[v3] Add a 'starti' command.
Commit Message
This works like 'start' but it stops at the first instruction rather than
the first line in main(). This is useful if one wants to single step
through runtime linker startup.
While here, introduce a RUN_ARGS_HELP macro for shared help text between
run, start, and starti. This includes expanding the help for start and
starti to include details from run's help text.
gdb/ChangeLog:
* NEWS (Changes since GDB 8.0): Add starti.
* infcmd.c (enum run_break): New.
(run_command_1): Queue pending event for RUN_STOP_AT_FIRST_INSN
case.
(run_command): Use enum run_how.
(start_command): Likewise.
(starti_command): New function.
(RUN_ARGS_HELP): New macro.
(_initialize_infcmd): Use RUN_ARGS_HELP for run and start
commands. Add starti command.
gdb/doc/ChangeLog:
* gdb.texinfo (Starting your Program): Add description of
starti command. Mention starti command as an alternative for
debugging the elaboration phase.
gdb/testsuite/ChangeLog:
* gdb.base/starti.c: New file.
* gdb.base/starti.exp: New file.
* lib/gdb.exp (gdb_starti_cmd): New procedure.
---
gdb/ChangeLog | 13 ++++++
gdb/NEWS | 3 ++
gdb/doc/ChangeLog | 6 +++
gdb/doc/gdb.texinfo | 18 ++++++--
gdb/infcmd.c | 86 +++++++++++++++++++++++++++++----------
gdb/testsuite/ChangeLog | 6 +++
gdb/testsuite/gdb.base/starti.c | 30 ++++++++++++++
gdb/testsuite/gdb.base/starti.exp | 51 +++++++++++++++++++++++
gdb/testsuite/lib/gdb.exp | 37 +++++++++++++++++
9 files changed, 224 insertions(+), 26 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/starti.c
create mode 100644 gdb/testsuite/gdb.base/starti.exp
Comments
On Monday, September 11, 2017 03:08:03 PM John Baldwin wrote:
> This works like 'start' but it stops at the first instruction rather than
> the first line in main(). This is useful if one wants to single step
> through runtime linker startup.
>
> While here, introduce a RUN_ARGS_HELP macro for shared help text between
> run, start, and starti. This includes expanding the help for start and
> starti to include details from run's help text.
>
> gdb/ChangeLog:
>
> * NEWS (Changes since GDB 8.0): Add starti.
> * infcmd.c (enum run_break): New.
> (run_command_1): Queue pending event for RUN_STOP_AT_FIRST_INSN
> case.
> (run_command): Use enum run_how.
> (start_command): Likewise.
> (starti_command): New function.
> (RUN_ARGS_HELP): New macro.
> (_initialize_infcmd): Use RUN_ARGS_HELP for run and start
> commands. Add starti command.
>
> gdb/doc/ChangeLog:
>
> * gdb.texinfo (Starting your Program): Add description of
> starti command. Mention starti command as an alternative for
> debugging the elaboration phase.
>
> gdb/testsuite/ChangeLog:
>
> * gdb.base/starti.c: New file.
> * gdb.base/starti.exp: New file.
> * lib/gdb.exp (gdb_starti_cmd): New procedure.
Ping?
Hi John,
This looks good to me, with a couple minor nits below.
On 09/11/2017 11:08 PM, John Baldwin wrote:
>
> -/* Implement the "run" command. If TBREAK_AT_MAIN is set, then insert
> - a temporary breakpoint at the begining of the main program before
> - running the program. */
> +/* Determine how the new inferior will behave. */
> +
> +enum run_how {
{ goes on next line.
> + /* Do not create any breakpoint. */
I wonder about tweaking this comment to avoid talking
about breakpoints, since this enum is not really strictly
about breakpoints anymore.
> + RUN_NORMAL,
> +
> + /* Stop at the beginning of the program's main function. */
> + RUN_STOP_AT_MAIN,
> +
> + /* Stop at the first instruction of the program. */
> + RUN_STOP_AT_FIRST_INSN
> +};
> +
> +/* This help string is used for the run, start, and starti commands.
