Work-around for C# CodeDom causing stack-overflow (CS1647) in csc.exe?

Question

I\'ve got a situation where I need to generate a class with a large string const. Code outside of my control causes my generated CodeDom tree to be emitted to C# source and

Answer 1

So am I right in saying you've got the C# source file with something like:

public const HugeString = "xxxxxxxxxxxx...." +
    "yyyyy....." +
    "zzzzz.....";

and you then try to compile it?

If so, I would try to edit the text file (in code, of course) before compiling. That should be relatively straightforward to do, as presumably they'll follow a rigidly-defined pattern (compared with human-generated source code). Convert it to have a single massive line for each constant. Let me know if you'd like some sample code to try this.

By the way, your repro succeeds with no errors on my box - which version of the framework are you using? (My box has the beta of 4.0 on, which may affect things.)

EDIT: How about changing it to not be a string constant? You'd need to break it up yourself, and emit it as a public static readonly field like this:

public static readonly HugeString = "xxxxxxxxxxxxxxxx" + string.Empty +
    "yyyyyyyyyyyyyyyyyyy" + string.Empty +
    "zzzzzzzzzzzzzzzzzzz";

Crucially, string.Empty is a public static readonly field, not a constant. That means the C# compiler will just emit a call to string.Concat which may well be okay. It'll only happen once at execution time of course - slower than doing it at compile-time, but it may be an easier workaround than anything else.

Answer 2

Note that if you declare the string as const, it will be copied in each assembly that uses this string in its code.

You may be better off with static readonly.

Another way would be to declare a readonly property that returns the string.

Answer 3

I have no idea how to change the behavior of the code generator, but you can change the stack size that the compiler uses with the /stack option of EditBin.EXE.

Example:

editbin /stack:100000,1000 csc.exe <options>

Following is an example of its use:

class App 
{
    private static long _Depth = 0;

    // recursive function to blow stack
    private static void GoDeep() 
    {
        if ((++_Depth % 10000) == 0) System.Console.WriteLine("Depth is " +
            _Depth.ToString());
        GoDeep();
    return;
    }

    public static void Main() {
        try 
        {
            GoDeep();
        } 
        finally 
        {
        }

        return;
    }
}




editbin /stack:100000,1000 q.exe
Depth is 10000
Depth is 20000

Unhandled Exception: StackOverflowException.

editbin /stack:1000000,1000 q.exe
Depth is 10000
Depth is 20000
Depth is 30000
Depth is 40000
Depth is 50000
Depth is 60000
Depth is 70000
Depth is 80000

Unhandled Exception: StackOverflowException.

Answer 4

Make sure the application pools in IIS have 32-bit applications enabled. That's all it took for me to cure this problem trying to compile a 32-bit app in Win7 64-bit. Oddly (or not), Microsoft could not supply this answer. After a full day of searching, I found this link to the fix on an Iron Speed Designer forum:

http://darrell.mozingo.net/2009/01/17/running-iis-7-in-32-bit-mode/

Answer 5

Using a CodeSnippetExpression and a manually quoted string, I was able to emit the source that I would have liked to have seen from Microsoft.CSharp.CSharpCodeGenerator.

So to answer the question above, replace this line:

field.InitExpression = new CodePrimitiveExpression(HugeString);

with this:

field.InitExpression = new CodeSnippetExpression(QuoteSnippetStringCStyle(HugeString));

And finally modify the private string quoting Microsoft.CSharp.CSharpCodeGenerator.QuoteSnippetStringCStyle method to not wrap after 80 chars:

private static string QuoteSnippetStringCStyle(string value)
{
    // CS1647: An expression is too long or complex to compile near '...'
    // happens if number of line wraps is too many (335440 is max for x64, 926240 is max for x86)

    // CS1034: Compiler limit exceeded: Line cannot exceed 16777214 characters
    // theoretically every character could be escaped unicode (6 chars), plus quotes, etc.

    const int LineWrapWidth = (16777214/6) - 4;
    StringBuilder b = new StringBuilder(value.Length+5);

    b.Append("\r\n\"");
    for (int i=0; i<value.Length; i++)
    {
        switch (value[i])
        {
            case '\u2028':
            case '\u2029':
            {
                int ch = (int)value[i];
                b.Append(@"\u");
                b.Append(ch.ToString("X4", CultureInfo.InvariantCulture));
                break;
            }
            case '\\':
            {
                b.Append(@"\\");
                break;
            }
            case '\'':
            {
                b.Append(@"\'");
                break;
            }
            case '\t':
            {
                b.Append(@"\t");
                break;
            }
            case '\n':
            {
                b.Append(@"\n");
                break;
            }
            case '\r':
            {
                b.Append(@"\r");
                break;
            }
            case '"':
            {
                b.Append("\\\"");
                break;
            }
            case '\0':
            {
                b.Append(@"\0");
                break;
            }
            default:
            {
                b.Append(value[i]);
                break;
            }
        }

        if ((i > 0) && ((i % LineWrapWidth) == 0))
        {
            if ((Char.IsHighSurrogate(value[i]) && (i < (value.Length - 1))) && Char.IsLowSurrogate(value[i + 1]))
            {
                b.Append(value[++i]);
            }
            b.Append("\"+\r\n");
            b.Append('"');
        }
    }
    b.Append("\"");
    return b.ToString();
}