[V3,3/3] CTF: multi-CU and archive support

Message ID 1617237594-24175-4-git-send-email-weimin.pan@oracle.com
State New
Headers show
Series
  • CTF: bug fixes and new features.
Related show

Commit Message

Weimin Pan via Gdb-patches April 1, 2021, 12:39 a.m.
Now gdb is capable of debugging executable, which consists of multiple 
compilation units, with CTF. An executable could potentially have one
or more archives, which, in CTF context, contain conflicting types.   
When comparing to DWARF2, there is a major difference in the type sections, 

all changes were made in ctfread.c where elfctf_build_psymtabs and 
scan_partial_symbols, with the new ctf_per_tu_data struct, were modify to 
handle archives which were treated as dependencies in gdb, via the ctf 
archive iterator and its callback build_ctf_archive_member, and were then 
expanded with expand_dependencies when psymtabs were expanded. 

Also changes were made to handle CTF's data object section and function
info section which now share the same format for their contents - an array 
of type IDs. New functions ctf_psymtab_add_stt_entries, which is called by 
ctf_psymtab_add_stt_obj and ctf_psymtab_add_stt_func, and add_stt_entries, 
which is called by add_stt_obj and add_stt_func when setting up psymtabs 
and full symtab, respectively.

---
 gdb/ChangeLog                             |  15 ++
 gdb/ctfread.c                             | 332 ++++++++++++++++++------------
 gdb/testsuite/ChangeLog                   |   5 +
 gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c |  18 ++
 gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c |  16 ++
 gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c |   3 +
 gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c |   4 +
 gdb/testsuite/gdb.ctf/cross-tu-cyclic.exp |  43 ++++
 gdb/testsuite/gdb.ctf/ctf-a.c             |  32 +++
 gdb/testsuite/gdb.ctf/ctf-a.h             |  22 ++
 gdb/testsuite/gdb.ctf/ctf-b.c             |  25 +++
 gdb/testsuite/gdb.ctf/ctf-b.h             |  22 ++
 gdb/testsuite/gdb.ctf/ctf-c.c             |  25 +++
 gdb/testsuite/gdb.ctf/ctf-c.h             |  21 ++
 gdb/testsuite/gdb.ctf/multi.exp           |  42 ++++
 15 files changed, 494 insertions(+), 131 deletions(-)
 create mode 100644 gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c
 create mode 100644 gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c
 create mode 100644 gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c
 create mode 100644 gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c
 create mode 100644 gdb/testsuite/gdb.ctf/cross-tu-cyclic.exp
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-a.c
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-a.h
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-b.c
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-b.h
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-c.c
 create mode 100644 gdb/testsuite/gdb.ctf/ctf-c.h
 create mode 100644 gdb/testsuite/gdb.ctf/multi.exp

-- 
1.8.3.1

Comments

Tom Tromey April 1, 2021, 5:30 p.m. | #1
>>>>> Weimin Pan via Gdb-patches <gdb-patches@sourceware.org> writes:


> Now gdb is capable of debugging executable, which consists of multiple 

> compilation units, with CTF. An executable could potentially have one

> or more archives, which, in CTF context, contain conflicting types.   


Thank you for the patch.  I can't really comment on most of it, since I
don't know much about CTF and I've never managed to even run one of the
CTF tests.  However, I did have a question.

> +      dp = (ctf_psymtab *)pst->dependencies[i];


gdb style is a space after the cast.

> +  if (isparent)

> +    pcu->parent_psymtab = pst;

> +  else

> +    pcu->imported_symtabs.push_back (pst);


The imported symtabs logic for partial symbol tables is to support a way
to "paste together" certain symtabs.

The idea in gdb is that when searching a psymtab for a symbol, all its
included psymtabs are also searched -- the tree of inclusions form a
kind of "virtual psymtab".

This is either used to represent header files (if user==nullptr) or the
DWARF "partial unit" feature (if user!=nullptr).

