Eliminate the two-level data structures behind location_specs

Currently, there's the location_spec hierarchy, and then some
location_spec subclasses have their own struct type holding all their
data fields.

I.e., there is this:

 location_spec
   explicit_location_spec
   linespec_location_spec
   address_location_spec
   probe_location_spec

and then these separate types:

  explicit_location
  linespec_location

where:

  explicit_location_spec
     has-a explicit_location
  linespec_location_spec
     has-a linespec_location

This patch eliminates explicit_location and linespec_location,
inlining their members in the corresponding location_spec type.

The location_spec subclasses were the ones currently defined in
location.c, so they are moved to the header.  Since the definitions of
the classes are now visible, we no longer need location_spec_deleter.

Some constructors that are used for cloning location_specs, like:

  explicit explicit_location_spec (const struct explicit_location *loc)

... were converted to proper copy ctors.

In the process, initialize_explicit_location is eliminated, and some
functions that returned the "data type behind a locspec", like
get_linespec_location are converted to downcast functions, like
as_linespec_location_spec.

Change-Id: Ia31ccef9382b25a52b00fa878c8df9b8cf2a6c5a

1 files changed, 12 insertions, 9 deletions

diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 029ced74..bab1c60 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -839,20 +839,23 @@ bppy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 	      }
 	    else
 	      {
-		struct explicit_location explicit_loc;
+		std::unique_ptr<explicit_location_spec> explicit_loc
+		  (new explicit_location_spec ());
 
-		initialize_explicit_location (&explicit_loc);
-		explicit_loc.source_filename = source;
-		explicit_loc.function_name = function;
-		explicit_loc.label_name = label;
+		explicit_loc->source_filename
+		  = source != nullptr ? xstrdup (source) : nullptr;
+		explicit_loc->function_name
+		  = function != nullptr ? xstrdup (function) : nullptr;
+		explicit_loc->label_name
+		  = label != nullptr ? xstrdup (label) : nullptr;
 
 		if (line != NULL)
-		  explicit_loc.line_offset =
-		    linespec_parse_line_offset (line.get ());
+		  explicit_loc->line_offset
+		    = linespec_parse_line_offset (line.get ());
 
-		explicit_loc.func_name_match_type = func_name_match_type;
+		explicit_loc->func_name_match_type = func_name_match_type;
 
-		locspec = new_explicit_location_spec (&explicit_loc);
+		locspec.reset (explicit_loc.release ());
 	      }
 
 	    const struct breakpoint_ops *ops