[RFA 4/5] Change rewrite_source_path to return a unique_xmalloc_ptr

[Tom Tromey <tom at tromey dot com>]

This changes rewrite_source_path to return a unique_xmalloc_ptr and
fixes up the callers.  This allows removing some cleanups.

ChangeLog
2017-08-18  Tom Tromey  <tom@tromey.com>

	* source.h (rewrite_source_path): Return a unique_xmalloc_ptr.
	* source.c (rewrite_source_path): Return a unique_xmalloc_ptr.
	(find_and_open_source, symtab_to_fullname): Update.
	* psymtab.c (psymtab_to_fullname): Update.
---
 gdb/ChangeLog |  7 +++++++
 gdb/psymtab.c | 15 ++++++---------
 gdb/source.c  | 50 +++++++++++++++++++-------------------------------
 gdb/source.h  |  2 +-
 4 files changed, 33 insertions(+), 41 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0257189..a15df78 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2017-08-18  Tom Tromey  <tom@tromey.com>
 
+	* source.h (rewrite_source_path): Return a unique_xmalloc_ptr.
+	* source.c (rewrite_source_path): Return a unique_xmalloc_ptr.
+	(find_and_open_source, symtab_to_fullname): Update.
+	* psymtab.c (psymtab_to_fullname): Update.
+
+2017-08-18  Tom Tromey  <tom@tromey.com>
+
 	* exec.c (exec_file_attach): Update.
 	* linux-thread-db.c (try_thread_db_load): Update.
 	* guile/scm-safe-call.c (gdbscm_safe_source_script): Update.
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 8283545..6307d6e 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -1199,23 +1199,20 @@ psymtab_to_fullname (struct partial_symtab *ps)
 	close (fd);
       else
 	{
-	  char *fullname;
-	  struct cleanup *back_to;
+	  gdb::unique_xmalloc_ptr<char> fullname;
 
 	  /* rewrite_source_path would be applied by find_and_open_source, we
 	     should report the pathname where GDB tried to find the file.  */
 
 	  if (ps->dirname == NULL || IS_ABSOLUTE_PATH (ps->filename))
-	    fullname = xstrdup (ps->filename);
+	    fullname.reset (xstrdup (ps->filename));
 	  else
-	    fullname = concat (ps->dirname, SLASH_STRING,
-			       ps->filename, (char *) NULL);
+	    fullname.reset (concat (ps->dirname, SLASH_STRING,
+				    ps->filename, (char *) NULL));
 
-	  back_to = make_cleanup (xfree, fullname);
-	  ps->fullname = rewrite_source_path (fullname);
+	  ps->fullname = rewrite_source_path (fullname.get ()).release ();
 	  if (ps->fullname == NULL)
-	    ps->fullname = xstrdup (fullname);
-	  do_cleanups (back_to);
+	    ps->fullname = fullname.release ();
 	}
     }
 
diff --git a/gdb/source.c b/gdb/source.c
index 0453f92..5403715 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -994,13 +994,12 @@ get_substitute_path_rule (const char *path)
 }
 
 /* If the user specified a source path substitution rule that applies
-   to PATH, then apply it and return the new path.  This new path must
-   be deallocated afterwards.
-   
+   to PATH, then apply it and return the new path.
+
    Return NULL if no substitution rule was specified by the user,
    or if no rule applied to the given PATH.  */
-   
-char *
+
+gdb::unique_xmalloc_ptr<char>
 rewrite_source_path (const char *path)
 {
   const struct substitute_path_rule *rule = get_substitute_path_rule (path);
@@ -1019,7 +1018,7 @@ rewrite_source_path (const char *path)
   strcpy (new_path, rule->to);
   strcat (new_path, path + from_len);
 
-  return new_path;
+  return gdb::unique_xmalloc_ptr<char> (new_path);
 }
 
 int
@@ -1030,7 +1029,6 @@ find_and_open_source (const char *filename,
   char *path = source_path;
   const char *p;
   int result;
-  struct cleanup *cleanup;
 
