libctf: eliminate dtd_u, part 2: arrays

This is even simpler than ints, floats and slices, with the only extra
complication being the need to manually transfer the array parameter in
the rarely-used function ctf_set_array.  (Arrays are unique in libctf in
that they can be modified post facto, not just created and appended to.
I'm not sure why they got this exemption, but it's easy to maintain.)

libctf/ChangeLog
2021-03-18  Nick Alcock  <nick.alcock@oracle.com>

	* ctf-impl.h (ctf_dtdef_t) <dtd_u.dtu_arr>: Remove.
	* ctf-create.c (ctf_add_array): Use the dtd_vlen, not dtu_arr.
	(ctf_set_array): Likewise.
	* ctf-serialize.c (ctf_emit_type_sect): Just copy the dtd_vlen.
	* ctf-types.c (ctf_array_info): Just use the vlen.

5 files changed, 27 insertions, 16 deletions

diff --git a/libctf/ChangeLog b/libctf/ChangeLog
index bf13839..25a32d2 100644
--- a/libctf/ChangeLog
+++ b/libctf/ChangeLog
@@ -1,5 +1,13 @@
 2021-03-18  Nick Alcock  <nick.alcock@oracle.com>
 
+	* ctf-impl.h (ctf_dtdef_t) <dtd_u.dtu_arr>: Remove.
+	* ctf-create.c (ctf_add_array): Use the dtd_vlen, not dtu_arr.
+	(ctf_set_array): Likewise.
+	* ctf-serialize.c (ctf_emit_type_sect): Just copy the dtd_vlen.
+	* ctf-types.c (ctf_array_info): Just use the vlen.
+
+2021-03-18  Nick Alcock  <nick.alcock@oracle.com>
+
 	* ctf-impl.h (ctf_dtdef_t) <dtd_u.dtu_enc>: Remove.
 	<dtd_u.dtu_slice>: Likewise.
 	<dtd_vlen>: New.
diff --git a/libctf/ctf-create.c b/libctf/ctf-create.c
index 90db712..bc46cfa 100644
--- a/libctf/ctf-create.c
+++ b/libctf/ctf-create.c
@@ -635,6 +635,7 @@ ctf_id_t
 ctf_add_array (ctf_dict_t *fp, uint32_t flag, const ctf_arinfo_t *arp)
 {
   ctf_dtdef_t *dtd;
+  ctf_array_t cta;
   ctf_id_t type;
   ctf_dict_t *tmp = fp;
 
@@ -658,12 +659,17 @@ ctf_add_array (ctf_dict_t *fp, uint32_t flag, const ctf_arinfo_t *arp)
     }
 
   if ((type = ctf_add_generic (fp, flag, NULL, CTF_K_ARRAY,
-			       0, &dtd)) == CTF_ERR)
+			       sizeof (ctf_array_t), &dtd)) == CTF_ERR)
     return CTF_ERR;		/* errno is set for us.  */
 
+  memset (&cta, 0, sizeof (ctf_array_t));
+
   dtd->dtd_data.ctt_info = CTF_TYPE_INFO (CTF_K_ARRAY, flag, 0);
   dtd->dtd_data.ctt_size = 0;
-  dtd->dtd_u.dtu_arr = *arp;
+  cta.cta_contents = (uint32_t) arp->ctr_contents;
+  cta.cta_index = (uint32_t) arp->ctr_index;
+  cta.cta_nelems = arp->ctr_nelems;
+  memcpy (dtd->dtd_vlen, &cta, sizeof (ctf_array_t));
 
   return type;
 }
@@ -672,6 +678,7 @@ int
 ctf_set_array (ctf_dict_t *fp, ctf_id_t type, const ctf_arinfo_t *arp)
 {
   ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, type);
+  ctf_array_t *vlen;
 
   if (!(fp->ctf_flags & LCTF_RDWR))
     return (ctf_set_errno (fp, ECTF_RDONLY));
@@ -680,8 +687,11 @@ ctf_set_array (ctf_dict_t *fp, ctf_id_t type, const ctf_arinfo_t *arp)
       || LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info) != CTF_K_ARRAY)
     return (ctf_set_errno (fp, ECTF_BADID));
 
