XslCompiledTransform fails with stack overflow - xslt

Question

I have a large XSLT file with 805 templates that, depending on the system and environment, fails with a stack overflow.
The development environment is Windows 7, InfoPath 2010 and C#. Although .NET 4.0 is installed, this version of InfoPath uses .NET 2.0.
The routine being used is:
private void TransformXML(String inputFileName, String transformFileName, String outputFileName)
{
CorralLog(String.Concat("Transform with ", transformFileName, ": ", inputFileName, " -> ", outputFileName));
using (XmlReader inputFile = XmlReader.Create(inputFileName, null))
{
XslCompiledTransform transform = new XslCompiledTransform(true);
XsltSettings settings = new XsltSettings(true, false);
transform.Load(transformFileName, settings, null);
using(XmlWriter outputFile = XmlWriter.Create(outputFileName))
{
filesToDelete.Add(outputFileName);
transform.Transform(inputFile, outputFile);
}
}
}
I can see some possibilities:
Increase the memory available to the 'transform.Load' command
Start a separate thread with more memory
Start a separate thread and execute the transform with 'msxsl.exe' (which always works)
Split up the XSLT file into smaller pieces and do a transformation multiple times
Does anyone have advice on which option to choose? Or any other suggestions?
Paul
The XLST file in question takes some elements from an XML file, changes the name for some elements, and produces another XML file. There are about 800 elements, each with its own template.
This code shows the three templates at the beginning of the XSLT file and two templates for copying elements: one for copying an element as is, and the other changing the name of the element. All subsequent templates are formatted in one of these two ways.
Is this syntax is causing recursion, or is the number of templates causing the stack overflow. (We have avoided the problem, but perhaps not solved it, by running this transform in a new thread.)
<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:my="http://schemas.microsoft.com/office/infopath/2003/myXSD/2011-03-16T10:53:27">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="/">
<xsl:apply-templates select="*"/>
</xsl:template>
<xsl:template match="/*">
<xsl:copy>
<xsl:apply-templates select="*"/>
</xsl:copy>
</xsl:template>
<xsl:template match="*">
<xsl:apply-templates select="*"/>
</xsl:template>
<xsl:template match="/SAN/ClientProfiles/ClientProfile">
<xsl:copy>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
<xsl:template match="/SAN/ClientProfiles/ClientProfile/Name">
<CompanyName>
<xsl:apply-templates/>
</CompanyName>
</xsl:template>

Answer 1

See whether the suggestions in http://blogs.msdn.com/b/xmlteam/archive/2011/09/26/effective-xml-part-5-something-went-really-wrong-outofmemoryexception-and-stackoverflowexception-thrown-when-using-xslcompiledtransform.aspx help avoid the problem.

Answer 2

The most likely cause of a stack overflow is deep recursion in your XSLT code. I would take a look at the relevant templates and see if they can be written some other way, e.g. to use divide-and-conquer recursion rather than head-tail recursion, or perhaps to take advantage of XSLT 2.0 - there are a couple of good XSLT 2.0 processors for .NET.