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c#.netvmwarevspherevmware-sdk

Building vSphere DLLs fails with CS8078: An expression is too long or complex to compile

I am following the documentation here Setting Up for Microsoft C# Development and at this step Building the C# vSphere DLLs I get the following in Developer Command Prompt:

C:\Users\user\Downloads\VMware-vSphereSDK-6.5.0-4571253\SDK\vsphere-ws\dotnet\bin>build.bat
        1 file(s) copied.
Fixing HttpNfcLeaseInfo type, adding missing leaseState property
Generating VimService.cs
Microsoft (R) Service Model Metadata Tool
[Microsoft (R) Windows (R) Communication Foundation, Version 4.6.1055.0]
Copyright (c) Microsoft Corporation.  All rights reserved.

Generating files...
C:\Users\user\Downloads\VMware-vSphereSDK-6.5.0-4571253\SDK\vsphere-ws\dotnet\bin\VimService.cs
Compiling original VimService.dll
Microsoft (R) Service Model Metadata Tool
[Microsoft (R) Windows (R) Communication Foundation, Version 4.6.1055.0]
Copyright (c) Microsoft Corporation.  All rights reserved.

Generating XML serializers...
C:\Users\user\Downloads\VMware-vSphereSDK-6.5.0-4571253\SDK\vsphere-ws\dotnet\bin\VimServiceSerializers.cs
        1 file(s) copied.
Optimizing VimService.cs by stripping serializer hint attributes.
Compiling optimized VimService.dll
FAILED

Looking at build.bat it looks like it is failing on this line:

echo Compiling optimized VimService.dll
csc /t:library /out:Vim25Service.dll VimService.cs VimServiceSerializers.cs >nul || goto ERROR

If I run csc /t:library /out:Vim25Service.dll VimService.cs VimServiceSerializers.cs manually i get the following:

C:\Users\user\Downloads\VMware-vSphereSDK-6.5.0-4571253\SDK\vsphere-ws\dotnet\bin>csc /t:library /out:Vim25Service.dll VimService.cs VimServiceSerializers.cs
Microsoft (R) Visual C# Compiler version 1.3.1.60616
Copyright (C) Microsoft Corporation. All rights reserved.

VimServiceSerializers.cs(32548,98): error CS8078: An expression is too long or complex to compile

I also tried with VS2017:

C:\Users\user\Downloads\VMware-vSphereSDK-6.5.0-4571253\SDK\vsphere-ws\dotnet\bin>csc /t:library /out:Vim25Service.dll VimService.cs VimServiceSerializers.cs
Microsoft (R) Visual C# Compiler version 2.0.0.61213
Copyright (C) Microsoft Corporation. All rights reserved.

VimServiceSerializers.cs(31372,109): error CS8078: An expression is too long or complex to compile

A behavior to note, on VimServiceSerializers.cs(#####,##) the line and column are different every time.

Googling error CS8078, found it is an issue with the compiler running out of stack space. https://stackoverflow.com/a/8160109/6656422

How do I successfully compile VmWare's code?

Solution

  • I figured it out. The serializer CS file has long uninterrupted stretches of if ... else if ... else if ... clauses. The compiler has to deal with the whole if/else expression at once, which causes it to run out of stack space.

    Fortunately, each branch in these else ifs terminates with a return statement. This makes all the else ifs functionally equivalent to just independent if statements, which are parsed independently.

    After making this substitution in a number of places, the file compiles. Here's my modified VimServiceSerializers.cs: https://1drv.ms/u/s!Al6mzY0CpY7EnHqBRDyg-z0ctrjk