[PATCH v4 2/2] gdb/mi: add a '--force' flag to the '-break-condition' command

Tankut Baris Aktemur via Gdb-patches
2021-04-22T14:36:16Z

Add a '--force' flag to the '-break-condition' command to be
able to force conditions.

gdb/ChangeLog:
2021-04-21 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>

* mi/mi-cmd-break.c (mi_cmd_break_condition): New function.
* mi/mi-cmds.c: Change the binding of "-break-condition" to
mi_cmd_break_condition.
* mi/mi-cmds.h (mi_cmd_break_condition): Declare.
* breakpoint.h (set_breakpoint_condition): Declare a new
overload.
* breakpoint.c (set_breakpoint_condition): New overloaded function
extracted out from ...
(condition_command): ... this.
* NEWS: Mention the change.

gdb/testsuite/ChangeLog:
2021-04-21 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>

* gdb.mi/mi-break.exp (test_forced_conditions): Add a test
for the -break-condition command's "--force" flag.

gdb/doc/ChangeLog:
2021-04-21 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>

* gdb.texinfo (GDB/MI Breakpoint Commands): Mention the
'--force' flag of the '-break-condition' command.
---
gdb/NEWS | 7 ++++
gdb/breakpoint.c | 59 ++++++++++++++++++-------------
gdb/breakpoint.h | 8 +++++
gdb/doc/gdb.texinfo | 6 ++--
gdb/mi/mi-cmd-break.c | 56 +++++++++++++++++++++++++++++
gdb/mi/mi-cmds.c | 4 +--
gdb/mi/mi-cmds.h | 1 +
gdb/testsuite/gdb.mi/mi-break.exp | 11 ++++++
8 files changed, 123 insertions(+), 29 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index 72bceb7266f..27429280aa5 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -39,6 +39,13 @@
is equivalent to the '-force-condition' flag of the CLI's "break"
command.

+ ** '-break-condition --force'
+
+ The MI -break-condition command now supports a '--force' flag to
+ forcibly define a condition even when the condition is invalid at
+ all locations of the selected breakpoint. This is equivalent to
+ the '-force' flag of the CLI's "cond" command.
+
* GDB now supports core file debugging for x86_64 Cygwin programs.

* GDB will now look for the .gdbinit file in a config directory before
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index c2d0ffba974..22899ca9117 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -973,6 +973,39 @@ set_breakpoint_condition (struct breakpoint *b, const char *exp,
gdb::observers::breakpoint_modified.notify (b);
}

+/* See breakpoint.h. */
+
+void
+set_breakpoint_condition (int bpnum, const char *exp, int from_tty,
+ bool force)
+{
+ struct breakpoint *b;
+ ALL_BREAKPOINTS (b)
+ if (b->number == bpnum)
+ {
+ /* Check if this breakpoint has a "stop" method implemented in an
+ extension language. This method and conditions entered into GDB
+ from the CLI are mutually exclusive. */
+ const struct extension_language_defn *extlang
+ = get_breakpoint_cond_ext_lang (b, EXT_LANG_NONE);
+
+ if (extlang != NULL)
+ {
+ error (_("Only one stop condition allowed. There is currently"
+ " a %s stop condition defined for this breakpoint."),
+ ext_lang_capitalized_name (extlang));
+ }
+ set_breakpoint_condition (b, exp, from_tty, force);
+
+ if (is_breakpoint (b))
+ update_global_location_list (UGLL_MAY_INSERT);
+
+ return;
+ }
+
+ error (_("No breakpoint number %d."), bpnum);
+}
+
/* The options for the "condition" command. */

struct condition_command_opts
@@ -1066,7 +1099,6 @@ condition_completer (struct cmd_list_element *cmd,
static void
condition_command (const char *arg, int from_tty)
{
- struct breakpoint *b;
const char *p;
int bnum;

@@ -1085,30 +1117,7 @@ condition_command (const char *arg, int from_tty)
if (bnum == 0)
error (_("Bad breakpoint argument: '%s'"), arg);

- ALL_BREAKPOINTS (b)
- if (b->number == bnum)
- {
- /* Check if this breakpoint has a "stop" method implemented in an
- extension language. This method and conditions entered into GDB
- from the CLI are mutually exclusive. */
- const struct extension_language_defn *extlang
- = get_breakpoint_cond_ext_lang (b, EXT_LANG_NONE);
-
- if (extlang != NULL)
- {
- error (_("Only one stop condition allowed. There is currently"
- " a %s stop condition defined for this breakpoint."),
- ext_lang_capitalized_name (extlang));
- }
- set_breakpoint_condition (b, p, from_tty, cc_opts.force_condition);
-
- if (is_breakpoint (b))
- update_global_location_list (UGLL_MAY_INSERT);
-
- return;
- }
-
- error (_("No breakpoint number %d."), bnum);
+ set_breakpoint_condition (bnum, p, from_tty, cc_opts.force_condition);
}

/* Check that COMMAND do not contain commands that are suitable
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index ded498f5562..2925f77df56 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1657,6 +1657,14 @@ extern void breakpoint_retire_moribund (void);
extern void set_breakpoint_condition (struct breakpoint *b, const char *exp,
int from_tty, bool force);

+/* Set break condition for the breakpoint with number BPNUM to EXP.
+ Raise an error if no breakpoint with the given number is found.
+ Also raise an error if the breakpoint already has stop conditions.
+ If FORCE, define the condition even if it is invalid in
+ all of the breakpoint locations. */
+extern void set_breakpoint_condition (int bpnum, const char *exp,
+ int from_tty, bool force);
+
/* Checks if we are catching syscalls or not.
Returns 0 if not, greater than 0 if we are. */
extern int catch_syscall_enabled (void);
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index cac7ceb4665..a7e045b0544 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -30509,13 +30509,15 @@ times="0"@}
@subsubheading Synopsis

@smallexample
- -break-condition @var{number} @var{expr}
+ -break-condition [ --force ] @var{number} @var{expr}
@end smallexample

Breakpoint @var{number} will stop the program only if the condition in
@var{expr} is true. The condition becomes part of the
@samp{-break-list} output (see the description of the @samp{-break-list}
-command below).
+command below). If the @samp{--force} flag is passed, the condition
+is forcibly defined even when it is invalid for all locations of
+breakpoint @var{number}.

