Pointer arithmetic doesn't work

[ghost]

Repro code:

#import "fmt.odin";

main :: proc() {
  buffer := make([]u32, 1);
  buffer[0] = 23;
  fmt.printf("initial buffer: %v\n", buffer);

  p: rawptr = ^buffer[0];

  p_u32 := cast(^u32)p;
  p_u32^ = 42;

  fmt.printf("changed buffer: %v\n", buffer);

  fmt.printf("p_u32 (should be 42): %d\n", p_u32^);
  p_u32 += 1;
  p_u32 -= 1;
  fmt.printf("p_u32 (should be 42): %d\n", p_u32^);
}

Prints:

initial buffer: [23]
changed buffer: [42]
p_u32 (should be 42): 42
p_u32 (should be 42): 0

[ghost]

Minus operator increments the address

[ghost]

I guess because Token_Add and Token_Sub share the same code: f320958#diff-5f7101e83ab40f9f58bba057da941225R1488

[ghost]

https://github.com/gingerBill/Odin/blob/b78e970/src/ssa.c#L1551

GB_PANIC("TODO(bill): Ptr arith");

Not sure if related!

[ghost]

Manual pointer arithmetic workaround:

  p_u32 += 1;
  p_u32 = cast(^u32)cast(rawptr)(cast(uint)cast(rawptr)p_u32 - 1 * size_of(u32));

Prints:

initial buffer: [23]
changed buffer: [42]
p_u32 (should be 42): 42
p_u32 (should be 42): 42

[gingerBill]

Fixed!

[ghost]

@gingerBill Thank you!