/*
* Parse and validate C declarations.
- * Copyright © 2011 Nick Bowler
+ * Copyright © 2011-2012 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 <assert.h>
#include <stdbool.h>
#include "typemap.h"
#include "parse.h"
#include "scan.h"
+#include "i18n.h"
+#include "normalize.h"
/*
- * Verify the declaration specifiers of a declaration.
+ * 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)
+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;
+ return false;
for (struct cdecl_declspec *c = specs; c; c = c->next) {
switch (cdecl_spec_kind(c)) {
}
continue;
case CDECL_SPEC_STOR:
+ if (top && abstract) {
+ fprintf(stderr, "type names cannot have storage-class specifiers\n");
+ return false;
+ }
+
+ if (!top && c->type != CDECL_STOR_REGISTER) {
+ fprintf(stderr, "function parameters may only have register storage\n");
+ return false;
+ }
+
if (++num_storage > 1) {
fprintf(stderr, "too many storage-class specifiers\n");
return false;
}
break;
case CDECL_SPEC_FUNC:
- if (d->type != CDECL_DECL_FUNCTION) {
+ if (abstract) {
+ fprintf(stderr, "type names cannot have function specifiers\n");
+ return false;
+ }
+
+ if (!top || d->type != CDECL_DECL_FUNCTION) {
fprintf(stderr, "only function declarations may have function specifiers.\n");
return false;
}
return 0;
}
+/*
+ * Function parameters and return types have a few restrictions that are
+ * really easy to check in comparison to the above absurdity.
+ */
+static int
+check_parameters(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl_declspec *spec;
+ struct cdecl *param;
+ bool has_void = false;
+
+ if (d->type != CDECL_DECL_FUNCTION)
+ return 0;
+
+ for (param = d->u.function.parameters; param; param = param->next) {
+ if (!valid_declspecs(param, false))
+ return -1;
+
+ /* Check for "void" function parameters as a special case. */
+ for (spec = param->specifiers; spec; spec = spec->next) {
+ if (param->declarators->type != CDECL_DECL_NULL)
+ continue;
+ if (spec->type != CDECL_TYPE_VOID)
+ continue;
+
+ if (spec != param->specifiers || spec->next != NULL) {
+ fprintf(stderr, "void parameter must not have extra specifiers\n");
+ return -1;
+ } else if (d->u.function.parameters->next) {
+ fprintf(stderr, "a void parameter must stand alone\n");
+ return -1;
+ } else if (d->u.function.variadic) {
+ fprintf(stderr, "variadic functions cannot have a void parameter\n");
+ return -1;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Functions cannot return arrays or functions. Since the parse tree is
+ * "inside-out", we need to look for functions as the child declarator.
+ */
+static int
+check_rettypes(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ if (!d->child || d->child->type != CDECL_DECL_FUNCTION)
+ return 0;
+
+ switch (d->type) {
+ case CDECL_DECL_FUNCTION:
+ fprintf(stderr, "functions cannot return functions\n");
+ return -1;
+ case CDECL_DECL_ARRAY:
+ fprintf(stderr, "functions cannot return arrays\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int
+check_arrays(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ if (!d->child || d->child->type != CDECL_DECL_ARRAY)
+ return 0;
+
+ switch (d->type) {
+ case CDECL_DECL_FUNCTION:
+ fprintf(stderr, "array members cannot be functions\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int
+normalize_specs(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl_function *func;
+ struct cdecl_pointer *ptr;
+
+ switch (d->type) {
+ case CDECL_DECL_POINTER:
+ ptr = &d->u.pointer;
