src/Compilers/VisualBasic/Test/Emit/PDB/PDBIteratorTests.vb - main - githubmirror/roslyn

src/Compilers/VisualBasic/Test/Emit/PDB/PDBIteratorTests.vb
589 строк24 KB
Fred Silberberg
Simplify sequence point display (#81104)
10 ноя 2025, 20:11
10 ноя 2025, 20:110544ad5
' 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.

Imports System.IO
Imports System.Reflection.Metadata
Imports Microsoft.CodeAnalysis.Emit
Imports Microsoft.CodeAnalysis.Test.Utilities
Imports Microsoft.Metadata.Tools
Imports Roslyn.Test.Utilities

Namespace Microsoft.CodeAnalysis.VisualBasic.UnitTests.PDB
    Public Class PDBIteratorTests
        Inherits BasicTestBase

        <WorkItem(2736, "https://github.com/dotnet/roslyn/issues/2736")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub SimpleIterator()
            Dim source =
<compilation>
    <file>
Imports System.Collections.Generic

Class C
    Public Iterator Function F() As IEnumerable(Of Integer)
        Yield 1
    End Function
End Class
    </file>
</compilation>

            Dim v = CompileAndVerify(source, options:=TestOptions.DebugDll)

            v.VerifyIL("C.VB$StateMachine_1_F.MoveNext", "
{
  // Code size       63 (0x3f)
  .maxstack  3
  .locals init (Boolean V_0,
                Integer V_1)
 ~IL_0000:  ldarg.0
  IL_0001:  ldfld      ""C.VB$StateMachine_1_F.$State As Integer""
  IL_0006:  stloc.1
  IL_0007:  ldloc.1
  IL_0008:  brfalse.s  IL_0012
  IL_000a:  br.s       IL_000c
  IL_000c:  ldloc.1
  IL_000d:  ldc.i4.1
  IL_000e:  beq.s      IL_0014
  IL_0010:  br.s       IL_0016
  IL_0012:  br.s       IL_0018
  IL_0014:  br.s       IL_0034
  IL_0016:  ldc.i4.0
  IL_0017:  ret
  IL_0018:  ldarg.0
  IL_0019:  ldc.i4.m1
  IL_001a:  dup
  IL_001b:  stloc.1
  IL_001c:  stfld      ""C.VB$StateMachine_1_F.$State As Integer""
 -IL_0021:  nop
 -IL_0022:  ldarg.0
  IL_0023:  ldc.i4.1
  IL_0024:  stfld      ""C.VB$StateMachine_1_F.$Current As Integer""
  IL_0029:  ldarg.0
  IL_002a:  ldc.i4.1
  IL_002b:  dup
  IL_002c:  stloc.1
  IL_002d:  stfld      ""C.VB$StateMachine_1_F.$State As Integer""
  IL_0032:  ldc.i4.1
  IL_0033:  ret
  IL_0034:  ldarg.0
  IL_0035:  ldc.i4.m1
  IL_0036:  dup
  IL_0037:  stloc.1
  IL_0038:  stfld      ""C.VB$StateMachine_1_F.$State As Integer""
 -IL_003d:  ldc.i4.0
  IL_003e:  ret
}
", sequencePointDisplay:=SequencePointDisplayMode.Minimal)
        End Sub

        <WorkItem(651996, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/651996")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub IteratorLambdaWithForEach()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections
Imports System.Collections.Generic

Module Program
    Sub Main(args As String())
        baz(Iterator Function(x)
                Yield 1
                Yield x
            End Function)
    End Sub

    Public Sub baz(Of T)(x As Func(Of Integer, IEnumerable(Of T)))
        For Each i In x(42)
            Console.Write(i)
        Next
    End Sub

