Implement explicit locations for Python breakpoints.

This introduces several new keywords to the bppy_init constructor.
The spec parameter is now optional but mutually exclusive to the
explicit keywords source, label, function and line.

gdb/ChangeLog

2017-12-07  Phil Muldoon  <pmuldoon@redhat.com>

       * python/py-breakpoint.c (bppy_init): Use string_to_event_location
       over basic location code. Implement explicit location keywords.
       (bppy_init_validate_args): New function.
       * NEWS: Document Python explicit breakpoint locations.

doc/ChangeLog

2017-12-07  Phil Muldoon  <pmuldoon@redhat.com>

       * python.texi (Breakpoints In Python): Add text relating
       to allowed explicit locations and keywords in gdb.Breakpoints.

testsuite/ChangeLog

2017-12-07  Phil Muldoon  <pmuldoon@redhat.com>

       * gdb.python/py-breakpoint.exp (test_bkpt_explicit_loc): Add new
       tests for explicit locations.

1 files changed, 121 insertions, 13 deletions

diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 2574683ed47..f865317ab33 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -32,6 +32,7 @@
 #include "language.h"
 #include "location.h"
 #include "py-event.h"
+#include "linespec.h"
 
 /* Number of live breakpoints.  */
 static int bppy_live;
@@ -631,25 +632,104 @@ bppy_get_ignore_count (PyObject *self, void *closure)
   return PyInt_FromLong (self_bp->bp->ignore_count);
 }
 
+/* Internal function to validate the Python parameters/keywords
+   provided to bppy_init.  */
+
+static int
+bppy_init_validate_args (const char *spec, char *source,
+			 char *function, char *label,
+			 char *line, enum bptype type)
+{
+  /* If spec is defined, ensure that none of the explicit location
+     keywords are also defined.  */
+  if (spec != NULL)
+    {
+      if (source != NULL || function != NULL || label != NULL || line != NULL)
+	{
+	  PyErr_SetString (PyExc_RuntimeError,
+			   _("Breakpoints specified with spec cannot "
+			     "have source, function, label or line defined."));
+	  return -1;
+	}
+    }
+  else
+    {
+      /* If spec isn't defined, ensure that the user is not trying to
+	 define a watchpoint with an explicit location.  */
+      if (type == bp_watchpoint)
+	{
+	  PyErr_SetString (PyExc_RuntimeError,
+			   _("Watchpoints cannot be set by explicit "
+			     "location parameters."));
+	  return -1;
+	}
+      else
+	{
+	  /* Otherwise, ensure some explicit locations are defined.  */
+	  if (source == NULL && function == NULL && label == NULL
+	      && line == NULL)
+	    {
+	      PyErr_SetString (PyExc_RuntimeError,
+			       _("Neither spec nor explicit location set."));
+	      return -1;
+	    }
+	  /* Finally, if source is specified, ensure that line, label
+	     or function are specified too.  */
+	  if (source != NULL && function == NULL && label == NULL
+	      && line == NULL)
+	    {
+	      PyErr_SetString (PyExc_RuntimeError,
+			       _("Specifying a source must also include a "
+				 "line, label or function."));
+	      return -1;
+	    }
+	}
+    }
+  return 1;
+}
+
 /* Python function to create a new breakpoint.  */
 static int
 bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 {
   static const char *keywords[] = { "spec", "type", "wp_class", "internal",
-				    "temporary", NULL };
-  const char *spec;
-  int type = bp_breakpoint;
+				    "temporary","source", "function",
+				    "label", "line", NULL };
+  const char *spec = NULL;
+  enum bptype type = bp_breakpoint;
   int access_type = hw_write;
   PyObject *internal = NULL;
   PyObject *temporary = NULL;
+  PyObject *lineobj = NULL;;
   int internal_bp = 0;
   int temporary_bp = 0;
+  gdb::unique_xmalloc_ptr<char> line;
+  char *label = NULL;
+  char *source = NULL;
+  char *function = NULL;
 
-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "s|iiOO", keywords,
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "|siiOOsssO", keywords,
 					&spec, &type, &access_type,
-					&internal, &temporary))
+					&internal,
+					&temporary, &source,
+					&function, &label, &lineobj))
     return -1;
 
+
+  if (lineobj != NULL)
+    {
+      if (PyInt_Check (lineobj))
+	line.reset (xstrprintf ("%ld", PyInt_AsLong (lineobj)));
+      else if (PyString_Check (lineobj))
+	line = python_string_to_host_string (lineobj);
+      else
+	{
+	  PyErr_SetString (PyExc_RuntimeError,
+			   _("Line keyword should be an integer or a string. "));
+	  return -1;
+	}
+    }
+
   if (internal)
     {
       internal_bp = PyObject_IsTrue (internal);
@@ -664,23 +744,47 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 	return -1;
     }
 
+  if (bppy_init_validate_args (spec, source, function, label, line.get (),
+			       type) == -1)
+    return -1;
+
   bppy_pending_object = (gdbpy_breakpoint_object *) self;
   bppy_pending_object->number = -1;
   bppy_pending_object->bp = NULL;
 
   TRY
     {
-      gdb::unique_xmalloc_ptr<char>
-	copy_holder (xstrdup (skip_spaces (spec)));
-      const char *copy = copy_holder.get ();
-
       switch (type)
 	{
 	case bp_breakpoint:
 	  {
-	    event_location_up location
-	      = string_to_event_location_basic (&copy, current_language,
-						symbol_name_match_type::WILD);
+	    event_location_up location;
+
+	    if (spec != NULL)
+	      {
+		gdb::unique_xmalloc_ptr<char>
+		  copy_holder (xstrdup (skip_spaces (spec)));
+		const char *copy = copy_holder.get ();
+
+		location  = string_to_event_location (&copy,
+						      current_language);
+	      }
+	    else
+	      {
+		struct explicit_location explicit_loc;
+
+		initialize_explicit_location (&explicit_loc);
+		explicit_loc.source_filename = source;
+		explicit_loc.function_name = function;
+		explicit_loc.label_name = label;
+
+		if (line != NULL)
+		  explicit_loc.line_offset =
+		    linespec_parse_line_offset (line.get ());
+
+		location = new_explicit_location (&explicit_loc);
+	      }
+
 	    create_breakpoint (python_gdbarch,
 			       location.get (), NULL, -1, NULL,
 			       0,
@@ -691,8 +795,12 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 			       0, 1, internal_bp, 0);
 	    break;
 	  }
-        case bp_watchpoint:
+	case bp_watchpoint:
 	  {
+	    gdb::unique_xmalloc_ptr<char>
+	      copy_holder (xstrdup (skip_spaces (spec)));
+	    char *copy = copy_holder.get ();
+
 	    if (access_type == hw_write)
 	      watch_command_wrapper (copy, 0, internal_bp);
 	    else if (access_type == hw_access)