In the bit of your introduction quoted above, though, it sounds like
this is probably not what you intend?  At least, I don't see how to
reconcile this with the "conflicting types" text.

Also I notice that the dependency tree isn't really represented in the
resulting symtabs, or at least it didn't seem that way to me.  I don't
know if this is invalid or not (there's probably no real rule), but it
at least seems a bit questionable.

If a CTF archive represents multiple compilation units, the more
ordinary thing to do would be to create one psymtab per each unit, and
just let them be separate.

I wonder if psymtabs are even needed or useful for CTF.  Depending on
how libctf works it might be preferable to get rid of them entirely and
just write a new implementation of quick_symbol_functions.

Anyway, if you did intend things to work this way, then it's fine by me.

thanks,
Tom

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 82602a5..48cd9af 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,20 @@ 
 2021-03-19  Weimin Pan  <weimin.pan@oracle.com>
 
+	* ctfread.c (ctf_per_tu_data): New struct.
+	(add_stt_entries): New funtion.
+	(add_stt_obj): Use it.
+	(add_stt_func): Likewise.
+	(ctf_psymtab_add_stt_entries): New function.
+	(ctf_psymtab_add_stt_obj): Use it.
+	(ctf_psymtab_add_stt_func): Likewise.
+	(ctf_psymtab::expand_psymtab): Call expand_dependencies to expand
+	archives.
+	(scan_partial_symbols): Set up partial symtab list.
+	(build_ctf_archive_member): New function.
+	(elfctf_build_psymtabs): Call Iterater to set up archives.
+
+2021-03-19  Weimin Pan  <weimin.pan@oracle.com>
+
 	* ctfread.c (fetch_tid_type): New function, use throughout file.
 	(read_forward_type): New function.
 	(read_type_record): Call read_forward_type.
diff --git a/gdb/ctfread.c b/gdb/ctfread.c
index f3374eb..124d14c 100644
--- a/gdb/ctfread.c
+++ b/gdb/ctfread.c
@@ -80,6 +80,7 @@ 
 #include "complaints.h"
 #include "block.h"
 #include "ctfread.h"
+#include "objfiles.h"
 #include "psympriv.h"
 
 #if ENABLE_LIBCTF
@@ -116,6 +117,7 @@  struct ctf_context
   ctf_dict_t *fp;
   struct objfile *of;
   partial_symtab *pst;
+  ctf_archive_t *arc;
   struct buildsym_compunit *builder;
 };
 
@@ -162,6 +164,17 @@  struct ctf_field_info
   std::vector<struct decl_field> nested_types_list;
 };
 
+/* Persistent data held for a translation unit.  */
+
+struct ctf_per_tu_data
+{
+  ctf_dict_t *fp;
+  struct objfile *of;
+  ctf_archive_t *arc;
+  ctf_psymtab *parent_psymtab;
+  std::vector <struct partial_symtab *> imported_symtabs;
+};
+
 
 /* Local function prototypes */
 
@@ -241,10 +254,8 @@  struct ctf_tid_and_type
   ids.tid = tid;
   ids.type = typ;
   slot = (struct ctf_tid_and_type **) htab_find_slot (htab, &ids, INSERT);
-  if (*slot)
-    complaint (_("An internal GDB problem: ctf_ id_t %ld type already set"),
-	       (tid));
-  *slot = XOBNEW (&of->objfile_obstack, struct ctf_tid_and_type);
+  if (*slot == 0)
+    *slot = XOBNEW (&of->objfile_obstack, struct ctf_tid_and_type);
   **slot = ids;
   return typ;
 }
@@ -940,7 +951,7 @@  struct ctf_tid_and_type
       if (target_type == nullptr)
 	{
 	  complaint (_("read_pointer_type: NULL target type (%ld)"), btid);
-	  target_type = objfile_type (ccp->of)->builtin_error;
+	  target_type = objfile_type (of)->builtin_error;
 	}
     }
 
@@ -1055,6 +1066,12 @@  struct ctf_tid_and_type
   struct type *type;
   uint32_t kind;
 
