9 /* declare [ident] as [storage] [function specs] [other crap] [qualifiers] [type specs] */
12 voutput(char *buf, size_t n, size_t off, const char *fmt, va_list ap)
15 return vsnprintf(NULL, 0, fmt, ap);
16 return vsnprintf(buf+off, n-off, fmt, ap);
19 static size_t output(char *buf, size_t n, size_t off, const char *fmt, ...)
25 ret = voutput(buf, n, off, fmt, ap);
31 static size_t advance_(char **buf, size_t *n, size_t amount)
44 static size_t advance(char **buf, size_t *n, size_t amount)
51 ret = advance_(buf, n, amount);
52 rc = snprintf(*buf, *n, " ");
53 return ret + advance_(buf, n, rc);
57 explain_qualifiers(char *buf, size_t n, struct cdecl_declspec *s)
59 unsigned long qualmap = 0;
60 size_t ret = 0, rc = 0;
62 for (struct cdecl_declspec *c = s; c; c = c->next) {
63 if (cdecl_spec_kind(c) != CDECL_SPEC_QUAL)
65 qualmap |= 1ul << (c->type & 0xff);
68 if (qualmap & (1ul << (CDECL_QUAL_RESTRICT & 0xff))) {
69 ret += advance(&buf, &n, rc);
70 rc = snprintf(buf, n, "restrict");
72 if (qualmap & (1ul << (CDECL_QUAL_VOLATILE & 0xff))) {
73 ret += advance(&buf, &n, rc);
74 rc = snprintf(buf, n, "volatile");
76 if (qualmap & (1ul << (CDECL_QUAL_CONST & 0xff))) {
77 ret += advance(&buf, &n, rc);
78 rc = snprintf(buf, n, "const");
84 /* Renders the type qualifiers and type specifiers in canonical form. */
86 explain_post_specs(char *buf, size_t n, struct cdecl_declspec *s)
88 const char *tag = NULL;
89 unsigned long typemap;
92 typemap = cdecl__build_typemap(s);
96 for (struct cdecl_declspec *c = s; c; c = c->next) {
97 if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
100 /* Valid C types have at most one identifier. */
105 rc = explain_qualifiers(buf, n, s);
106 ret += advance(&buf, &n, rc);
108 rc = snprintf(buf, n, "%s", cdecl__explain_typemap(typemap));
110 ret += advance(&buf, &n, rc);
111 rc = snprintf(buf, n, "%s", tag);
117 static const char *explain_storage(unsigned spec)
120 case CDECL_STOR_TYPEDEF:
122 case CDECL_STOR_EXTERN:
124 case CDECL_STOR_STATIC:
126 case CDECL_STOR_AUTO:
128 case CDECL_STOR_REGISTER:
135 /* Renders the storage-class and function specifiers in canonical form. */
136 static size_t explain_pre_specs(char *buf, size_t n, struct cdecl_declspec *s)
138 unsigned long funcmap = 0;
139 const char *storage = NULL;
142 for (struct cdecl_declspec *c = s; c; c = c->next) {
143 switch (cdecl_spec_kind(c)) {
144 case CDECL_SPEC_FUNC:
145 funcmap |= 1ul << (c->type & 0xff);
147 case CDECL_SPEC_STOR:
148 /* Valid C declarations have at most one
149 * storage-class specifier. */
150 storage = explain_storage(c->type);
156 ret += output(buf, n, ret, "%s", storage);
157 if (funcmap & (1ul << (CDECL_FUNC_INLINE & 0xff)))
158 ret += output(buf, n, ret, "%.*s%s", !!ret, "", "inline");
162 /* Renders the name of the thing being declared. */
164 explain_prologue(char *buf, size_t n, struct cdecl_declarator *d)
168 case CDECL_DECL_NULL:
169 return snprintf(buf, n, "type");
170 case CDECL_DECL_IDENT:
171 return snprintf(buf, n, "declare %s as", d->u.ident);
179 explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
183 rc = explain_qualifiers(buf, n, p->qualifiers);
184 ret += advance(&buf, &n, rc);
186 return ret + snprintf(buf, n, "pointer to");
190 explain_array(char *buf, size_t n, struct cdecl_array *a)
192 size_t ret = 0, rc = 0;
195 rc = snprintf(buf, n, "variable-length array");
197 rc = snprintf(buf, n, "array");
198 ret += advance(&buf, &n, rc);
201 rc = snprintf(buf, n, "%s", a->vla);
202 ret += advance(&buf, &n, rc);
203 } else if (a->length) {
204 rc = snprintf(buf, n, "%ju", a->length);
205 ret += advance(&buf, &n, rc);
208 return ret + snprintf(buf, n, "of");
212 explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
216 if (d->type == CDECL_DECL_IDENT || d->type == CDECL_DECL_NULL)
219 rc = explain_declarators(buf, n, d->child);
220 ret += advance(&buf, &n, rc);
223 case CDECL_DECL_POINTER:
224 return ret + explain_pointer(buf, n, &d->u.pointer);
225 case CDECL_DECL_ARRAY:
226 return ret + explain_array(buf, n, &d->u.array);
232 size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
236 rc = explain_prologue(buf, n, decl->declarators);
237 ret += advance(&buf, &n, rc);
239 rc = explain_pre_specs(buf, n, decl->specifiers);
240 ret += advance(&buf, &n, rc);
242 rc = explain_declarators(buf, n, decl->declarators);
243 ret += advance(&buf, &n, rc);
245 return ret + explain_post_specs(buf, n, decl->specifiers);