/*
- * Parse and validate C declarations.
- * Copyright © 2011 Nick Bowler
+ * Parse and validate C declarations.
+ * Copyright © 2011-2012, 2020-2021, 2023 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 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.
+ * 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/>.
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
+
+#include <config.h>
#include <stdio.h>
#include <assert.h>
#include <stdbool.h>
#include "cdecl.h"
-#include "typemap.h"
+#include "cdecl-internal.h"
#include "parse.h"
#include "scan.h"
+#include "errmsg.h"
+
+/*
+ * We can represent type specifiers as a bitmap, which gives us a finite
+ * list of acceptable bitmap values according to the C standard. However,
+ * the "long" specifier is allowed to occur more than once, but only at most
+ * 2 times. Treat it as a special case, assigning an unused bit to represent
+ * the second long.
+ */
+#define MAP_LLONG_BIT 31
+#define MAP_LONG_BIT (CDECL_TYPE_LONG-CDECL_SPEC_TYPE)
+#define CDECL_TYPE_LLONG (CDECL_SPEC_TYPE+MAP_LLONG_BIT)
+
+#include "typemap.h"
/*
- * Verify the declaration specifiers of a declaration.
+ * Convert the declaration specifiers to a bitmap with each bit
+ * corresponding to one specific type specifier.
*/
-static bool valid_declspecs(struct cdecl *decl)
+static int valid_typespec(struct cdecl_declspec *s)
+{
+ unsigned long map = 0;
+
+ for (struct cdecl_declspec *c = s; c; c = c->next) {
+ unsigned long bit;
+
+ if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
+ continue;
+
+ bit = c->type - CDECL_SPEC_TYPE;
+ assert(bit < MAP_LLONG_BIT);
+ bit = 1ul << bit;
+
+ /* "long" special case */
+ if ((map & bit) == 1ul << MAP_LONG_BIT)
+ bit = 1ul << MAP_LLONG_BIT;
+
+ if (map & bit) {
+ if (bit == 1ul << MAP_LLONG_BIT)
+ cdecl__errmsg(CDECL__ETOOLONG);
+ else
+ cdecl__errmsg(CDECL__EDUPTYPE);
+ return false;
+ }
+ map |= bit;
+ }
+
+ if (typemap_is_valid(map))
+ return true;
+
+ if (map == 0)
+ cdecl__errmsg(CDECL__ENOTYPE);
+ else
+ cdecl__errmsg(CDECL__EBADTYPE);
+
+ return false;
+}
+
+/*
+ * Verify the declaration specifiers of a declaration. If top is true, treat
+ * this as a top-level declaration. Otherwise, treat this as a function
+ * parameter (which carries additional constraints).
+ */
+static bool valid_declspecs(struct cdecl *decl, bool top)
{
struct cdecl_declspec *specs = decl->specifiers;
struct cdecl_declarator *d = decl->declarators;
+ bool abstract = cdecl_is_abstract(d);
unsigned num_storage = 0;
- unsigned long typemap;
- typemap = cdecl__build_typemap(specs);
- if (typemap == -1)
- return -1;
+ if (!valid_typespec(specs))
+ return false;
for (struct cdecl_declspec *c = specs; c; c = c->next) {
switch (cdecl_spec_kind(c)) {
if (c->type == CDECL_TYPE_VOID &&
(d->type == CDECL_DECL_IDENT
|| d->type == CDECL_DECL_ARRAY)) {
- fprintf(stderr, "invalid declaration of type void\n");
+ cdecl__errmsg(CDECL__EBADVOID);
return false;
}
continue;
case CDECL_SPEC_STOR:
+ if (top && abstract) {
+ cdecl__errmsg(CDECL__ETYPESTOR);
+ return false;
+ }
+
+ if (!top && c->type != CDECL_STOR_REGISTER) {
+ cdecl__errmsg(CDECL__EFUNCSTOR);
+ return false;
+ }
+
if (++num_storage > 1) {
- fprintf(stderr, "too many storage-class specifiers\n");
+ cdecl__errmsg(CDECL__EMANYSTOR);
return false;
}
break;
* pointer qualifier list, which isn't checked here.
