gdb/breakpoint: add a 'force_condition' parameter to 'create_breakpoint'

The 'create_breakpoint' function takes a 'parse_extra' argument that
determines whether the condition, thread, and force-condition
specifiers should be parsed from the extra string or be used from the
function arguments.  However, for the case when 'parse_extra' is
false, there is no way to pass the force-condition specifier.  This
patch adds it as a new argument.

Also, in the case when parse_extra is false, the current behavior is
as if the condition is being forced.  This is a bug.  The default
behavior should reject the breakpoint.  See below for a demo of this
incorrect behavior.  (The MI command '-break-insert' uses the
'create_breakpoint' function with parse_extra=0.)

  $ gdb -q --interpreter=mi3 /tmp/simple
  =thread-group-added,id="i1"
  =cmd-param-changed,param="history save",value="on"
  =cmd-param-changed,param="auto-load safe-path",value="/"
  ~"Reading symbols from /tmp/simple...\n"
  (gdb)
  -break-insert -c junk -f main
  &"warning: failed to validate condition at location 1, disabling:\n  "
  &"No symbol \"junk\" in current context.\n"
  ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="<MULTIPLE>",cond="junk",times="0",original-location="main",locations=[{number="1.1",enabled="N",addr="0x000000000000114e",func="main",file="/tmp/simple.c",fullname="/tmp/simple.c",line="2",thread-groups=["i1"]}]}
  (gdb)
  break main if junk
  &"break main if junk\n"
  &"No symbol \"junk\" in current context.\n"
  ^error,msg="No symbol \"junk\" in current context."
  (gdb)
  break main -force-condition if junk
  &"break main -force-condition if junk\n"
  ~"Note: breakpoint 1 also set at pc 0x114e.\n"
  &"warning: failed to validate condition at location 1, disabling:\n  "
  &"No symbol \"junk\" in current context.\n"
  ~"Breakpoint 2 at 0x114e: file /tmp/simple.c, line 2.\n"
  =breakpoint-created,bkpt={number="2",type="breakpoint",disp="keep",enabled="y",addr="<MULTIPLE>",cond="junk",times="0",original-location="main",locations=[{number="2.1",enabled="N",addr="0x000000000000114e",func="main",file="/tmp/simple.c",fullname="/tmp/simple.c",line="2",thread-groups=["i1"]}]}
  ^done
  (gdb)

After applying this patch, we get the behavior below:

  (gdb)
  -break-insert -c junk -f main
  ^error,msg="No symbol \"junk\" in current context."

This restores the behavior that is present in the existing releases.

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

	* breakpoint.h (create_breakpoint): Add a new parameter,
	'force_condition'.
	* breakpoint.c (create_breakpoint): Use the 'force_condition'
	argument when 'parse_extra' is false to check if the condition
	is invalid at all of the breakpoint locations.
	Update the users below.
	(break_command_1)
	(dprintf_command)
	(trace_command)
	(ftrace_command)
	(strace_command)
	(create_tracepoint_from_upload): Update.
	* guile/scm-breakpoint.c (gdbscm_register_breakpoint_x): Update.
	* mi/mi-cmd-break.c (mi_cmd_break_insert_1): Update.
	* python/py-breakpoint.c (bppy_init): Update.
	* python/py-finishbreakpoint.c (bpfinishpy_init): Update.

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

	* gdb.mi/mi-break.exp: Extend with checks for invalid breakpoint
	conditions.

1 files changed, 6 insertions, 0 deletions

diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index c30656971bb..ded498f5562 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1409,6 +1409,11 @@ enum breakpoint_create_flags
    the condition, thread, and extra string from EXTRA_STRING, ignoring
    the similarly named parameters.
 
+   If FORCE_CONDITION is true, the condition is accepted even when it is
+   invalid at all of the locations.  However, if PARSE_EXTRA is non-zero,
+   the FORCE_CONDITION parameter is ignored and the corresponding argument
+   is parsed from EXTRA_STRING.
+
    If INTERNAL is non-zero, the breakpoint number will be allocated
    from the internal breakpoint count.
 
@@ -1418,6 +1423,7 @@ extern int create_breakpoint (struct gdbarch *gdbarch,
 			      struct event_location *location,
 			      const char *cond_string, int thread,
 			      const char *extra_string,
+			      bool force_condition,
 			      int parse_extra,
 			      int tempflag, enum bptype wanted_type,
 			      int ignore_count,