EnC: Implements support for #line mappings

Roslyn.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.28503.202
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31319.15
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "RoslynDeployment", "src\Deployment\RoslynDeployment.csproj", "{600AF682-E097-407B-AD85-EE3CED37E680}"
 EndProject
@@ -1274,6 +1274,22 @@ Global
 		{21B49277-E55A-45EF-8818-744BCD6CB732}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{21B49277-E55A-45EF-8818-744BCD6CB732}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{21B49277-E55A-45EF-8818-744BCD6CB732}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BB987FFC-B758-4F73-96A3-923DE8DCFF1A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BB987FFC-B758-4F73-96A3-923DE8DCFF1A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BB987FFC-B758-4F73-96A3-923DE8DCFF1A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BB987FFC-B758-4F73-96A3-923DE8DCFF1A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1B73FB08-9A17-497E-97C5-FA312867D51B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1B73FB08-9A17-497E-97C5-FA312867D51B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1B73FB08-9A17-497E-97C5-FA312867D51B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1B73FB08-9A17-497E-97C5-FA312867D51B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{AE976DE9-811D-4C86-AEBB-DCDC1226D754}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{AE976DE9-811D-4C86-AEBB-DCDC1226D754}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{AE976DE9-811D-4C86-AEBB-DCDC1226D754}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{AE976DE9-811D-4C86-AEBB-DCDC1226D754}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3829F774-33F2-41E9-B568-AE555004FC62}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3829F774-33F2-41E9-B568-AE555004FC62}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3829F774-33F2-41E9-B568-AE555004FC62}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3829F774-33F2-41E9-B568-AE555004FC62}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/Compilers/CSharp/Portable/PublicAPI.Unshipped.txt

@@ -27,3 +27,4 @@ Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax.GlobalKeyword.get -> M
 Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax.Update(Microsoft.CodeAnalysis.SyntaxToken globalKeyword, Microsoft.CodeAnalysis.SyntaxToken usingKeyword, Microsoft.CodeAnalysis.SyntaxToken staticKeyword, Microsoft.CodeAnalysis.CSharp.Syntax.NameEqualsSyntax alias, Microsoft.CodeAnalysis.CSharp.Syntax.NameSyntax name, Microsoft.CodeAnalysis.SyntaxToken semicolonToken) -> Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax
 Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax.WithGlobalKeyword(Microsoft.CodeAnalysis.SyntaxToken globalKeyword) -> Microsoft.CodeAnalysis.CSharp.Syntax.UsingDirectiveSyntax
 *REMOVED*Microsoft.CodeAnalysis.CSharp.SyntaxKind.DataKeyword = 8441 -> Microsoft.CodeAnalysis.CSharp.SyntaxKind
+override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.GetLineMappings(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Collections.Generic.IEnumerable<Microsoft.CodeAnalysis.LineMapping>

src/Compilers/CSharp/Portable/Syntax/CSharpLineDirectiveMap.cs

@@ -135,6 +135,10 @@ public override LineVisibility GetLineVisibility(SourceText sourceText, int posi
             }
         }
 
+        // C# does not have unknown visibility state
+        protected override LineVisibility GetUnknownStateVisibility(int index)
+            => throw ExceptionUtilities.Unreachable;
+
         internal override FileLinePositionSpan TranslateSpanAndVisibility(SourceText sourceText, string treeFilePath, TextSpan span, out bool isHiddenPosition)
         {
             var lines = sourceText.Lines;

src/Compilers/CSharp/Portable/Syntax/CSharpSyntaxTree.cs

@@ -8,6 +8,7 @@
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Threading;
@@ -607,6 +608,17 @@ public override IList<TextChange> GetChanges(SyntaxTree oldTree)
 
         #region LinePositions and Locations
 
+        private CSharpLineDirectiveMap GetDirectiveMap()
+        {
+            if (_lazyLineDirectiveMap == null)
+            {
+                // Create the line directive map on demand.
+                Interlocked.CompareExchange(ref _lazyLineDirectiveMap, new CSharpLineDirectiveMap(this), null);
+            }
+
+            return _lazyLineDirectiveMap;
+        }
+
         /// <summary>
         /// Gets the location in terms of path, line and column for a given span.
         /// </summary>
@@ -617,9 +629,7 @@ public override IList<TextChange> GetChanges(SyntaxTree oldTree)
         /// </returns>
         /// <remarks>The values are not affected by line mapping directives (<c>#line</c>).</remarks>
         public override FileLinePositionSpan GetLineSpan(TextSpan span, CancellationToken cancellationToken = default)
-        {
-            return new FileLinePositionSpan(this.FilePath, GetLinePosition(span.Start), GetLinePosition(span.End));
-        }
+            => new(FilePath, GetLinePosition(span.Start, cancellationToken), GetLinePosition(span.End, cancellationToken));
 
