X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/7022b70b587d5d4a7f4a24dc3943326e9cba4ad1..41d0e2f8f2dc0ec50526ff6e4b8ff12936d1f90e:/src/explain.c

diff --git a/src/explain.c b/src/explain.c
index 60e880b..0d9c957 100644
--- a/src/explain.c
+++ b/src/explain.c
@@ -1,209 +1,138 @@
+/*
+ *  Render C declarations as English.
+ *  Copyright © 2011, 2021 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <inttypes.h>
+#include <stdbool.h>
 #include <assert.h>
 
 #include "cdecl.h"
-#include "typemap.h"
-
-/* declare [ident] as [storage] [function specs] [other crap] [qualifiers] [type specs] */
+#include "cdecl-internal.h"
 
+/*
+ * 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
-voutput(char *buf, size_t n, size_t off, const char *fmt, va_list ap)
-{
-	if (off >= n)
-		return vsnprintf(NULL, 0, fmt, ap);
-	return vsnprintf(buf+off, n-off, fmt, ap);
-}
-
-static size_t output(char *buf, size_t n, size_t off, const char *fmt, ...)
+explain_prologue(char *buf, size_t n, struct cdecl_declarator *d, bool top)
 {
-	va_list ap;
-	size_t ret;
-
-	va_start(ap, fmt);
-	ret = voutput(buf, n, off, fmt, ap);
-	va_end(ap);
+	size_t ret = 0, rc = 0;
 
-	return ret;
-}
+	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);
+		}
 
-static size_t advance_(char **buf, size_t *n, size_t amount)
-{
-	if (amount >= *n) {
-		*n   = 0;
-		*buf = 0;
-	} else {
-		*buf += amount;
-		*n   -= amount;
+		d = d->child;
 	}
 
-	return amount;
+	assert(0);
 }
 
-static size_t advance(char **buf, size_t *n, size_t amount)
+static size_t
+explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
 {
-	size_t ret, rc;
+	size_t ret = 0, rc;
 
-	if (!amount)
-		return 0;
+	rc = cdecl__explain_specs(buf, n, p->qualifiers, CDECL_SPEC_QUAL);
+	ret += cdecl__advance(&buf, &n, rc);
 
-	ret = advance_(buf, n, amount);
-	rc = snprintf(*buf, *n, " ");
-	return ret + advance_(buf, n, rc);
+	return ret + snprintf(buf, n, "pointer to");
 }
 
 static size_t
-explain_qualifiers(char *buf, size_t n, struct cdecl_declspec *s)
+explain_array(char *buf, size_t n, struct cdecl_array *a)
 {
-	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 (a->vla)
+		rc = snprintf(buf, n, "variable-length array");
+	else
+		rc = snprintf(buf, n, "array");
+	ret += cdecl__advance(&buf, &n, rc);
 
-	if (qualmap & (1ul << (CDECL_QUAL_RESTRICT & 0xff))) {
-		ret += advance(&buf, &n, rc);
-		rc = snprintf(buf, n, "restrict");
-	}
-	if (qualmap & (1ul << (CDECL_QUAL_VOLATILE & 0xff))) {
-		ret += advance(&buf, &n, rc);
-		rc = snprintf(buf, n, "volatile");
-	}
-	if (qualmap & (1ul << (CDECL_QUAL_CONST & 0xff))) {
-		ret += advance(&buf, &n, rc);
-		rc = snprintf(buf, n, "const");
+	if (a->vla) {
+		rc = snprintf(buf, n, "%s", a->vla);
+		ret += cdecl__advance(&buf, &n, rc);
+	} else if (a->length) {
+		rc = snprintf(buf, n, "%" PRIuMAX, a->length);
+		ret += cdecl__advance(&buf, &n, rc);
 	}
 
-	return ret + rc;
+	return ret + snprintf(buf, n, "of");
 }
 
-/* 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)
+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)
 {
-	const char *tag = NULL;
-	unsigned long typemap;
 	size_t ret = 0, rc;
 
-	typemap = cdecl__build_typemap(s);
-	if (typemap == -1)
-		return 0;
+	rc = explain_prologue(buf, n, decl->declarators, top);
+	ret += cdecl__advance(&buf, &n, rc);
 
-	for (struct cdecl_declspec *c = s; c; c = c->next) {
-		if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
-			continue;
+	rc = cdecl__explain_pre_specs(buf, n, decl->specifiers);
+	ret += cdecl__advance(&buf, &n, rc);
 
