[Bug jit/95296] New: Segfault when trying to return a void value

[Bug jit/95296] New: Segfault when trying to return a void value

[bouanto at zoho dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95296

            Bug ID: 95296
           Summary: Segfault when trying to return a void value
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: jit
          Assignee: dmalcolm at gcc dot gnu.org
          Reporter: bouanto at zoho dot com
  Target Milestone: ---

Created attachment 48589
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48589&action=edit
Complete example reproducing the segfault

Hi.

When trying to return a void value this way, this makes the code segfault:

    gcc_jit_type *void_type = gcc_jit_context_get_type (ctxt,
GCC_JIT_TYPE_VOID);
    gcc_jit_lvalue *return_value = gcc_jit_function_new_local(func, NULL,
void_type, "void");
    gcc_jit_block_end_with_return (block, NULL,
gcc_jit_lvalue_as_rvalue(return_value));

Could you please fix it so that it shows an error instead of segfaulting?
Thanks.

[Bug jit/95296] Segfault when trying to return a void value

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95296

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-05-24
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Thanks for filing this.

It looks like calls to (at least):
  gcc_jit_function_new_local
  gcc_jit_context_new_global
should gracefully fail with an error if the client code attempts to create a
variable of void type.

Similarly we may need additional checking throughout for uses of rvalues of
void type (but I need to check this).

[Bug jit/95296] Segfault when trying to return a void value

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95296

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Malcolm <dmalcolm@gcc.gnu.org>:

https://gcc.gnu.org/g:6f7585deedc140667fd496b48c9fc4f7d625605c

commit r11-636-g6f7585deedc140667fd496b48c9fc4f7d625605c
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Sun May 24 18:36:36 2020 -0400

    jit: check for void types [PR 95296]

    PR jit/95296 reports an ICE when using libgccjit to create a local of void
    type.

    This patch adds checking to various API entrypoints in libgccjit.c so that
    they fail gracefully with an error if the client code attempts to create
    various kinds of rvalues or types involving void types.
    The patch documents these and various pre-existing restrictions on types
    in the API.

    gcc/jit/ChangeLog:
            PR jit/95296
            * docs/topics/expressions.rst (Unary Operations): Document that
            result_type of gcc_jit_context_new_unary_op must be a numeric type.
            (Binary Operations): Likewise for gcc_jit_context_new_binary_op.
            (Global variables): Document that "type" of
            gcc_jit_context_new_global must be non-`void`.
            * docs/topics/function-pointers.rst
            (gcc_jit_context_new_function_ptr_type): Document that the
            param_types must be non-void, but that return_type may be.
            * docs/topics/functions.rst (Params): Document that
            gcc_jit_context_new_param's type must be non-void.
            (Functions): Likewise for gcc_jit_function_new_local.
            * docs/topics/types.rst (gcc_jit_context_new_array_type): Document
            that the type must be non-void.
            (gcc_jit_context_new_field): Likewise.
            * docs/_build/texinfo/Makefile: Regenerate.
            * docs/_build/texinfo/libgccjit.texi: Regenerate.
            * libgccjit.c (gcc_jit_context_new_array_type): Fail if
            element_type is void.
            (gcc_jit_context_new_field): Likewise for "type".
            (gcc_jit_context_new_function_ptr_type): Likewise for each
            element of param_types.
            (gcc_jit_context_new_param): Likewise for "type".
            (gcc_jit_context_new_global): Likewise.
            (gcc_jit_function_new_local): Likewise.
            (gcc_jit_type_get_aligned): Likewise.

    gcc/testsuite/ChangeLog:
            PR jit/95296
            * jit.dg/test-error-gcc_jit_context_new_global-void-type.c: New
            test.
            * jit.dg/test-error-gcc_jit_function_new_local-void-type.c: New
            test.
            * jit.dg/test-fuzzer.c (fuzzer_init): Allow for make_random_type
            to return NULL.
            (get_random_type): Allow for elements in f->types to be NULL.

[Bug jit/95296] Segfault when trying to return a void value

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95296

David Malcolm <dmalcolm at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Should be fixed by the above commit.