On Mon, Aug 17, 2015 at 8:01 PM, Marek Polacek <pola...@redhat.com> wrote:
> Here we were crashing on an invalid call to posix_memalign. The code in
> lower_builtin_posix_memalign assumed that the call had valid arguments.
> The reason the C FE doesn't reject this code is, in short, that
> int <T> () is compatible with int <T> (void **, size_t, size_t) and we
> use the former -- so convert_arguments doesn't complain.
>
> So I think let's validate the arguments in lower_stmt. I decided to
> give an error if we see an invalid usage of posix_memalign, since
> other code (e.g. alias machinery) assumes correct arguments as well.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
I don't think you can give errors here. Note that the "appropriate"
way to do the check is to simply use
if (gimple_builtin_call_types_compatible_p (stmt, decl))
not lowering in case it's not compatible is ok.
Thanks,
Richard.
> 2015-08-17 Marek Polacek <pola...@redhat.com>
>
> PR middle-end/67222
> * gimple-low.c: Include "builtins.h".
> (lower_stmt): Validate arguments of posix_memalign.
>
> * gcc.dg/torture/pr67222.c: New test.
>
> diff --git gcc/gimple-low.c gcc/gimple-low.c
> index d4697e2..03194f0 100644
> --- gcc/gimple-low.c
> +++ gcc/gimple-low.c
> @@ -39,6 +39,7 @@ along with GCC; see the file COPYING3. If not see
> #include "langhooks.h"
> #include "gimple-low.h"
> #include "tree-nested.h"
> +#include "builtins.h"
>
> /* The differences between High GIMPLE and Low GIMPLE are the
> following:
> @@ -345,10 +346,22 @@ lower_stmt (gimple_stmt_iterator *gsi, struct
> lower_data *data)
> data->cannot_fallthru = false;
> return;
> }
> - else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN
> - && flag_tree_bit_ccp)
> + else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN)
> {
> - lower_builtin_posix_memalign (gsi);
> + if (gimple_call_num_args (stmt) != 3
> + || !validate_gimple_arglist (dyn_cast <gcall *> (stmt),
> + POINTER_TYPE, INTEGER_TYPE,
> + INTEGER_TYPE, VOID_TYPE))
> + {
> + error_at (gimple_location (stmt), "invalid arguments "
> + "to %qD", decl);
> + gsi_next (gsi);
> + return;
> + }
> + if (flag_tree_bit_ccp)
> + lower_builtin_posix_memalign (gsi);
> + else
> + gsi_next (gsi);
> return;
> }
> }
> diff --git gcc/testsuite/gcc.dg/torture/pr67222.c
> gcc/testsuite/gcc.dg/torture/pr67222.c
> index e69de29..cf39aa1 100644
> --- gcc/testsuite/gcc.dg/torture/pr67222.c
> +++ gcc/testsuite/gcc.dg/torture/pr67222.c
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wno-implicit-function-declaration" } */
> +
> +void
> +foo (void **p)
> +{
> + posix_memalign (); /* { dg-error "invalid arguments" } */
> + posix_memalign (p); /* { dg-error "invalid arguments" } */
> + posix_memalign (0); /* { dg-error "invalid arguments" } */
> + posix_memalign (p, 1); /* { dg-error "invalid arguments" } */
> + posix_memalign (p, "foo"); /* { dg-error "invalid arguments" } */
> + posix_memalign ("gnu", "gcc"); /* { dg-error "invalid arguments" } */
> + posix_memalign (1, p); /* { dg-error "invalid arguments" } */
> + posix_memalign (1, 2); /* { dg-error "invalid arguments" } */
> + posix_memalign (1, 2, 3); /* { dg-error "invalid arguments" } */
> + posix_memalign (p, p, p); /* { dg-error "invalid arguments" } */
> + posix_memalign (p, "qui", 3); /* { dg-error "invalid arguments" } */
> + posix_memalign (p, 1, 2);
> +}
>
> Marek
