Trim sequence point column numbers greater than 0xffff. (#32688)

Fixes https://github.com/dotnet/roslyn/issues/20118

src/Compilers/CSharp/Test/Emit/PDB/PDBTests.cs

@@ -526,6 +526,130 @@ public void CustomDebugEntryPoint_Errors()
                 Diagnostic(ErrorCode.ERR_DebugEntryPointNotSourceMethodDefinition));
         }
 
+        [ConditionalFact(typeof(WindowsOnly), Reason = ConditionalSkipReason.NativePdbRequiresDesktop)]
+        [WorkItem(768862, "https://devdiv.visualstudio.com/DevDiv/_workitems/edit/768862")]
+        public void TestLargeLineDelta()
+        {
+            var verbatim = string.Join("\r\n", Enumerable.Repeat("x", 1000));
+
+            var source = $@"
+class C {{ public static void Main() => System.Console.WriteLine(@""{verbatim}""); }}
+";
+            var c = CreateCompilationWithMscorlib40AndSystemCore(source, options: TestOptions.DebugDll);
+            c.VerifyPdb("C.Main", @"
+<symbols>
+  <files>
+    <file id=""1"" name="""" language=""C#"" />
+  </files>
+  <methods>
+    <method containingType=""C"" name=""Main"">
+      <customDebugInfo>
+        <using>
+          <namespace usingCount=""0"" />
+        </using>
+      </customDebugInfo>
+      <sequencePoints>
+        <entry offset=""0x0"" startLine=""2"" startColumn=""40"" endLine=""1001"" endColumn=""4"" document=""1"" />
+      </sequencePoints>
+    </method>
+  </methods>
+</symbols>
+", format: DebugInformationFormat.PortablePdb);
+
+            // Native PDBs only support spans with line delta <= 127 (7 bit)
+            // https://github.com/Microsoft/microsoft-pdb/blob/master/include/cvinfo.h#L4621
+            c.VerifyPdb("C.Main", @"
+<symbols>
+  <files>
+    <file id=""1"" name="""" language=""C#"" />
+  </files>
+  <methods>
+    <method containingType=""C"" name=""Main"">
+      <customDebugInfo>
+        <using>
+          <namespace usingCount=""0"" />
+        </using>
+      </customDebugInfo>
+      <sequencePoints>
+        <entry offset=""0x0"" startLine=""2"" startColumn=""40"" endLine=""129"" endColumn=""4"" document=""1"" />
+      </sequencePoints>
+    </method>
+  </methods>
+</symbols>
+", format: DebugInformationFormat.Pdb);
+        }
+
+        [ConditionalFact(typeof(WindowsOnly), Reason = ConditionalSkipReason.NativePdbRequiresDesktop)]
+        [WorkItem(20118, "https://github.com/dotnet/roslyn/issues/20118")]
+        public void TestLargeStartAndEndColumn_SameLine()
+        {
+            var spaces = new string(' ', 0x10000);
+
+            var source = $@"
+class C 
+{{ 
+    public static void Main() => 
+        {spaces}System.Console.WriteLine(""{spaces}""); 
+}}
+";
+            var c = CreateCompilationWithMscorlib40AndSystemCore(source, options: TestOptions.DebugDll);
+            c.VerifyPdb("C.Main", @"
+<symbols>
+  <files>
+    <file id=""1"" name="""" language=""C#"" />
+  </files>
+  <methods>
+    <method containingType=""C"" name=""Main"">
+      <customDebugInfo>
+        <using>
+          <namespace usingCount=""0"" />
+        </using>
+      </customDebugInfo>
+      <sequencePoints>
+        <entry offset=""0x0"" startLine=""5"" startColumn=""65533"" endLine=""5"" endColumn=""65534"" document=""1"" />
+      </sequencePoints>
+    </method>
+  </methods>
+</symbols>
+");
+        }
+
+        [ConditionalFact(typeof(WindowsOnly), Reason = ConditionalSkipReason.NativePdbRequiresDesktop)]
+        [WorkItem(20118, "https://github.com/dotnet/roslyn/issues/20118")]
+        public void TestLargeStartAndEndColumn_DifferentLine()
+        {
+            var spaces = new string(' ', 0x10000);
+
+            var source = $@"
+class C 
+{{ 
+    public static void Main() => 
+        {spaces}System.Console.WriteLine(
+        ""{spaces}""); 
+}}
+";
+            var c = CreateCompilationWithMscorlib40AndSystemCore(source, options: TestOptions.DebugDll);
+            c.VerifyPdb("C.Main", @"
+<symbols>
+  <files>
+    <file id=""1"" name="""" language=""C#"" />
+  </files>
+  <methods>
+    <method containingType=""C"" name=""Main"">
+      <customDebugInfo>
+        <using>
+          <namespace usingCount=""0"" />
+        </using>
+      </customDebugInfo>
+      <sequencePoints>
+        <entry offset=""0x0"" startLine=""5"" startColumn=""65534"" endLine=""6"" endColumn=""65534"" document=""1"" />
+      </sequencePoints>
+    </method>
+  </methods>
+</symbols>
+");
+        }
+
         #endregion
 
