[RFA 1/5] Change gdb_abspath to return a unique_xmalloc_ptr

[Tom Tromey <tom at tromey dot com>]

This changes gdb_abspath to return a unique_xmalloc_ptr, and fixes up
the callers.  This allows the removal of a cleanup, and also puts
ownership rules into the API, where they belong.

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

	* compile/compile.c (compile_file_command): Use
	gdb::unique_xmalloc_ptr, std::string.
	* utils.c (gdb_abspath): Change return type.
	* source.c (openp): Update.
	* objfiles.c (allocate_objfile): Update.
	* main.c (set_gdb_data_directory): Update.
	* utils.h (gdb_abspath): Return a gdb::unique_xmalloc_ptr.
---
 gdb/ChangeLog         | 10 ++++++++++
 gdb/compile/compile.c | 11 +++--------
 gdb/main.c            |  4 ++--
 gdb/objfiles.c        | 11 +++++++----
 gdb/source.c          |  2 +-
 gdb/utils.c           | 21 +++++++++------------
 gdb/utils.h           |  2 +-
 7 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7ad3f4c..e75d1b7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,4 +1,14 @@
 2017-08-18  Tom Tromey  <tom@tromey.com>
+
+	* compile/compile.c (compile_file_command): Use
+	gdb::unique_xmalloc_ptr, std::string.
+	* utils.c (gdb_abspath): Change return type.
+	* source.c (openp): Update.
+	* objfiles.c (allocate_objfile): Update.
+	* main.c (set_gdb_data_directory): Update.
+	* utils.h (gdb_abspath): Return a gdb::unique_xmalloc_ptr.
+
+2017-08-18  Tom Tromey  <tom@tromey.com>
 	    Pedro Alves  <palves@redhat.com>
 
 	* spu-multiarch.c (parse_spufs_run): Use scoped_restore.
diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index bca7b57..91e084f 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -90,8 +90,6 @@ static void
 compile_file_command (char *arg, int from_tty)
 {
   enum compile_i_scope_types scope = COMPILE_I_SIMPLE_SCOPE;
-  char *buffer;
-  struct cleanup *cleanup;
 
   scoped_restore save_async = make_scoped_restore (&current_ui->async, 0);
 
@@ -115,12 +113,9 @@ compile_file_command (char *arg, int from_tty)
     error (_("Unknown argument specified."));
 
   arg = skip_spaces (arg);
-  arg = gdb_abspath (arg);
-  cleanup = make_cleanup (xfree, arg);
-  buffer = xstrprintf ("#include \"%s\"\n", arg);
-  make_cleanup (xfree, buffer);
-  eval_compile_command (NULL, buffer, scope, NULL);
-  do_cleanups (cleanup);
+  gdb::unique_xmalloc_ptr<char> abspath = gdb_abspath (arg);
+  std::string buffer = string_printf ("#include \"%s\"\n", abspath.get ());
+  eval_compile_command (NULL, buffer.c_str (), scope, NULL);
 }
 
 /* Handle the input from the 'compile code' command.  The
diff --git a/gdb/main.c b/gdb/main.c
index 9813041..886e17f 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -128,10 +128,10 @@ set_gdb_data_directory (const char *new_datadir)
      isn't canonical, but that's ok.  */
   if (!IS_ABSOLUTE_PATH (gdb_datadir))
     {
-      char *abs_datadir = gdb_abspath (gdb_datadir);
+      gdb::unique_xmalloc_ptr<char> abs_datadir = gdb_abspath (gdb_datadir);
 
       xfree (gdb_datadir);
-      gdb_datadir = abs_datadir;
+      gdb_datadir = abs_datadir.release ();
     }
 }
 
diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index d261c87..ff99ca6 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -386,22 +386,25 @@ allocate_objfile (bfd *abfd, const char *name, objfile_flags flags)
 
   objfile_alloc_data (objfile);
 
+  gdb::unique_xmalloc_ptr<char> name_holder;
   if (name == NULL)
     {
       gdb_assert (abfd == NULL);
       gdb_assert ((flags & OBJF_NOT_FILENAME) != 0);
-      expanded_name = xstrdup ("<<anonymous objfile>>");
+      expanded_name = "<<anonymous objfile>>";
     }
   else if ((flags & OBJF_NOT_FILENAME) != 0
 	   || is_target_filename (name))
-    expanded_name = xstrdup (name);
+    expanded_name = name;
   else
-    expanded_name = gdb_abspath (name);
+    {
+      name_holder = gdb_abspath (name);
+      expanded_name = name_holder.get ();
+    }
   objfile->original_name
     = (char *) obstack_copy0 (&objfile->objfile_obstack,
 			      expanded_name,
 			      strlen (expanded_name));
-  xfree (expanded_name);
 
   /* Update the per-objfile information that comes from the bfd, ensuring
      that any data that is reference is saved in the per-objfile data
diff --git a/gdb/source.c b/gdb/source.c
index 769d9ef..e2a507d 100644
--- a/gdb/source.c
+++ b/gdb/source.c
@@ -913,7 +913,7 @@ done:
       else if ((opts & OPF_RETURN_REALPATH) != 0)
 	*filename_opened = gdb_realpath (filename);
       else
-	*filename_opened = gdb_abspath (filename);
+	*filename_opened = gdb_abspath (filename).release ();
     }
 
   errno = last_errno;
diff --git a/gdb/utils.c b/gdb/utils.c
index 96ae709..9959c01 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -2761,28 +2761,25 @@ gdb_realpath_keepfile (const char *filename)
 
 /* Return PATH in absolute form, performing tilde-expansion if necessary.
    PATH cannot be NULL or the empty string.
-   This does not resolve symlinks however, use gdb_realpath for that.
-   Space for the result is allocated with malloc.
-   If the path is already absolute, it is strdup'd.
-   If there is a problem computing the absolute path, the path is returned
-   unchanged (still strdup'd).  */
+   This does not resolve symlinks however, use gdb_realpath for that.  */
 
-char *
+gdb::unique_xmalloc_ptr<char>
 gdb_abspath (const char *path)
 {
   gdb_assert (path != NULL && path[0] != '\0');
 
   if (path[0] == '~')
-    return tilde_expand (path);
+    return gdb::unique_xmalloc_ptr<char> (tilde_expand (path));
 
   if (IS_ABSOLUTE_PATH (path))
-    return xstrdup (path);
+    return gdb::unique_xmalloc_ptr<char> (xstrdup (path));
 
   /* Beware the // my son, the Emacs barfs, the botch that catch...  */
-  return concat (current_directory,
-	    IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
-		 ? "" : SLASH_STRING,
-		 path, (char *) NULL);
+  return gdb::unique_xmalloc_ptr<char>
+    (concat (current_directory,
+	     IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
+	     ? "" : SLASH_STRING,
+	     path, (char *) NULL));
 }
 
 ULONGEST
diff --git a/gdb/utils.h b/gdb/utils.h
index bb5fadc..a2a959f 100644
--- a/gdb/utils.h
+++ b/gdb/utils.h
@@ -256,7 +256,7 @@ extern char *gdb_realpath (const char *);
 
 extern char *gdb_realpath_keepfile (const char *);
 
-extern char *gdb_abspath (const char *);
+extern gdb::unique_xmalloc_ptr<char> gdb_abspath (const char *);
 
 extern int gdb_filename_fnmatch (const char *pattern, const char *string,
 				 int flags);
-- 
2.9.4