+  vlen = (ctf_array_t *) dtd->dtd_vlen;
   fp->ctf_flags |= LCTF_DIRTY;
-  dtd->dtd_u.dtu_arr = *arp;
+  vlen->cta_contents = (uint32_t) arp->ctr_contents;
+  vlen->cta_index = (uint32_t) arp->ctr_index;
+  vlen->cta_nelems = arp->ctr_nelems;
 
   return 0;
 }
diff --git a/libctf/ctf-impl.h b/libctf/ctf-impl.h
index 742b4b3..c1ce50b 100644
--- a/libctf/ctf-impl.h
+++ b/libctf/ctf-impl.h
@@ -196,7 +196,6 @@ typedef struct ctf_dtdef
   union
   {
     ctf_list_t dtu_members;	/* struct, union, or enum */
-    ctf_arinfo_t dtu_arr;	/* array */
     uint32_t *dtu_argv;		/* function */
   } dtd_u;
 } ctf_dtdef_t;
diff --git a/libctf/ctf-serialize.c b/libctf/ctf-serialize.c
index f07cb61..d8e78f3 100644
--- a/libctf/ctf-serialize.c
+++ b/libctf/ctf-serialize.c
@@ -857,7 +857,6 @@ ctf_emit_type_sect (ctf_dict_t *fp, unsigned char **tptr)
       uint32_t kind = LCTF_INFO_KIND (fp, dtd->dtd_data.ctt_info);
       uint32_t vlen = LCTF_INFO_VLEN (fp, dtd->dtd_data.ctt_info);
 
-      ctf_array_t cta;
       size_t len;
       ctf_stype_t *copied;
       const char *name;
@@ -888,11 +887,8 @@ ctf_emit_type_sect (ctf_dict_t *fp, unsigned char **tptr)
 	  break;
 
 	case CTF_K_ARRAY:
-	  cta.cta_contents = (uint32_t) dtd->dtd_u.dtu_arr.ctr_contents;
-	  cta.cta_index = (uint32_t) dtd->dtd_u.dtu_arr.ctr_index;
-	  cta.cta_nelems = dtd->dtd_u.dtu_arr.ctr_nelems;
-	  memcpy (t, &cta, sizeof (cta));
-	  t += sizeof (cta);
+	  memcpy (t, dtd->dtd_vlen, sizeof (struct ctf_array));
+	  t += sizeof (struct ctf_array);
 	  break;
 
 	case CTF_K_FUNCTION:
diff --git a/libctf/ctf-types.c b/libctf/ctf-types.c
index ae24381..8c983d5 100644
--- a/libctf/ctf-types.c
+++ b/libctf/ctf-types.c
@@ -1520,14 +1520,12 @@ ctf_array_info (ctf_dict_t *fp, ctf_id_t type, ctf_arinfo_t *arp)
     return (ctf_set_errno (ofp, ECTF_NOTARRAY));
 
   if ((dtd = ctf_dynamic_type (ofp, type)) != NULL)
+    ap = (const ctf_array_t *) dtd->dtd_vlen;
+  else
     {
-      *arp = dtd->dtd_u.dtu_arr;
-      return 0;
+      ctf_get_ctt_size (fp, tp, NULL, &increment);
+      ap = (const ctf_array_t *) ((uintptr_t) tp + increment);
     }
-
-  (void) ctf_get_ctt_size (fp, tp, NULL, &increment);
-
-  ap = (const ctf_array_t *) ((uintptr_t) tp + increment);
   arp->ctr_contents = ap->cta_contents;
   arp->ctr_index = ap->cta_index;
   arp->ctr_nelems = ap->cta_nelems;