[PATCH v2] gdb/python: add allow_pending parameter to gdb.Breakpoint constructor

["Tomáš Hrnčiar" <thrnciar@redhat.com>]

Add a new allow_pending parameter to the gdb.Breakpoint constructor.
Setting the new parameter to False causes GDB to raise an error instead
of creating a pending breakpoint.  By default this parameter is True,
which allows pending breakpoints to be created, preserving the existing
behaviour.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12816
---
 gdb/NEWS                                   |  6 ++
 gdb/doc/python.texi                        | 17 +++--
 gdb/python/py-breakpoint.c                 | 16 +++--
 gdb/testsuite/gdb.python/py-breakpoint.exp | 82 ++++++++++++++++++++--
 4 files changed, 109 insertions(+), 12 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index 5d0c4745653..eb637a21724 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -79,6 +79,12 @@ info locals
   The new "-shadowed on|off" option overrides the "set print shadowed"
   setting for a single invocation of the command.
 
+* Python API
+
+  ** The gdb.Breakpoint constructor now takes an optional
+     'allow_pending' argument.  Setting it to False causes GDB to raise
+     an error instead of creating a pending breakpoint.
+
 *** Changes in GDB 18
 
 * Support for the Common Trace Format (CTF) has been removed.  GDB now
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index ddb347361f7..0b24698a77f 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -6953,7 +6953,7 @@ create both breakpoints and watchpoints.  The second accepts separate Python
 arguments similar to @ref{Explicit Locations}, and can only be used to create
 breakpoints.
 
-@defun Breakpoint.__init__ (spec @r{[}, type @r{][}, wp_class @r{][}, internal @r{][}, temporary @r{][}, qualified @r{]})
+@defun Breakpoint.__init__ (spec @r{[}, type @r{][}, wp_class @r{][}, internal @r{][}, temporary @r{][}, qualified @r{][}, allow_pending @r{]})
 Create a new breakpoint according to @var{spec}, which is a string naming the
 location of a breakpoint, or an expression that defines a watchpoint.  The
 string should describe a location in a format recognized by the @code{break}
@@ -6983,16 +6983,25 @@ the function passed in @code{spec} as a fully-qualified name.  It is equivalent
 to @code{break}'s @code{-qualified} flag (@pxref{Linespec Locations} and
 @ref{Explicit Locations}).
 
+The optional @var{allow_pending} argument is a boolean that controls whether
+the created breakpoint can be pending or not
+(@pxref{Set Breaks,,Pending Breakpoints}).  The @var{allow_pending} argument is
+set to @code{True} by default and is only considered when @var{type} is
+@code{gdb.BP_BREAKPOINT} or @code{gdb.BP_HARDWARE_BREAKPOINT}.  If
+the @var{allow_pending} argument is set to @code{False} and the breakpoint
+location cannot be resolved, a @code{gdb.error} exception is raised
+instead of creating a pending breakpoint.
+
 @end defun
 
-@defun Breakpoint.__init__ (@r{[} source @r{][}, function @r{][}, label @r{][}, line @r{]}, @r{][} internal @r{][}, temporary @r{][}, qualified @r{]})
+@defun Breakpoint.__init__ (@r{[} source @r{][}, function @r{][}, label @r{][}, line @r{]}, @r{][} internal @r{][}, temporary @r{][}, qualified @r{][}, allow_pending @r{]})
 This second form of creating a new breakpoint specifies the explicit
 location (@pxref{Explicit Locations}) using keywords.  The new breakpoint will
 be created in the specified source file @var{source}, at the specified
 @var{function}, @var{label} and @var{line}.
 
-@var{internal}, @var{temporary} and @var{qualified} have the same usage as
-explained previously.
+@var{internal}, @var{temporary}, @var{qualified} and @var{allow_pending} have
+the same usage as explained previously.
 @end defun
 
 The available types are represented by constants defined in the @code{gdb}
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index b1615db1be3..7261bd8e25b 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -914,7 +914,8 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 {
   static const char *keywords[] = { "spec", "type", "wp_class", "internal",
 				    "temporary","source", "function",
-				    "label", "line", "qualified", NULL };
+				    "label", "line", "qualified",
+				    "allow_pending", nullptr };
   const char *spec = NULL;
   enum bptype type = bp_breakpoint;
   int access_type = hw_write;
@@ -928,13 +929,16 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
   char *source = NULL;
   char *function = NULL;
   PyObject *qualified = Py_False;
+  PyObject *allow_pending = Py_True;
 
-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "|siiOOsssOO!", keywords,
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "|siiOOsssOO!O!",
+					keywords,
 					&spec, &type, &access_type,
 					&internal,
 					&temporary, &source,
 					&function, &label, &lineobj,
-					&PyBool_Type, &qualified))
+					&PyBool_Type, &qualified,
+					&PyBool_Type, &allow_pending))
     return -1;
 
 
@@ -1022,12 +1026,16 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 	    const struct breakpoint_ops *ops
 	      = breakpoint_ops_for_location_spec (locspec.get (), false);
 