+  if (info_verbose)
+    {
+      printf_filtered (_("ctf_add_type_cb adding tid %lx..."), tid);
+      gdb_flush (gdb_stdout);
+    }
+
   /* Check if tid's type has already been defined.  */
   type = get_tid_type (ccp->of, tid);
   if (type != nullptr)
@@ -1141,7 +1158,8 @@  struct ctf_tid_and_type
 	if (type)
 	  {
 	    sym = new_symbol (ccp, type, id);
-	    sym->compute_and_set_names (name, false, ccp->of->per_bfd);
+	    if (sym != nullptr)
+	      sym->compute_and_set_names (name, false, ccp->of->per_bfd);
 	  }
 	break;
       case CTF_K_STRUCT:
@@ -1171,81 +1189,48 @@  struct ctf_tid_and_type
   return 0;
 }
 
-/* Add an ELF STT_OBJ symbol with index IDX to the symbol table.  */
+/* Add entries in either data objects or function info section, controlled
+   by FUNCTIONS.  */
 
-static struct symbol *
-add_stt_obj (struct ctf_context *ccp, unsigned long idx)
+static void
+add_stt_entries (struct ctf_context *ccp, int functions)
 {
-  struct symbol *sym;
-  struct type *type;
+  ctf_next_t *i = nullptr;
+  const char *tname;
   ctf_id_t tid;
+  struct symbol *sym = nullptr;
+  struct type *type;
 
-  if ((tid = ctf_lookup_by_symbol (ccp->fp, idx)) == CTF_ERR)
-    return nullptr;
-
-  type = fetch_tid_type (ccp, tid);
-  if (type == nullptr)
-    return nullptr;
-
-  sym = new_symbol (ccp, type, tid);
-
-  return sym;
+  while ((tid = ctf_symbol_next (ccp->fp, &i, &tname, functions)) != CTF_ERR)
+    {
+      type = get_tid_type (ccp->of, tid);
+      if (type == nullptr)
+	continue;
+      sym = new (&ccp->of->objfile_obstack) symbol;
+      OBJSTAT (ccp->of, n_syms++);
+      SYMBOL_TYPE (sym) = type;
+      SYMBOL_DOMAIN (sym) = VAR_DOMAIN;
+      SYMBOL_ACLASS_INDEX (sym) = LOC_STATIC;
+      sym->compute_and_set_names (tname, false, ccp->of->per_bfd);
+      add_symbol_to_list (sym, ccp->builder->get_global_symbols ());
+      set_symbol_address (ccp->of, sym, tname);
+    }
 }
 
-/* Add an ELF STT_FUNC symbol with index IDX to the symbol table.  */
+/* Add entries in data objects section.  */
 
-static struct symbol *
-add_stt_func (struct ctf_context *ccp, unsigned long idx)
+static void
+add_stt_obj (struct ctf_context *ccp)
 {
-  struct type *ftype, *atyp, *rettyp;
-  struct symbol *sym;
-  ctf_funcinfo_t finfo;
-  ctf_id_t argv[32];
-  uint32_t argc;
-  ctf_id_t tid;
-  struct type *void_type = objfile_type (ccp->of)->builtin_void;
-
-  if (ctf_func_info (ccp->fp, idx, &finfo) == CTF_ERR)
-    return nullptr;
-
-  argc = finfo.ctc_argc;
-  if (ctf_func_args (ccp->fp, idx, argc, argv) == CTF_ERR)
-    return nullptr;
-
-  char *name = ctf_type_aname_raw (ccp->fp, idx);
-  if (name == nullptr)
-    return nullptr;
-
-  tid = ctf_lookup_by_symbol (ccp->fp, idx);
-  ftype = fetch_tid_type (ccp, tid);
-  if ((finfo.ctc_flags & CTF_FUNC_VARARG) != 0)
-    ftype->set_has_varargs (true);
-  ftype->set_num_fields (argc);
-
-  /* If argc is 0, it has a "void" type.  */
-  if (argc != 0)
-    ftype->set_fields
-      ((struct field *) TYPE_ZALLOC (ftype, argc * sizeof (struct field)));
-
-  /* TYPE_FIELD_TYPE must never be NULL.  Fill it with void_type, if failed
-     to find the argument type.  */
-  for (int iparam = 0; iparam < argc; iparam++)
-    {
-      atyp = fetch_tid_type (ccp, argv[iparam]);
-      if (atyp)
-	ftype->field (iparam).set_type (atyp);
-      else
-	ftype->field (iparam).set_type (void_type);
-    }
+  add_stt_entries (ccp, 0);
+}
 
