/*
* Render C declarations as English.
* Copyright © 2011 Nick Bowler
*
* This program 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 of the License, 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. If not, see .
*/
#include
#include
#include
#include
#include
#include "cdecl.h"
#include "typemap.h"
#include "output.h"
static size_t
explain_qualifiers(char *buf, size_t n, struct cdecl_declspec *s)
{
unsigned long qualmap = 0;
size_t ret = 0, rc = 0;
for (struct cdecl_declspec *c = s; c; c = c->next) {
if (cdecl_spec_kind(c) != CDECL_SPEC_QUAL)
continue;
qualmap |= 1ul << (c->type & 0xff);
}
if (qualmap & (1ul << (CDECL_QUAL_RESTRICT & 0xff))) {
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "restrict");
}
if (qualmap & (1ul << (CDECL_QUAL_VOLATILE & 0xff))) {
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "volatile");
}
if (qualmap & (1ul << (CDECL_QUAL_CONST & 0xff))) {
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "const");
}
return ret + rc;
}
/* Renders the type qualifiers and type specifiers in canonical form. */
static size_t
explain_post_specs(char *buf, size_t n, struct cdecl_declspec *s)
{
const char *tag = NULL;
unsigned long typemap;
size_t ret = 0, rc;
typemap = cdecl__build_typemap(s);
if (typemap == -1)
return 0;
for (struct cdecl_declspec *c = s; c; c = c->next) {
if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
continue;
/* Valid C types have at most one identifier. */
if (c->ident)
tag = c->ident;
}
rc = explain_qualifiers(buf, n, s);
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "%s", cdecl__explain_typemap(typemap));
if (tag) {
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "%s", tag);
}
return ret + rc;
}
static size_t explain_storage(char *buf, size_t n, unsigned spec)
{
switch (spec) {
case CDECL_STOR_TYPEDEF:
return snprintf(buf, n, "typedef");
case CDECL_STOR_EXTERN:
return snprintf(buf, n, "extern");
case CDECL_STOR_STATIC:
return snprintf(buf, n, "static");
case CDECL_STOR_AUTO:
return snprintf(buf, n, "auto");
case CDECL_STOR_REGISTER:
return snprintf(buf, n, "register");
default:
assert(0);
}
}
/* Renders the storage-class and function specifiers in canonical form. */
static size_t explain_pre_specs(char *buf, size_t n, struct cdecl_declspec *s)
{
unsigned long funcmap = 0;
size_t ret = 0, rc = 0;
for (struct cdecl_declspec *c = s; c; c = c->next) {
switch (cdecl_spec_kind(c)) {
case CDECL_SPEC_FUNC:
funcmap |= 1ul << (c->type & 0xff);
break;
case CDECL_SPEC_STOR:
/* Valid C declarations have at most one
* storage-class specifier. */
rc = explain_storage(buf, n, c->type);
break;
}
}
if (funcmap & (1ul << (CDECL_FUNC_INLINE & 0xff))) {
ret += cdecl__advance(&buf, &n, rc);
rc = snprintf(buf, n, "inline");
}
return ret + rc;
}
/*
* Renders the start of the thing being declared. If top is true, print
* the "declare" or "type" keywords at the front, as appropriate.
*/
static size_t
explain_prologue(char *buf, size_t n, struct cdecl_declarator *d, bool top)
{
size_t ret = 0, rc = 0;
while (d) {
switch (d->type) {
case CDECL_DECL_NULL:
if (top)
return snprintf(buf, n, "type");
return 0;
case CDECL_DECL_IDENT:
if (top)
rc = snprintf(buf, n, "declare");
ret += cdecl__advance(&buf, &n, rc);
return ret + snprintf(buf, n, "%s as", d->u.ident);
}
d = d->child;
}
}
static size_t
explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
{
size_t ret = 0, rc;
rc = explain_qualifiers(buf, n, p->qualifiers);
ret += cdecl__advance(&buf, &n, rc);
return ret + snprintf(buf, n, "pointer to");
}
static size_t
explain_array(char *buf, size_t n, struct cdecl_array *a)
{
size_t ret = 0, rc = 0;
if (a->vla)
rc = snprintf(buf, n, "variable-length array");
else
rc = snprintf(buf, n, "array");
ret += cdecl__advance(&buf, &n, rc);
if (a->vla) {
rc = snprintf(buf, n, "%s", a->vla);
ret += cdecl__advance(&buf, &n, rc);
} else if (a->length) {
rc = snprintf(buf, n, "%ju", a->length);
ret += cdecl__advance(&buf, &n, rc);
}
return ret + snprintf(buf, n, "of");
}
static size_t
explain_declarators(char *buf, size_t n, struct cdecl_declarator *decl);
static size_t explain_decl(char *buf, size_t n, struct cdecl *decl, bool top)
{
size_t ret = 0, rc;
rc = explain_prologue(buf, n, decl->declarators, top);
ret += cdecl__advance(&buf, &n, rc);
rc = explain_pre_specs(buf, n, decl->specifiers);
ret += cdecl__advance(&buf, &n, rc);
rc = explain_declarators(buf, n, decl->declarators);
ret += cdecl__advance(&buf, &n, rc);
return ret + explain_post_specs(buf, n, decl->specifiers);
}
static size_t explain_function(char *buf, size_t n, struct cdecl_function *f)
{
size_t ret = 0, rc = 0;
rc = snprintf(buf, n, "function");
ret += cdecl__advance(&buf, &n, rc);
if (f->parameters) {
rc = snprintf(buf, n, "(");
ret += cdecl__advance_(&buf, &n, rc);
for (struct cdecl *p = f->parameters; p; p = p->next) {
rc = explain_decl(buf, n, p, false);
ret += cdecl__advance_(&buf, &n, rc);
if (p->next)
rc = snprintf(buf, n, ",");
else if (f->variadic)
rc = snprintf(buf, n, ", ...)");
else
rc = snprintf(buf, n, ")");
ret += cdecl__advance(&buf, &n, rc);
}
}
return ret + snprintf(buf, n, "returning");
}
static size_t
explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
{
size_t ret = 0, rc;
if (d->type == CDECL_DECL_IDENT || d->type == CDECL_DECL_NULL)
return 0;
rc = explain_declarators(buf, n, d->child);
ret += cdecl__advance(&buf, &n, rc);
switch (d->type) {
case CDECL_DECL_POINTER:
return ret + explain_pointer(buf, n, &d->u.pointer);
case CDECL_DECL_ARRAY:
return ret + explain_array(buf, n, &d->u.array);
case CDECL_DECL_FUNCTION:
return ret + explain_function(buf, n, &d->u.function);
default:
assert(0);
}
}
size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
{
return explain_decl(buf, n, decl, true);
}