Struct getting created with ANSI instead of Unicode string fields, leading to wrong Marshal.SizeOf result

[palenshus]

Actual behavior

When I gen code for the WER_REPORT_INFORMATION struct, the size returned by Marshal.SizeOf() is incorrect. I believe what's happening is it's treating the internal strings as 1-byte per char instead of 2-bytes per char, leading to a size ~50% what it should be.

Here's what's generated:

internal partial struct WER_REPORT_INFORMATION
{
	/// <summary>The size of this structure, in bytes.</summary>
	internal uint dwSize;
	/// <summary>A handle to the process for which the report is being generated. If this member is <b>NULL</b>, this is the calling process.</summary>
	internal win32.Foundation.HANDLE hProcess;
	/// <summary>The name used to look up consent settings. If this member is empty, the default is the name specified by the <i>pwzEventType</i> parameter of <a href="https://docs.microsoft.com/windows/desktop/api/werapi/nf-werapi-werreportcreate">WerReportCreate</a>.</summary>
	internal __char_64 wzConsentKey;
	/// <summary>The display name. If this member is empty, the default is the name specified by <i>pwzEventType</i> parameter of <a href="https://docs.microsoft.com/windows/desktop/api/werapi/nf-werapi-werreportcreate">WerReportCreate</a>.</summary>
	internal __char_128 wzFriendlyEventName;
	/// <summary>The name of the application. If this parameter is empty, the default is the base name of the image file.</summary>
	internal __char_128 wzApplicationName;
	/// <summary>The full path to the application.</summary>
	internal __char_260 wzApplicationPath;
	/// <summary>A description of the problem. This description is displayed in <b>Problem Reports and Solutions</b> on Windows Vista or the problem reports pane of the <b>Action Center</b> on Windows 7.</summary>
	internal __char_512 wzDescription;
	/// <summary>A handle to the parent window.</summary>
	internal win32.Foundation.HWND hwndParent;

    ...
}

And here's the native struct:

typedef struct _WER_REPORT_INFORMATION {
  DWORD  dwSize;
  HANDLE hProcess;
  WCHAR  wzConsentKey[64];
  WCHAR  wzFriendlyEventName[128];
  WCHAR  wzApplicationName[128];
  WCHAR  wzApplicationPath[MAX_PATH];
  WCHAR  wzDescription[512];
  HWND   hwndParent;
} WER_REPORT_INFORMATION, *PWER_REPORT_INFORMATION;

When I call Marshal.SizeOf(reportInformation), it returns 1120.

When I try to call WerReportCreate with this struct, it returns E_INVALIDARG.

Expected behavior

The SizeOf call should return 2204 (or 2208 due to 8-byte packing).

Repro steps

1. NativeMethods.txt content:

WerReportCreate

2. NativeMethods.json content (if present):

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

WER_REPORT_INFORMATION reportInformation = default;
reportInformation.dwSize = (uint)Marshal.SizeOf(reportInformation);
reportInformation.hProcess = (HANDLE)IntPtr.Zero;
reportInformation.hwndParent = (HWND)IntPtr.Zero;
"A functional problem was detected and logs were collected for further investigation.".AsSpan().CopyTo(reportInformation.wzDescription.AsSpan());
"Diagnostic Tracing".AsSpan().CopyTo(reportInformation.wzFriendlyEventName.AsSpan());

Marshal.ThrowExceptionForHR(PInvoke.WerReportCreate(
    eventType,
    WER_REPORT_TYPE.WerReportCritical,
    reportInformation,
    out nint reportHandle));

Context

• CsWin32 version: 0.1.506-beta
• Target Framework: .NET 6.0

[AArnott]

This is surprising. I can repro and am investigating.

[palenshus]

Works like a charm now, thanks!!