-  sym = new_symbol (ccp, ftype, tid);
-  rettyp = fetch_tid_type (ccp, finfo.ctc_return);
-  if (rettyp != nullptr)
-    SYMBOL_TYPE (sym) = rettyp;
-  else
-    SYMBOL_TYPE (sym) = void_type;
+/* Add entries in function info section.  */
 
-  return sym;
+static void
+add_stt_func (struct ctf_context *ccp)
+{
+  add_stt_entries (ccp, 1);
 }
 
 /* Get text segment base for OBJFILE, TSIZE contains the segment size.  */
@@ -1268,12 +1253,20 @@  struct ctf_tid_and_type
 		  struct objfile *of, CORE_ADDR text_offset)
 {
   struct ctf_context *ccp;
+  ctf_psymtab *dp;
 
   ccp = pst->context;
   ccp->builder = new buildsym_compunit
 		       (of, of->original_name, nullptr,
 		       language_c, text_offset);
   ccp->builder->record_debugformat ("ctf");
+
+  for (int i = 0; i < pst->number_of_dependencies; i++)
+    {
+      dp = (ctf_psymtab *)pst->dependencies[i];
+      dp->context->builder = ccp->builder;
+      dp->context->of = of;
+    }
 }
 
 /* Finish reading symbol/type definitions in CTF format.
@@ -1315,46 +1308,94 @@  struct ctf_tid_and_type
 	       ctf_errmsg (ctf_errno (ccp->fp)));
 }
 
+/* Add entries in either data objects or function info section, controlled
+   by FUNCTIONS, to psymtab.  */
+
+static void
+ctf_psymtab_add_stt_entries (ctf_dict_t *cfp, ctf_psymtab *pst,
+			     struct objfile *of, int functions)
+{
+  ctf_next_t *i = nullptr;
+  ctf_id_t tid;
+  const char *tname;
+
+  while ((tid = ctf_symbol_next (cfp, &i, &tname, functions)) != CTF_ERR)
+    {
+      uint32_t kind = ctf_type_kind (cfp, tid);
+      address_class aclass;
+      domain_enum tdomain;
+      switch (kind)
+	{
+	  case CTF_K_STRUCT:
+	  case CTF_K_UNION:
+	  case CTF_K_ENUM:
+	    tdomain = STRUCT_DOMAIN;
+	    break;
+	  default:
+	    tdomain = VAR_DOMAIN;
+	    break;
+	}
+
+      if (kind == CTF_K_FUNCTION)
+	aclass = LOC_STATIC;
+      else if (kind == CTF_K_CONST)
+	aclass = LOC_CONST;
+      else
+	aclass = LOC_TYPEDEF;
+
+      pst->add_psymbol (tname, true,
+			tdomain, aclass, -1,
+			psymbol_placement::GLOBAL,
+			0, language_c, of);
+    }
+}
+
+/* Add entries in data objects section to psymtab.  */
+
+static void
+ctf_psymtab_add_stt_obj (ctf_dict_t *cfp, ctf_psymtab *pst,
+			 struct objfile *of)
+{
+  ctf_psymtab_add_stt_entries (cfp, pst, of, 0);
+}
+
+/* Add entries in function info section to psymtab.  */
+
+static void
+ctf_psymtab_add_stt_func (ctf_dict_t *cfp, ctf_psymtab *pst,
+			  struct objfile *of)
+{
+  ctf_psymtab_add_stt_entries (cfp, pst, of, 1);
+}
+
 /* Read in full symbols for PST, and anything it depends on.  */
 
 void
 ctf_psymtab::expand_psymtab (struct objfile *objfile)
 {
-  struct symbol *sym;
   struct ctf_context *ccp;
 
   gdb_assert (!readin);
 
   ccp = context;
+  expand_dependencies (objfile);
 