> + It is defined as a macro to prevent duplication. */
> +
> +#define RUN_ARGS_HELP \
> +"You may specify arguments to give it.\n\
> +Args may include \"*\", or \"[...]\"; they are expanded using the\n\
> +shell that will start the program (specified by the \"$SHELL\"\
> +environment\nvariable). Input and output redirection with \">\",\
> +\"<\", or \">>\"\nare also allowed.\n\n\
You have a "\n" in the middle of some lines above. Was that intended?
I'd expect to see instead lines broken at \n, ending with \n\ .
> +With no arguments, uses arguments last specified (with \"run\" \
> +or \"set args\").\n\
> +To cancel previous arguments and run with no arguments,\n\
> +use \"set args\" without arguments.\n\
> +To start the inferior without using a shell, use \"set \
> +startup-with-shell off\"."
> +
> diff --git a/gdb/testsuite/gdb.base/starti.c b/gdb/testsuite/gdb.base/starti.c
> new file mode 100644
> index 0000000000..dc098fe8aa
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/starti.c
> @@ -0,0 +1,30 @@
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +#include <stdio.h>
This isn't necessary, AFAICS.
> +
> +int x;
> +
> +__attribute__((constructor)) void ctor()
> +{
> + x = 1;
> +}
> +
> +int main()
> +{
> + return 0;
> +}
Space before parens, line break after return type.
We follow GNU convention in tests too, unless different syntax is
relevant for the test.
Thanks,
Pedro Alves
On Tuesday, September 19, 2017 03:35:31 PM Pedro Alves wrote:
> Hi John,
>
> This looks good to me, with a couple minor nits below.
>
> On 09/11/2017 11:08 PM, John Baldwin wrote:
>
> >
> > -/* Implement the "run" command. If TBREAK_AT_MAIN is set, then insert
> > - a temporary breakpoint at the begining of the main program before
> > - running the program. */
> > +/* Determine how the new inferior will behave. */
> > +
> > +enum run_how {
>
> { goes on next line.
Ok.
> > + /* Do not create any breakpoint. */
>
> I wonder about tweaking this comment to avoid talking
> about breakpoints, since this enum is not really strictly
> about breakpoints anymore.
Hmm, how about:
enum run_how
{
/* Run program without any explicit stop during startup. */
RUN_NORMAL,
...
> > +/* This help string is used for the run, start, and starti commands.
> > + It is defined as a macro to prevent duplication. */
> > +
> > +#define RUN_ARGS_HELP \
> > +"You may specify arguments to give it.\n\
> > +Args may include \"*\", or \"[...]\"; they are expanded using the\n\
> > +shell that will start the program (specified by the \"$SHELL\"\
> > +environment\nvariable). Input and output redirection with \">\",\
> > +\"<\", or \">>\"\nare also allowed.\n\n\
>
> You have a "\n" in the middle of some lines above. Was that intended?
> I'd expect to see instead lines broken at \n, ending with \n\ .
Those were just copy and pasted from the run help. I think they were there
to avoid overflowing 80 columns in the source. I've rewrapped the text so
that newlines are at the end.
> > diff --git a/gdb/testsuite/gdb.base/starti.c b/gdb/testsuite/gdb.base/starti.c
> > new file mode 100644
> > index 0000000000..dc098fe8aa
> > --- /dev/null
> > +++ b/gdb/testsuite/gdb.base/starti.c
> > @@ -0,0 +1,30 @@
>
> > + You should have received a copy of the GNU General Public License
> > + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> > +
> > +#include <stdio.h>
>
> This isn't necessary, AFAICS.
Oops, yes.
> > +
> > +int x;
> > +
> > +__attribute__((constructor)) void ctor()
> > +{
> > + x = 1;
> > +}
> > +
> > +int main()
> > +{
> > + return 0;
> > +}
>
> Space before parens, line break after return type.
> We follow GNU convention in tests too, unless different syntax is
> relevant for the test.
Ok. (Ironically I copied both the spurious #include and bad style
from start.c.)
On 09/19/2017 06:49 PM, John Baldwin wrote:
> Hmm, how about:
>
> enum run_how
> {
> /* Run program without any explicit stop during startup. */
> RUN_NORMAL,
Sounds fine.
>> You have a "\n" in the middle of some lines above. Was that intended?
>> I'd expect to see instead lines broken at \n, ending with \n\ .
