[PATCH] D15097: [Sema] Issue a warning for integer overflow in struct initializer

[Akira Hatanaka via cfe-commits]

ping

On Mon, Nov 30, 2015 at 4:30 PM, Akira Hatanaka <ahatanak at gmail.com> wrote:

> ahatanak created this revision.
> ahatanak added a subscriber: cfe-commits.
>
> Issue a warning if an initializing integer expression overflows.
>
> For example, clang should issue a warning when compiling the following
> code because 4 * 1024 * 1024 * 1024 doesn't fit into a 32-bit integer:
>
> struct s {
> unsigned x;
> } s = {
>  .x = 4 * 1024 * 1024 * 1024
> };
>
> http://reviews.llvm.org/D15097
>
> Files:
>   lib/Sema/SemaChecking.cpp
>   test/Sema/integer-overflow.c
>
> Index: test/Sema/integer-overflow.c
> ===================================================================
> --- test/Sema/integer-overflow.c
> +++ test/Sema/integer-overflow.c
> @@ -145,3 +145,11 @@
>  // expected-warning at +1 2{{overflow in expression; result is 536870912
> with type 'int'}}
>    return ((4608 * 1024 * 1024) + ((uint64_t)(4608 * 1024 * 1024)));
>  }
> +
> +struct s {
> +  unsigned x;
> +  unsigned y;
> +} s = {
> +  .y = 5,
> +  .x = 4 * 1024 * 1024 * 1024  // expected-warning {{overflow in
> expression; result is 0 with type 'int'}}
> +};
> Index: lib/Sema/SemaChecking.cpp
> ===================================================================
> --- lib/Sema/SemaChecking.cpp
> +++ lib/Sema/SemaChecking.cpp
> @@ -7817,6 +7817,10 @@
>  void Sema::CheckForIntOverflow (Expr *E) {
>    if (isa<BinaryOperator>(E->IgnoreParenCasts()))
>      E->IgnoreParenCasts()->EvaluateForOverflow(Context);
> +  else if (auto InitList = dyn_cast<InitListExpr>(E))
> +    for (Expr *E : InitList->inits())
> +      if (isa<BinaryOperator>(E->IgnoreParenCasts()))
> +        E->IgnoreParenCasts()->EvaluateForOverflow(Context);
>  }
>
>  namespace {
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20151214/522add88/attachment-0001.html>