Tail recursion elimination transforms a tail call into a loop.
If compInitMem is set, we may need to zero-initialize some locals. Normally it's done in the prolog
but the loop we are creating can't include the prolog. The fix is to insert zero-initialization
for all non-parameter non-temp locals in the loop. Liveness phase will remove unnecessary initializations.
We never hit this case with normal C# code since C# definite assignment rules ensure that there are
no uninitialized locals in the generated msil. In the repro the method with tail recursion is a dynamic method
and it has an uninitialized local.
fgInsertStmtBefore(block, paramAssignmentInsertionPoint, arg0AssignmentStmt);
}
+ // If compInitMem is set, we may need to zero-initialize some locals. Normally it's done in the prolog
+ // but this loop can't include the prolog. Since we don't have liveness information, we insert zero-initialization
+ // for all non-parameter non-temp locals. Liveness phase will remove unnecessary initializations.
+ if (info.compInitMem)
+ {
+ unsigned varNum;
+ LclVarDsc* varDsc;
+ for (varNum = 0, varDsc = lvaTable; varNum < info.compLocalsCount; varNum++, varDsc++)
+ {
+ if (!varDsc->lvIsParam)
+ {
+ assert(!varDsc->lvIsTemp);
+ var_types lclType = varDsc->TypeGet();
+ GenTreePtr lcl = gtNewLclvNode(varNum, lclType);
+ GenTreePtr init = nullptr;
+ if (lclType == TYP_STRUCT)
+ {
+ const bool isVolatile = false;
+ const bool isCopyBlock = false;
+ init = gtNewBlkOpNode(lcl, gtNewIconNode(0), varDsc->lvSize(), isVolatile, isCopyBlock);
+ init = fgMorphInitBlock(init);
+ }
+ else
+ {
+ GenTreePtr zero = gtNewZeroConNode(genActualType(lclType));
+ init = gtNewAssignNode(lcl, zero);
+ }
+ GenTreePtr initStmt = gtNewStmt(init, callILOffset);
+ fgInsertStmtBefore(block, last, initStmt);
+ }
+ }
+ }
+
// Remove the call
fgRemoveStmt(block, last);
--- /dev/null
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.IO;
+using System.Xml;
+using System.Xml.XPath;
+using System.Xml.Xsl;
+
+
+namespace XSLTest
+{
+ class Program
+ {
+ // In this test a dynamic method with tail-prefixed call is created.
+ // One of the locals is not explicitly initialized but a flag to init locals is set.
+ // (That never happens in normal C# methods due to C# definite assignment rules.)
+ // The jit performs an optimization transforming the tail call into a loop.
+ // The bug was that the local was only zero-initialized for the first iteration of the loop.
+
+ static int Main(string[] args)
+ {
+ string inputXml = "Input.xml";
+ string inputXsl = "Transform.xsl";
+
+ return DotNetXslCompiledTransform(inputXml, inputXsl);
+ }
+
+ private static int DotNetXslCompiledTransform(string inputXml, string inputXsl)
+ {
+ XslCompiledTransform transform = new XslCompiledTransform();
+ transform.Load(inputXsl);
+
+ StringWriter stringWriter = new StringWriter();
+ XmlWriter writer = new XmlTextWriter(stringWriter);
+
+ transform.Transform(inputXml, null, writer);
+
+ string transformResult = stringWriter.ToString();
+ if (transformResult == "<!--20.0 20.0 20.0 20.0 20.0--> 40 40 40 40 40")
+ {
+ Console.WriteLine("SUCCESS");
+ return 100;
+ }
+ else
+ {
+ Console.WriteLine("FAILURE");
+ return 0;
+ }
+ }
+ }
+}
+
--- /dev/null
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+ <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.props))\dir.props" />
+ <PropertyGroup>
+ <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+ <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+ <AssemblyName>$(MSBuildProjectName)</AssemblyName>
+ <SchemaVersion>2.0</SchemaVersion>
+ <ProjectGuid>{95DFC527-4DC1-495E-97D7-E94EE1F7140D}</ProjectGuid>
+ <OutputType>Exe</OutputType>
+ <ProjectTypeGuids>{786C830F-07A1-408B-BD7F-6EE04809D6DB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+ <SolutionDir Condition="$(SolutionDir) == '' Or $(SolutionDir) == '*Undefined*'">..\..\</SolutionDir>
+ </PropertyGroup>
+ <!-- Default configurations to help VS understand the configurations -->
+ <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+ </PropertyGroup>
+ <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+ </PropertyGroup>
+ <ItemGroup>
+ <CodeAnalysisDependentAssemblyPaths Condition=" '$(VS100COMNTOOLS)' != '' " Include="$(VS100COMNTOOLS)..\IDE\PrivateAssemblies">
+ <Visible>False</Visible>
+ </CodeAnalysisDependentAssemblyPaths>
+ </ItemGroup>
+ <PropertyGroup>
+ <DebugType></DebugType>
+ <Optimize>True</Optimize>
+ </PropertyGroup>
+ <ItemGroup>
+ <Compile Include="$(MSBuildProjectName).cs" />
+ <Reference Include="System.Private.Xml" />
+ <Content Include="Input.xml">
+ <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+ </Content>
+ <Content Include="Transform.xsl">
+ <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+ </Content>
+ </ItemGroup>
+ <ItemGroup>
+ <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
+ </ItemGroup>
+ <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
+ <PropertyGroup Condition=" '$(MsBuildProjectDirOverride)' != '' ">
+ </PropertyGroup>
+</Project>
--- /dev/null
+<?xml version="1.0" encoding="UTF-8"?>
+<root>
+ <bla test="20.0 20.0 20.0 20.0 20.0"/>
+</root>
\ No newline at end of file
--- /dev/null
+<?xml version="1.0" encoding="utf-8"?>
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:l="http://www.schema.de/XSL/ST4DocuManagerlang" version="1.0">
+ <xsl:template match="/">
+ <xsl:for-each select="/root/bla">
+ <xsl:comment>
+ <xsl:value-of select="@test"/>
+ </xsl:comment>
+ <xsl:call-template name="duplicate">
+ <xsl:with-param name="value" select="@test" />
+ </xsl:call-template>
+ </xsl:for-each>
+ </xsl:template>
+
+ <xsl:template name="duplicate">
+ <xsl:param name="value" />
+ <xsl:param name="result" />
+ <xsl:choose>
+ <xsl:when test="contains($value, ' ')">
+ <xsl:call-template name="duplicate">
+ <xsl:with-param name="value" select="substring-after($value, ' ')" />
+ <xsl:with-param name="result" select="concat($result,' ', substring-before($value, ' ') * 2)" />
+ </xsl:call-template>
+ </xsl:when>
+ <xsl:otherwise>
+ <xsl:value-of select="concat($result,' ', $value * 2)" />
+ </xsl:otherwise>
+ </xsl:choose>
+ </xsl:template>
+
+</xsl:stylesheet>
\ No newline at end of file
projects / platform / upstream / coreclr.git / commitdiff