_vforked, "");
}
else
{
@@ -713,20 +749,7 @@ holding the child stopped. Try \"set detach-on-fork\" or \
struct inferior *parent_inf, *child_inf;
struct program_space *parent_pspace;

- if (info_verbose || debug_infrun)
- {
- target_terminal_ours ();
- if (has_vforked)
- fprintf_filtered (gdb_stdlog,
- _("Attaching after process %d "
- "vfork to child process %d.\n"),
- parent_pid, child_pid);
- else
- fprintf_filtered (gdb_stdlog,
- _("Attaching after process %d "
- "fork to child process %d.\n"),
- parent_pid, child_pid);
- }
+ print_fork_attach (child_pid, parent_pid, has_vforked);

/* Add the new inferior first, so that the target_detach below
doesn't unpush the target. */
@@ -762,7 +785,10 @@ holding the child stopped. Try \"set detach-on-fork\" or \
parent_inf->waiting_for_vfork_done = 0;
}
else if (detach_fork)
- target_detach (NULL, 0);
+ {
+ print_fork_detach (parent_pid, follow_child, has_vforked, "");
+ target_detach (NULL, 0);
+ }

/* Note that the detach above makes PARENT_INF dangling. */

@@ -929,21 +955,13 @@ handle_vfork_child_exec_or_exit (int exec)
inf->aspace = NULL;
inf->pspace = NULL;

- if (debug_infrun || info_verbose)
- {
- target_terminal_ours ();
-
- if (exec)
- fprintf_filtered (gdb_stdlog,
- "Detaching vfork parent process "
- "%d after child exec.\n",
- inf->vfork_parent->pid);
- else
- fprintf_filtered (gdb_stdlog,
- "Detaching vfork parent process "
- "%d after child exit.\n",
- inf->vfork_parent->pid);
- }
+ /* Print verbose/debug info message. Hardcoded 1's designate
+ that we are detaching a parent and that it is after a vfork,
+ respectively. */
+ if (exec)
+ print_fork_detach (inf->vfork_parent->pid, 1, 1, "exec");
+ else
+ print_fork_detach (inf->vfork_parent->pid, 1, 1, "exit");

target_detach (NULL, 0);

diff --git a/gdb/testsuite/gdb.base/foll-fork.exp b/gdb/testsuite/gdb.base/foll-fork.exp
index ad8b750..06ba1b5 100644
--- a/gdb/testsuite/gdb.base/foll-fork.exp
+++ b/gdb/testsuite/gdb.base/foll-fork.exp
@@ -115,7 +115,11 @@ proc test_follow_fork { who detach cmd } {
# Set up the output we expect to see after we run.
set expected_re ""
if {$who == "child"} {
- set expected_re "Attaching after.* fork to.*set breakpoint here.*"
+ set expected_re "Attaching after.* fork to.*"
+ if {$detach == "on"} {
+ append expected_re "Detaching after fork from .*"
+ }
+ append expected_re "set breakpoint here.*"
} elseif {$who == "parent" && $detach == "on"} {
set expected_re "Detaching after fork from .*set breakpoint here.*"
} else {
@@ -218,9 +222,9 @@ proc catch_fork_child_follow {} {
"Temporary breakpoint.*, line $bp_after_fork.*" \
"set follow-fork child, tbreak"

- gdb_test "continue" \
- "Attaching after.* fork to.* at .*$bp_after_fork.*" \
- "set follow-fork child, hit tbreak"
+ set expected_re "Attaching after.* fork to.*Detaching after fork from"
+ append expected_re " .* at .*$bp_after_fork.*"
+ gdb_test "continue" $expected_re "set follow-fork child, hit tbreak"

# The parent has been detached; allow time for any output it might
# generate to arrive, so that output doesn't get confused with
diff --git a/gdb/testsuite/gdb.base/foll-vfork.exp b/gdb/testsuite/gdb.base/foll-vfork.exp
index fe3663c..968db13 100644
--- a/gdb/testsuite/gdb.base/foll-vfork.exp
+++ b/gdb/testsuite/gdb.base/foll-vfork.exp
@@ -121,7 +121,7 @@ proc vfork_parent_follow_through_step {} {

set test "step"
gdb_test_multiple "next" $test {
- -re "Detaching after fork from.*if \\(pid == 0\\).*$gdb_prompt " {
+ -re "Detaching after vfork from.*if \\(pid == 0\\).*$gdb_prompt " {
pass $test
}
}
@@ -146,7 +146,7 @@ proc vfork_parent_follow_to_bp {} {

set test "continue to bp"
gdb_test_multiple "continue" $test {
- -re ".*Detaching after fork from child process.*Breakpoint.*${bp_location}.*$gdb_prompt " {
+ -re ".*Detaching after vfork from child process.*Breakpoint.*${bp_location}.*$gdb_prompt " {
pass $test
}
}
@@ -195,7 +195,7 @@ proc vfork_and_exec_child_follow_to_main_bp {} {

set test "continue to bp"
gdb_test_multiple "continue" $test {
- -re "Attaching after.* vfork to.*xecuting new program.*Breakpoint.*vforked-prog.c:${linenum}.*$gdb_prompt " {
+ -re "Attaching after.* vfork to.*Detaching vfork parent.*xecuting new program.*Breakpoint.*vforked-prog.c:${linenum}.*$gdb_prompt " {
pass $test
}
}
@@ -239,7 +239,7 @@ proc vfork_and_exec_child_follow_through_step {} {
#
set linenum [gdb_get_line_number "printf(\"Hello from vforked-prog" ${srcfile2}]
gdb_test_multiple "next" $test {
- -re "Attaching after fork to.*Executing new program.*Breakpoint.*vforked-prog.c:${linenum}.*$gdb_prompt " {
+ -re "Attaching after vfork to.*Executing new program.*Breakpoint.*vforked-prog.c:${linenum}.*$gdb_prompt " {
pass "$test"
}
}
--
1.7.0.4