]> git.draconx.ca Git - cdecl99.git/blobdiff - src/parse-decl.c
Don't allow restrict-qualified pointers to functions.
[cdecl99.git] / src / parse-decl.c
index c210f7cce52981d96d41bfd2eb9511a63955a49f..4489532cdaa1f232862968c47871dafe53431f65 100644 (file)
@@ -1,6 +1,6 @@
 /*
  *  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
@@ -15,6 +15,7 @@
  *  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>
@@ -23,6 +24,8 @@
 #include "typemap.h"
 #include "parse.h"
 #include "scan.h"
+#include "i18n.h"
+#include "normalize.h"
 
 /*
  * Verify the declaration specifiers of a declaration.  If top is true, treat
@@ -33,12 +36,13 @@ 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)) {
@@ -51,6 +55,11 @@ static bool valid_declspecs(struct cdecl *decl, bool top)
                        }
                        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;
@@ -72,6 +81,11 @@ static bool valid_declspecs(struct cdecl *decl, bool top)
                        }
                        break;
                case CDECL_SPEC_FUNC:
+                       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;
@@ -251,6 +265,10 @@ reduce_parentheses(struct cdecl_declarator **p, struct cdecl_declarator *d)
        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)
 {
@@ -265,24 +283,108 @@ check_parameters(struct cdecl_declarator **p, struct cdecl_declarator *d)
                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 (spec->type == CDECL_TYPE_VOID
-                           && param->declarators->type == CDECL_DECL_NULL)
-                               has_void = true;
+                       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;
+                       }
                }
        }
 
-       if (has_void && d->u.function.parameters->next) {
-               fprintf(stderr, "a void parameter must stand alone\n");
+       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;
-       } else if (has_void && d->u.function.variadic) {
-               fprintf(stderr, "variadic functions cannot have a void parameter\n");
+       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
@@ -322,24 +424,101 @@ static bool forall_declarators(struct cdecl *decl,
 
 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, true))
                        goto err;
@@ -347,6 +526,11 @@ struct cdecl *cdecl_parse_decl(const char *declstr)
 
        return decl;
 err:
-       cdecl_free(decl);
+       cdecl__free(decl);
        return NULL;
 }
+
+void cdecl_free(struct cdecl *decl)
+{
+       cdecl__free(decl);
+}