libctf: map from old to corresponding newly-added types in ctf_add_type

This lets you call ctf_type_mapping (dest_fp, src_fp, src_type_id)
and get told what type ID the corresponding type has in the target
ctf_file_t.  This works even if it was added by a recursive call, and
because it is stored in the target ctf_file_t it works even if we
had to add one type to multiple ctf_file_t's as part of conflicting
type handling.

We empty out this mapping after every archive is linked: because it maps
input to output fps, and we only visit each input fp once, its contents
are rendered entirely useless every time the source fp changes.

v3: add several missing mapping additions.  Add ctf_dynhash_empty, and
    empty after every input archive.
v5: fix tabdamage.

libctf/
	* ctf-impl.h (ctf_file_t): New field ctf_link_type_mapping.
	(struct ctf_link_type_mapping_key): New.
	(ctf_hash_type_mapping_key): Likewise.
	(ctf_hash_eq_type_mapping_key): Likewise.
	(ctf_add_type_mapping): Likewise.
	(ctf_type_mapping): Likewise.
	(ctf_dynhash_empty): Likewise.
	* ctf-open.c (ctf_file_close): Update accordingly.
	* ctf-create.c (ctf_update): Likewise.
	(ctf_add_type): Populate the mapping.
	* ctf-hash.c (ctf_hash_type_mapping_key): Hash a type mapping key.
	(ctf_hash_eq_type_mapping_key): Check the key for equality.
	(ctf_dynhash_insert): Fix comment typo.
	(ctf_dynhash_empty): New.
	* ctf-link.c (ctf_add_type_mapping): New.
	(ctf_type_mapping): Likewise.
	(empty_link_type_mapping): New.
	(ctf_link_one_input_archive): Call it.

1 files changed, 17 insertions, 3 deletions

diff --git a/libctf/ctf-create.c b/libctf/ctf-create.c
index fc37d6a40f8..90e45f340b1 100644
--- a/libctf/ctf-create.c
+++ b/libctf/ctf-create.c
@@ -473,6 +473,7 @@ ctf_update (ctf_file_t *fp)
   nfp->ctf_link_inputs = fp->ctf_link_inputs;
   nfp->ctf_link_outputs = fp->ctf_link_outputs;
   nfp->ctf_syn_ext_strtab = fp->ctf_syn_ext_strtab;
+  nfp->ctf_link_type_mapping = fp->ctf_link_type_mapping;
 
   nfp->ctf_snapshot_lu = fp->ctf_snapshots;
 
@@ -485,6 +486,7 @@ ctf_update (ctf_file_t *fp)
   fp->ctf_link_inputs = NULL;
   fp->ctf_link_outputs = NULL;
   fp->ctf_syn_ext_strtab = NULL;
+  fp->ctf_link_type_mapping = NULL;
 
   fp->ctf_dvhash = NULL;
   memset (&fp->ctf_dvdefs, 0, sizeof (ctf_list_t));
@@ -1557,6 +1559,7 @@ ctf_add_type (ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type)
   ctf_funcinfo_t ctc;
 
   ctf_hash_t *hp;
+  ctf_id_t orig_src_type = src_type;
 
   if (!(dst_fp->ctf_flags & LCTF_RDWR))
     return (ctf_set_errno (dst_fp, ECTF_RDONLY));
@@ -1640,7 +1643,10 @@ ctf_add_type (ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type)
 	      if (memcmp (&src_en, &dst_en, sizeof (ctf_encoding_t)) == 0)
 		{
 		  if (kind != CTF_K_SLICE)
-		    return dst_type;
+		    {
+		      ctf_add_type_mapping (src_fp, src_type, dst_fp, dst_type);
+		      return dst_type;
+		    }
 		}
 	      else
 		  {
@@ -1679,7 +1685,10 @@ ctf_add_type (ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type)
 	      int match;	/* Do the encodings match?  */
 
 	      if (kind != CTF_K_INTEGER && kind != CTF_K_FLOAT && kind != CTF_K_SLICE)
-		return dtd->dtd_type;
+		{
+		  ctf_add_type_mapping (src_fp, src_type, dst_fp, dtd->dtd_type);
+		  return dtd->dtd_type;
+		}
 
 	      sroot = (flag & CTF_ADD_ROOT);
 	      droot = (LCTF_INFO_ISROOT (dst_fp,
@@ -1698,7 +1707,10 @@ ctf_add_type (ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type)
 	      if (match && sroot == droot)
 		{
 		  if (kind != CTF_K_SLICE)
-		    return dtd->dtd_type;
+		    {
+		      ctf_add_type_mapping (src_fp, src_type, dst_fp, dtd->dtd_type);
+		      return dtd->dtd_type;
+		    }
 		}
 	      else if (!match && sroot && droot)
 		{
@@ -1939,6 +1951,8 @@ ctf_add_type (ctf_file_t *dst_fp, ctf_file_t *src_fp, ctf_id_t src_type)
       return (ctf_set_errno (dst_fp, ECTF_CORRUPT));
     }
 
+  if (dst_type != CTF_ERR)
+    ctf_add_type_mapping (src_fp, orig_src_type, dst_fp, dst_type);
   return dst_type;
 }