+	    auto_boolean pending_enabled
+	      = (allow_pending == Py_True
+		 ? AUTO_BOOLEAN_TRUE
+		 : AUTO_BOOLEAN_FALSE);
 	    create_breakpoint (gdbpy_enter::get_gdbarch (),
 			       locspec.get (), NULL, -1, -1, NULL, false,
 			       0,
 			       temporary_bp, type,
 			       0,
-			       AUTO_BOOLEAN_TRUE,
+			       pending_enabled,
 			       ops,
 			       0, 1, internal_bp, 0);
 	    break;
diff --git a/gdb/testsuite/gdb.python/py-breakpoint.exp b/gdb/testsuite/gdb.python/py-breakpoint.exp
index 8b19a11b1f6..c78a321d055 100644
--- a/gdb/testsuite/gdb.python/py-breakpoint.exp
+++ b/gdb/testsuite/gdb.python/py-breakpoint.exp
@@ -628,10 +628,82 @@ proc_with_prefix test_bkpt_address {} {
 }
 
 proc_with_prefix test_bkpt_pending {} {
+    global srcfile testfile
+
+    clean_restart ${testfile}
+
     delete_breakpoints
     gdb_breakpoint "nosuchfunction" -allow-pending
     gdb_test "python print (gdb.breakpoints()\[0\].pending)" "True" \
 	"Check pending status of pending breakpoint"
+
+    delete_breakpoints
+    with_test_prefix "allow_pending=True" {
+	gdb_test "python bp1 = gdb.Breakpoint (source=\"$srcfile\",\
+	    line=\"900\", allow_pending=True)" \
+	    [multi_line \
+		 "^No compiled code for line 900 in file \[^\r\n\]+\\." \
+		 "Breakpoint $::decimal \[^\r\n\]+ pending\\."] \
+	    "set pending explicit breakpoint by source and missing line"
+	gdb_test_no_output "python assert(bp1.pending)" \
+	    "verify pending explicit breakpoint created for missing line"
+	gdb_test "python bp1 = gdb.Breakpoint (function=\"blah\",\
+	    allow_pending=True)" \
+	    [multi_line \
+		 "Function \"blah\" not defined.*" \
+		 "Breakpoint $::decimal \[^\r\n\]+ pending\\."] \
+	    "set pending explicit breakpoint by missing function"
+	gdb_test_no_output "python assert(bp1.pending)" \
+	    "verify pending explicit breakpoint created for missing function"
+	gdb_test "python bp1 = gdb.Breakpoint (\"missing_function\",\
+	    allow_pending=True)" \
+	    [multi_line \
+		 "Function \"missing_function\" not defined.*" \
+		 "Breakpoint $::decimal \[^\r\n\]+ pending\\."] \
+	    "set pending breakpoint by missing function"
+	gdb_test_no_output "python assert(bp1.pending)" \
+	    "verify pending breakpoint created for missing function"
+	gdb_test_no_output "python assert(len(gdb.breakpoints()) == 3)" \
+	    "verify expected number of pending breakpoints were created"
+    }
+
+    delete_breakpoints
+    with_test_prefix "allow_pending=False" {
+	gdb_test "python bp1 = gdb.Breakpoint (source=\"$srcfile\",\
+	    line=\"900\", allow_pending=False)" \
+	    [multi_line \
+		 "Python Exception <class 'gdb.error'>: No compiled code for\
+		  line 900 in file \[^\r\n\]+\\." \
+		 "Error occurred in Python: No compiled code for line 900 in\
+		  file \[^\r\n\]+\\."] \
+	    "set invalid explicit breakpoint by source and missing line"
+	gdb_test "python bp1 = gdb.Breakpoint (function=\"blah\",\
+	    allow_pending=False)" \
+	    [multi_line \
+		 "Python Exception <class 'gdb.error'>: Function \"blah\" not\
+		  defined\\." \
+		 "Error occurred in Python: Function \"blah\" not defined\\."] \
+	    "set invalid explicit breakpoint by missing function"
+	gdb_test "python bp1 = gdb.Breakpoint (\"missing_function\",\
+	    allow_pending=False)" \
+	    [multi_line \
+		 "Python Exception <class 'gdb.error'>: Function\
+		  \"missing_function\" not defined\\." \
+		 "Error occurred in Python: Function \"missing_function\" not\
+		  defined\\."] \
+	    "set invalid breakpoint by missing function"
+	gdb_test_no_output "python assert(len(gdb.breakpoints()) == 0)" \
+	    "verify no pending breakpoints were created"
+    }
+
+    # Test allow_pending with a non-bool type.
+    delete_breakpoints
+    gdb_test "python gdb.Breakpoint (\"multiply\", allow_pending=None)" \
+	[multi_line \
+	     "Python Exception <class 'TypeError'>: argument 11 must be bool,\
+	      not None" \
+	     "Error occurred in Python: argument 11 must be bool, not None"] \
+	"allow_pending non_bool_type"
 }
 
 # Helper proc to install an event listener for a given breakpoint
@@ -744,12 +816,14 @@ proc_with_prefix test_bkpt_explicit_loc {} {
 	"set invalid explicit breakpoint by missing source and line"
     gdb_test "python bp1 = gdb.Breakpoint (source=\"$srcfile\", line=\"900\")" \
 	[multi_line \
-	     "^No compiled code for line 900 in file \"$srcfile\"\\." \
+	     "^No compiled code for line 900 in file \[^\r\n\]+\\." \
 	     "Breakpoint $::decimal \[^\r\n\]+ pending\\."] \
-	"set invalid explicit breakpoint by source and invalid line"
+	"set pending explicit breakpoint by source and missing line"
     gdb_test "python bp1 = gdb.Breakpoint (function=\"blah\")" \
-	"Function \"blah\" not defined.*" \
-	"set invalid explicit breakpoint by missing function"
+	[multi_line \
+	    "Function \"blah\" not defined.*" \
+	    "Breakpoint $::decimal \[^\r\n\]+ pending\\."] \
+	"set pending explicit breakpoint by missing function"
 
     delete_breakpoints
     gdb_test "catch throw" "Catchpoint .* \\(throw\\)"
-- 
2.56.0