End Module
    </file>
</compilation>

            Dim compilation = CompilationUtils.CreateCompilationWithMscorlib40AndVBRuntime(source, TestOptions.DebugExe)
            compilation.VerifyPdb("Program+_Closure$__+VB$StateMachine___Lambda$__0-0.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <entryPoint declaringType="Program" methodName="Main" parameterNames="args"/>
    <methods>
        <method containingType="Program+_Closure$__+VB$StateMachine___Lambda$__0-0" name="MoveNext">
            <customDebugInfo>
                <encLocalSlotMap>
                    <slot kind="20" offset="4"/>
                    <slot kind="27" offset="4"/>
                    <slot kind="21" offset="4"/>
                </encLocalSlotMap>
            </customDebugInfo>
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x2c" startLine="7" startColumn="13" endLine="7" endColumn="33" document="1"/>
                <entry offset="0x2d" startLine="8" startColumn="17" endLine="8" endColumn="24" document="1"/>
                <entry offset="0x48" startLine="9" startColumn="17" endLine="9" endColumn="24" document="1"/>
                <entry offset="0x68" startLine="10" startColumn="13" endLine="10" endColumn="25" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x6a">
                <importsforward declaringType="Program" methodName="Main" parameterNames="args"/>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <WorkItem(651996, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/651996"), WorkItem(789705, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/789705")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub IteratorWithLiftedMultipleSameNameLocals()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic

Module Module1

    Sub Main()
        For Each i In Goo
            Console.Write(i)
        Next
    End Sub

    Iterator Function Goo() As IEnumerable(Of Integer)
        Dim arr(1) As Integer
        arr(0) = 42

        For Each x In arr
            Yield x
            Yield x
        Next

        For Each x In "abc"
            Yield System.Convert.ToInt32(x)
            Yield System.Convert.ToInt32(x)
        Next

    End Function

End Module
    </file>
</compilation>

            Dim compilation = CompilationUtils.CreateCompilationWithMscorlib40AndVBRuntime(source, TestOptions.DebugExe)

            ' VERY IMPORTANT!!!! We must have locals named $VB$ResumableLocal_x$1 and $VB$ResumableLocal_x$2 here
            '                    Even though they do not really exist in IL, EE will rely on them for scoping     
            compilation.VerifyPdb("Module1+VB$StateMachine_1_Goo.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <entryPoint declaringType="Module1" methodName="Main"/>
    <methods>
        <method containingType="Module1+VB$StateMachine_1_Goo" name="MoveNext">
            <customDebugInfo>
                <hoistedLocalScopes format="portable">
                    <slot startOffset="0x41" endOffset="0x183"/>
                    <slot/>
                    <slot/>
                    <slot startOffset="0x6d" endOffset="0xcf"/>
                    <slot/>
                    <slot/>
                    <slot startOffset="0xf7" endOffset="0x167"/>
                </hoistedLocalScopes>
                <encLocalSlotMap>
                    <slot kind="20" offset="-1"/>
                    <slot kind="27" offset="-1"/>
                    <slot kind="1" offset="54"/>
                    <slot kind="1" offset="139"/>
                </encLocalSlotMap>
            </customDebugInfo>
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x41" startLine="12" startColumn="5" endLine="12" endColumn="55" document="1"/>
                <entry offset="0x42" startLine="13" startColumn="13" endLine="13" endColumn="19" document="1"/>
                <entry offset="0x4e" startLine="14" startColumn="9" endLine="14" endColumn="20" document="1"/>
                <entry offset="0x58" startLine="16" startColumn="9" endLine="16" endColumn="26" document="1"/>
                <entry offset="0x6b" hidden="true" document="1"/>
                <entry offset="0x80" startLine="17" startColumn="13" endLine="17" endColumn="20" document="1"/>
                <entry offset="0xa0" startLine="18" startColumn="13" endLine="18" endColumn="20" document="1"/>
                <entry offset="0xc0" startLine="19" startColumn="9" endLine="19" endColumn="13" document="1"/>
                <entry offset="0xc1" hidden="true" document="1"/>
                <entry offset="0xcf" hidden="true" document="1"/>
                <entry offset="0xe0" hidden="true" document="1"/>
                <entry offset="0xe3" startLine="21" startColumn="9" endLine="21" endColumn="28" document="1"/>
                <entry offset="0xf5" hidden="true" document="1"/>
                <entry offset="0x10e" startLine="22" startColumn="13" endLine="22" endColumn="44" document="1"/>
                <entry offset="0x133" startLine="23" startColumn="13" endLine="23" endColumn="44" document="1"/>
                <entry offset="0x158" startLine="24" startColumn="9" endLine="24" endColumn="13" document="1"/>
                <entry offset="0x159" hidden="true" document="1"/>
                <entry offset="0x167" hidden="true" document="1"/>
                <entry offset="0x17b" hidden="true" document="1"/>
                <entry offset="0x181" startLine="26" startColumn="5" endLine="26" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x183">
                <importsforward declaringType="Module1" methodName="Main"/>
                <scope startOffset="0x41" endOffset="0x182">
                    <local name="$VB$ResumableLocal_arr$0" il_index="0" il_start="0x41" il_end="0x182" attributes="0"/>
                    <scope startOffset="0x6d" endOffset="0xce">
                        <local name="$VB$ResumableLocal_x$3" il_index="3" il_start="0x6d" il_end="0xce" attributes="0"/>
                    </scope>
                    <scope startOffset="0xf7" endOffset="0x166">
                        <local name="$VB$ResumableLocal_x$6" il_index="6" il_start="0xf7" il_end="0x166" attributes="0"/>
                    </scope>
                </scope>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <WorkItem(827337, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/827337"), WorkItem(836491, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/836491")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub LocalCapturedAndHoisted()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic

