SetRawUTF8

procedure SetRawUTF8(var Dest: RawUTF8; text: pointer; len: integer);
{$ifdef FPC}inline;
begin
  if (len>128) or (len=0) or (text<>pointer(Dest)) then
    SetString(Dest,PAnsiChar(text),len) else
    SetLength(Dest,len);
end;
{$else}
{$ifdef PUREPASCAL}
var P: PStrRec;
begin
  if (len>128) or (len=0) or (PtrInt(Dest)=0) or     // Dest=''
    (PStrRec(PtrInt(Dest)-STRRECSIZE)^.refCnt<>1) then
    SetString(Dest,PAnsiChar(text),len) else begin
    if PStrRec(Pointer(PtrInt(Dest)-STRRECSIZE))^.length<>len then begin
      P := Pointer(PtrInt(Dest)-STRRECSIZE);
      ReallocMem(P,len+(STRRECSIZE+1));
      P^.length := len;
      pointer(Dest) := pointer(PAnsiChar(P)+STRRECSIZE);
      PByteArray(Dest)[len] := 0;
    end;
    Move(pointer(text)^,pointer(Dest)^,len);
  end;
end;
{$else}
asm // eax=@Dest text=edx len=ecx
    cmp ecx,128 // avoid huge move() in ReallocMem()
{$ifdef UNICODE}
    ja @3
{$else}
    ja System.@LStrFromPCharLen
{$endif}
    or ecx,ecx // len=0
{$ifdef UNICODE}
    jz @3
{$else}
    jz System.@LStrFromPCharLen
{$endif}
    push ebx
    mov ebx,[eax]
    test ebx,ebx
    jnz @2
@0: pop ebx
{$ifdef UNICODE}
@3: push CP_UTF8 // UTF-8 code page for Delphi 2009+
    call System.@LStrFromPCharLen // we need a call, not a jmp here
    ret
{$else}
    jmp System.@LStrFromPCharLen
{$endif}
@2: cmp dword ptr [ebx-8],1
    jne @0
    cmp dword ptr [ebx-4],ecx
    je @1
    sub ebx,STRRECSIZE
    push edx
    push eax
    push ecx
    push ebx
    mov eax,esp // ReallocMem() over ebx pointer on stack
    lea edx,ecx+STRRECSIZE+1
    call System.@ReallocMem
    pop ebx
    pop ecx
    add ebx,STRRECSIZE
    pop eax
    pop edx
    mov [eax],ebx
    mov dword ptr [ebx-4],ecx
    mov byte ptr [ebx+ecx],0
@1: mov eax,edx
    mov edx,ebx
    call Move
    pop ebx
end;
{$endif}
{$endif}