[fpc-devel] 019605: Safety check for "const s: string" (similar to Range or Overflow checks)

[Florian Klämpfl]

May I propose a more generic solution:
- with some switch (-gc?) a call to checkpointer is inkoved at the end
of a procedure for const ref. counted types. Together with -gh this
catches the common case:

{$h+}
var
  s : string;

procedure proc;
  begin
    s:='1234';
  end;

procedure Foo(const s: string);
  begin
    proc;
    pbyte(s)^:=1; // force checkpointer call on s for testing purposes
  end;

begin
  setlength(s,10);
  Foo(s);
end.

If this is not enough
- we can introduce a compiler switch (or reuse an existing) which builds
a checksum on the relevant data of a const parameter on function entry.
At function exit, this checksum is checked.