*/
if (c->type == CDECL_QUAL_RESTRICT) {
- fprintf(stderr, "only pointer types can be restrict-qualified.\n");
+ cdecl__errmsg(CDECL__EBADQUAL);
return false;
}
break;
case CDECL_SPEC_FUNC:
- /*
- * We don't support functions yet.
- */
- fprintf(stderr, "only function declarations may have function specifiers.\n");
- return false;
+ if (abstract || !top || d->type != CDECL_DECL_FUNCTION) {
+ cdecl__errmsg(CDECL__ENOTFUNC);
+ return false;
+ }
+
+ break;
default:
assert(0);
}
* if a declarator could be interpreted as something other than a function,
* do that.
*
- * - The function declarator has a null child declarator.
- * - The function declarator has exactly one parameter, and is not variadic.
- * - The function parameter has a type specifier, and it is a typedef name.
- * - The function parameter has no other declaration specifiers.
- * - The function parameter does not declare an identifier.
- *
* Since cdecl99 supports things like [*] in any context (in C, such constructs
* are only valid in function parameter lists), we don't treat them specially
* here.
return false; /* e.g. int (int) */
if (d->u.function.parameters->specifiers->next)
return false; /* e.g. int (size_t const) */
+ if (d->u.function.parameters->declarators->type == CDECL_DECL_POINTER)
+ return false; /* e.g. int (x *) */
return true;
}
free(d->child);
free(d);
- return 1;
+ return 0;
}
/*
* simplify_functions pass.
*/
-static int
-reduce_parentheses(struct cdecl_declarator **p, struct cdecl_declarator *d)
+static struct cdecl *fake_function_param(struct cdecl_declarator *d)
{
struct cdecl *param;
if (d->type != CDECL_DECL_FUNCTION)
- return 0;
+ return NULL;
param = d->u.function.parameters;
- if (param && param->specifiers == NULL) {
- struct cdecl_declarator *decl;
+ if (!param || param->specifiers)
+ return NULL;
- assert(!param->next);
+ assert(!param->next);
+ return param;
+}
- decl = param->declarators;
- if (decl->type == CDECL_DECL_NULL) {
- free(decl);
- free(param);
- d->u.function.parameters = NULL;
- return 0;
+static int
+reduce_parentheses(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl *param;
+ int fake = 0;
+
+ while ((param = fake_function_param(d))) {
+ struct cdecl_declarator *decl = param->declarators;
+ d->u.function.parameters = NULL;
+
+ if (decl->type != CDECL_DECL_NULL) {
+ if (d->child->type != CDECL_DECL_NULL) {
+ /* Found fake parameter on real function. */
+ d->u.function.parameters = param;
+ cdecl__errmsg(CDECL__EBADPARAM);
+ return -1;
+ }
+
+ param->declarators = d;
+ *p = d = decl;
+ fake = 1;
}
- if (d->child->type != CDECL_DECL_NULL) {
- fprintf(stderr, "invalid function parameter\n");
+ cdecl__free(param);
+ }
+
+ simplify_functions(p, d);
+ if (fake && (*p)->type == CDECL_DECL_FUNCTION) {
+ /* Started with a fake function but ended with a real one. */
+ cdecl__errmsg(CDECL__EMANYPAREN);
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Returns nonzero iff the given specifier list contains a specifier
+ * of the indicated type.
+ */
+static int have_specifier(struct cdecl_declspec *s, unsigned type)
+{
+ for (; s; s = s->next)
+ if (s->type == type)
+ return 1;
+ return 0;
+}
+
+/*
+ * Check syntax restrictions on a function declarator's child declarator.
+ * That is, "pointer to function", "array of function" and "function
+ * returning function".
+ *
+ * Returns -1 if the declaration is invalid, or 0 otherwise.
