Hello. I have DLL written on Pascal and "headers" for use it (types and functions signatures definitions). How I can port "headers" to D?

Calling convention is `stdcall` (`extern (Windows)` for D), arguments of some functions is structs of structs and etc with static array fields:

```Pascal
type
  TOneHarmonic = record
    Koef: Single;
    Angle: Single;
  end;

  THarmonicsArray = array[2..50] of TOneHarmonic;
  TInterharmonicsArray = array[1..49] of TOneHarmonic;

  TVoltageCurrentOneFaza = record
    KalibKoef: Single;
    IncludeMainFreq: Boolean;
    MainFreqVoltCur: TOneHarmonic;
    Harmonics: THarmonicsArray;
    Interharmonics: TInterharmonicsArray;
  end;

  TVoltageCurrent = record
    Enable: Boolean;
    NominalID: Byte;
    Faza_A: TVoltageCurrentOneFaza;
    Faza_B: TVoltageCurrentOneFaza;
    Faza_C: TVoltageCurrentOneFaza;
  end;

  TSignal = record
    HasInterharmonics: Boolean;
    Voltage: TVoltageCurrent;
    Current: TVoltageCurrent;
    ...
  end;
  ...
```

in other file

```Pascal
function CheckSignalData(SignalData: PUserSignalData): Word;
  stdcall; external SIGNALK2MDLL;
```
PUserSignalData is pointer to TUserSignalData, first field of TUserSignalData is Signal, other fields is pointers to other types

If I understand correctly
1. `Single` is `float` in D, `Byte` is `byte`, `Boolean` is `bool`, `Word` is `ushort`
2. `array[A..B] of TFoo` is `TFoo[B-A+1]` (static array)

Can I rewrite records to structs like this?

```d
alias Word = short;
alias Single = float;
alias Byte = byte;
alias Boolean = bool;

struct OneHarmonic
{
    Single coef;
    Single angle;
}

alias HarmonicArray = OneHarmonic[49];

// TVoltageCurrentOneFaza
struct PhaseInfo
{
    // Must I align fields and/or structs?
    Single calibCoef;
    Boolean includeMainFreq;
    OneHarmonic mainFreqVoltCur;
    HarmonicArray harmonics; // Can I replace Pascal static arrays with D static arrays?
    HarmonicArray interharmonics;
}

// TVoltageCurrent
struct ChannelInfo
{
    Boolean enable;
    Byte nominalID;
    PhaseInfo[3] phase; // Can I replace 3 fields to static array?
}

struct Signal
{
    Boolean hasInterharmonics;
    ChannelInfo voltage;
    ChannelInfo current; // #1
    ...
}
```

In this case I have error about current values (#1) and I think I badly rewrite Pascal records to D structs (ChannelInfo, PhaseInfo, OneHarmonic) and lose alignments and/or something else.

PS original pascal naming is very bad, I know

On Wednesday, 25 October 2017 at 03:12:56 UTC, Oleg B wrote:
> Calling convention is `stdcall` (`extern (Windows)` for D), arguments of some functions is structs of structs and etc with static array fields:

Fun fact, D has extern(Pascal): https://dlang.org/spec/attribute.html#linkage


I don't know the details  of the rest... but I think you're right about what you have so far.

I'd suggest just trying it and seeing if the functions return what you expect.

On Wednesday, 25 October 2017 at 03:12:56 UTC, Oleg B wrote:
> Hello. I have DLL written on Pascal and "headers" for use it (types and functions signatures definitions). How I can port "headers" to D?
>
> Calling convention is `stdcall` (`extern (Windows)` for D), arguments of some functions is structs of structs and etc with static array fields:
>
> ```Pascal
> type
>   TOneHarmonic = record
>     Koef: Single;
>     Angle: Single;
>   end;
>
>   THarmonicsArray = array[2..50] of TOneHarmonic;
>   TInterharmonicsArray = array[1..49] of TOneHarmonic;
>
>   TVoltageCurrentOneFaza = record
>     KalibKoef: Single;
>     IncludeMainFreq: Boolean;
>     MainFreqVoltCur: TOneHarmonic;
>     Harmonics: THarmonicsArray;
>     Interharmonics: TInterharmonicsArray;
>   end;
>
>   TVoltageCurrent = record
>     Enable: Boolean;
>     NominalID: Byte;
>     Faza_A: TVoltageCurrentOneFaza;
>     Faza_B: TVoltageCurrentOneFaza;
>     Faza_C: TVoltageCurrentOneFaza;
>   end;
>
>   TSignal = record
>     HasInterharmonics: Boolean;
>     Voltage: TVoltageCurrent;
>     Current: TVoltageCurrent;
>     ...
>   end;
>   ...
> ```
>
> in other file
>
> ```Pascal
> function CheckSignalData(SignalData: PUserSignalData): Word;
>   stdcall; external SIGNALK2MDLL;
> ```
> PUserSignalData is pointer to TUserSignalData, first field of TUserSignalData is Signal, other fields is pointers to other types
>
> If I understand correctly
> 1. `Single` is `float` in D, `Byte` is `byte`, `Boolean` is `bool`, `Word` is `ushort`

No Pascal's "Byte" is D's "ubyte". But unless NominalID goes over 127 this is not the source of the problem.