   /* Iterate over entries in data types section.  */
   if (ctf_type_iter (ccp->fp, ctf_add_type_cb, ccp) == CTF_ERR)
-    complaint (_("ctf_type_iter psymtab_to_symtab failed - %s"),
+    complaint (_("ctf_type_iter expand_psymtab failed - %s"),
 	       ctf_errmsg (ctf_errno (ccp->fp)));
 
 
   /* Iterate over entries in variable info section.  */
   if (ctf_variable_iter (ccp->fp, ctf_add_var_cb, ccp) == CTF_ERR)
-    complaint (_("ctf_variable_iter psymtab_to_symtab failed - %s"),
+    complaint (_("ctf_variable_iter expand_psymtab failed - %s"),
 	       ctf_errmsg (ctf_errno (ccp->fp)));
 
   /* Add entries in data objects and function info sections.  */
-  for (unsigned long i = 0; ; i++)
-    {
-      sym = add_stt_obj (ccp, i);
-      if (sym == nullptr)
-	{
-	  if (ctf_errno (ccp->fp) == EINVAL
-	      || ctf_errno (ccp->fp) == ECTF_NOSYMTAB)
-	    break;
-	  sym = add_stt_func (ccp, i);
-	}
-      if (sym == nullptr)
-	continue;
-
-      set_symbol_address (ccp->of, sym, sym->linkage_name ());
-    }
+  add_stt_obj (ccp);
+  add_stt_func (ccp);
 
+  ctf_dict_close (ccp->fp);
   readin = true;
 }
 
@@ -1407,6 +1448,7 @@  struct ctf_tid_and_type
 
 static ctf_psymtab *
 create_partial_symtab (const char *name,
+		       ctf_archive_t *arc,
 		       ctf_dict_t *cfp,
 		       struct objfile *objfile)
 {
@@ -1416,10 +1458,11 @@  struct ctf_tid_and_type
   pst = new ctf_psymtab (name, objfile, 0);
 
   ccx = XOBNEW (&objfile->objfile_obstack, struct ctf_context);
+  ccx->arc = arc;
   ccx->fp = cfp;
+  ctf_ref (cfp);
   ccx->of = objfile;
   ccx->pst = pst;
-  ccx->builder = nullptr;
   pst->context = ccx;
 
   return pst;
@@ -1506,12 +1549,23 @@  struct ctf_tid_and_type
    debugging information is available.  */
 
 static void
-scan_partial_symbols (ctf_dict_t *cfp, struct objfile *of)
+scan_partial_symbols (ctf_dict_t *cfp,
+		      struct ctf_per_tu_data *pcu,
+		      const char *aname)
 {
-  bfd *abfd = of->obfd;
-  const char *name = bfd_get_filename (abfd);
-  ctf_psymtab *pst = create_partial_symtab (name, cfp, of);
+  struct objfile *of = pcu->of;
+  bool isparent = 0;
+
+  if (info_verbose)
+    {
+      printf_filtered (_("Scanning partial symbols for %s..."), aname);
+      gdb_flush (gdb_stdout);
+    }
 