+ */
+static int check_function_child(struct cdecl_declarator *d)
+{
+ struct cdecl_pointer *ptr;
+
+ switch (d->type) {
+ case CDECL_DECL_POINTER:
+ ptr = &d->u.pointer;
+ if (have_specifier(ptr->qualifiers, CDECL_QUAL_RESTRICT)) {
+ /* pointer to function cannot be restrict qualified. */
+ cdecl__errmsg(CDECL__ERESTRICTFUNC);
return -1;
}
+ return 0;
+ case CDECL_DECL_FUNCTION:
+ /* function returning function is never allowed. */
+ cdecl__errmsg(CDECL__ERETFUNC);
+ return -1;
+ case CDECL_DECL_ARRAY:
+ /* array of function is never allowed. */
+ cdecl__errmsg(CDECL__EFUNCARRAY);
+ return -1;
+ }
- free(d->child);
- free(param);
- free(d);
- *p = decl;
+ return 0;
+}
- /*
- * We may have replaced d with another fake function which
- * also needs to be eliminated.
- */
- if (reduce_parentheses(p, decl) < 0)
- return -1;
+/*
+ * Check a function parameter declaration for validity, which means it has a
+ * valid combination of declaration specifiers and, if it is a void parameter,
+ * that it is the one special case where this is allowed.
+ *
+ * Returns -1 if the declaration is invalid, or 0 otherwise.
+ */
+static int check_function_param(struct cdecl_function *f, struct cdecl *param)
+{
+ if (!valid_declspecs(param, false))
+ return -1;
+
+ /* Check for "void" function parameters as a special case. */
+ if (param->declarators->type == CDECL_DECL_NULL
+ && have_specifier(param->specifiers, CDECL_TYPE_VOID))
+ {
+ struct cdecl *fp = f->parameters;
- /*
- * If the remaining declarator is a function, make sure it's
- * valid by checking its reducibility.
- */
- decl = *p;
- if (decl->type == CDECL_DECL_FUNCTION
- && decl->child->type == CDECL_DECL_NULL
- && !function_is_reducible(decl)) {
- fprintf(stderr, "too many parentheses in function\n");
+ if (f->variadic || fp->next || fp->specifiers->next) {
+ cdecl__errmsg(CDECL__EVOIDPARAM);
return -1;
}
+ }
+
+ return 0;
+}
+
+/*
+ * Normalize the specifier lists for function parameters, and then check the
+ * function declarator for validity.
+ *
+ * Returns -1 if the declaration is invalid, or 0 otherwise.
+ */
+static int postproc_function(struct cdecl_declarator *d)
+{
+ struct cdecl_function *func = &d->u.function;
+ struct cdecl *param;
+ int rc;
+
+ for (param = func->parameters; param; param = param->next) {
+ param->specifiers = cdecl__normalize_specs(param->specifiers);
- return 1;
+ if ((rc = check_function_param(func, param)) < 0)
+ return rc;
+ }
+
+ return check_function_child(d->child);
+}
+
+static int
+postproc_common(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl_pointer *ptr;
+
+ switch (d->type) {
+ case CDECL_DECL_POINTER:
+ ptr = &d->u.pointer;
+ ptr->qualifiers = cdecl__normalize_specs(ptr->qualifiers);
+ return 0;
+ case CDECL_DECL_FUNCTION:
+ return postproc_function(d);
+ case CDECL_DECL_ARRAY:
+ if (d->child && d->child->type == CDECL_DECL_FUNCTION) {
+ /* function returning array is never allowed. */
+ cdecl__errmsg(CDECL__ERETARRAY);
+ return -1;
+ }
+ return 0;
}
return 0;
* depth-first preorder traversal. The function is given a pointer to the
* declarator as well as to the pointer which was used to reach that
* declarator: this can be used to rewrite entire subtrees.
+ *
+ * The called function may return a negative value to indicate an error
+ * which terminates traversal.
+ *
+ * Returns 0 on success, or a negative value on failure.