Public Class C
    Private Iterator Function Iterator_Lambda_Hoisted() As IEnumerable(Of Integer)
        Dim x As Integer = 1
        Dim y As Integer = 2

        Dim a As Func(Of Integer) = Function() x + y

        Yield x + y
        x.ToString()
        y.ToString()
    End Function
End Class
    </file>
</compilation>

            Dim compilation = CompilationUtils.CreateCompilationWithMscorlib40AndVBRuntime(
                    source,
                    TestOptions.ReleaseDll)

            ' Goal: We're looking for the double-mangled name "$VB$ResumableLocal_$VB$Closure_$0".
            ' Note: since the method is first, it is recording the imports (rather than using an importsforward)
            compilation.VerifyPdb("C+VB$StateMachine_1_Iterator_Lambda_Hoisted.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <methods>
        <method containingType="C+VB$StateMachine_1_Iterator_Lambda_Hoisted" name="MoveNext">
            <customDebugInfo>
                <hoistedLocalScopes format="portable">
                    <slot startOffset="0x19" endOffset="0x98"/>
                </hoistedLocalScopes>
            </customDebugInfo>
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x19" hidden="true" document="1"/>
                <entry offset="0x24" startLine="6" startColumn="13" endLine="6" endColumn="29" document="1"/>
                <entry offset="0x30" startLine="7" startColumn="13" endLine="7" endColumn="29" document="1"/>
                <entry offset="0x3c" startLine="9" startColumn="13" endLine="9" endColumn="53" document="1"/>
                <entry offset="0x43" startLine="11" startColumn="9" endLine="11" endColumn="20" document="1"/>
                <entry offset="0x74" startLine="12" startColumn="9" endLine="12" endColumn="21" document="1"/>
                <entry offset="0x85" startLine="13" startColumn="9" endLine="13" endColumn="21" document="1"/>
                <entry offset="0x96" startLine="14" startColumn="5" endLine="14" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x98">
                <namespace name="System" importlevel="file"/>
                <namespace name="System.Collections.Generic" importlevel="file"/>
                <currentnamespace name=""/>
                <scope startOffset="0x19" endOffset="0x97">
                    <local name="$VB$ResumableLocal_$VB$Closure_$0" il_index="0" il_start="0x19" il_end="0x97" attributes="0"/>
                </scope>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <WorkItem(827337, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/827337"), WorkItem(836491, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/836491")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub LocalCapturedAndNotHoisted()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic

Public Class C
    Private Iterator Function Iterator_Lambda_NotHoisted() As IEnumerable(Of Integer)
        Dim x As Integer = 1
        Dim y As Integer = 2

        Dim a As Func(Of Integer) = Function() x + y

        Yield x + y
    End Function
End Class
    </file>
</compilation>

            Dim compilation = CompilationUtils.CreateCompilationWithMscorlib40AndVBRuntime(
                    source,
                    TestOptions.ReleaseDll)