+  if (strcmp (aname, ".ctf") == 0)
+    isparent = 1;
+
+  ctf_psymtab *pst = create_partial_symtab (aname, pcu->arc, cfp, of);
   struct ctf_context *ccx = pst->context;
 
   if (ctf_type_iter (cfp, ctf_psymtab_type_cb, ccx) == CTF_ERR)
@@ -1525,46 +1579,39 @@  struct ctf_tid_and_type
   /* Scan CTF object and function sections which correspond to each
      STT_FUNC or STT_OBJECT entry in the symbol table,
      pick up what init_symtab has done.  */
-  for (unsigned long idx = 0; ; idx++)
-    {
-      ctf_id_t tid;
-      if ((tid = ctf_lookup_by_symbol (cfp, idx)) == CTF_ERR)
-	{
-	if (ctf_errno (cfp) == EINVAL || ctf_errno (cfp) == ECTF_NOSYMTAB)
-	  break;	// Done, reach end of the section.
-	else
-	  continue;
-	}
-      gdb::unique_xmalloc_ptr<char> tname (ctf_type_aname_raw (cfp, tid));
-      uint32_t kind = ctf_type_kind (cfp, tid);
-      address_class aclass;
-      domain_enum tdomain;
-      switch (kind)
-	{
-	  case CTF_K_STRUCT:
-	  case CTF_K_UNION:
-	  case CTF_K_ENUM:
-	    tdomain = STRUCT_DOMAIN;
-	    break;
-	  default:
-	    tdomain = VAR_DOMAIN;
-	    break;
-	}
+  ctf_psymtab_add_stt_obj (cfp, pst, of);
+  ctf_psymtab_add_stt_func (cfp, pst, of);
 
-      if (kind == CTF_K_FUNCTION)
-	aclass = LOC_STATIC;
-      else if (kind == CTF_K_CONST)
-	aclass = LOC_CONST;
-      else
-	aclass = LOC_TYPEDEF;
+  pst->end ();
 
-      pst->add_psymbol (tname.get (), true,
-			tdomain, aclass, -1,
-			psymbol_placement::STATIC,
-			0, language_c, of);
+  if (isparent)
+    pcu->parent_psymtab = pst;
+  else
+    pcu->imported_symtabs.push_back (pst);
+}
+
+/* Callback to build the psymtab for archive member NAME.  */
+
+static int
+build_ctf_archive_member (ctf_dict_t *ctf, const char *name, void *arg)
+{
+  struct ctf_per_tu_data *tup = (struct ctf_per_tu_data *) arg;
+  ctf_dict_t *parent = tup->fp;
+
+  if (strcmp (name, ".ctf") != 0)
+    {
+      ctf_import (ctf, parent);
     }
 
-  pst->end ();
+  if (info_verbose)
+    {
+      printf_filtered (_("Scanning archive member %s..."), name);
+      gdb_flush (gdb_stdout);
+    }
+
+  scan_partial_symbols (ctf, tup, name);
+
+  return 0;
 }
 
 /* Read CTF debugging information from a BFD section.  This is
@@ -1574,6 +1621,7 @@  struct ctf_tid_and_type
 void
 elfctf_build_psymtabs (struct objfile *of)
 {
+  struct ctf_per_tu_data pcu;
   bfd *abfd = of->obfd;
   int err;
 
@@ -1588,7 +1636,29 @@  struct ctf_tid_and_type
 	   bfd_get_filename (abfd), ctf_errmsg (err));
   ctf_dict_key.emplace (of, fp);
 
-  scan_partial_symbols (fp, of);
+  pcu.fp = fp;
+  pcu.of = of;
+  pcu.arc = arc;
+
+  if (ctf_archive_iter (arc, build_ctf_archive_member, &pcu) < 0)
+    error (_("ctf_archive_iter failed in input file %s: - %s"),
+	   bfd_get_filename (abfd), ctf_errmsg (err));
+
+  static int arch_cnt = pcu.imported_symtabs.size ();
+  struct partial_symtab *parent_pst = pcu.parent_psymtab;
+
+  if (parent_pst != nullptr && arch_cnt != 0)
+    {
+      /* Fill in the 'dependencies'.  */
+      parent_pst->number_of_dependencies = arch_cnt;
+      parent_pst->dependencies
+	= of->partial_symtabs->allocate_dependencies (arch_cnt);
+      for (int i = 0; i < arch_cnt; ++i)
+	{
+	  parent_pst->dependencies[i]
+	    = pcu.imported_symtabs.at (i);
+	}
+    }
 }
 
