123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202 |
- /* C declarator syntax glue.
- Copyright (C) 2019-2022 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>
- void
- ctf_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;
- }
- void
- ctf_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);
- }
- void
- ctf_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. */
- if (is_qual && prec == CTF_PREC_BASE)
- 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;
- }
|