            ' Goal: We're looking for the single-mangled name "$VB$Closure_0".
            compilation.VerifyPdb("C+VB$StateMachine_1_Iterator_Lambda_NotHoisted.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <methods>
        <method containingType="C+VB$StateMachine_1_Iterator_Lambda_NotHoisted" name="MoveNext">
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x19" hidden="true" document="1"/>
                <entry offset="0x1f" startLine="6" startColumn="13" endLine="6" endColumn="29" document="1"/>
                <entry offset="0x26" startLine="7" startColumn="13" endLine="7" endColumn="29" document="1"/>
                <entry offset="0x2d" startLine="11" startColumn="9" endLine="11" endColumn="20" document="1"/>
                <entry offset="0x54" startLine="12" startColumn="5" endLine="12" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x56">
                <namespace name="System" importlevel="file"/>
                <namespace name="System.Collections.Generic" importlevel="file"/>
                <currentnamespace name=""/>
                <scope startOffset="0x19" endOffset="0x55">
                    <local name="$VB$Closure_0" il_index="1" il_start="0x19" il_end="0x55" attributes="0"/>
                </scope>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <WorkItem(827337, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/827337"), WorkItem(836491, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/836491")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub LocalHoistedAndNotCapture()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic

Public Class C
    Private Iterator Function Iterator_NoLambda_Hoisted() As IEnumerable(Of Integer)
        Dim x As Integer = 1
        Dim y As Integer = 2
        Yield x + y
        x.ToString()
        y.ToString()
    End Function
End Class
    </file>
</compilation>

            Dim compilation = CreateCompilationWithMscorlib40AndVBRuntime(source, TestOptions.ReleaseDll)

            ' Goal: We're looking for the single-mangled names "$VB$ResumableLocal_x$0" and "$VB$ResumableLocal_y$1".
            compilation.VerifyPdb("C+VB$StateMachine_1_Iterator_NoLambda_Hoisted.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <methods>
        <method containingType="C+VB$StateMachine_1_Iterator_NoLambda_Hoisted" name="MoveNext">
            <customDebugInfo>
                <hoistedLocalScopes format="portable">
                    <slot startOffset="0x19" endOffset="0x68"/>
                    <slot startOffset="0x19" endOffset="0x68"/>
                </hoistedLocalScopes>
            </customDebugInfo>
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x19" startLine="6" startColumn="13" endLine="6" endColumn="29" document="1"/>
                <entry offset="0x20" startLine="7" startColumn="13" endLine="7" endColumn="29" document="1"/>
                <entry offset="0x27" startLine="8" startColumn="9" endLine="8" endColumn="20" document="1"/>
                <entry offset="0x4e" startLine="9" startColumn="9" endLine="9" endColumn="21" document="1"/>
                <entry offset="0x5a" startLine="10" startColumn="9" endLine="10" endColumn="21" document="1"/>
                <entry offset="0x66" startLine="11" startColumn="5" endLine="11" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x68">
                <namespace name="System" importlevel="file"/>
                <namespace name="System.Collections.Generic" importlevel="file"/>
                <currentnamespace name=""/>
                <scope startOffset="0x19" endOffset="0x67">
                    <local name="$VB$ResumableLocal_x$0" il_index="0" il_start="0x19" il_end="0x67" attributes="0"/>
                    <local name="$VB$ResumableLocal_y$1" il_index="1" il_start="0x19" il_end="0x67" attributes="0"/>
                </scope>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <WorkItem(827337, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/827337"), WorkItem(836491, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/836491")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub LocalNotHoistedAndNotCaptured()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic

Public Class C
    Private Iterator Function Iterator_NoLambda_NotHoisted() As IEnumerable(Of Integer)
        Dim x As Integer = 1
        Dim y As Integer = 2
        Yield x + y
    End Function
End Class
    </file>
</compilation>

            Dim compilation = CreateCompilationWithMscorlib40AndVBRuntime(source, TestOptions.ReleaseDll)

            ' Goal: We're looking for the unmangled names "x" and "y".
            compilation.VerifyPdb("C+VB$StateMachine_1_Iterator_NoLambda_NotHoisted.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <methods>
        <method containingType="C+VB$StateMachine_1_Iterator_NoLambda_NotHoisted" name="MoveNext">
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x19" startLine="6" startColumn="13" endLine="6" endColumn="29" document="1"/>
                <entry offset="0x1b" startLine="7" startColumn="13" endLine="7" endColumn="29" document="1"/>
                <entry offset="0x1d" startLine="8" startColumn="9" endLine="8" endColumn="20" document="1"/>
                <entry offset="0x3a" startLine="9" startColumn="5" endLine="9" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x3c">
                <namespace name="System" importlevel="file"/>
                <namespace name="System.Collections.Generic" importlevel="file"/>
                <currentnamespace name=""/>
                <scope startOffset="0x19" endOffset="0x3b">
                    <local name="x" il_index="1" il_start="0x19" il_end="0x3b" attributes="0"/>
                    <local name="y" il_index="2" il_start="0x19" il_end="0x3b" attributes="0"/>
                </scope>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        ''' <summary>
        ''' Sequence points of MoveNext method shall not be affected by DebuggerHidden attribute. 
        ''' The method contains user code that can be edited during debugging and might need remapping.
        ''' </summary>
        <WorkItem(667579, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/667579")>
        <ConditionalFact(GetType(WindowsOnly), Reason:=ConditionalSkipReason.NativePdbRequiresDesktop)>
        Public Sub DebuggerHiddenIterator()
            Dim source =
<compilation>
    <file>
Imports System
Imports System.Collections.Generic
Imports System.Diagnostics
Module Module1