+ ptr->qualifiers = cdecl__normalize_specs(ptr->qualifiers);
+ break;
+ case CDECL_DECL_FUNCTION:
+ func = &d->u.function;
+ for (struct cdecl *i = func->parameters; i; i = i->next)
+ i->specifiers = cdecl__normalize_specs(i->specifiers);
+ break;
+ }
+
+ return 0;
+}
+
+static int
+check_qualifiers(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl_declspec *spec;
+ struct cdecl_pointer *ptr;
+
+ if (!d->child || d->child->type != CDECL_DECL_POINTER)
+ return 0;
+
+ ptr = &d->child->u.pointer;
+ for (spec = ptr->qualifiers; spec; spec = spec->next) {
+ if (spec->type == CDECL_QUAL_RESTRICT
+ && d->type == CDECL_DECL_FUNCTION) {
+ fprintf(stderr, "function pointers cannot be restrict-qualified\n");
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
/*
* Traverse the parse tree, calling a function on every declarator in a
* depth-first preorder traversal. The function is given a pointer to the
struct cdecl *cdecl_parse_decl(const char *declstr)
{
+ struct cdecl_declspec *norm_specs;
YY_BUFFER_STATE state;
+ yyscan_t scanner;
struct cdecl *decl;
int rc;
- state = yy_scan_string(declstr);
- rc = yyparse(&decl);
- yy_delete_buffer(state);
+ cdecl__init_i18n();
+ rc = cdecl__yylex_init(&scanner);
if (rc != 0)
return NULL;
+ state = cdecl__yy_scan_string(declstr, scanner);
+ rc = cdecl__yyparse(scanner, &decl);
+ cdecl__yy_delete_buffer(state, scanner);
+ cdecl__yylex_destroy(scanner);
+
+ if (rc != 0)
+ return NULL;
+
+ /*
+ * Since the top-level specifiers are shared between each top-level
+ * declarator, we need to normalize them once and then propagate the
+ * new specifier list.
+ */
+ norm_specs = cdecl__normalize_specs(decl->specifiers);
+
for (struct cdecl *i = decl; i; i = i->next) {
+ i->specifiers = norm_specs;
+
if (!forall_declarators(i, reduce_parentheses))
goto err;
if (!forall_declarators(i, simplify_functions))
goto err;
+ if (!forall_declarators(i, check_parameters))
+ goto err;
+ if (!forall_declarators(i, check_rettypes))
+ goto err;
+ if (!forall_declarators(i, check_arrays))
+ goto err;
+ if (!forall_declarators(i, normalize_specs))
+ goto err;
+ if (!forall_declarators(i, check_qualifiers))
+ goto err;
+
+ if (!valid_declspecs(i, true))
+ goto err;
+
+ if (cdecl_is_abstract(i->declarators)
+ && (i != decl || i->next)) {
+ fprintf(stderr, "mixing type names and declarations is not allowed\n");
+ goto err;
+ }
+ }
+
+ return decl;
+err:
+ cdecl__free(decl);
+ return NULL;
+}
+
+struct cdecl *cdecl_parse_english(const char *english)
+{
+ YY_BUFFER_STATE state;
+ yyscan_t scanner;
+ struct cdecl *decl;
+ int rc;
+
+ cdecl__init_i18n();
+
+ rc = cdecl__yylex_init_extra(true, &scanner);
+ if (rc != 0)
+ return NULL;
+
+ state = cdecl__yy_scan_string(english, scanner);
+ rc = cdecl__yyparse(scanner, &decl);
+ cdecl__yy_delete_buffer(state, scanner);
+ cdecl__yylex_destroy(scanner);
+
+ if (rc != 0)
+ return NULL;
+
+ for (struct cdecl *i = decl; i; i = i->next) {
+ i->specifiers = cdecl__normalize_specs(i->specifiers);
+
+ if (!forall_declarators(i, check_parameters))
+ goto err;
+ if (!forall_declarators(i, check_rettypes))
+ goto err;
+ if (!forall_declarators(i, check_arrays))
+ goto err;
+ if (!forall_declarators(i, normalize_specs))
+ goto err;
+ if (!forall_declarators(i, check_qualifiers))
+ goto err;
- if (!valid_declspecs(i))
+ if (!valid_declspecs(i, true))
goto err;
}
return decl;
err:
- cdecl_free(decl);
+ cdecl__free(decl);
return NULL;
}
+
+void cdecl_free(struct cdecl *decl)
+{
+ cdecl__free(decl);
+}
projects / cdecl99.git / blobdiff