 #else
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 22ee55c..868a0b9 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@ 
 2021-03-19  Weimin Pan  <weimin.pan@oracle.com>
 
+	* gdb.ctf/cross-tu-cyclic.exp: New file.
+	* gdb.ctf/multi.exp: New file.
+
+2021-03-19  Weimin Pan  <weimin.pan@oracle.com>
+
 	* gdb.base/ctf-ptype.c: Add struct link containing a forward
 	reference type.
 	* gdb.base/ctf-ptype.exp: Add "ptype struct link"
diff --git a/gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c
new file mode 100644
index 0000000..fe52b9e
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-1.c
@@ -0,0 +1,18 @@ 
+struct A;
+struct B
+{
+  int foo;
+  struct A *bar;
+};
+
+struct A
+{
+  long a;
+  struct B *foo;
+};
+
+static struct A *foo __attribute__((used));
+
+int main()
+{
+}
diff --git a/gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c
new file mode 100644
index 0000000..aa2d177
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-2.c
@@ -0,0 +1,16 @@ 
+struct B;
+struct A
+{
+  long a;
+  struct B *foo;
+  struct C *bar;
+};
+
+struct C
+{
+  struct B *foo;
+  int b;
+};
+
+static struct C *foo __attribute__((used));
+static struct A *bar __attribute__((used));
diff --git a/gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c
new file mode 100644
index 0000000..19947e8
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-3.c
@@ -0,0 +1,3 @@ 
+struct A { struct B *foo; };
+static struct A *a __attribute__((__used__));
+static struct A *conflicty __attribute__((__used__));
diff --git a/gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c
new file mode 100644
index 0000000..6e0c957
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/cross-tu-cyclic-4.c
@@ -0,0 +1,4 @@ 
+struct A { struct B *foo; };
+struct B { struct B *next; };
+static struct A *a __attribute__((__used__));
+static struct B *conflicty __attribute__((__used__));
diff --git a/gdb/testsuite/gdb.ctf/cross-tu-cyclic.exp b/gdb/testsuite/gdb.ctf/cross-tu-cyclic.exp
new file mode 100644
index 0000000..734892d
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/cross-tu-cyclic.exp
@@ -0,0 +1,43 @@ 
+# Copyright 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file is a subset of ptype.exp written by Rob Savoye. (rob@cygnus.com)
+
+if [skip_ctf_tests] {
+    unsupported "no CTF debug format support, or CTF disabled in GDB"
+    return 0
+}
+
+standard_testfile cross-tu-cyclic-1.c  cross-tu-cyclic-2.c \
+	cross-tu-cyclic-3.c  cross-tu-cyclic-4.c
+
+# Using `-gt` generates full-fledged CTF debug information.
+set opts "additional_flags=-gt -Wl,--export-dynamic"
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	  [list $srcfile $srcfile2 $srcfile3 $srcfile4] \
+	  [list $opts nowarnings]] } {
+    return 0
+}
+
+# Create and source the file that provides information about the compiler
+# used to compile the test case.
+if [get_compiler_info] {
+    return -1
+}
+
+# Same thing with struct and union.
+gdb_test "ptype struct A" "type = struct A \{\[\r\n\]+\[ \t\]+long a;\[\r\n\]+\[ \t\]+struct B \\*foo;\[\r\n\]+\}.*" "ptype structure A"
+gdb_test "ptype struct B" "type = struct B \{\[\r\n\]+\[ \t\]+int foo;\[\r\n\]+\[ \t\]+struct A \\*bar;\[\r\n\]+\}.*" "ptype structure B"
+gdb_test "ptype struct C" "type = struct C \{\[\r\n\]+\[ \t\]+struct B \\*foo;\[\r\n\]+\[ \t\]+int b;\[\r\n\]+\}.*" "ptype structure C"
