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)
41 if (amount + 1 >= *n) {
54 explain_qualifiers(char *buf, size_t n, struct cdecl_declspec *s)
56 unsigned long qualmap = 0;
57 size_t ret = 0, rc = 0;
59 for (struct cdecl_declspec *c = s; c; c = c->next) {
60 if (cdecl_spec_kind(c) != CDECL_SPEC_QUAL)
62 qualmap |= 1ul << (c->type & 0xff);
65 if (qualmap & (1ul << (CDECL_QUAL_RESTRICT & 0xff))) {
66 ret += advance(&buf, &n, rc);
67 rc = snprintf(buf, n, "restrict");
69 if (qualmap & (1ul << (CDECL_QUAL_VOLATILE & 0xff))) {
70 ret += advance(&buf, &n, rc);
71 rc = snprintf(buf, n, "volatile");
73 if (qualmap & (1ul << (CDECL_QUAL_CONST & 0xff))) {
74 ret += advance(&buf, &n, rc);
75 rc = snprintf(buf, n, "const");
81 /* Renders the type qualifiers and type specifiers in canonical form. */
83 explain_post_specs(char *buf, size_t n, struct cdecl_declspec *s)
85 const char *tag = NULL;
86 unsigned long typemap;
89 typemap = cdecl__build_typemap(s);
93 for (struct cdecl_declspec *c = s; c; c = c->next) {
94 if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
97 /* Valid C types have at most one identifier. */
102 rc = explain_qualifiers(buf, n, s);
103 ret += advance(&buf, &n, rc);
105 rc = snprintf(buf, n, "%s", cdecl__explain_typemap(typemap));
107 ret += advance(&buf, &n, rc);
108 rc = snprintf(buf, n, "%s", tag);
114 static const char *explain_storage(unsigned spec)
117 case CDECL_STOR_TYPEDEF:
119 case CDECL_STOR_EXTERN:
121 case CDECL_STOR_STATIC:
123 case CDECL_STOR_AUTO:
125 case CDECL_STOR_REGISTER:
132 /* Renders the storage-class and function specifiers in canonical form. */
133 static size_t explain_pre_specs(char *buf, size_t n, struct cdecl_declspec *s)
135 unsigned long funcmap = 0;
136 const char *storage = NULL;
139 for (struct cdecl_declspec *c = s; c; c = c->next) {
140 switch (cdecl_spec_kind(c)) {
141 case CDECL_SPEC_FUNC:
142 funcmap |= 1ul << (c->type & 0xff);
144 case CDECL_SPEC_STOR:
145 /* Valid C declarations have at most one
146 * storage-class specifier. */
147 storage = explain_storage(c->type);
153 ret += output(buf, n, ret, "%s", storage);
154 if (funcmap & (1ul << (CDECL_FUNC_INLINE & 0xff)))
155 ret += output(buf, n, ret, "%.*s%s", !!ret, "", "inline");
159 static struct cdecl_declarator *next_declarator(struct cdecl_declarator *d)
162 case CDECL_DECL_IDENT:
164 case CDECL_DECL_POINTER:
165 return d->u.pointer.declarator;
166 case CDECL_DECL_ARRAY:
167 return d->u.array.declarator;
173 /* Renders the name of the thing being declared. */
175 explain_prologue(char *buf, size_t n, struct cdecl_declarator *d)
178 if (d->type == CDECL_DECL_IDENT) {
180 return snprintf(buf, n, "type");
181 return snprintf(buf, n, "declare %s as", d->u.ident);
183 d = next_declarator(d);
188 explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
192 rc = explain_qualifiers(buf, n, p->qualifiers);
193 ret += advance(&buf, &n, rc);
195 return ret + snprintf(buf, n, "pointer to");
199 explain_array(char *buf, size_t n, struct cdecl_array *a)
201 size_t ret = 0, rc = 0;
204 rc = snprintf(buf, n, "variable-length array");
206 rc = snprintf(buf, n, "array");
207 ret += advance(&buf, &n, rc);
210 rc = snprintf(buf, n, "%s", a->vla);
211 ret += advance(&buf, &n, rc);
212 } else if (a->length) {
213 rc = snprintf(buf, n, "%ju", a->length);
214 ret += advance(&buf, &n, rc);
217 return ret + snprintf(buf, n, "of");
221 explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
225 if (d->type == CDECL_DECL_IDENT)
228 rc = explain_declarators(buf, n, next_declarator(d));
229 ret += advance(&buf, &n, rc);
232 case CDECL_DECL_POINTER:
233 return ret + explain_pointer(buf, n, &d->u.pointer);
234 case CDECL_DECL_ARRAY:
235 return ret + explain_array(buf, n, &d->u.array);
241 size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
245 rc = explain_prologue(buf, n, decl->declarators);
246 ret += advance(&buf, &n, rc);
248 rc = explain_pre_specs(buf, n, decl->specifiers);
249 ret += advance(&buf, &n, rc);
251 rc = explain_declarators(buf, n, decl->declarators);
252 ret += advance(&buf, &n, rc);
254 return ret + explain_post_specs(buf, n, decl->specifiers);