         #region Method Bodies

src/Compilers/Core/Portable/CodeGen/RawSequencePoint.cs

@@ -9,7 +9,7 @@ namespace Microsoft.CodeAnalysis.CodeGen
     /// Represents a sequence point before translation by #line/ExternalSource directives.
     /// </summary>
     [DebuggerDisplay("{GetDebuggerDisplay(),nq}")]
-    internal struct RawSequencePoint
+    internal readonly struct RawSequencePoint
     {
         internal readonly SyntaxTree SyntaxTree;
         internal readonly int ILMarker;

src/Compilers/Core/Portable/CodeGen/SequencePointList.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System;
-using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Diagnostics;
-using System.Linq;
-using System.Text;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Text;
-using Roslyn.Utilities;
-using Cci = Microsoft.Cci;
 
 namespace Microsoft.CodeAnalysis.CodeGen
 {
@@ -22,8 +16,6 @@ namespace Microsoft.CodeAnalysis.CodeGen
     /// </summary>
     internal class SequencePointList
     {
-        internal const int HiddenSequencePointLine = 0xFEEFEE;
-
         private readonly SyntaxTree _tree;
         private readonly OffsetAndSpan[] _points;
         private SequencePointList _next;  // Linked list of all points.
@@ -142,7 +134,7 @@ private static OffsetAndSpan[] GetSubArray(ArrayBuilder<RawSequencePoint> seqPoi
                     // a hidden sequence point.
 
                     bool isHidden = span == RawSequencePoint.HiddenSequencePointSpan;
-                    FileLinePositionSpan fileLinePositionSpan = default(FileLinePositionSpan);
+                    FileLinePositionSpan fileLinePositionSpan = default;
                     if (!isHidden)
                     {
                         fileLinePositionSpan = currentTree.GetMappedLineSpanAndVisibility(span, out isHidden);
@@ -161,9 +153,9 @@ private static OffsetAndSpan[] GetSubArray(ArrayBuilder<RawSequencePoint> seqPoi
                             builder.Add(new Cci.SequencePoint(
                                 lastDebugDocument,
                                 offset: offsetAndSpan.Offset,
-                                startLine: HiddenSequencePointLine,
+                                startLine: Cci.SequencePoint.HiddenLine,
                                 startColumn: 0,
-                                endLine: HiddenSequencePointLine,
+                                endLine: Cci.SequencePoint.HiddenLine,
                                 endColumn: 0));
                         }
                     }
@@ -178,13 +170,34 @@ private static OffsetAndSpan[] GetSubArray(ArrayBuilder<RawSequencePoint> seqPoi
 
