Safe version of the EnumProcessModulesEx function seems to be incorrect

[lowleveldesign]

Actual behavior

I think that the safe version of the EnumProcessModulesEx has an invalid type for the lphModule parameter:

static unsafe winmdroot.Foundation.BOOL EnumProcessModulesEx(SafeHandle hProcess, out FreeLibrarySafeHandle lphModule, uint cb, out uint lpcbNeeded, winmdroot.System.ProcessStatus.ENUM_PROCESS_MODULES_EX_FLAGS dwFilterFlag)

The unsafe version:

static extern unsafe winmdroot.Foundation.BOOL EnumProcessModulesEx(winmdroot.Foundation.HANDLE hProcess, winmdroot.Foundation.HMODULE* lphModule, uint cb, uint* lpcbNeeded, winmdroot.System.ProcessStatus.ENUM_PROCESS_MODULES_EX_FLAGS dwFilterFlag);

Expected behavior

I would expect lphModule to be an out array or a HMODULE pointer (like in the unsafe version).

Repro steps

1. NativeMethods.txt content:

   EnumProcessModulesEx

2. NativeMethods.json content (if present):

3. Any of your own code that should be shared?

Context

• CsWin32 version: 0.3.106
• Target Framework: net8.0

[lowleveldesign]

I observed a similar error (one element instead of array) for the StartServiceCtrlDispatcher method:

static extern winmdroot.Foundation.BOOL StartServiceCtrlDispatcher(in winmdroot.System.Services.SERVICE_TABLE_ENTRYW lpServiceStartTable);

lpServiceStartTable should be a pointer or an array of SERVICE_TABLE_ENTRYW.

[AArnott]

Agreed. Thank you for reporting. I believe this is a bug in the metadata, where these two function should have NativeArrayInfoAttribute applied to the pointer parameters in question. I'll move this issue to the right repo.

[mikebattista]

EnumProcessModulesEx has a [MemorySize] attribute on lphModule. Do you have support for that attribute?

[Out][MemorySize(BytesParamIndex = 2)] HMODULE* lphModule, [In] uint cb

[mikebattista]

Reactivate if you don't have what you need already for EnumProcessModulesEx.

[AArnott]

Is MemorySize meant to imply an array? I thought that was just for buffers. How do you decide whether to use NativeArrayInfo vs. MemorySize?

[mikebattista]

It's based on the SAL annotations.

https://github.com/microsoft/win32metadata/blob/185c3ef016663ab8201878da7efab0a2cff0bcc7/generation/WinSDK/RecompiledIdlHeaders/um/Psapi.h#L158

Additional context on the attribute is at https://github.com/microsoft/win32metadata/issues/284 as well.

[AArnott]

Ok. I'll see what I can do in CsWin32 then.

[AArnott]

@mikebattista I've been researching from your links, and I believe NativeArrayInfo is still warranted on this function. As precedent, I call on:

Function	Parameter	Array?	Attributes
VirtualQueryEx	lpBuffer	No	MemorySize
StartServiceCtrlDispatcherW	lpServiceStartTable	Yes	NativeArrayInfo (you recently added)
EnumProcessModules	lphModule	Yes	MemorySize
EnumProcessModulesEx	lphModule	Yes	MemorySize
WriteFile	lpBuffer	Yes	MemorySize

Having MemorySize on the EnumProcessModulesEx makes sense because the size is controlled by byte count rather than array element count. But having a NativeArrayElement attribute as well (even without any properties set) is important so that cswin32 can distinguish between a pointer to one element vs. an array of elements.

Should we move this issue back to win32metadata?

[AArnott]

WriteFile is one that was somewhat problematic for CsWin32 in the past. Per https://github.com/microsoft/win32metadata/issues/1555#issuecomment-1528200787, @mikebattista suggested that MemorySize should not be construed to mean an array. So I believe when a parameter is an array, we ought to apply the NativeArrayInfoAttribute.