Re: [RFA 4/9] Explicit locations v2 - Add address locations

[Keith Seitz <keiths at redhat dot com>]

This is an update of this patch based on changes from reviews of 
previous patches.

Keith

Changes since last version:
  - remove SAVE_SPEC stuff
  - canonicalize_linespec: remove expression stuff
  - ditto convert_linespec_to_sals
  - event_location_to_string_const: compute return value
    (aka remove SAVE_SPEC)
  - new_address_location

ChangeLog
2014-05-29  Keith Seitz  <keiths@redhat.com>

	* breakpoint.c (create_thread_event_breakpoint): Convert
	linespec to address location.
	(init_breakpoint_sal): Likewise.
	* linespec.c (canonicalize_linespec): Do not handle address
	locations here.
	(convert_address_location_to_sals): New function; contents moved
	from ...
	(convert_linespc_to_sals): ... here.
	(parse_linespec): Remove address locations from linespec grammar.
	Remove handling of address locations.
	(event_location_to_sals): Handle ADDRESS_LOCATION.
	(linespec_expression_to_pc): Export.
	* linespec.h (linespec_expression_to_pc): Add declaration.
	* location.c (copy_event_location): Handle address locations.
	(delete_event_location): Likewise.
	(event_location_to_string): Likewise.
	(string_to_event_location): Likewise.
	(event_location_empty_p): Likewise.
	* location.h (enum event_location_type): Add EVENT_LOCATION_ADDRESS.
	(struct event_location.u) <address>: New member.
	(ADDRESS_LOCATION): Define accessor macro.
	* python/py-finishbreakpoint.c (bpfinishpy_init): Remove local
	variable `finish_pc'.
	Convert linespec to address location.
	* spu-tdep.c (spu_catch_start): Convert linespec to address
	location.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index c4727da..ef60f44 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -7538,9 +7538,7 @@ create_thread_event_breakpoint (struct gdbarch *gdbarch, CORE_ADDR address)
 
   b->enable_state = bp_enabled;
   /* location has to be used or breakpoint_re_set will delete me.  */
-  b->location = new_linespec_location (NULL);
-  EVENT_LOCATION_LINESPEC (b->location)
-    = xstrprintf ("*%s", paddress (b->loc->gdbarch, b->loc->address));
+  b->location = new_address_location (b->loc->address);
 
   update_global_location_list_nothrow (1);
 
@@ -9423,11 +9421,7 @@ init_breakpoint_sal (struct breakpoint *b, struct gdbarch *gdbarch,
   if (location != NULL)
     b->location = location;
   else
-    {
-      b->location = new_linespec_location (NULL);
-      EVENT_LOCATION_LINESPEC (b->location)
-	= xstrprintf ("*%s", paddress (b->loc->gdbarch, b->loc->address));
-   }
+    b->location = new_address_location (b->loc->address);
   b->filter = filter;
 }
 
diff --git a/gdb/linespec.c b/gdb/linespec.c
index 92482b4..8ea0c7b 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -317,7 +317,7 @@ static void iterate_over_file_blocks (struct symtab *symtab,
 static void initialize_defaults (struct symtab **default_symtab,
 				 int *default_line);
 
-static CORE_ADDR linespec_expression_to_pc (const char **exp_ptr);
+CORE_ADDR linespec_expression_to_pc (const char **exp_ptr);
 
 static struct symtabs_and_lines decode_objc (struct linespec_state *self,
 					     linespec_p ls,
@@ -1766,77 +1766,68 @@ linespec_parse_basic (linespec_parser *parser)
 static void
 canonicalize_linespec (struct linespec_state *state, linespec_p ls)
 {
+  struct ui_file *buf;
+  int need_colon = 0;
+
   /* If canonicalization was not requested, no need to do anything.  */
   if (!state->canonical)
     return;
 