                         if (lastDebugDocument != null)
                         {
+                            int startLine = (fileLinePositionSpan.StartLinePosition.Line == -1) ? 0 : fileLinePositionSpan.StartLinePosition.Line + 1;
+                            int endLine = (fileLinePositionSpan.EndLinePosition.Line == -1) ? 0 : fileLinePositionSpan.EndLinePosition.Line + 1;
+                            int startColumn = fileLinePositionSpan.StartLinePosition.Character + 1;
+                            int endColumn = fileLinePositionSpan.EndLinePosition.Character + 1;
+
+                            // Trim column number if necessary.
+                            // Column must be in range [0, 0xffff) and end column must be greater than start column if on the same line.
+                            // The Portable PDB specifies 0x10000, but System.Reflection.Metadata reader has an off-by-one error.
+                            // Windows PDBs allow the same range.
+                            const int MaxColumn = ushort.MaxValue - 1;
+
+                            if (startColumn > MaxColumn)
+                            {
+                                startColumn = (startLine == endLine) ? MaxColumn - 1 : MaxColumn;
+                            }
+
+                            if (endColumn > MaxColumn)
+                            {
+                                endColumn = MaxColumn;
+                            }
+
                             builder.Add(new Cci.SequencePoint(
                                 lastDebugDocument,
                                 offset: offsetAndSpan.Offset,
-                                startLine: (fileLinePositionSpan.StartLinePosition.Line == -1) ? 0 : fileLinePositionSpan.StartLinePosition.Line + 1,
-                                startColumn: fileLinePositionSpan.StartLinePosition.Character + 1,
-                                endLine: (fileLinePositionSpan.EndLinePosition.Line == -1) ? 0 : fileLinePositionSpan.EndLinePosition.Line + 1,
-                                endColumn: fileLinePositionSpan.EndLinePosition.Character + 1
+                                startLine: startLine,
+                                startColumn: (ushort)startColumn,
+                                endLine: endLine,
+                                endColumn: (ushort)endColumn
                             ));
                         }
                     }

src/Compilers/Core/Portable/PEWriter/SequencePoint.cs

@@ -8,22 +8,24 @@ namespace Microsoft.Cci
 {
     [SuppressMessage("Performance", "CA1067", Justification = "Equality not actually implemented")]
     [DebuggerDisplay("{" + nameof(GetDebuggerDisplay) + "(),nq}")]
-    internal struct SequencePoint
+    internal readonly struct SequencePoint
     {
+        public const int HiddenLine = 0xfeefee;
+
         public readonly int Offset;
         public readonly int StartLine;
-        public readonly int StartColumn;
         public readonly int EndLine;
-        public readonly int EndColumn;
+        public readonly ushort StartColumn;
+        public readonly ushort EndColumn;
         public readonly DebugSourceDocument Document;
 
         public SequencePoint(
             DebugSourceDocument document,
             int offset,
             int startLine,
-            int startColumn,
+            ushort startColumn,
             int endLine,
-            int endColumn)
+            ushort endColumn)
         {
             Debug.Assert(document != null);
 
@@ -35,7 +37,7 @@ internal struct SequencePoint
             Document = document;
         }
 
-        public bool IsHidden => StartLine == 0xfeefee;
+        public bool IsHidden => StartLine == HiddenLine;
 
         public override int GetHashCode()
         {

src/ExpressionEvaluator/Core/Test/ExpressionCompiler/ExpressionCompilerTestHelpers.cs

@@ -758,7 +758,7 @@ internal static uint GetOffset(int methodToken, ISymUnmanagedReader symReader, i
                 {
                     var sequencePoints = symMethod.GetSequencePoints();
                     ilOffset = atLineNumber < 0
-                        ? sequencePoints.Where(sp => sp.StartLine != SequencePointList.HiddenSequencePointLine).Select(sp => sp.Offset).FirstOrDefault()
+                        ? sequencePoints.Where(sp => sp.StartLine != Cci.SequencePoint.HiddenLine).Select(sp => sp.Offset).FirstOrDefault()
                         : sequencePoints.First(sp => sp.StartLine == atLineNumber).Offset;
                 }
             }