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)
32 cdecl__emit(dst, cdecl__emit_specs(dst, s, mask));
36 * If declarator declares an identifier foo, then emit "foo as "; otherwise
40 explain_name(struct output_state *dst, struct cdecl_declarator *d)
45 if (d->type == CDECL_DECL_IDENT) {
46 cdecl__emit(dst, d->u.ident);
47 cdecl__emit(dst, " as ");
52 * For a pointer declarator, emit "[QUAL ]pointer to ", where
53 * QUAL is the (possibly empty) list of qualifiers.
56 explain_pointer(struct output_state *dst, struct cdecl_pointer *p)
58 explain_specs(dst, p->qualifiers, -1);
59 cdecl__emit(dst, "pointer to ");
63 * For an array declarator, emit "[variable-length ]array [X ]of ", where
64 * for a variable-length array X is the (possibly omitted) identifier name,
65 * and for normal arrays X is the (possibly omitted) length.
68 explain_array(struct output_state *dst, struct cdecl_array *a)
73 cdecl__emit(dst, "variable-length ");
74 cdecl__emit(dst, "array ");
77 rc = cdecl__emit(dst, a->vla);
79 rc = snprintf(dst->dst, dst->dstlen, "%.0" PRIuMAX, a->length);
80 cdecl__advance(dst, rc);
83 cdecl__emit(dst, " of " + !rc);
87 explain_declarators(struct output_state *dst, struct cdecl_declarator *decl);
89 static void explain_decl(struct output_state *dst, struct cdecl *decl)
91 explain_name(dst, decl->declarators);
92 explain_specs(dst, decl->specifiers, PRE_SPECS);
93 explain_declarators(dst, decl->declarators);
94 cdecl__emit_specs(dst, decl->specifiers, POST_SPECS);
98 * For a function declarator, emit "function [PARAM ]returning ", where
99 * PARAM is the (omitted in the case of an empty non-prototype identifier
100 * list) parameter or identifier lists enclosed in parentheses.
103 explain_function(struct output_state *dst, struct cdecl_function *f)
105 cdecl__emit(dst, "function ");
110 cdecl__emit(dst, "(");
112 for (p = f->parameters; p; p = p->next) {
113 explain_decl(dst, p);
115 cdecl__emit(dst, ", ");
119 cdecl__emit(dst, ", ...) ");
121 cdecl__emit(dst, ") ");
124 cdecl__emit(dst, "returning ");
128 explain_declarators(struct output_state *dst, struct cdecl_declarator *d)
130 if (d->type == CDECL_DECL_IDENT || d->type == CDECL_DECL_NULL)
133 explain_declarators(dst, d->child);
136 case CDECL_DECL_POINTER:
137 explain_pointer(dst, &d->u.pointer);
139 case CDECL_DECL_ARRAY:
140 explain_array(dst, &d->u.array);
142 case CDECL_DECL_FUNCTION:
143 explain_function(dst, &d->u.function);
150 size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
152 struct output_state dst = { buf, n };
154 if (cdecl_is_abstract(decl->declarators))
155 cdecl__emit(&dst, "type ");
157 cdecl__emit(&dst, "declare ");
159 explain_decl(&dst, decl);