-  /* Shortcut expressions, which can only appear by themselves.  */
-  if (ls->expression != NULL)
-    {
-      state->canonical->location
-	= new_linespec_location (ls->expression);
-    }
-  else
-    {
-      struct ui_file *buf;
-      int need_colon = 0;
+  buf = mem_fileopen ();
 
-      buf = mem_fileopen ();
+  state->canonical->location = new_linespec_location (NULL);
 
-      state->canonical->location = new_linespec_location (NULL);
+  if (ls->source_filename)
+    {
+      fputs_unfiltered (ls->source_filename, buf);
+      need_colon = 1;
+    }
 
-      if (ls->source_filename)
-	{
-	  fputs_unfiltered (ls->source_filename, buf);
-	  need_colon = 1;
-	}
+  if (ls->function_name)
+    {
+      if (need_colon)
+	fputc_unfiltered (':', buf);
+      fputs_unfiltered (ls->function_name, buf);
+      need_colon = 1;
+    }
 
-      if (ls->function_name)
-	{
-	  if (need_colon)
-	    fputc_unfiltered (':', buf);
-	  fputs_unfiltered (ls->function_name, buf);
-	  need_colon = 1;
-	}
+  if (ls->label_name)
+    {
+      if (need_colon)
+	fputc_unfiltered (':', buf);
 
-      if (ls->label_name)
+      if (ls->function_name == NULL)
 	{
-	  if (need_colon)
-	    fputc_unfiltered (':', buf);
-
-	  if (ls->function_name == NULL)
-	    {
-	      struct symbol *s;
-
-	      /* No function was specified, so add the symbol name.  */
-	      gdb_assert (ls->labels.function_symbols != NULL
-			  && (VEC_length (symbolp, ls->labels.function_symbols)
-			      == 1));
-	      s = VEC_index (symbolp, ls->labels.function_symbols, 0);
-	      fputs_unfiltered (SYMBOL_NATURAL_NAME (s), buf);
-	      fputc_unfiltered (':', buf);
-	    }
-
-	  fputs_unfiltered (ls->label_name, buf);
-	  need_colon = 1;
-	  state->canonical->special_display = 1;
+	  struct symbol *s;
+
+	  /* No function was specified, so add the symbol name.  */
+	  gdb_assert (ls->labels.function_symbols != NULL
+		      && (VEC_length (symbolp, ls->labels.function_symbols)
+			  == 1));
+	  s = VEC_index (symbolp, ls->labels.function_symbols, 0);
+	  fputs_unfiltered (SYMBOL_NATURAL_NAME (s), buf);
+	  fputc_unfiltered (':', buf);
 	}
 
-      if (ls->line_offset.sign != LINE_OFFSET_UNKNOWN)
-	{
-	  if (need_colon)
-	    fputc_unfiltered (':', buf);
-	  fprintf_filtered (buf, "%s%d",
-			    (ls->line_offset.sign == LINE_OFFSET_NONE ? ""
-			     : (ls->line_offset.sign
-				== LINE_OFFSET_PLUS ? "+" : "-")),
-			    ls->line_offset.offset);
-	}
+      fputs_unfiltered (ls->label_name, buf);
+      need_colon = 1;
+      state->canonical->special_display = 1;
+    }
 
-      EVENT_LOCATION_LINESPEC (state->canonical->location)
-	= ui_file_xstrdup (buf, NULL);
-      ui_file_delete (buf);
+  if (ls->line_offset.sign != LINE_OFFSET_UNKNOWN)
+    {
+      if (need_colon)
+	fputc_unfiltered (':', buf);
+      fprintf_filtered (buf, "%s%d",
+			(ls->line_offset.sign == LINE_OFFSET_NONE ? ""
+			 : (ls->line_offset.sign
+			    == LINE_OFFSET_PLUS ? "+" : "-")),
+			ls->line_offset.offset);
     }
+
+  EVENT_LOCATION_LINESPEC (state->canonical->location)
+    = ui_file_xstrdup (buf, NULL);
+  ui_file_delete (buf);
 }
 