diff --git a/gdb/testsuite/gdb.ctf/ctf-a.c b/gdb/testsuite/gdb.ctf/ctf-a.c
new file mode 100644
index 0000000..9aa2a8f
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-a.c
@@ -0,0 +1,32 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "ctf-a.h"
+
+static struct A a __attribute__((used));
+
+extern struct C *foo ();
+extern int bar ();
+
+int main ()
+{
+  struct C *cp;
+  cp = foo ();
+  if (cp)
+    return bar ();
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.ctf/ctf-a.h b/gdb/testsuite/gdb.ctf/ctf-a.h
new file mode 100644
index 0000000..297d740
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-a.h
@@ -0,0 +1,22 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+struct A {
+  struct B *b;
+  struct A *next;
+};
+
diff --git a/gdb/testsuite/gdb.ctf/ctf-b.c b/gdb/testsuite/gdb.ctf/ctf-b.c
new file mode 100644
index 0000000..c3a8ce5
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-b.c
@@ -0,0 +1,25 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "ctf-b.h"
+
+static struct B b __attribute__((used));
+
+int bar ()
+{
+  return b.wombat;
+}
diff --git a/gdb/testsuite/gdb.ctf/ctf-b.h b/gdb/testsuite/gdb.ctf/ctf-b.h
new file mode 100644
index 0000000..9dbdd7d
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-b.h
@@ -0,0 +1,22 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+struct B {
+  struct C *c;
+  int wombat;
+};
+
diff --git a/gdb/testsuite/gdb.ctf/ctf-c.c b/gdb/testsuite/gdb.ctf/ctf-c.c
new file mode 100644
index 0000000..b4051b3
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-c.c
@@ -0,0 +1,25 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "ctf-c.h"
+
+static struct C c __attribute__((used));
+
+struct C * foo ()
+{
+  return &c;
+}
diff --git a/gdb/testsuite/gdb.ctf/ctf-c.h b/gdb/testsuite/gdb.ctf/ctf-c.h
new file mode 100644
index 0000000..fb18157
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/ctf-c.h
@@ -0,0 +1,21 @@ 
+/* This test program is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+struct C {
+  struct A *a;
+  int b;
+};
diff --git a/gdb/testsuite/gdb.ctf/multi.exp b/gdb/testsuite/gdb.ctf/multi.exp
new file mode 100644
index 0000000..973115e
--- /dev/null
+++ b/gdb/testsuite/gdb.ctf/multi.exp
@@ -0,0 +1,42 @@ 
+# Copyright 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file is a subset of ptype.exp written by Rob Savoye. (rob@cygnus.com)
+
+if [skip_ctf_tests] {
+    unsupported "no CTF debug format support, or CTF disabled in GDB"
+    return 0
+}
+
+standard_testfile ctf-a.c ctf-b.c ctf-c.c
+
+# Using `-gt` generates full-fledged CTF debug information.
+set opts "additional_flags=-gt -Wl,--export-dynamic"
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+	  [list $srcfile $srcfile2 $srcfile3] \
+	  [list $opts nowarnings]] } {
+    return 0
+}
+
+# Create and source the file that provides information about the compiler
+# used to compile the test case.
+if [get_compiler_info] {
+    return -1
+}
+
+# Same thing with struct and union.
+gdb_test "ptype struct A" "type = struct A \{\[\r\n\]+\[ \t\]+struct B \\*b;\[\r\n\]+\[ \t\]+struct A \\*next;\[\r\n\]+\}.*" "ptype structure A"
+gdb_test "ptype struct B" "type = struct B \{\[\r\n\]+\[ \t\]+struct C \\*c;\[\r\n\]+\[ \t\]+int \\wombat;\[\r\n\]+\}.*" "ptype structure B"
+gdb_test "ptype struct C" "type = struct C \{\[\r\n\]+\[ \t\]+struct A \\*a;\[\r\n\]+\[ \t\]+int b;\[\r\n\]+\}.*" "ptype structure C"