2 * Render C declarations as English.
3 * Copyright © 2011, 2021, 2023 Nick Bowler
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
25 #include "cdecl-internal.h"
27 #define PRE_SPECS (CDECL_SPEC_FUNC|CDECL_SPEC_STOR)
28 #define POST_SPECS (CDECL_SPEC_QUAL|CDECL_SPEC_TYPE)
30 static void explain_specs(struct output_state *dst, struct cdecl_declspec *s, unsigned mask)
34 rc = cdecl__emit_specs(dst, s, mask);
35 cdecl__emit(dst, " " + !rc);
39 * If declarator declares an identifier foo, then emit "foo as "; otherwise
43 explain_name(struct output_state *dst, struct cdecl_declarator *d)
48 if (d->type == CDECL_DECL_IDENT) {
49 cdecl__emit(dst, d->u.ident);
50 cdecl__emit(dst, " as ");
55 * For a pointer declarator, emit "[QUAL ]pointer to ", where
56 * QUAL is the (possibly empty) list of qualifiers.
59 explain_pointer(struct output_state *dst, struct cdecl_pointer *p)
61 explain_specs(dst, p->qualifiers, -1);
62 cdecl__emit(dst, "pointer to ");
66 * For an array declarator, emit "[variable-length ]array [X ]of ", where
67 * for a variable-length array X is the (possibly omitted) identifier name,
68 * and for normal arrays X is the (possibly omitted) length.
71 explain_array(struct output_state *dst, struct cdecl_array *a)
76 cdecl__emit(dst, "variable-length ");
77 cdecl__emit(dst, "array ");
80 rc = cdecl__emit(dst, a->vla);
82 rc = snprintf(dst->dst, dst->dstlen, "%.0" PRIuMAX, a->length);
83 cdecl__advance(dst, rc);
86 cdecl__emit(dst, " of " + !rc);
90 explain_declarators(struct output_state *dst, struct cdecl_declarator *decl);
92 static void explain_decl(struct output_state *dst, struct cdecl *decl)
94 explain_name(dst, decl->declarators);
95 explain_specs(dst, decl->specifiers, PRE_SPECS);
96 explain_declarators(dst, decl->declarators);
97 cdecl__emit_specs(dst, decl->specifiers, POST_SPECS);
101 * For a function declarator, emit "function [PARAM ]returning ", where
102 * PARAM is the (omitted in the case of an empty non-prototype identifier
103 * list) parameter or identifier lists enclosed in parentheses.
106 explain_function(struct output_state *dst, struct cdecl_function *f)
108 cdecl__emit(dst, "function ");
113 cdecl__emit(dst, "(");
115 for (p = f->parameters; p; p = p->next) {
116 explain_decl(dst, p);
118 cdecl__emit(dst, ", ");
122 cdecl__emit(dst, ", ...) ");
124 cdecl__emit(dst, ") ");
127 cdecl__emit(dst, "returning ");
131 explain_declarators(struct output_state *dst, struct cdecl_declarator *d)
133 if (d->type == CDECL_DECL_IDENT || d->type == CDECL_DECL_NULL)
136 explain_declarators(dst, d->child);
139 case CDECL_DECL_POINTER:
140 explain_pointer(dst, &d->u.pointer);
142 case CDECL_DECL_ARRAY:
143 explain_array(dst, &d->u.array);
145 case CDECL_DECL_FUNCTION:
146 explain_function(dst, &d->u.function);
153 size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
155 struct output_state dst = { buf, n };
157 if (cdecl_is_abstract(decl->declarators))
158 cdecl__emit(&dst, "type ");
160 cdecl__emit(&dst, "declare ");
162 explain_decl(&dst, decl);