 /* Given a line offset in LS, construct the relevant SALs.  */
@@ -1990,6 +1981,27 @@ create_sals_line_offset (struct linespec_state *self,
   return values;
 }
 
+/* Convert the given ADDRESS into SaLs.  */
+
+static struct symtabs_and_lines
+convert_address_location_to_sals (struct linespec_state *self,
+				  CORE_ADDR address)
+{
+  struct symtab_and_line sal;
+  struct symtabs_and_lines sals = {NULL, 0};
+
+  sal = find_pc_line (address, 0);
+  sal.pc = address;
+  sal.section = find_pc_overlay (address);
+  sal.explicit_pc = 1;
+  add_sal_to_sals (self, &sals, &sal, core_addr_to_string (address), 1);
+
+  if (self->canonical != NULL)
+    self->canonical->location = new_address_location (address);
+
+  return sals;
+}
+
 /* Create and return SALs from the linespec LS.  */
 
 static struct symtabs_and_lines
@@ -1997,18 +2009,7 @@ convert_linespec_to_sals (struct linespec_state *state, linespec_p ls)
 {
   struct symtabs_and_lines sals = {NULL, 0};
 
-  if (ls->expression != NULL)
-    {
-      struct symtab_and_line sal;
-
-      /* We have an expression.  No other attribute is allowed.  */
-      sal = find_pc_line (ls->expr_pc, 0);
-      sal.pc = ls->expr_pc;
-      sal.section = find_pc_overlay (ls->expr_pc);
-      sal.explicit_pc = 1;
-      add_sal_to_sals (state, &sals, &sal, ls->expression, 1);
-    }
-  else if (ls->labels.label_symbols != NULL)
+  if (ls->labels.label_symbols != NULL)
     {
       /* We have just a bunch of functions/methods or labels.  */
       int i;
@@ -2108,8 +2109,7 @@ convert_linespec_to_sals (struct linespec_state *state, linespec_p ls)
 
    The basic grammar of linespecs:
 
-   linespec -> expr_spec | var_spec | basic_spec
-   expr_spec -> '*' STRING
+   linespec -> var_spec | basic_spec
    var_spec -> '$' (STRING | NUMBER)
 
    basic_spec -> file_offset_spec | function_spec | label_spec
@@ -2205,33 +2205,7 @@ parse_linespec (linespec_parser *parser, const char **argptr)
   token = linespec_lexer_lex_one (parser);
 
   /* It must be either LSTOKEN_STRING or LSTOKEN_NUMBER.  */
-  if (token.type == LSTOKEN_STRING && *LS_TOKEN_STOKEN (token).ptr == '*')
-    {
-      char *expr;
-      const char *copy;
-
-      /* User specified an expression, *EXPR.  */
-      copy = expr = copy_token_string (token);
-      cleanup = make_cleanup (xfree, expr);
-      PARSER_RESULT (parser)->expr_pc = linespec_expression_to_pc (&copy);
-      discard_cleanups (cleanup);
-      PARSER_RESULT (parser)->expression = expr;
-
-      /* This is a little hacky/tricky.  If linespec_expression_to_pc
-	 did not evaluate the entire token, then we must find the
-	 string COPY inside the original token buffer.  */
-      if (*copy != '\0')
-	{
-	  PARSER_STREAM (parser) = strstr (parser->lexer.saved_arg, copy);
-	  gdb_assert (PARSER_STREAM (parser) != NULL);
-	}
-
-      /* Consume the token.  */
-      linespec_lexer_consume_token (parser);
-
-      goto convert_to_sals;
-    }
-  else if (token.type == LSTOKEN_STRING && *LS_TOKEN_STOKEN (token).ptr == '$')
+  if (token.type == LSTOKEN_STRING && *LS_TOKEN_STOKEN (token).ptr == '$')
     {
       char *var;
 
