Explicit locations: introduce explicit locations

This patch add support for explicit locations and switches many linespec
locations to this new location type.  This patch also converts all
linespec locations entered by the user to an explicit representation
internally (thus bypassing the linespec parser when resetting the
breakpoint).

This patch does not introduce any user-visible changes.


gdb/ChangeLog:

	* break-catch-throw.c (re_set_exception_catchpoint): Convert
	linespec into explicit location.
	* breakpoint.c (create_overlay_breakpoint)
	(create_longjmp_master_breakpoint)
	(create_std_terminate_master_breakpoint)
	(create_exception_master_breakpoint): Convert linespec into explicit
	location.
	(update_static_tracepoint): Convert linespec into explicit location.
	* linespec.c (enum offset_relative_sign, struct line_offset): Move
	location.h.
	(struct linespec) <expression, expr_pc, source_filename>
	<function_name, label_name, line_offset>: Replace with ...
	<explicit>: ... this.
	<is_linespec>: New member.
	(PARSER_EXPLICIT): New accessor macro.
	(undefined_label_error): New function.
	(source_file_not_found_error): New function.
	(linespec_parse_basic): The parser result is now an explicit location.
	Use PARSER_EXPLICIT to access it.
	Use undefined_label_error.
	(canonicalize_linespec): Convert canonical linespec into explicit
	location.
	Move string representation of location to explicit_location_to_linespec
	and use it and explicit_location_to_string to save string
	representations of the canonical location.
	(create_sals_line_offset, convert_linespec_to_sals): `ls' contains an
	explicit location.  Update all references.
	(convert_explicit_location_to_sals): New function.
	(parse_linespec): Use PARSER_EXPLICIT to access the parser
	result's explicit location.
	(linespec_state_constructor): Initialize is_linespec.
	Use PARSER_EXPLICIT.
	(linespec_parser_delete): Use PARSER_EXPLICIT to access the parser's
	result.
	(event_location_to_sals): For linespec locations, set is_linespec.
	Handle explicit locations.
	(decode_objc): 'ls' contains an explicit location now. Update all
	references.
	(symtabs_from_filename): Use source_file_not_found_error.
	* location.c (struct event_location.u) <explicit>: New member.
	(initialize_explicit_location): New function.
	(initialize_event_location): Initialize explicit locations.
	(new_explicit_location, get_explicit_location)
	(get_explicit_location_const): New functions.
	(explicit_to_string_internal): New function; most of contents moved
	from canonicalize_linespec.
	(explicit_location_to_string): New function.
	(explicit_location_to_linespec): New function.
	(copy_event_location, delete_event_location)
	(event_location_to_string_const, event_location_empty_p): Handle
	explicit locations.
	* location.h (enum offset_relative_sign, struct line_offset): Move
	here from linespec.h.
	(enum event_location_type): Add EXPLICIT_LOCATION.
	(struct explicit_location): New structure.
	(explicit_location_to_string): Declare.
	(explicit_location_to_linespec): Declare.
	(new_explicit_location, get_explicit_locationp
	(get_explicit_location_const, initialize_explicit_location): Declare.

1 files changed, 87 insertions, 0 deletions

diff --git a/gdb/location.h b/gdb/location.h
index 63318ba..3082d9e 100644
--- a/gdb/location.h
+++ b/gdb/location.h
@@ -22,6 +22,32 @@
 struct language_defn;
 struct event_location;
 
+/* An enumeration of possible signs for a line offset.  */
+
+enum offset_relative_sign
+{
+  /* No sign  */
+  LINE_OFFSET_NONE,
+
+  /* A plus sign ("+")  */
+  LINE_OFFSET_PLUS,
+
+  /* A minus sign ("-")  */
+  LINE_OFFSET_MINUS,
+
+  /* A special "sign" for unspecified offset.  */
+  LINE_OFFSET_UNKNOWN
+};
+
+/* A line offset in a location.  */
+
+struct line_offset
+{
+  /* Line offset and any specified sign.  */
+  int offset;
+  enum offset_relative_sign sign;
+};
+
 /* An enumeration of the various ways to specify a stop event
    location (used with create_breakpoint).  */
 
@@ -33,15 +59,52 @@ enum event_location_type
   /* An address in the inferior.  */
   ADDRESS_LOCATION,
 
+  /* An explicit location.  */
+  EXPLICIT_LOCATION,
+
   /* A probe location.  */
   PROBE_LOCATION
 };
 
+/* An explicit location.  This structure is used to bypass the
+   parsing done on linespecs.  It still has the same requirements
+   as linespecs, though.  For example, source_filename requires
+   at least one other field.  */
+
+struct explicit_location
+{
+  /* The source filename. Malloc'd.  */
+  char *source_filename;
+
+  /* The function name.  Malloc'd.  */
+  char *function_name;
+
+  /* The name of a label.  Malloc'd.  */
+  char *label_name;
+
+  /* A line offset relative to the start of the symbol
+     identified by the above fields or the current symtab
+     if the other fields are NULL.  */
+  struct line_offset line_offset;
+};
+
 /* Return the type of the given event location.  */
 
 extern enum event_location_type
   event_location_type (const struct event_location *);
 
+/* Return a malloc'd explicit string representation of the given
+   explicit location.  The location must already be canonicalized/valid.  */
+
+extern char *
+  explicit_location_to_string (const struct explicit_location *explicit);
+
+/* Return a malloc'd linespec string representation of the given
+   explicit location.  The location must already be canonicalized/valid.  */
+
+extern char *
+  explicit_location_to_linespec (const struct explicit_location *explicit);
+
 /* Return a string representation of the LOCATION.
    This function may return NULL for unspecified linespecs,
    e.g, LOCATION_LINESPEC and addr_string is NULL.
@@ -87,6 +150,30 @@ extern struct event_location *
 extern const char *
   get_probe_location (const struct event_location *location);
 
+/* Initialize the given explicit location.  */
+
+extern void initialize_explicit_location (struct explicit_location *explicit);
+
+/* Create a new explicit location.  If not NULL, EXPLICIT is checked for
+   validity.  If invalid, an exception is thrown.
+
+   The return result is malloc'd and should be freed with
+   delete_event_location.  */
+
+extern struct event_location *
+  new_explicit_location (const struct explicit_location *explicit);
+
+/* Return the explicit location of the given event_location
+   (which must be of type EXPLICIT_LOCATION).  */
+
+extern struct explicit_location *
+  get_explicit_location (struct event_location *location);
+
+/* A const version of the above.  */
+
+extern const struct explicit_location *
+  get_explicit_location_const (const struct event_location *location);
+
 /* Free an event location and any associated data.  */
 
 extern void delete_event_location (struct event_location *location);