*/
-static bool forall_declarators(struct cdecl *decl,
+static int forall_declarators(struct cdecl *decl,
int f(struct cdecl_declarator **, struct cdecl_declarator *))
{
struct cdecl_declarator *d, **p;
- for (p = &decl->declarators, d = *p; d; p = &d->child, d = *p) {
- switch (f(p, d)) {
- case 0:
- break;
- case 1:
- d = *p;
- break;
- case -1:
- return false;
- default:
- assert(0);
- }
+ for (p = &decl->declarators; *p; p = &d->child) {
+ int rc;
+
+ rc = f(p, *p);
+ if (rc < 0)
+ return rc;
+ d = *p;
if (d->type == CDECL_DECL_FUNCTION) {
struct cdecl *i;
for (i = d->u.function.parameters; i; i = i->next) {
- if (!forall_declarators(i, f))
- return false;
+ rc = forall_declarators(i, f);
+ if (rc < 0)
+ return rc;
}
}
}
- return true;
+ return 0;
}
-struct cdecl *cdecl_parse_decl(const char *declstr)
+static struct cdecl *do_parse(const char *str, int english_mode)
{
YY_BUFFER_STATE state;
+ yyscan_t scanner;
struct cdecl *decl;
- int rc;
- state = yy_scan_string(declstr);
- rc = yyparse(&decl);
- yy_delete_buffer(state);
+#if YYDEBUG
+ extern int cdecl__yydebug;
+ cdecl__yydebug = 1;
+#endif
- if (rc != 0)
+ cdecl__init_i18n();
+ if (cdecl__yylex_init_extra(english_mode, &scanner) != 0)
return NULL;
- for (struct cdecl *i = decl; i; i = i->next) {
- if (!forall_declarators(i, reduce_parentheses))
- goto err;
- if (!forall_declarators(i, simplify_functions))
- goto err;
+ state = cdecl__yy_scan_string(str, scanner);
+ if (cdecl__yyparse(scanner, &decl) != 0)
+ decl = NULL;
+ cdecl__yy_delete_buffer(state, scanner);
+ cdecl__yylex_destroy(scanner);
+
+ return decl;
+}
+
+static int do_postprocess(struct cdecl *decl, int english_mode)
+{
+ struct cdecl_declspec *norm_specs;
+ struct cdecl *i;
+
+ /*
+ * For a C declaration with more than one full declarator, the
+ * specifier list is common to all of them. Normalize it once,
+ * then propagate that to all the linked cdecl structures.
+ *
+ * In english mode, the cdecl structure list always has exactly
+ * one entry so we don't need to do anything differently.
+ */
+ norm_specs = cdecl__normalize_specs(decl->specifiers);
+ for (i = decl; i; i = i->next)
+ i->specifiers = norm_specs;
+
+ for (i = decl; i; i = i->next) {
+ if (!english_mode) {
+ if (forall_declarators(i, reduce_parentheses) < 0)
+ return 0;
+ }
+
+ if (forall_declarators(i, postproc_common) < 0)
+ return 0;
+
+ if (!valid_declspecs(i, true))
+ return 0;
+
+ if (decl->next && cdecl_is_abstract(i->declarators)) {
+ /* Abstract full declarators: there can only be one. */
+ cdecl__errmsg(CDECL__EDECLTYPE);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+static struct cdecl *parse_common(const char *str, int english_mode)
+{
+ struct cdecl *decl;
+
+ if (!(decl = do_parse(str, english_mode)))
+ return NULL;
- if (!valid_declspecs(i))
- goto err;
+ if (!do_postprocess(decl, english_mode)) {
+ cdecl__free(decl);
+ return NULL;
}
return decl;
-err:
- cdecl_free(decl);
- return NULL;
+}
+
+struct cdecl *cdecl_parse_decl(const char *declstr)
+{
+ return parse_common(declstr, false);
+}
+
+struct cdecl *cdecl_parse_english(const char *english)
+{
+ return parse_common(english, true);
+}
+
+void cdecl_free(struct cdecl *decl)
+{
+ cdecl__free(decl);
}
projects / cdecl99.git / blobdiff