@subsubheading @value{GDBN} Command

diff --git a/gdb/mi/mi-cmd-break.c b/gdb/mi/mi-cmd-break.c
index fec75a8da5a..1a217ecab03 100644
--- a/gdb/mi/mi-cmd-break.c
+++ b/gdb/mi/mi-cmd-break.c
@@ -385,6 +385,62 @@ mi_cmd_dprintf_insert (const char *command, char **argv, int argc)
mi_cmd_break_insert_1 (1, command, argv, argc);
}

+/* Implements the -break-condition command.
+ See the MI manual for the list of options. */
+
+void
+mi_cmd_break_condition (const char *command, char **argv, int argc)
+{
+ enum option
+ {
+ FORCE_CONDITION_OPT,
+ };
+
+ static const struct mi_opt opts[] =
+ {
+ {"-force", FORCE_CONDITION_OPT, 0},
+ { 0, 0, 0 }
+ };
+
+ /* Parse arguments. */
+ int oind = 0;
+ char *oarg;
+ bool force_condition = false;
+
+ while (true)
+ {
+ int opt = mi_getopt ("-break-condition", argc, argv,
+ opts, &oind, &oarg);
+ if (opt < 0)
+ break;
+
+ switch (opt)
+ {
+ case FORCE_CONDITION_OPT:
+ force_condition = true;
+ break;
+ }
+ }
+
+ /* There must be at least two more args: a bpnum and a condition
+ expression. */
+ if (oind + 1 >= argc)
+ error (_("-break-condition: Missing arguments"));
+
+ int bpnum = atoi (argv[oind]);
+
+ /* The rest form the condition expr. */
+ std::string expr (argv[oind + 1]);
+ for (int i = oind + 2; i < argc; ++i)
+ {
+ expr += " ";
+ expr += argv[i];
+ }
+
+ set_breakpoint_condition (bpnum, expr.c_str (), 0 /* from_tty */,
+ force_condition);
+}
+
enum wp_type
{
REG_WP,
diff --git a/gdb/mi/mi-cmds.c b/gdb/mi/mi-cmds.c
index df4290ae5dc..1ed8b6f9126 100644
--- a/gdb/mi/mi-cmds.c
+++ b/gdb/mi/mi-cmds.c
@@ -45,8 +45,8 @@ static struct mi_cmd mi_cmds[] =
DEF_MI_CMD_MI ("add-inferior", mi_cmd_add_inferior),
DEF_MI_CMD_CLI_1 ("break-after", "ignore", 1,
&mi_suppress_notification.breakpoint),
- DEF_MI_CMD_CLI_1 ("break-condition","cond", 1,
- &mi_suppress_notification.breakpoint),
+ DEF_MI_CMD_MI_1 ("break-condition", mi_cmd_break_condition,
+ &mi_suppress_notification.breakpoint),
DEF_MI_CMD_MI_1 ("break-commands", mi_cmd_break_commands,
&mi_suppress_notification.breakpoint),
DEF_MI_CMD_CLI_1 ("break-delete", "delete breakpoint", 1,
diff --git a/gdb/mi/mi-cmds.h b/gdb/mi/mi-cmds.h
index 4c05a4734a8..8da2e393919 100644
--- a/gdb/mi/mi-cmds.h
+++ b/gdb/mi/mi-cmds.h
@@ -36,6 +36,7 @@ extern mi_cmd_argv_ftype mi_cmd_ada_task_info;
extern mi_cmd_argv_ftype mi_cmd_add_inferior;
extern mi_cmd_argv_ftype mi_cmd_break_insert;
extern mi_cmd_argv_ftype mi_cmd_dprintf_insert;
+extern mi_cmd_argv_ftype mi_cmd_break_condition;
extern mi_cmd_argv_ftype mi_cmd_break_commands;
extern mi_cmd_argv_ftype mi_cmd_break_passcount;
extern mi_cmd_argv_ftype mi_cmd_break_watch;
diff --git a/gdb/testsuite/gdb.mi/mi-break.exp b/gdb/testsuite/gdb.mi/mi-break.exp
index 3b264ecdebd..b6ef3483004 100644
--- a/gdb/testsuite/gdb.mi/mi-break.exp
+++ b/gdb/testsuite/gdb.mi/mi-break.exp
@@ -424,6 +424,17 @@ proc_with_prefix test_forced_conditions {} {
mi_gdb_test "-dprintf-insert -c bad --force-condition callme \"Hello\"" \
"${warning}\\^done,$bp" \
"dprintf with forced condition"
+
+ # Define a plain breakpoint first, and a condition later.
+ mi_create_breakpoint "callme" "define a bp" ""
+ mi_gdb_test "-break-condition --force 16 bad == 42" \
+ "${warning}\\^done" \
+ "invalid condition is forced"
+ set args [list -cond "bad == 42" -locations "\\\[$loc\\\]"]
+ set bp [eval mi_make_breakpoint_multi $args]
+ mi_gdb_test "-break-info 16" \
+ "\\^done,[mi_make_breakpoint_table [list $bp]]" \
+ "invalid condition is defined"
}

proc test_break {mi_mode} {
--
2.17.1