FFI is slightly broken on FPC 3.0

[ollydev]

Here are the results of running the FFI tests (lazarus-1.6 branch) on FPC 3.0:

Win32:

• CDECL - (38/38)

• STDCALL - (38/38)

• REGISTER - (38/38)

• PASCAL - (30/38)

  • All individually pass, but will cause a crash (sigsegv) later on.

procedure Proc3(a: UInt8; b: Int64; c: UInt32; d: Int16; e: UInt16; f: Int32; g: UInt64; h: Int8)
procedure Proc9(a: TStatPackArr; b: TStrArr; constref c: TStatStrArr; d: TIntArr; e: TStatIntArr)
procedure Proc10(a: TShortRec; b: TPackRec; constref c: TStrRec; d: TLargeRec)
function Func2(const a, b, c: Int8): UInt8
function Func7(const a: Boolean): Boolean
function Func15(const a: TStatPackArr): TStatPackArr
function Func18(const a: TShortRec): TShortRec
function Func19(const a: TPackRec): TPackRec
function Func20(constref a: TStrRec): TStrRec

Win64:

• DEFAULT - (37/38)

function Func6(const a: Currency): Currency

Linux64 (Ubuntu):

• DEFAULT - (38/38)

Linux32:

• Not supported we should probably warn or disable FFI usage?

[nielsAD]

Thanks for looking into this. I think the win64 issues with Currency might be a FPC regression. According to their bugtracker, the issue will be fixed in the upcoming 3.0.2 release.

I'm afraid the pascal calling convention could be a libffi bug. I assume this line should also check for FFI_PASCAL. This is just a hunch, though.

[nielsAD]

85a3c52 should have fixed the pascal calling convention issues. I haven't been able to test FPC 3.0.2 yet to see if it resolves the Currency issues.

[ollydev]

New issue:

Returning a string from C++ seems to fail using FFI, yet works using the native importing method.

https://villavu.com/forum/showthread.php?t=117233

[ghost]

@Olly-, @nielsAD: All Win64 tests pass with Lazarus 1.8RC5 and FPC 3.0.4.