Enums nested in Structs, variables with values in Structs

[kirill-21]

Hello. I have to questions:

1. Am i converting this right?

typedef struct _TEST_NAME {
// variables

union
	{
		UCHAR FlagGroup[4];
		ULONG Flags;

		struct
		{
			ULONG PackagedBinary			: 1;
			ULONG MarkedForRemoval			: 1;
			ULONG ImageDll					: 1;
			ULONG LoadNotificationsSent		: 1;
			ULONG TelemetryEntryProcessed	: 1;
			ULONG ProcessStaticImport		: 1;
			ULONG InLegacyLists				: 1;
			ULONG InIndexes					: 1;
			ULONG ShimDll					: 1;
			ULONG InExceptionTable			: 1;
			ULONG ReservedFlags1			: 2;
			ULONG LoadInProgress			: 1;
			ULONG ReservedFlags2			: 1; 
			ULONG EntryProcessed			: 1;
			ULONG ReservedFlags3			: 3;
			ULONG DontCallForThreads		: 1;
			ULONG ProcessAttachCalled		: 1;
			ULONG ProcessAttachFailed		: 1;
			ULONG CorDeferredValidate		: 1;
			ULONG CorImage					: 1;
			ULONG DontRelocate				: 1;
			ULONG CorILOnly					: 1;
			ULONG ReservedFlags5			: 3;
			ULONG Redirected				: 1;
			ULONG ReservedFlags6			: 2;
			ULONG CompatDatabaseProcessed	: 1;
		};
	};

// variables
} TEST_NAME, PTEST_NAME*;

sealed class TEST_NAME extends Struct {
  // variables
  external _union1 union;
  // variables
}

sealed  class _union1 extends Union {
 @Array(4)
 external Array<Uint8> FlagGroup;
 @Uint32()
 external int Flags;
 external _nestedStruct1 nestedStruct;
}

sealed class _nestedStruct1 extends Struct {
 // What here? Like this? How do i specify this ": 1"? If i do something like
 // "= 1", it shows an error. Do i even need to specify this values?
  @Uint32()
  external int packagedBinary;
  @Uint32()
  external int markedForRemoval;
  @Uint32()
  external int imageDll;
  @Uint32()
  external int loadNotificationsSent;
  @Uint32()
  external int telemetryEntryProcessed;
  @Uint32()
  external int processStaticImport;
  @Uint32()
  external int inLegacyLists;
  @Uint32()
  external int inIndexes;
  @Uint32()
  external int shimDll;
  @Uint32()
  external int inExceptionTable;
  @Uint32()
  external int reservedFlags1;
  @Uint32()
  external int loadInProgress;
  @Uint32()
  external int reservedFlags2;
  @Uint32()
  external int entryProcessed;
  @Uint32()
  external int reservedFlags3;
  @Uint32()
  external int dontCallForThreads;
  @Uint32()
  external int processAttachCalled;
  @Uint32()
  external int processAttachFailed;
  @Uint32()
  external int corDeferredValidate;
  @Uint32()
  external int corImage;
  @Uint32()
  external int dontRelocate;
  @Uint32()
  external int corILOnly;
  @Uint32()
  external int reservedFlags5;
  @Uint32()
  external int redirected;
  @Uint32()
  external int reservedFlags6;
  @Uint32()
  external int compatDatabaseProcessed;
}

2. How do i insert an enum in Struct?

typedef enum _LDR_DLL_LOAD_REASON
{
    LoadReasonStaticDependency,
    LoadReasonStaticForwarderDependency,
    LoadReasonDynamicForwarderDependency,
    LoadReasonDelayloadDependency,
    LoadReasonDynamicLoad,
    LoadReasonAsImageLoad,
    LoadReasonAsDataLoad,
    LoadReasonEnclavePrimary, // REDSTONE3
    LoadReasonEnclaveDependency,
    LoadReasonUnknown = -1
} LDR_DLL_LOAD_REASON, *PLDR_DLL_LOAD_REASON;

typedef struct _TEST_NAME {
// variables
LDR_DLL_LOAD_REASON LoadReason;
ULONG ImplicitPathOptions;
// variables
}

[dcharkes]

Hey @kirill-21, have you checked out package:ffigen yet? It can automatically generate the dart:ffi bindings from C header files.

[kirill-21]

Hey @kirill-21, have you checked out package:ffigen yet? It can automatically generate the dart:ffi bindings from C header files.

I tried, it generated an empty struct)

[dcharkes]

Are all the headers correctly included? Any error messages earlier on in the log?

[dcharkes]

Ah, I missed a part of the issue. It has bitfields. Which we don't support currently:

• https://github.com/dart-lang/ffigen/issues/84
• dart:ffi Struct bit fields dart-lang/sdk#38954

If you know what the size of your field is you can replace the whole bitfield with a same-size integer and do the bitshifting in Dart.

[kirill-21]

Is there any way to check the size in C?

[dcharkes]

8 bytes on x64: https://godbolt.org/z/jn7G33zKP
4 bytes on ia32: https://godbolt.org/z/oxa41jnr1

(You can sum up the bits manually as well 😄 which is precisely 32, but it's probably safer to use sizeof to see what the compiler is actually doing.)