/*
* Render C declarations as English.
- * Copyright © 2011 Nick Bowler
+ * Copyright © 2011, 2021, 2023-2024 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
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+
#include <config.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <assert.h>
+#include <inttypes.h>
#include "cdecl.h"
-#include "output.h"
+#include "cdecl-internal.h"
+
+#define PRE_SPECS (CDECL_SPEC_FUNC|CDECL_SPEC_STOR)
+#define POST_SPECS (CDECL_SPEC_QUAL|CDECL_SPEC_TYPE)
+
+static void explain_specs(struct output_state *dst, struct cdecl_declspec *s, unsigned mask)
+{
+ cdecl__emit(dst, cdecl__emit_specs(dst, s, mask));
+}
/*
- * Renders the start of the thing being declared. If top is true, print
- * the "declare" or "type" keywords at the front, as appropriate.
+ * If declarator declares an identifier foo, then emit "foo as "; otherwise
+ * emit nothing.
*/
-static size_t
-explain_prologue(char *buf, size_t n, struct cdecl_declarator *d, bool top)
+static void
+explain_name(struct output_state *dst, struct cdecl_declarator *d)
{
- 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);
- }
-
+ while (d->child)
d = d->child;
- }
- assert(0);
+ if (d->type == CDECL_DECL_IDENT) {
+ cdecl__emit(dst, d->u.ident);
+ cdecl__emit(dst, " as ");
+ }
}
-static size_t
-explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
+/*
+ * For a pointer declarator, emit "[QUAL ]pointer to ", where
+ * QUAL is the (possibly empty) list of qualifiers.
+ */
+static void
+explain_pointer(struct output_state *dst, struct cdecl_pointer *p)
{
- size_t ret = 0, rc;
-
- rc = cdecl__explain_specs(buf, n, p->qualifiers, CDECL_SPEC_QUAL);
- ret += cdecl__advance(&buf, &n, rc);
-
- return ret + snprintf(buf, n, "pointer to");
+ explain_specs(dst, p->qualifiers, -1);
+ cdecl__emit(dst, "pointer to ");
}
-static size_t
-explain_array(char *buf, size_t n, struct cdecl_array *a)
+/*
+ * For an array declarator, emit "[variable-length ]array [X ]of ", where
+ * for a variable-length array X is the (possibly omitted) identifier name,
+ * and for normal arrays X is the (possibly omitted) length.
+ */
+static void
+explain_array(struct output_state *dst, 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);
+ size_t rc = 0;
+ cdecl__emit(dst, "variable-length array " + (a->vla ? 0 : 16));
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);
+ rc = cdecl__emit(dst, a->vla);
+ } else {
+ rc = cdecl__emit_uint(dst, a->length);
}
-
- return ret + snprintf(buf, n, "of");
+ cdecl__emit(dst, " of " + !rc);
}
-static size_t
-explain_declarators(char *buf, size_t n, struct cdecl_declarator *decl);
+static void
+explain_declarators(struct output_state *dst, struct cdecl_declarator *decl);
-static size_t explain_decl(char *buf, size_t n, struct cdecl *decl, bool top)
+static void explain_decl(struct output_state *dst, struct cdecl *decl)
{
- size_t ret = 0, rc;
-
- rc = explain_prologue(buf, n, decl->declarators, top);
- ret += cdecl__advance(&buf, &n, rc);
-
- rc = cdecl__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 + cdecl__explain_post_specs(buf, n, decl->specifiers);
+ explain_name(dst, decl->declarators);
+ explain_specs(dst, decl->specifiers, PRE_SPECS);
+ explain_declarators(dst, decl->declarators);
+ cdecl__emit_specs(dst, decl->specifiers, POST_SPECS);
}
-static size_t explain_function(char *buf, size_t n, struct cdecl_function *f)
+/*
+ * For a function declarator, emit "function [PARAM ]returning ", where
+ * PARAM is the (omitted in the case of an empty non-prototype identifier
+ * list) parameter or identifier lists enclosed in parentheses.
+ */
+static void
+explain_function(struct output_state *dst, struct cdecl_function *f)
{
- size_t ret = 0, rc = 0;
-
- rc = snprintf(buf, n, "function");
- ret += cdecl__advance(&buf, &n, rc);
+ int tail_offset = 7;
+ cdecl__emit(dst, "function ");
if (f->parameters) {
- rc = snprintf(buf, n, "(");
- ret += cdecl__advance_(&buf, &n, rc);
+ struct cdecl *p;
- for (struct cdecl *p = f->parameters; p; p = p->next) {
- rc = explain_decl(buf, n, p, false);
- ret += cdecl__advance_(&buf, &n, rc);
+ cdecl__emit(dst, "(");
+ for (p = f->parameters; p; p = p->next) {
+ explain_decl(dst, p);
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);
+ cdecl__emit(dst, ", ");
}
- }
- return ret + snprintf(buf, n, "returning");
+ tail_offset = f->variadic ? 0 : 5;
+ }
+ cdecl__emit(dst, ", ...) returning " + tail_offset);
}
-static size_t
-explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
+static void
+explain_declarators(struct output_state *dst, 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);
+ if (d->child)
+ explain_declarators(dst, d->child);
switch (d->type) {
case CDECL_DECL_POINTER:
- return ret + explain_pointer(buf, n, &d->u.pointer);
+ explain_pointer(dst, &d->u.pointer);
+ return;
case CDECL_DECL_ARRAY:
- return ret + explain_array(buf, n, &d->u.array);
+ explain_array(dst, &d->u.array);
+ return;
case CDECL_DECL_FUNCTION:
- return ret + explain_function(buf, n, &d->u.function);
- default:
- assert(0);
+ explain_function(dst, &d->u.function);
+ return;
}
}
size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
{
- return explain_decl(buf, n, decl, true);
+ struct output_state dst = { buf, n };
+
+ if (cdecl_is_abstract(decl->declarators))
+ cdecl__emit(&dst, "type ");
+ else
+ cdecl__emit(&dst, "declare ");
+
+ explain_decl(&dst, decl);
+ return dst.accum;
}
projects / cdecl99.git / blobdiff