>
> Those were just copy and pasted from the run help. I think they were there
> to avoid overflowing 80 columns in the source. I've rewrapped the text so
> that newlines are at the end.
Thanks.
>> Space before parens, line break after return type.
>> We follow GNU convention in tests too, unless different syntax is
>> relevant for the test.
>
> Ok. (Ironically I copied both the spurious #include and bad style
> from start.c.)
Yeah, sorry about that. It was only in recent years that we
started following that rule; older tests will be using
random styles.
Thanks,
Pedro Alves
John Baldwin <jhb@FreeBSD.org> writes:
> +# Continue to the start of main(). The constructor should have run so
> +# 'x' should be 1.
> +
> +gdb_breakpoint main
> +gdb_test_sequence "continue" "" {
> + "\\$2 = 1"
> + ".*Breakpoint .*main \\(\\) at .*starti.c.*"
Here is a test failure, captured by buildbot,
https://sourceware.org/ml/gdb-testers/2017-q3/msg04381.html
(gdb) gdb_expect_list pattern: /\$2 = 1/
continue^M
Continuing.^M
$2 = 1^M
gdb_expect_list pattern: /.*Breakpoint .*main \(\) at .*starti.c.*/
^M
Breakpoint 1, Python Exception <type 'exceptions.NameError'> Installation error: gdb.execute_unwinders function is missing: ^M
main () at /home/yao/SourceCode/gnu/gdb/git/gdb/testsuite/gdb.base/starti.c:29^M
29 return 0;^M
(gdb) gdb_expect_list pattern: //
FAIL: gdb.base/starti.exp: continue (pattern 3 + sentinel) (timeout)
Can you take a look?
@@ -1,3 +1,16 @@
+2017-09-11 John Baldwin <jhb@FreeBSD.org>
+
+ * NEWS (Changes since GDB 8.0): Add starti.
+ * infcmd.c (enum run_break): New.
+ (run_command_1): Queue pending event for RUN_STOP_AT_FIRST_INSN
+ case.
+ (run_command): Use enum run_how.
+ (start_command): Likewise.
+ (starti_command): New function.
+ (RUN_ARGS_HELP): New macro.
+ (_initialize_infcmd): Use RUN_ARGS_HELP for run and start
+ commands. Add starti command.
+
2017-09-11 Tom Tromey <tom@tromey.com>
* demangle.c (demangle_command): Update.
@@ -69,6 +69,9 @@ set debug separate-debug-file
show debug separate-debug-file
Control the display of debug output about separate debug file search.
+starti
+ Start the debugged program stopping at the first instruction.
+
* TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
`o' for nexti.
@@ -1,3 +1,9 @@
+2017-09-11 John Baldwin <jhb@FreeBSD.org>
+
+ * gdb.texinfo (Starting your Program): Add description of
+ starti command. Mention starti command as an alternative for
+ debugging the elaboration phase.
+
2017-09-11 Tom Tromey <tom@tromey.com>
* python.texi (Events In Python): Document new events.
@@ -2117,10 +2117,20 @@ reused if no argument is provided during subsequent calls to
@samp{start} or @samp{run}.
It is sometimes necessary to debug the program during elaboration. In
-these cases, using the @code{start} command would stop the execution of
-your program too late, as the program would have already completed the
-elaboration phase. Under these circumstances, insert breakpoints in your
-elaboration code before running your program.
+these cases, using the @code{start} command would stop the execution
+of your program too late, as the program would have already completed
+the elaboration phase. Under these circumstances, either insert
+breakpoints in your elaboration code before running your program or
+use the @code{starti} command.
+
+@kindex starti
+@item starti
+@cindex run to first instruction
+The @samp{starti} command does the equivalent of setting a temporary
+breakpoint at the first instruction of a program's execution and then
+invoking the @samp{run} command. For programs containing an
+elaboration phase, the @code{starti} command will stop execution at
+the start of the elaboration phase.