@@ -2453,6 +2427,12 @@ event_location_to_sals (linespec_parser *parser,
       }
       break;
 
+    case ADDRESS_LOCATION:
+      result
+	= convert_address_location_to_sals (PARSER_STATE (parser),
+					    EVENT_LOCATION_ADDRESS (location));
+      break;
+
     default:
       gdb_assert_not_reached ("unhandled event location type");
     }
@@ -2647,7 +2627,7 @@ initialize_defaults (struct symtab **default_symtab, int *default_line)
 /* Evaluate the expression pointed to by EXP_PTR into a CORE_ADDR,
    advancing EXP_PTR past any parsed text.  */
 
-static CORE_ADDR
+CORE_ADDR
 linespec_expression_to_pc (const char **exp_ptr)
 {
   if (current_program_space->executing_startup)
diff --git a/gdb/linespec.h b/gdb/linespec.h
index 658f2a1..df5820a 100644
--- a/gdb/linespec.h
+++ b/gdb/linespec.h
@@ -152,4 +152,8 @@ extern struct symtabs_and_lines decode_line_with_current_source (char *, int);
 
 extern struct symtabs_and_lines decode_line_with_last_displayed (char *, int);
 
+/* Evaluate the expression pointed to by EXP_PTR into a CORE_ADDR,
+   advancing EXP_PTR past any parsed text.  */
+
+extern CORE_ADDR linespec_expression_to_pc (const char **exp_ptr);
 #endif /* defined (LINESPEC_H) */
diff --git a/gdb/location.c b/gdb/location.c
index 57900bf..3c430db 100644
--- a/gdb/location.c
+++ b/gdb/location.c
@@ -53,6 +53,20 @@ new_linespec_location (const char *linespec)
   return location;
 }
 
+/* Create a new address location.  The return result is malloc'd
+   and should be freed with delete_event_location.  */
+
+struct event_location *
+new_address_location (CORE_ADDR addr)
+{
+  struct event_location *location;
+
+  location = XNEW (struct event_location);
+  initialize_event_location (location, ADDRESS_LOCATION);
+  EVENT_LOCATION_ADDRESS (location) = addr;
+  return location;
+}
+
 /* Return a copy of the given SRC location.  */
 
 struct event_location *
@@ -71,6 +85,10 @@ copy_event_location (const struct event_location *src)
       EVENT_LOCATION_LINESPEC (dst) = xstrdup (EVENT_LOCATION_LINESPEC (src));
       break;
 
+    case ADDRESS_LOCATION:
+      EVENT_LOCATION_ADDRESS (dst) = EVENT_LOCATION_ADDRESS (src);
+      break;
+
     default:
       gdb_assert_not_reached ("unknown event location type");
     }
@@ -111,6 +129,10 @@ delete_event_location (struct event_location *location)
 	  xfree (EVENT_LOCATION_LINESPEC (location));
 	  break;
 
+	case ADDRESS_LOCATION:
+	  /* Nothing to do.  */
+	  break;
+
 	default:
 	  gdb_assert_not_reached ("unknown event location type");
 	}
@@ -138,6 +160,12 @@ event_location_to_string_const (const struct event_location *location)
 	result = xstrdup (EVENT_LOCATION_LINESPEC (location));
       break;
 
+    case ADDRESS_LOCATION:
+      result
+	= xstrprintf ("*%s",
+		      core_addr_to_string (EVENT_LOCATION_ADDRESS (location)));
+      break;
+
     default:
       gdb_assert_not_reached ("unknown event location type");
     }
@@ -171,9 +199,24 @@ string_to_event_location (char **stringp,
 {
   struct event_location *location;
 
