GCC Bugzilla Bug 25802

GCC doesn't diagnose function-scope VM declarations of variables with external
or internal linkage.  (VM declarations of function-local statics are OK.)  Four
tests (all should be rejected unconditionally, none are even with -std=c99
-pedantic-errors):

extern int (*a)[];
void f(int b) { extern int (*a)[b]; }

static int (*a)[];
void f(int b) { extern int (*a)[b]; }

extern int (*a)[];
void f(int b) { typedef int (*T)[b]; extern T a; }

static int (*a)[];
void f(int b) { typedef int (*T)[b]; extern T a; }

Confirmed.

I have a fix for this, will post.

Subject: Bug 25802

Author: mrs
Date: Thu May 18 18:22:12 2006
New Revision: 113888

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=113888
Log:
        Fix up vla, vm and [*] sematics.

        PR c/18740
        PR c/7948
        PR c/25802
        * c-tree.h (struct c_arg_info): Add had_vla_unspec.
        (c_vla_unspec_p): Add.
        (c_vla_type_p): Add.
        * c-decl.c (struct c_scope): Add had_vla_unspec.
        (build_array_declarator): Add support for [*].
        (grokdeclarator): Likewise.
        (grokparms): Likewise.
        (get_parm_info): Likewise.
        * c-objc-common.c (c_vla_unspec_p): Likewise.
        * c-objc-common.h (LANG_HOOKS_TREE_INLINING_VAR_MOD_TYPE_P): Likewise.
        * c-parser.c (c_parser_typeof_specifier): Evaluate arguments to
        typeof when argument is a variably modified type not inside sizeof or
alignof.
        (c_parser_direct_declarator_inner): Propagate errors.
        (c_parser_sizeof_expression): Add support for [*].
        * c-typeck.c (c_vla_type_p): Add.
        (composite_type): Add support for vla compositing.
        (comptypes_internal): Add support for vla compatibility.
        (c_expr_sizeof_expr): Evaluate vla arguments.
        * tree.c (variably_modified_type_p): Update comment for [*].

testsuite:
        * gcc.dg/c90-arraydecl-1.c: Update for vla, vm [*] fixups.
        * gcc.dg/vla-4.c: Add.
        * gcc.dg/vla-5.c: Add.
        * gcc.dg/vla-6.c: Add.

Added:
    trunk/gcc/testsuite/gcc.dg/vla-4.c
    trunk/gcc/testsuite/gcc.dg/vla-5.c
    trunk/gcc/testsuite/gcc.dg/vla-6.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-decl.c
    trunk/gcc/c-objc-common.c
    trunk/gcc/c-objc-common.h
    trunk/gcc/c-parser.c
    trunk/gcc/c-tree.h
    trunk/gcc/c-typeck.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/c90-arraydecl-1.c
    trunk/gcc/tree.c

aka radr://4336222

Fixed for 4.2.

*** Bug 29126 has been marked as a duplicate of this bug. ***