@anchor{set exec-wrapper}
@kindex set exec-wrapper
@@ -518,12 +518,24 @@ prepare_execution_command (struct target_ops *target, int background)
}
}
-/* Implement the "run" command. If TBREAK_AT_MAIN is set, then insert
- a temporary breakpoint at the begining of the main program before
- running the program. */
+/* Determine how the new inferior will behave. */
+
+enum run_how {
+ /* Do not create any breakpoint. */
+ RUN_NORMAL,
+
+ /* Stop at the beginning of the program's main function. */
+ RUN_STOP_AT_MAIN,
+
+ /* Stop at the first instruction of the program. */
+ RUN_STOP_AT_FIRST_INSN
+};
+
+/* Implement the "run" command. Force a stop during program start if
+ requested by RUN_HOW. */
static void
-run_command_1 (char *args, int from_tty, int tbreak_at_main)
+run_command_1 (char *args, int from_tty, enum run_how run_how)
{
const char *exec_file;
struct cleanup *old_chain;
@@ -532,6 +544,7 @@ run_command_1 (char *args, int from_tty, int tbreak_at_main)
struct target_ops *run_target;
int async_exec;
struct cleanup *args_chain;
+ CORE_ADDR pc;
dont_repeat ();
@@ -569,8 +582,8 @@ run_command_1 (char *args, int from_tty, int tbreak_at_main)
/* Done. Can now set breakpoints, change inferior args, etc. */
- /* Insert the temporary breakpoint if a location was specified. */
- if (tbreak_at_main)
+ /* Insert temporary breakpoint in main function if requested. */
+ if (run_how == RUN_STOP_AT_MAIN)
tbreak_command (main_name (), 0);
exec_file = get_exec_file (0);
@@ -630,6 +643,15 @@ run_command_1 (char *args, int from_tty, int tbreak_at_main)
has done its thing; now we are setting up the running program. */
post_create_inferior (¤t_target, 0);
+ /* Queue a pending event so that the program stops immediately. */
+ if (run_how == RUN_STOP_AT_FIRST_INSN)
+ {
+ thread_info *thr = inferior_thread ();
+ thr->suspend.waitstatus_pending_p = 1;
+ thr->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
+ thr->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
+ }
+
/* Start the target running. Do not use -1 continuation as it would skip
breakpoint right at the entry point. */
proceed (regcache_read_pc (get_current_regcache ()), GDB_SIGNAL_0);
@@ -642,7 +664,7 @@ run_command_1 (char *args, int from_tty, int tbreak_at_main)
static void
run_command (char *args, int from_tty)
{
- run_command_1 (args, from_tty, 0);
+ run_command_1 (args, from_tty, RUN_NORMAL);
}
/* Start the execution of the program up until the beginning of the main
@@ -658,7 +680,16 @@ start_command (char *args, int from_tty)
error (_("No symbol table loaded. Use the \"file\" command."));
/* Run the program until reaching the main procedure... */
- run_command_1 (args, from_tty, 1);
+ run_command_1 (args, from_tty, RUN_STOP_AT_MAIN);
+}
+
+/* Start the execution of the program stopping at the first
+ instruction. */
+
+static void
+starti_command (char *args, int from_tty)
+{
+ run_command_1 (args, from_tty, RUN_STOP_AT_FIRST_INSN);
}
static int
@@ -3178,6 +3209,22 @@ info_proc_cmd_all (char *args, int from_tty)
info_proc_cmd_1 (args, IP_ALL, from_tty);
}
+/* This help string is used for the run, start, and starti commands.
+ It is defined as a macro to prevent duplication. */
+
+#define RUN_ARGS_HELP \
+"You may specify arguments to give it.\n\
+Args may include \"*\", or \"[...]\"; they are expanded using the\n\
+shell that will start the program (specified by the \"$SHELL\"\
+environment\nvariable). Input and output redirection with \">\",\
+\"<\", or \">>\"\nare also allowed.\n\n\
+With no arguments, uses arguments last specified (with \"run\" \
+or \"set args\").\n\
+To cancel previous arguments and run with no arguments,\n\
+use \"set args\" without arguments.\n\
+To start the inferior without using a shell, use \"set \
+startup-with-shell off\"."