-  location = new_linespec_location (*stringp);
-  if (*stringp != NULL)
-    *stringp += strlen (*stringp);
+  /* First, check if the string is an address location.  */
+  if (*stringp != NULL && **stringp == '*')
+    {
+      const char *arg, *orig;
+      CORE_ADDR addr;
+
+      orig = arg = *stringp;
+      addr = linespec_expression_to_pc (&arg);
+      location = new_address_location (addr);
+      *stringp += arg - orig;
+    }
+  else
+    {
+      /* Everything else is a linespec.  */
+      location = new_linespec_location (*stringp);
+      if (*stringp != NULL)
+	*stringp += strlen (*stringp);
+    }
 
   return location;
 }
@@ -188,6 +231,9 @@ event_location_empty_p (const struct event_location *location)
     case LINESPEC_LOCATION:
       return EVENT_LOCATION_LINESPEC (location) == NULL;
 
+    case ADDRESS_LOCATION:
+      return 0;
+
     default:
       gdb_assert_not_reached ("unknown event location type");
     }
diff --git a/gdb/location.h b/gdb/location.h
index 418e271..1daefb6 100644
--- a/gdb/location.h
+++ b/gdb/location.h
@@ -27,7 +27,10 @@ struct language_defn;
 enum event_location_type
 {
   /* A traditional linespec.  */
-  LINESPEC_LOCATION
+  LINESPEC_LOCATION,
+
+  /* An address in the inferior.  */
+  ADDRESS_LOCATION
 };
 
 /* An event location used to set a stop event in the inferior.
@@ -47,6 +50,10 @@ struct event_location
        probes.  */
     char *addr_string;
 #define EVENT_LOCATION_LINESPEC(S) ((S)->u.addr_string)
+
+    /* An address in the inferior.  */
+    CORE_ADDR address;
+#define EVENT_LOCATION_ADDRESS(S) ((S)->u.address)
   } u;
 
   /* Cached string representation of this location.  This is used to
@@ -85,6 +92,12 @@ extern struct cleanup *
 extern struct event_location *
   new_linespec_location (const char *linespec);
 
+/* Create a new address location.  The return result is malloc'd
+   and should be freed with delete_event_location.  */
+
+extern struct event_location *
+  new_address_location (CORE_ADDR addr);
+
 /* Return a copy of the given SRC location.  */
 
 extern struct event_location *
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index c29037a..c97bb0a 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -167,9 +167,8 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
   struct frame_id frame_id;
   PyObject *internal = NULL;
   int internal_bp = 0;
-  CORE_ADDR finish_pc, pc;
+  CORE_ADDR pc;
   volatile struct gdb_exception except;
-  char small_buf[100];
   struct symbol *function;
 
   if (!PyArg_ParseTupleAndKeywords (args, kwargs, "|OO", keywords,
@@ -291,10 +290,8 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
       struct event_location location;
 
       /* Set a breakpoint on the return address.  */
-      initialize_event_location (&location, LINESPEC_LOCATION);
-      finish_pc = get_frame_pc (prev_frame);
-      xsnprintf (small_buf, sizeof (small_buf), "*%s", hex_string (finish_pc));
-      EVENT_LOCATION_LINESPEC (&location) = small_buf;
+      initialize_event_location (&location, ADDRESS_LOCATION);
+      EVENT_LOCATION_ADDRESS (&location) = get_frame_pc (prev_frame);
       create_breakpoint (python_gdbarch,
                          &location, NULL, thread, NULL,
                          0,
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index fcfe066..4ff742f 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -2001,8 +2001,8 @@ spu_catch_start (struct objfile *objfile)
 
   /* Use a numerical address for the set_breakpoint command to avoid having
      the breakpoint re-set incorrectly.  */
-  initialize_event_location (&location, LINESPEC_LOCATION);
-  EVENT_LOCATION_LINESPEC (&location) = xstrdup (core_addr_to_string (pc));
+  initialize_event_location (&location, ADDRESS_LOCATION);
+  EVENT_LOCATION_ADDRESS (&location) = pc;
   create_breakpoint (get_objfile_arch (objfile), &location,
 		     NULL /* cond_string */, -1 /* thread */,
 		     NULL /* extra_string */,