[Backend] Fix C-like printing

[NeoQuix]

Proposal

With the new ArrayType and the refactor of GlobalVariable the C-like code generation does not work as expected.
Therefore:

• fix casting to arrays (there is no cast into an array in C)
• fix pointer to an array into an explicit array pointer (see example below)
• fix printing of array elements (e.g. jump tables etc.) => maybe add a config option
• add new tests

To understand C arrays a bit better look at the following examples:

C arrays are used with a lot of syntax sugar.
All of these calls are equivalent, but are represented differently in assembly.

char a[] = "Some string";

char* b = "Some other string";

char c[] = "Some other other string";
char* d = c;
...
puts(a);
puts(b);
puts(c);
puts(d);

a/c will be real arrays (e.g. bytes in memory, and puts will load the address via lea), and b/d will be pointers to arrays in memory (e.g. puts will load the value of the pointer).

But:

1. Technically a pointer must take the address of an variable, therefore: char* b = c is actually char* b = &c
2. The pointer itself points to an array, but char* is used for strings and chars. But C actually has a representation for pointers to arrays: char (*e)[]. Therefore we can represent a pointer to an array as: char (*a)[] = &a;.

If we insert the value of the string, as it is possible for b, the expression would be: char (*a)[] = &"Some string"; which again is valid C code. The & could be dropped and is again valid c code.

The compiler will only generate type warnings when using these kind of arrays, because it will expect a const char*.
But because C can implicitly cast the array back to an const char, the code still works.

To conclude:
The lifter will now actually represent the correct relation ship, e.g. d will be a pointer to an char array.
Therefore we can (and should) represent this relation ship with the explicit style, e.g. char (*a)[] = &"Some string";.
(Maybe drop at least the & to be a bit more friendly)

Approach

.

[rihi]

https://c-faq.com/aryptr/index.html is a nice resources on any confusions with c arrays and sheds some light on how we need to treat array types when generating c code.