(Ada) crash assigning to record component which is an array
Consider the following code, which declares a variabled called "input"
of type "parameter", which is a record with one component called "u2",
where the type of that component is a simple 3-element array of
floating point values:
type Float_Array_3 is array (1 .. 3) of Float;
type parameters is record
u2 : Float_Array_3;
end record;
input : parameters;
Trying to assign a value to input.u2 causes GDB to crash:
Here, lhs_type is a TYPE_CODE_TYPEDEF. ada_is_direct_array_type
knows how to handle it, but TYPE_ARRAY_LOWER_BOUND_VALUE assumes
that the given type is a TYPE_CODE_ARRAY. As such, it ends up
accessing some fields in lhs_type which it shouldn't, and kaboom.
We fixed this issue by making sure that the TYPE_CODE_TYPEDEF
layer gets stripped.
Once this is done, we hit a different kind of error, also leading to
a SEGV, this time in assign_component. The code looks like this:
if (TYPE_CODE (value_type (lhs)) == TYPE_CODE_ARRAY)
[...]
else
[...]
Because once again lhs is a TYPE_CODE_TYPEDEF, the check fail,
and we end up assuming that lhs is a struct, executing the "else"
block, which is: