Explicit locations: introduce new struct event_location-based API

This patch introduces the new breakpoint/"linespec" API based on
a new struct event_location.  This API currently only supports
traditional linespecs, maintaining the status quo of the code base.
Future patches will add additional functionality for other location
types such as address locations.

gdb/ChangeLog:

	* Makefile.in (SFILES): Add location.c.
	(HFILES_NO_SRCDIR): Add location.h.
	(COMMON_OBS): Add location.o.
	* linespec.c (linespec_lex_to_end): New function.
	* linespec.h (linespec_lex_to_end): Declare.
	* location.c: New file.
	* location.h: New file.

1 files changed, 220 insertions, 0 deletions

diff --git a/gdb/location.c b/gdb/location.c
new file mode 100644
index 0000000..44f3dc6
--- /dev/null
+++ b/gdb/location.c
@@ -0,0 +1,220 @@
+/* Data structures and API for event locations in GDB.
+   Copyright (C) 2013-2015 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "gdb_assert.h"
+#include "location.h"
+#include "symtab.h"
+#include "language.h"
+#include "linespec.h"
+#include "cli/cli-utils.h"
+#include "probe.h"
+
+#include <ctype.h>
+#include <string.h>
+
+/* An event location used to set a stop event in the inferior.
+   This structure is an amalgam of the various ways
+   to specify where a stop event should be set.  */
+
+struct event_location
+{
+  /* The type of this breakpoint specification.  */
+  enum event_location_type type;
+#define EL_TYPE(PTR) (PTR)->type
+
+  union
+  {
+    /* A generic "this is a string specification" for a location.
+       This representation is used by both "normal" linespecs and
+       probes.  */
+    char *addr_string;
+#define EL_LINESPEC(PTR) ((PTR)->u.addr_string)
+  } u;
+
+  /* Cached string representation of this location.  This is used, e.g., to
+     save stop event locations to file.  Malloc'd.  */
+  char *as_string;
+#define EL_STRING(PTR) ((PTR)->as_string)
+};
+
+/* See description in location.h.  */
+
+enum event_location_type
+event_location_type (const struct event_location *location)
+{
+  return EL_TYPE (location);
+}
+
+/* See description in location.h.  */
+
+struct event_location *
+new_linespec_location (char **linespec)
+{
+  struct event_location *location;
+
+  location = XCNEW (struct event_location);
+  EL_TYPE (location) = LINESPEC_LOCATION;
+  if (*linespec != NULL)
+    {
+      char *p;
+      char *orig = *linespec;
+
+      linespec_lex_to_end (linespec);
+      p = remove_trailing_whitespace (orig, *linespec);
+      if ((p - orig) > 0)
+	EL_LINESPEC (location) = savestring (orig, p - orig);
+    }
+  return location;
+}
+
+/* See description in location.h.  */
+
+const char *
+get_linespec_location (const struct event_location *location)
+{
+  gdb_assert (EL_TYPE (location) == LINESPEC_LOCATION);
+  return EL_LINESPEC (location);
+}
+
+/* See description in location.h.  */
+
+struct event_location *
+copy_event_location (const struct event_location *src)
+{
+  struct event_location *dst;
+
+  dst = XCNEW (struct event_location);
+  EL_TYPE (dst) = EL_TYPE (src);
+  if (EL_STRING (src) != NULL)
+    EL_STRING (dst) = xstrdup (EL_STRING (src));
+
+  switch (EL_TYPE (src))
+    {
+    case LINESPEC_LOCATION:
+      if (EL_LINESPEC (src) != NULL)
+	EL_LINESPEC (dst) = xstrdup (EL_LINESPEC (src));
+      break;
+
+    default:
+      gdb_assert_not_reached ("unknown event location type");
+    }
+
+  return dst;
+}
+
+/* A cleanup function for struct event_location.  */
+
+static void
+delete_event_location_cleanup (void *data)
+{
+  struct event_location *location = (struct event_location *) data;
+
+  delete_event_location (location);
+}
+
+/* See description in location.h.  */
+
+struct cleanup *
+make_cleanup_delete_event_location (struct event_location *location)
+{
+  return make_cleanup (delete_event_location_cleanup, location);
+}
+
+/* See description in location.h.  */
+
+void
+delete_event_location (struct event_location *location)
+{
+  if (location != NULL)
+    {
+      xfree (EL_STRING (location));
+
+      switch (EL_TYPE (location))
+	{
+	case LINESPEC_LOCATION:
+	  xfree (EL_LINESPEC (location));
+	  break;
+
+	default:
+	  gdb_assert_not_reached ("unknown event location type");
+	}
+
+      xfree (location);
+    }
+}
+
+/* See description in location.h.  */
+
+const char *
+event_location_to_string (struct event_location *location)
+{
+  if (EL_STRING (location) == NULL)
+    {
+      switch (EL_TYPE (location))
+	{
+	case LINESPEC_LOCATION:
+	  if (EL_LINESPEC (location) != NULL)
+	    EL_STRING (location) = xstrdup (EL_LINESPEC (location));
+	  break;
+
+	default:
+	  gdb_assert_not_reached ("unknown event location type");
+	}
+    }
+
+  return EL_STRING (location);
+}
+
+/* See description in location.h.  */
+
+struct event_location *
+string_to_event_location (char **stringp,
+			  const struct language_defn *language)
+{
+  struct event_location *location;
+
+  location = new_linespec_location (stringp);
+  return location;
+}
+
+/* See description in location.h.  */
+
+int
+event_location_empty_p (const struct event_location *location)
+{
+  switch (EL_TYPE (location))
+    {
+    case LINESPEC_LOCATION:
+      /* Linespecs are never "empty."  (NULL is a valid linespec)  */
+      return 0;
+
+    default:
+      gdb_assert_not_reached ("unknown event location type");
+    }
+}
+
+/* See description in location.h.  */
+
+void
+set_event_location_string (struct event_location *location,
+			   const char *string)
+{
+  xfree (EL_STRING (location));
+  EL_STRING (location) = string == NULL ?  NULL : xstrdup (string);
+}