-		/* Valid C types have at most one identifier. */
-		if (c->ident)
-			tag = c->ident;
-	}
-
-	rc = explain_qualifiers(buf, n, s);
-	ret += advance(&buf, &n, rc);
-
-	rc = snprintf(buf, n, "%s", cdecl__explain_typemap(typemap));
-	if (tag) {
-		ret += advance(&buf, &n, rc);
-		rc = snprintf(buf, n, "%s", tag);
-	}
-
-	return ret + rc;
-}
-
-static const char *explain_storage(unsigned spec)
-{
-	switch (spec) {
-	case CDECL_STOR_TYPEDEF:
-		return "typedef";
-	case CDECL_STOR_EXTERN:
-		return "extern";
-	case CDECL_STOR_STATIC:
-		return "static";
-	case CDECL_STOR_AUTO:
-		return "auto";
-	case CDECL_STOR_REGISTER:
-		return "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;
-	const char *storage = NULL;
-	size_t ret = 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. */
-			storage = explain_storage(c->type);
-			break;
-		}
-	}
+	rc = explain_declarators(buf, n, decl->declarators);
+	ret += cdecl__advance(&buf, &n, rc);
 
-	if (storage)
-		ret += output(buf, n, ret, "%s", storage);
-	if (funcmap & (1ul << (CDECL_FUNC_INLINE & 0xff)))
-		ret += output(buf, n, ret, "%.*s%s", !!ret, "", "inline");
-	return ret;
+	return ret + cdecl__explain_post_specs(buf, n, decl->specifiers);
 }
 
-/* Renders the name of the thing being declared. */
-static size_t
-explain_prologue(char *buf, size_t n, struct cdecl_declarator *d)
+static size_t explain_function(char *buf, size_t n, struct cdecl_function *f)
 {
-	while (d) {
-		if (d->type == CDECL_DECL_IDENT) {
-			if (!d->u.ident)
-				return snprintf(buf, n, "type");
-			return snprintf(buf, n, "declare %s as", d->u.ident);
-		}
-		d = d->child;
-	}
-}
+	size_t ret = 0, rc = 0;
 
-static size_t
-explain_pointer(char *buf, size_t n, struct cdecl_pointer *p)
-{
-	size_t ret = 0, rc;
+	rc = snprintf(buf, n, "function");
+	ret += cdecl__advance(&buf, &n, rc);
 
-	rc = explain_qualifiers(buf, n, p->qualifiers);
-	ret += advance(&buf, &n, rc);
+	if (f->parameters) {
+		rc = snprintf(buf, n, "(");
+		ret += cdecl__advance_(&buf, &n, rc);
 
-	return ret + snprintf(buf, n, "pointer to");
-}
+		for (struct cdecl *p = f->parameters; p; p = p->next) {
+			rc = explain_decl(buf, n, p, false);
+			ret += cdecl__advance_(&buf, &n, rc);
 
-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 += advance(&buf, &n, rc);
-
-	if (a->vla) {
-		rc = snprintf(buf, n, "%s", a->vla);
-		ret += advance(&buf, &n, rc);
-	} else if (a->length) {
-		rc = snprintf(buf, n, "%ju", a->length);
-		ret += 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, "of");
+	return ret + snprintf(buf, n, "returning");
 }
 
 static size_t
@@ -211,17 +140,19 @@ explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
 {
 	size_t ret = 0, rc;
 
-	if (d->type == CDECL_DECL_IDENT)
+	if (d->type == CDECL_DECL_IDENT || d->type == CDECL_DECL_NULL)
 		return 0;
 
 	rc = explain_declarators(buf, n, d->child);
-	ret += advance(&buf, &n, rc);
+	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);
 	}
@@ -229,16 +160,5 @@ explain_declarators(char *buf, size_t n, struct cdecl_declarator *d)
 
 size_t cdecl_explain(char *buf, size_t n, struct cdecl *decl)
 {
-	size_t ret = 0, rc;
-
-	rc = explain_prologue(buf, n, decl->declarators);
-	ret += advance(&buf, &n, rc);
-
-	rc = explain_pre_specs(buf, n, decl->specifiers);
-	ret += advance(&buf, &n, rc);
-
-	rc = explain_declarators(buf, n, decl->declarators);
-	ret += advance(&buf, &n, rc);
-
-	return ret + explain_post_specs(buf, n, decl->specifiers);
+	return explain_decl(buf, n, decl, true);
 }