> 2. `array[A..B] of TFoo` is `TFoo[B-A+1]` (static array)

No A-B. In Pascal the upper bound of a range (like here but i'm not sure this i called like that in the grammar) or of a slice is inclusive.

>
> Can I rewrite records to structs like this?
>
> ```d
> alias Word = short;
> alias Single = float;
> alias Byte = byte;
> alias Boolean = bool;
>
> struct OneHarmonic
> {
>     Single coef;
>     Single angle;
> }
>
> alias HarmonicArray = OneHarmonic[49];

48 !

> // TVoltageCurrentOneFaza
> struct PhaseInfo
> {
>     // Must I align fields and/or structs?

No, unless the record is packed.

>     Single calibCoef;
>     Boolean includeMainFreq;
>     OneHarmonic mainFreqVoltCur;
>     HarmonicArray harmonics; // Can I replace Pascal static arrays with D static arrays?
>     HarmonicArray interharmonics;
> }
>
> // TVoltageCurrent
> struct ChannelInfo
> {
>     Boolean enable;
>     Byte nominalID;
>     PhaseInfo[3] phase; // Can I replace 3 fields to static array?

yes

> }
>
> struct Signal
> {
>     Boolean hasInterharmonics;
>     ChannelInfo voltage;
>     ChannelInfo current; // #1
>     ...
> }
> ```
>
> In this case I have error about current values (#1) and I think I badly rewrite Pascal records to D structs (ChannelInfo, PhaseInfo, OneHarmonic) and lose alignments and/or something else.
>
> PS original pascal naming is very bad, I know

Most likely the problem is the array length.

On Wednesday, 25 October 2017 at 03:12:56 UTC, Oleg B wrote:
> Hello. I have DLL written on Pascal and "headers" for use it (types and functions signatures definitions). How I can port "headers" to D?
>
> [...]

Hi,

this thread might be interesting for you, if you use Delphi
http://forum.dlang.org/post/hpodoabutuakfxbzzcyy@forum.dlang.org

This thread describes a bridge between the D Programming Language and Delphi.

Kind regards
André

On Wednesday, 25 October 2017 at 04:30:12 UTC, Basile B. wrote:
> On Wednesday, 25 October 2017 at 03:12:56 UTC, Oleg B wrote:
>> 2. `array[A..B] of TFoo` is `TFoo[B-A+1]` (static array)
>
> No A-B. In Pascal the upper bound of a range (like here but i'm not sure this i called like that in the grammar) or of a slice is inclusive.
>
>> alias HarmonicArray = OneHarmonic[49];
>
> 48 !
>
> Most likely the problem is the array length.

If I wrote `array[5..7] of ...` I get array that can be indexed by `5`, `6` and `7`, right? It means that array have 3 elements. If A=5, B=7 then length of array is B-A+1, 7-5+1=3. In my case I have [1..49] and [2..50] ranges: 49-1+1=49, 50-2+1=49. I don't understand why length must be 48...
In any case I tried 48 and CheckSignalData function returns other error code, but it point to current field too (incorrect value of coefs - it can be if floating point value is badly read).

On Wednesday, 25 October 2017 at 03:36:54 UTC, Adam D. Ruppe wrote:
> I'd suggest just trying it and seeing if the functions return what you expect.

Unfortunately they returns unexpected codes. Otherwise I wouldn't post question here. I go here then I have no idea to resolve problem.

On Wednesday, 25 October 2017 at 10:47:56 UTC, Oleg B wrote:
> On Wednesday, 25 October 2017 at 04:30:12 UTC, Basile B. wrote:
> If I wrote `array[5..7] of ...` I get array that can be indexed by `5`, `6` and `7`, right? It means that array have 3 elements. If A=5, B=7 then length of array is B-A+1, 7-5+1=3. In my case I have [1..49] and [2..50] ranges: 49-1+1=49, 50-2+1=49. I don't understand why length must be 48...

Yeah of course, me neither.