[6/8] save memory in init_type

[Tom Tromey <tromey at redhat dot com>]

While constifying init_type, I was curious about the strings passed to
it by its various callers.

So, I examined all the callers and what I found is that the argument is
in most cases either a constant string (not requiring copying), or NULL,
or a string already saved on the objfile obstack.

The only exception to this was a call in fixup_go_packaging.

This patch changes init_type so that it does not copy its argument, and
changes fixup_go_packaging to do the copying instead.  This lets us save
some memory.

Tom

	* dwarf2read.c (fixup_go_packaging): Save package name
	on objfile obstack.
	* gdbtypes.c (init_type): Don't copy name.
---
 gdb/dwarf2read.c |    8 ++++++--
 gdb/gdbtypes.c   |   11 ++++-------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 5368f34..af57c66 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -6826,15 +6826,19 @@ fixup_go_packaging (struct dwarf2_cu *cu)
   if (package_name != NULL)
     {
       struct objfile *objfile = cu->objfile;
+      const char *saved_package_name = obsavestring (package_name,
+						     strlen (package_name),
+						     &objfile->objfile_obstack);
       struct type *type = init_type (TYPE_CODE_MODULE, 0, 0,
-				     package_name, objfile);
+				     saved_package_name, objfile);
       struct symbol *sym;
 
       TYPE_TAG_NAME (type) = TYPE_NAME (type);
 
       sym = OBSTACK_ZALLOC (&objfile->objfile_obstack, struct symbol);
       SYMBOL_SET_LANGUAGE (sym, language_go);
-      SYMBOL_SET_NAMES (sym, package_name, strlen (package_name), 1, objfile);
+      SYMBOL_SET_NAMES (sym, saved_package_name,
+			strlen (saved_package_name), 0, objfile);
       /* This is not VAR_DOMAIN because we want a way to ensure a lookup of,
 	 e.g., "main" finds the "main" module and not C's main().  */
       SYMBOL_DOMAIN (sym) = STRUCT_DOMAIN;
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 62bf589..77d2a8c 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1939,10 +1939,9 @@ allocate_gnat_aux_type (struct type *type)
 
 /* Helper function to initialize the standard scalar types.
 
-   If NAME is non-NULL, then we make a copy of the string pointed
-   to by name in the objfile_obstack for that objfile, and initialize
-   the type name to that copy.  There are places (mipsread.c in particular),
-   where init_type is called with a NULL value for NAME).  */
+   If NAME is non-NULL, then it is used to initialize the type name.
+   Note that NAME is not copied; it is required to have a lifetime at
+   least as long as OBJFILE.  */
 
 struct type *
 init_type (enum type_code code, int length, int flags,
@@ -1980,9 +1979,7 @@ init_type (enum type_code code, int length, int flags,
   if (flags & TYPE_FLAG_GNU_IFUNC)
     TYPE_GNU_IFUNC (type) = 1;
 
-  if (name)
-    TYPE_NAME (type) = obsavestring (name, strlen (name),
-				     &objfile->objfile_obstack);
+  TYPE_NAME (type) = name;
 
   /* C++ fancies.  */
 
-- 
1.7.7.6