Introduce and use make_unique_xstrdup

Adds an utility function to make it shorter to write the common case
of wrapping an xstrdup with a unique_xmalloc_ptr, and uses it
throughout.

Note: I tried to put this in common/common-utils.h near skip_spaces,
etc. but that is included in common/common-defs.h before
common/gdb_unique_ptr.h is included, so it would fail to compile
because gdb::unique_xmalloc_ptr isn't defined at that point yet.  I
tried moving the gdb_unique_ptr.h inclusion before common-utils.h, but
that doesn't work because gdb_unique_ptr.h depends on common-utils.h
for xfree.

gdb/ChangeLog:
2019-06-04  Pedro Alves  <palves@redhat.com>

	* common/gdb_unique_ptr.h (make_unique_xstrdup): New.

	* ada-lang.c (catch_ada_completer): Use make_unique_xstrdup.
	* breakpoint.c (condition_completer): Likewise.
	* cli/cli-dump.c (scan_expression): Likewise.
	* common/filestuff.c (mkdir_recursive): Likewise.
	* common/gdb_tilde_expand.c (gdb_tilde_expand_up)
	* common/pathstuff.c (gdb_realpath, gdb_realpath_keepfile)
	(gdb_abspath): Likewise.
	* compile/compile-cplus-types.c
	(compile_cplus_instance::decl_name): Likewise.
	* completer.c (complete_explicit_location):
	(signal_completer, reg_or_group_completer_1): Likewise.
	* cp-support.c (cp_remove_params_if_any): Likewise.
	* fbsd-tdep.c (fbsd_core_vnode_path): Likewise.
	* guile/scm-safe-call.c (gdbscm_safe_eval_string): Likewise.
	* infcmd.c (strip_bg_char): Likewise.
	* linespec.c (copy_token_string): Likewise.
	* mi/mi-main.c (output_cores): Likewise.
	* psymtab.c (psymtab_search_name):
	* symfile.c (test_set_ext_lang_command): Likewise.
	* target.c (target_fileio_read_stralloc): Likewise.
	* tui/tui-regs.c (tui_reggroup_completer): Likewise.
	* value.c (complete_internalvar): Likewise.

gdb/gdbserver/ChangeLog:
2019-06-04  Pedro Alves  <palves@redhat.com>

	* server.c (captured_main): Use make_unique_xstrdup.

4 files changed, 14 insertions, 6 deletions

diff --git a/gdb/common/filestuff.c b/gdb/common/filestuff.c
index 1ca6248..c7b8c69 100644
--- a/gdb/common/filestuff.c
+++ b/gdb/common/filestuff.c
@@ -462,7 +462,7 @@ is_regular_file (const char *name, int *errno_ptr)
 bool
 mkdir_recursive (const char *dir)
 {
-  gdb::unique_xmalloc_ptr<char> holder (xstrdup (dir));
+  auto holder = make_unique_xstrdup (dir);
   char * const start = holder.get ();
   char *component_start = start;
   char *component_end = start;
diff --git a/gdb/common/gdb_tilde_expand.c b/gdb/common/gdb_tilde_expand.c
index fc338ff..326df8f 100644
--- a/gdb/common/gdb_tilde_expand.c
+++ b/gdb/common/gdb_tilde_expand.c
@@ -91,5 +91,5 @@ gdb_tilde_expand_up (const char *dir)
   gdb_assert (glob.pathc () > 0);
   /* "glob" may return more than one match to the path provided by the
      user, but we are only interested in the first match.  */
-  return gdb::unique_xmalloc_ptr<char> (xstrdup (glob.pathv ()[0]));
+  return make_unique_xstrdup (glob.pathv ()[0]);
 }
diff --git a/gdb/common/gdb_unique_ptr.h b/gdb/common/gdb_unique_ptr.h
index a4be2bb..67a5f26 100644
--- a/gdb/common/gdb_unique_ptr.h
+++ b/gdb/common/gdb_unique_ptr.h
@@ -56,4 +56,12 @@ struct noop_deleter
 
 } /* namespace gdb */
 
+/* Dup STR and return a unique_xmalloc_ptr for the result.  */
+
+static inline gdb::unique_xmalloc_ptr<char>
+make_unique_xstrdup (const char *str)
+{
+  return gdb::unique_xmalloc_ptr<char> (xstrdup (str));
+}
+
 #endif /* COMMON_GDB_UNIQUE_PTR_H */
diff --git a/gdb/common/pathstuff.c b/gdb/common/pathstuff.c
index 2b1669a..e0e048d 100644
--- a/gdb/common/pathstuff.c
+++ b/gdb/common/pathstuff.c
@@ -65,7 +65,7 @@ gdb_realpath (const char *filename)
        we might not be able to display the original casing in a given
        path.  */
     if (len > 0 && len < MAX_PATH)
-      return gdb::unique_xmalloc_ptr<char> (xstrdup (buf));
+      return make_unique_xstrdup (buf);
   }
 #else
   {
@@ -77,7 +77,7 @@ gdb_realpath (const char *filename)
 #endif
 
   /* This system is a lost cause, just dup the buffer.  */
-  return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
+  return make_unique_xstrdup (filename);
 }
 
 /* See common/pathstuff.h.  */
@@ -92,7 +92,7 @@ gdb_realpath_keepfile (const char *filename)
   /* Extract the basename of filename, and return immediately
      a copy of filename if it does not contain any directory prefix.  */
   if (base_name == filename)
-    return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
+    return make_unique_xstrdup (filename);
 
   dir_name = (char *) alloca ((size_t) (base_name - filename + 2));
   /* Allocate enough space to store the dir_name + plus one extra
@@ -135,7 +135,7 @@ gdb_abspath (const char *path)
     return gdb_tilde_expand_up (path);
 
   if (IS_ABSOLUTE_PATH (path))
-    return gdb::unique_xmalloc_ptr<char> (xstrdup (path));
+    return make_unique_xstrdup (path);
 
   /* Beware the // my son, the Emacs barfs, the botch that catch...  */
   return gdb::unique_xmalloc_ptr<char>