+
void
_initialize_infcmd (void)
{
@@ -3384,24 +3431,19 @@ Specifying -a and an ignore count simultaneously is an error."));
add_com_alias ("fg", "cont", class_run, 1);
c = add_com ("run", class_run, run_command, _("\
-Start debugged program. You may specify arguments to give it.\n\
-Args may include \"*\", or \"[...]\"; they are expanded using the\n\
-shell that will start the program (specified by the \"$SHELL\"\
-environment\nvariable). Input and output redirection with \">\",\
-\"<\", or \">>\"\nare also allowed.\n\n\
-With no arguments, uses arguments last specified (with \"run\" \
-or \"set args\").\n\
-To cancel previous arguments and run with no arguments,\n\
-use \"set args\" without arguments.\n\
-To start the inferior without using a shell, use \"set \
-startup-with-shell off\"."));
+Start debugged program.\n"
+RUN_ARGS_HELP));
set_cmd_completer (c, filename_completer);
add_com_alias ("r", "run", class_run, 1);
c = add_com ("start", class_run, start_command, _("\
-Run the debugged program until the beginning of the main procedure.\n\
-You may specify arguments to give to your program, just as with the\n\
-\"run\" command."));
+Start the debugged program stopping at the beginning of the main procedure.\n"
+RUN_ARGS_HELP));
+ set_cmd_completer (c, filename_completer);
+
+ c = add_com ("starti", class_run, starti_command, _("\
+Start the debugged program stopping at the first instruction.\n"
+RUN_ARGS_HELP));
set_cmd_completer (c, filename_completer);
add_com ("interrupt", class_run, interrupt_command,
@@ -1,3 +1,9 @@
+2017-09-11 John Baldwin <jhb@FreeBSD.org>
+
+ * gdb.base/starti.c: New file.
+ * gdb.base/starti.exp: New file.
+ * lib/gdb.exp (gdb_starti_cmd): New procedure.
+
2017-09-11 Tom Tromey <tom@tromey.com>
* gdb.base/ena-dis-br.exp (test_ena_dis_br): Update test.
new file mode 100644
@@ -0,0 +1,30 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2017 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 <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+
+int x;
+
+__attribute__((constructor)) void ctor()
+{
+ x = 1;
+}
+
+int main()
+{
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,51 @@
+# Copyright 2017 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 <http://www.gnu.org/licenses/>.
+
+
+standard_testfile
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
+ return -1
+}
+
+# Define a stop hook that outputs the value of 'x'
+
+gdb_test_multiple "define hook-stop" "hook-stop" {
+ -re "Type commands for definition of \"hook-stop\".\r\nEnd with a line saying just \"end\".\r\n>$" {
+ gdb_test "print x\nend" "" "hook-stop"
+ }
+}
+
+if { [gdb_starti_cmd] < 0 } {
+ untested starti
+ return -1
+}
+
+# The program should stop at the first instruction, so the constructor
+# should not have run yet and 'x' should be 0.
+
+gdb_test_sequence "" "starti" {
+ "Program stopped."
+ "\\$1 = 0"
+}
+
+# Continue to the start of main(). The constructor should have run so
+# 'x' should be 1.
+
+gdb_breakpoint main
+gdb_test_sequence "continue" "" {
+ "\\$2 = 1"
+ ".*Breakpoint .*main \\(\\) at .*starti.c.*"
+}
@@ -370,6 +370,43 @@ proc gdb_start_cmd {args} {
return -1
}
+# Generic starti command. Return 0 if we could start the program, -1
+# if we could not.
+#
+# N.B. This function does not wait for gdb to return to the prompt,
+# that is the caller's responsibility.
+
+proc gdb_starti_cmd {args} {
+ global gdb_prompt use_gdb_stub
+
+ foreach command [gdb_init_commands] {
+ send_gdb "$command\n"
+ gdb_expect 30 {
+ -re "$gdb_prompt $" { }
+ default {
+ perror "gdb_init_command for target failed"
+ return -1
+ }
+ }
+ }
+
+ if $use_gdb_stub {
+ return -1
+ }
+
+ send_gdb "starti $args\n"
+ gdb_expect 60 {
+ -re "The program .* has been started already.*y or n. $" {
+ send_gdb "y\n"
+ exp_continue
+ }
+ -re "Starting program: \[^\r\n\]*" {
+ return 0
+ }
+ }
+ return -1
+}
+
# Set a breakpoint at FUNCTION. If there is an additional argument it is
# a list of options; the supported options are allow-pending, temporary,
# message, no-message, and passfail.