[Bug c/77531] __attribute__((alloc_size(1,2))) could also warn on multiplication overflow

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77531

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Thu Dec  8 23:50:40 2016
New Revision: 243470

URL: https://gcc.gnu.org/viewcvs?rev=243470&root=gcc&view=rev
Log:
PR c/77531 - __attribute__((alloc_size(1,2))) could also warn on multiplication
overflow
PR c/78284 - warn on malloc with very large arguments

gcc/c-family/ChangeLog:

        PR c/78284
        * c.opt (-Walloc-zero, -Walloc-size-larger-than): New options.

gcc/ChangeLog:

        PR c/78284
        * builtin-attrs.def (ATTR_ALLOC_SIZE, ATTR_RETURNS_NONNULL): New
        identifier tree nodes.
        (ATTR_ALLOCA_SIZE_1_NOTHROW_LEAF_LIST): New attribute list.
        (ATTR_MALLOC_SIZE_1_NOTHROW_LIST): Same.
        (ATTR_MALLOC_SIZE_1_NOTHROW_LEAF_LIST): Same.
        (ATTR_MALLOC_SIZE_1_2_NOTHROW_LEAF_LIST): Same.
        (ATTR_ALLOC_SIZE_2_NOTHROW_LEAF_LIST): Same.
        * builtins.c (expand_builtin_alloca): Call
        maybe_warn_alloc_args_overflow.
        * builtins.def (aligned_alloc, calloc, malloc, realloc):
        Add attribute alloc_size.
        (alloca): Add attribute alloc_size and returns_nonnull.
        * calls.h (maybe_warn_alloc_args_overflow): Declare.
        * calls.c (alloc_max_size, operand_signed_p): New functions.
        (maybe_warn_alloc_args_overflow): Define.
        (initialize_argument_information): Diagnose overflow in functions
        declared with attaribute alloc_size.
        * doc/invoke.texi (Warning Options): Document -Walloc-zero and
        -Walloc-size-larger-than.

gcc/testsuite/ChangeLog:

        PR c/78284
        * gcc.dg/attr-alloc_size-3.c: New test.
        * gcc.dg/attr-alloc_size-4.c: New test.
        * gcc.dg/attr-alloc_size-5.c: New test.
        * gcc.dg/attr-alloc_size-6.c: New test.
        * gcc.dg/attr-alloc_size-7.c: New test.
        * gcc.dg/attr-alloc_size-8.c: New test.
        * gcc.dg/attr-alloc_size-9.c: New test.
        * gcc/testsuite/gcc.dg/errno-1.c: Adjust.


Added:
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-3.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-4.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-5.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-6.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-7.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-8.c
    trunk/gcc/testsuite/gcc.dg/attr-alloc_size-9.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c.opt
    trunk/gcc/calls.c
    trunk/gcc/calls.h
    trunk/gcc/doc/invoke.texi
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/errno-1.c