Re: [RFA 06/13] Replace start_rbreak_breakpoints and end_rbreak_breakpoints

[Tom Tromey <tom@tromey.com>]

>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:

Simon> Your patch LGTM.  But how is the "string" string freed in
Simon> rbreak_command?

It is leaked, which apparently is a regression introduced by an earlier
patch of mine.  Sorry about that!  I've updated the patch as appended to
fix this problem.

Tom

commit 391e4d7aa45fc4947632aa06a7aa462eeef3377c
Author: Tom Tromey <tom@tromey.com>
Date:   Wed Nov 1 09:00:09 2017 -0600

    Replace start_rbreak_breakpoints and end_rbreak_breakpoints
    
    This replaces start_rbreak_breakpoints and end_rbreak_breakpoints with
    a new scoped class.  This allows the removal of a cleanup.
    
    This also fixes an earlier memory leak regression, by changing
    "string" to be a std::string.
    
    gdb/ChangeLog
    2017-11-03  Tom Tromey  <tom@tromey.com>
    
            * breakpoint.c
            (scoped_rbreak_breakpoints::scoped_rbreak_breakpoints): Rename
            from start_rbreak_breakpoints.
            (scoped_rbreak_breakpoints): Rename from end_rbreak_breakpoints.
            * breakpoint.h (class scoped_rbreak_breakpoints): New.
            (start_rbreak_breakpoints, end_rbreak_breakpoints): Remove.
            * symtab.c (do_end_rbreak_breakpoints): Remove.
            (rbreak_command): Use scoped_rbreak_breakpoints, std::string.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ce6c8db631..56b7e903bc 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2017-11-03  Tom Tromey  <tom@tromey.com>
+
+	* breakpoint.c
+	(scoped_rbreak_breakpoints::scoped_rbreak_breakpoints): Rename
+	from start_rbreak_breakpoints.
+	(scoped_rbreak_breakpoints): Rename from end_rbreak_breakpoints.
+	* breakpoint.h (class scoped_rbreak_breakpoints): New.
+	(start_rbreak_breakpoints, end_rbreak_breakpoints): Remove.
+	* symtab.c (do_end_rbreak_breakpoints): Remove.
+	(rbreak_command): Use scoped_rbreak_breakpoints, std::string.
+
 2017-11-02  Tom Tromey  <tom@tromey.com>
 
 	* cp-namespace.c (reset_directive_searched): Remove.
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 0bf47d5f56..61e41283b1 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -644,8 +644,7 @@ static int rbreak_start_breakpoint_count;
 /* Called at the start an "rbreak" command to record the first
    breakpoint made.  */
 
-void
-start_rbreak_breakpoints (void)
+scoped_rbreak_breakpoints::scoped_rbreak_breakpoints ()
 {
   rbreak_start_breakpoint_count = breakpoint_count;
 }
@@ -653,8 +652,7 @@ start_rbreak_breakpoints (void)
 /* Called at the end of an "rbreak" command to record the last
    breakpoint made.  */
 
-void
-end_rbreak_breakpoints (void)
+scoped_rbreak_breakpoints::~scoped_rbreak_breakpoints ()
 {
   prev_breakpoint_count = rbreak_start_breakpoint_count;
 }
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 9a9433bd66..69b63ea932 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -1601,10 +1601,18 @@ extern VEC(breakpoint_p) *static_tracepoints_here (CORE_ADDR addr);
    that each command is suitable for tracepoint command list.  */
 extern void check_tracepoint_command (char *line, void *closure);
 
-/* Call at the start and end of an "rbreak" command to register
-   breakpoint numbers for a later "commands" command.  */
-extern void start_rbreak_breakpoints (void);
-extern void end_rbreak_breakpoints (void);
+/* Create an instance of this to start registering breakpoint numbers
+   for a later "commands" command.  */
+
+class scoped_rbreak_breakpoints
+{
+public:
+
+  scoped_rbreak_breakpoints ();
+  ~scoped_rbreak_breakpoints ();
+
+  DISABLE_COPY_AND_ASSIGN (scoped_rbreak_breakpoints);
+};
 
 /* Breakpoint iterator function.
 
diff --git a/gdb/symtab.c b/gdb/symtab.c
index 16a6b2eb6f..25b3de0dfb 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -4506,20 +4506,10 @@ rbreak_command_wrapper (char *regexp, int from_tty)
   rbreak_command (regexp, from_tty);
 }
 
-/* A cleanup function that calls end_rbreak_breakpoints.  */
-
-static void
-do_end_rbreak_breakpoints (void *ignore)
-{
-  end_rbreak_breakpoints ();
-}
-
 static void
 rbreak_command (char *regexp, int from_tty)
 {
-  struct cleanup *old_chain;
-  char *string = NULL;
-  int len = 0;
+  std::string string;
   const char **files = NULL;
   const char *file_name;
   int nfiles = 0;
@@ -4550,8 +4540,7 @@ rbreak_command (char *regexp, int from_tty)
 						       FUNCTIONS_DOMAIN,
 						       nfiles, files);
 
-  start_rbreak_breakpoints ();
-  old_chain = make_cleanup (do_end_rbreak_breakpoints, NULL);
+  scoped_rbreak_breakpoints finalize;
   for (const symbol_search &p : symbols)
     {
       if (p.msymbol.minsym == NULL)
@@ -4559,20 +4548,9 @@ rbreak_command (char *regexp, int from_tty)
 	  struct symtab *symtab = symbol_symtab (p.symbol);
 	  const char *fullname = symtab_to_fullname (symtab);
 
-	  int newlen = (strlen (fullname)
-			+ strlen (SYMBOL_LINKAGE_NAME (p.symbol))
-			+ 4);
-
-	  if (newlen > len)
-	    {
-	      string = (char *) xrealloc (string, newlen);
-	      len = newlen;
-	    }
-	  strcpy (string, fullname);
-	  strcat (string, ":'");
-	  strcat (string, SYMBOL_LINKAGE_NAME (p.symbol));
-	  strcat (string, "'");
-	  break_command (string, from_tty);
+	  string = (std::string (fullname) + ":'"
+		    + SYMBOL_LINKAGE_NAME (p.symbol) + "'");
+	  break_command (&string[0], from_tty);
 	  print_symbol_info (FUNCTIONS_DOMAIN,
 			     p.symbol,
 			     p.block,
@@ -4580,24 +4558,14 @@ rbreak_command (char *regexp, int from_tty)
 	}
       else
 	{
-	  int newlen = (strlen (MSYMBOL_LINKAGE_NAME (p.msymbol.minsym)) + 3);
-
-	  if (newlen > len)
-	    {
-	      string = (char *) xrealloc (string, newlen);
-	      len = newlen;
-	    }
-	  strcpy (string, "'");
-	  strcat (string, MSYMBOL_LINKAGE_NAME (p.msymbol.minsym));
-	  strcat (string, "'");
+	  string = (std::string ("'")
+		    + MSYMBOL_LINKAGE_NAME (p.msymbol.minsym) + "'");
 
-	  break_command (string, from_tty);
+	  break_command (&string[0], from_tty);
 	  printf_filtered ("<function, no debug info> %s;\n",
 			   MSYMBOL_PRINT_NAME (p.msymbol.minsym));
 	}
     }
-
-  do_cleanups (old_chain);
 }
 \f