Re: [CIL users] Simplifying --dosimplify, continued (+updated patch)

[Pavel S. <pav...@gm...>]

Thanks, Gabriel! After implementing your suggestions, the patch looks 
much more concise.  Attached.

Using simplification of structs with --no-convert-field offsets yeilds 
an assertion failure ("Cannot find component .foo of bar").  Could it be 
the result of contradiction between splitting structures and attempts to 
keep the structural information instead of relying to a low-level memory 
model?

Assume that the code (the original or an "intermediate" version) looks 
like this.

struct A {int x; int y;};
struct B {struct A a;};
int some_function(struct A *ptr) { return ptr->y; }
int main()
{
       struct B b;
       some_function(&b.a);
}

I do not really understand the intent of split structus, but could it, 
under some circumstances, result in something like this:

in main()
{
       int x_in_a, y_in_a;
       some_function(&x_in_a);
}

The converted some_function then won't have any access to y_in_a, 
because all expressions like ((*int)(&x_in_a) + 4) should not appear in 
the generated code, and there's no other way to reach y_in_a in the 
fixed code.  If such situation may appear with split structures, then 
splitting structures should be suppressed when using --no-convert-field-
offsets, like it is in the patch.

However, I do not really understand in what cases splitting structures 
happens.  Is the situation like the one above feasible?

-- 
Pavel Shved
website: http://coldattic.info/
e-mail: pav...@gm...