   /* Quick way out if we already know its full name.  */
 
@@ -1039,7 +1037,7 @@ find_and_open_source (const char *filename,
       /* The user may have requested that source paths be rewritten
          according to substitution rules he provided.  If a substitution
          rule applies to this path, then apply it.  */
-      char *rewritten_fullname = rewrite_source_path (*fullname);
+      char *rewritten_fullname = rewrite_source_path (*fullname).release ();
 
       if (rewritten_fullname != NULL)
         {
@@ -1062,21 +1060,17 @@ find_and_open_source (const char *filename,
       *fullname = NULL;
     }
 
-  cleanup = make_cleanup (null_cleanup, NULL);
-
+  gdb::unique_xmalloc_ptr<char> rewritten_dirname;
   if (dirname != NULL)
     {
       /* If necessary, rewrite the compilation directory name according
          to the source path substitution rules specified by the user.  */
 
-      char *rewritten_dirname = rewrite_source_path (dirname);
+      rewritten_dirname = rewrite_source_path (dirname);
 
       if (rewritten_dirname != NULL)
-        {
-          make_cleanup (xfree, rewritten_dirname);
-          dirname = rewritten_dirname;
-        }
-      
+	dirname = rewritten_dirname.get ();
+
       /* Replace a path entry of $cdir with the compilation directory
 	 name.  */
 #define	cdir_len	5
@@ -1098,17 +1092,15 @@ find_and_open_source (const char *filename,
 	}
     }
 
+  gdb::unique_xmalloc_ptr<char> rewritten_filename;
   if (IS_ABSOLUTE_PATH (filename))
     {
       /* If filename is absolute path, try the source path
 	 substitution on it.  */
-      char *rewritten_filename = rewrite_source_path (filename);
+      rewritten_filename = rewrite_source_path (filename);
 
       if (rewritten_filename != NULL)
-        {
-          make_cleanup (xfree, rewritten_filename);
-          filename = rewritten_filename;
-        }
+	filename = rewritten_filename.get ();
     }
 
   result = openp (path, OPF_SEARCH_IN_PATH | OPF_RETURN_REALPATH, filename,
@@ -1122,7 +1114,6 @@ find_and_open_source (const char *filename,
 			OPEN_MODE, fullname);
     }
 
-  do_cleanups (cleanup);
   return result;
 }
 
@@ -1164,23 +1155,20 @@ symtab_to_fullname (struct symtab *s)
 	close (fd);
       else
 	{
-	  char *fullname;
-	  struct cleanup *back_to;
+	  gdb::unique_xmalloc_ptr<char> fullname;
 
 	  /* rewrite_source_path would be applied by find_and_open_source, we
 	     should report the pathname where GDB tried to find the file.  */
 
 	  if (SYMTAB_DIRNAME (s) == NULL || IS_ABSOLUTE_PATH (s->filename))
-	    fullname = xstrdup (s->filename);
+	    fullname.reset (xstrdup (s->filename));
 	  else
-	    fullname = concat (SYMTAB_DIRNAME (s), SLASH_STRING,
-			       s->filename, (char *) NULL);
+	    fullname.reset (concat (SYMTAB_DIRNAME (s), SLASH_STRING,
+				    s->filename, (char *) NULL));
 
-	  back_to = make_cleanup (xfree, fullname);
-	  s->fullname = rewrite_source_path (fullname);
+	  s->fullname = rewrite_source_path (fullname.get ()).release ();
 	  if (s->fullname == NULL)
-	    s->fullname = xstrdup (fullname);
-	  do_cleanups (back_to);
+	    s->fullname = fullname.release ();
 	}
     } 
 
diff --git a/gdb/source.h b/gdb/source.h
index ee9f3fa..263715a 100644
--- a/gdb/source.h
+++ b/gdb/source.h
@@ -48,7 +48,7 @@ extern int find_and_open_source (const char *filename,
    negative number for error.  */
 extern int open_source_file (struct symtab *s);
 
-extern char *rewrite_source_path (const char *path);
+extern gdb::unique_xmalloc_ptr<char> rewrite_source_path (const char *path);
 
 extern const char *symtab_to_fullname (struct symtab *s);
 
-- 
2.9.4