/* C declarator syntax glue.   Copyright (C) 2019-2026 Free Software Foundation, Inc.    This file is part of libctf.    libctf 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, 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; see the file COPYING.  If not see   <http://www.gnu.org/licenses/>.  */ /* CTF Declaration Stack    In order to implement ctf_type_name(), we must convert a type graph back   into a C type declaration.  Unfortunately, a type graph represents a storage   class ordering of the type whereas a type declaration must obey the C rules   for operator precedence, and the two orderings are frequently in conflict.   For example, consider these CTF type graphs and their C declarations:    CTF_K_POINTER -> CTF_K_FUNCTION -> CTF_K_INTEGER  : int (*)()   CTF_K_POINTER -> CTF_K_ARRAY -> CTF_K_INTEGER     : int (*)[]    In each case, parentheses are used to raise operator * to higher lexical   precedence, so the string form of the C declaration cannot be constructed by   walking the type graph links and forming the string from left to right.    The functions in this file build a set of stacks from the type graph nodes   corresponding to the C operator precedence levels in the appropriate order.   The code in ctf_type_name() can then iterate over the levels and nodes in   lexical precedence order and construct the final C declaration string.  */ #include <ctf-impl.h>#include <string.h> voidctf_decl_init (ctf_decl_t *cd){  int i;   memset (cd, 0, sizeof (ctf_decl_t));   for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++)    cd->cd_order[i] = CTF_PREC_BASE - 1;   cd->cd_qualp = CTF_PREC_BASE;  cd->cd_ordp = CTF_PREC_BASE;} voidctf_decl_fini (ctf_decl_t *cd){  ctf_decl_node_t *cdp, *ndp;  int i;   for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++)    {      for (cdp = ctf_list_next (&cd->cd_nodes[i]); cdp != NULL; cdp = ndp)	{	  ndp = ctf_list_next (cdp);	  free (cdp);	}    }  free (cd->cd_buf);} voidctf_decl_push (ctf_decl_t *cd, ctf_dict_t *fp, ctf_id_t type){  ctf_decl_node_t *cdp;  ctf_decl_prec_t prec;  uint32_t kind, n = 1;  int is_qual = 0;   const ctf_type_t *tp;  ctf_arinfo_t ar;   if ((tp = ctf_lookup_by_id (&fp, type)) == NULL)    {      cd->cd_err = fp->ctf_errno;      return;    }   switch (kind = LCTF_INFO_KIND (fp, tp->ctt_info))    {    case CTF_K_ARRAY:      (void) ctf_array_info (fp, type, &ar);      ctf_decl_push (cd, fp, ar.ctr_contents);      n = ar.ctr_nelems;      prec = CTF_PREC_ARRAY;      break;     case CTF_K_TYPEDEF:      if (ctf_strptr (fp, tp->ctt_name)[0] == '\0')	{	  ctf_decl_push (cd, fp, tp->ctt_type);	  return;	}      prec = CTF_PREC_BASE;      break;     case CTF_K_FUNCTION:      ctf_decl_push (cd, fp, tp->ctt_type);      prec = CTF_PREC_FUNCTION;      break;     case CTF_K_POINTER:      ctf_decl_push (cd, fp, tp->ctt_type);      prec = CTF_PREC_POINTER;      break;     case CTF_K_SLICE:      /* Slices themselves have no print representation and should not appear in	 the decl stack.  */      ctf_decl_push (cd, fp, ctf_type_reference (fp, type));      return;     case CTF_K_VOLATILE:    case CTF_K_CONST:    case CTF_K_RESTRICT:      ctf_decl_push (cd, fp, tp->ctt_type);      prec = cd->cd_qualp;      is_qual++;      break;     default:      prec = CTF_PREC_BASE;    }   if ((cdp = malloc (sizeof (ctf_decl_node_t))) == NULL)    {      cd->cd_err = EAGAIN;      return;    }   cdp->cd_type = type;  cdp->cd_kind = kind;  cdp->cd_n = n;   if (ctf_list_next (&cd->cd_nodes[prec]) == NULL)    cd->cd_order[prec] = cd->cd_ordp++;   /* Reset cd_qualp to the highest precedence level that we've seen so     far that can be qualified (CTF_PREC_BASE or CTF_PREC_POINTER).  */   if (prec > cd->cd_qualp && prec < CTF_PREC_ARRAY)    cd->cd_qualp = prec;   /* By convention qualifiers of base types precede the type specifier (e.g.     const int vs. int const) even though the two forms are equivalent.     As of gcc-14.2.0, arrays must also be prepended in order to dump with the     dimensions properly ordered.  */   if ((is_qual && prec == CTF_PREC_BASE) || ((kind == CTF_K_ARRAY) &&    (fp->ctf_openflags & (CTF_F_ARRNELEMS))))    ctf_list_prepend (&cd->cd_nodes[prec], cdp);  else    ctf_list_append (&cd->cd_nodes[prec], cdp);} _libctf_printflike_ (2, 3)void ctf_decl_sprintf (ctf_decl_t *cd, const char *format, ...){  va_list ap;  char *str;  int n;   if (cd->cd_enomem)    return;   va_start (ap, format);  n = vasprintf (&str, format, ap);  va_end (ap);   if (n > 0)    {      char *newbuf;      if ((newbuf = ctf_str_append (cd->cd_buf, str)) != NULL)	cd->cd_buf = newbuf;    }   /* Sticky error condition.  */  if (n < 0 || cd->cd_buf == NULL)    {      free (cd->cd_buf);      cd->cd_buf = NULL;      cd->cd_enomem = 1;    }   free (str);} char *ctf_decl_buf (ctf_decl_t *cd){  char *buf = cd->cd_buf;  cd->cd_buf = NULL;  return buf;}