[PATCH 1/3] libctf: create: addition of non-root types should not return root types

[Nick Alcock]

If you add a non-root type to a dict, you should always get a new, unique
type ID back, even if a root-visible type with the same name already exists.
Unfortunately, if the root-visible type is a forward, and you're adding a
non-root-visible struct, union, or enum, the machinery to detect forwards
and promote them to the concrete type fires in this case and returns the
root-visible type!  If this is an enum being inserted hidden because its
enumerands conflict with some other enum, this will lead to failure later
on: in any case, it's seriously counterintuitive to add a non-root- visible
type and get a root-visible one instead.

Fix this by checking the root-visible flag properly and only checking for
forwards if this type is root-visible.  (This may lead to a certain degree
of proliferation of non-root-visible forwards: we can add a cleanup pass for
those later if needed.)

libctf/
	* ctf-create.c (ctf_add_struct_sized): Check the root-visible flag when
	doing forward promotion.
	(ctf_add_union_sized): Likewise.
	(ctf_add_enum): Likewise.
---
 libctf/ctf-create.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libctf/ctf-create.c b/libctf/ctf-create.c
index 25dd44def3b..ca984e81b51 100644
--- a/libctf/ctf-create.c
+++ b/libctf/ctf-create.c
@@ -788,7 +788,7 @@ ctf_add_struct_sized (ctf_dict_t *fp, uint32_t flag, const char *name,
   size_t initial_vlen = sizeof (ctf_lmember_t) * INITIAL_VLEN;
 
   /* Promote root-visible forwards to structs.  */
-  if (name != NULL)
+  if (name != NULL && flag == CTF_ADD_ROOT)
     type = ctf_lookup_by_rawname (fp, CTF_K_STRUCT, name);
 
   /* Prohibit promotion if this type was ctf_open()ed.  */
@@ -832,7 +832,7 @@ ctf_add_union_sized (ctf_dict_t *fp, uint32_t flag, const char *name,
   size_t initial_vlen = sizeof (ctf_lmember_t) * INITIAL_VLEN;
 
   /* Promote root-visible forwards to unions.  */
-  if (name != NULL)
+  if (name != NULL && flag == CTF_ADD_ROOT)
     type = ctf_lookup_by_rawname (fp, CTF_K_UNION, name);
 
   /* Prohibit promotion if this type was ctf_open()ed.  */
@@ -875,7 +875,7 @@ ctf_add_enum (ctf_dict_t *fp, uint32_t flag, const char *name)
   size_t initial_vlen = sizeof (ctf_enum_t) * INITIAL_VLEN;
 
   /* Promote root-visible forwards to enums.  */
-  if (name != NULL)
+  if (name != NULL && flag == CTF_ADD_ROOT)
     type = ctf_lookup_by_rawname (fp, CTF_K_ENUM, name);
 
   /* Prohibit promotion if this type was ctf_open()ed.  */
-- 
2.48.1.283.g18c60a128c