    Sub Main()
        For Each i In Goo
            Console.Write(i)
        Next
    End Sub

    &lt;DebuggerHidden&gt;
    Iterator Function Goo() As IEnumerable(Of Integer)
        Yield 1
        Yield 2
    End Function

End Module
    </file>
</compilation>

            Dim compilation = CompilationUtils.CreateCompilationWithMscorlib40AndVBRuntime(source, TestOptions.DebugExe)
            compilation.VerifyPdb("Module1+VB$StateMachine_1_Goo.MoveNext",
<symbols>
    <files>
        <file id="1" name="" language="VB"/>
    </files>
    <entryPoint declaringType="Module1" methodName="Main"/>
    <methods>
        <method containingType="Module1+VB$StateMachine_1_Goo" name="MoveNext">
            <customDebugInfo>
                <encLocalSlotMap>
                    <slot kind="20" offset="-1"/>
                    <slot kind="27" offset="-1"/>
                </encLocalSlotMap>
            </customDebugInfo>
            <sequencePoints>
                <entry offset="0x0" hidden="true" document="1"/>
                <entry offset="0x2c" startLine="13" startColumn="5" endLine="13" endColumn="55" document="1"/>
                <entry offset="0x2d" startLine="14" startColumn="9" endLine="14" endColumn="16" document="1"/>
                <entry offset="0x48" startLine="15" startColumn="9" endLine="15" endColumn="16" document="1"/>
                <entry offset="0x63" startLine="16" startColumn="5" endLine="16" endColumn="17" document="1"/>
            </sequencePoints>
            <scope startOffset="0x0" endOffset="0x65">
                <importsforward declaringType="Module1" methodName="Main"/>
            </scope>
        </method>
    </methods>
</symbols>)
        End Sub

        <Fact>
        <WorkItem(8473, "https://github.com/dotnet/roslyn/issues/8473")>
        Public Sub PortableStateMachineDebugInfo()
            Dim src = "
Imports System.Collections.Generic
Public Class C
    Iterator Function M() As IEnumerable(Of Integer) 
       Yield 1
    End Function
End Class"
            Dim compilation = CreateEmptyCompilation(src, LatestVbReferences, options:=TestOptions.DebugDll)
            compilation.VerifyDiagnostics()

            Dim peStream = New MemoryStream()
            Dim pdbStream = New MemoryStream()
            Dim result = compilation.Emit(peStream, pdbStream, options:=EmitOptions.Default.WithDebugInformationFormat(DebugInformationFormat.PortablePdb))
            pdbStream.Position = 0

            Using provider = MetadataReaderProvider.FromPortablePdbStream(pdbStream)
                Dim mdReader = provider.GetMetadataReader()
                Dim writer = New StringWriter()
                Dim visualizer = New MetadataVisualizer(mdReader, writer, MetadataVisualizerOptions.NoHeapReferences)
                visualizer.WriteMethodDebugInformation()

                AssertEx.AssertEqualToleratingWhitespaceDifferences("
MethodDebugInformation (index: 0x31, size: 40): 
================================================
   IL   
================================================
1: nil  
2: nil  
3: nil  
4: nil  
5:      
{
  Kickoff Method: 0x06000002 (MethodDef)
  Locals: 0x11000002 (StandAloneSig)
  Document: #1
  IL_0000: <hidden>
  IL_0021: (4, 5) - (4, 53)
  IL_0022: (5, 8) - (5, 15)
  IL_003D: (6, 5) - (6, 17)
}
6: nil  
7: nil  
8: nil  
9: nil  
a: nil", writer.ToString())
            End Using
        End Sub
    End Class
End Namespace