         /// <summary>
         /// Gets the location in terms of path, line and column after applying source line mapping directives (<c>#line</c>).
@@ -638,25 +648,18 @@ public override FileLinePositionSpan GetLineSpan(TextSpan span, CancellationToke
         /// </para>
         /// </returns>
         public override FileLinePositionSpan GetMappedLineSpan(TextSpan span, CancellationToken cancellationToken = default)
-        {
-            if (_lazyLineDirectiveMap == null)
-            {
-                // Create the line directive map on demand.
-                Interlocked.CompareExchange(ref _lazyLineDirectiveMap, new CSharpLineDirectiveMap(this), null);
-            }
-
-            return _lazyLineDirectiveMap.TranslateSpan(this.GetText(cancellationToken), this.FilePath, span);
-        }
+            => GetDirectiveMap().TranslateSpan(GetText(cancellationToken), this.FilePath, span);
 
+        /// <inheritdoc/>
         public override LineVisibility GetLineVisibility(int position, CancellationToken cancellationToken = default)
-        {
-            if (_lazyLineDirectiveMap == null)
-            {
-                // Create the line directive map on demand.
-                Interlocked.CompareExchange(ref _lazyLineDirectiveMap, new CSharpLineDirectiveMap(this), null);
-            }
+            => GetDirectiveMap().GetLineVisibility(GetText(cancellationToken), position);
 
-            return _lazyLineDirectiveMap.GetLineVisibility(this.GetText(cancellationToken), position);
+        /// <inheritdoc/>
+        public override IEnumerable<LineMapping> GetLineMappings(CancellationToken cancellationToken = default)
+        {
+            var map = GetDirectiveMap();
+            Debug.Assert(map.Entries.Length >= 1);
+            return (map.Entries.Length == 1) ? Array.Empty<LineMapping>() : map.GetLineMappings(GetText(cancellationToken).Lines);
         }
 
         /// <summary>
@@ -667,30 +670,14 @@ public override LineVisibility GetLineVisibility(int position, CancellationToken
         /// <param name="isHiddenPosition">When the method returns, contains a boolean value indicating whether this span is considered hidden or not.</param>
         /// <returns>A resulting <see cref="FileLinePositionSpan"/>.</returns>
         internal override FileLinePositionSpan GetMappedLineSpanAndVisibility(TextSpan span, out bool isHiddenPosition)
-        {
-            if (_lazyLineDirectiveMap == null)
-            {
-                // Create the line directive map on demand.
-                Interlocked.CompareExchange(ref _lazyLineDirectiveMap, new CSharpLineDirectiveMap(this), null);
-            }
-
-            return _lazyLineDirectiveMap.TranslateSpanAndVisibility(this.GetText(), this.FilePath, span, out isHiddenPosition);
-        }
+            => GetDirectiveMap().TranslateSpanAndVisibility(GetText(), FilePath, span, out isHiddenPosition);
 
         /// <summary>
         /// Gets a boolean value indicating whether there are any hidden regions in the tree.
         /// </summary>
         /// <returns>True if there is at least one hidden region.</returns>
         public override bool HasHiddenRegions()
-        {
-            if (_lazyLineDirectiveMap == null)
-            {
-                // Create the line directive map on demand.
-                Interlocked.CompareExchange(ref _lazyLineDirectiveMap, new CSharpLineDirectiveMap(this), null);
-            }
-
-            return _lazyLineDirectiveMap.HasAnyHiddenRegions();
-        }
+            => GetDirectiveMap().HasAnyHiddenRegions();
 
         /// <summary>
         /// Given the error code and the source location, get the warning state based on <c>#pragma warning</c> directives.
@@ -756,10 +743,8 @@ bool isGeneratedHeuristic()
 
         private GeneratedKind _lazyIsGeneratedCode = GeneratedKind.Unknown;
 
-        private LinePosition GetLinePosition(int position)
-        {
-            return this.GetText().Lines.GetLinePosition(position);
-        }
+        private LinePosition GetLinePosition(int position, CancellationToken cancellationToken)
+            => GetText(cancellationToken).Lines.GetLinePosition(position);
 
         /// <summary>
         /// Gets a <see cref="Location"/> for the specified text <paramref name="span"/>.

src/Compilers/CSharp/Test/Syntax/Diagnostics/LocationsTests.cs

@@ -5,10 +5,10 @@
 #nullable disable
 
 using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.IO;
 using System.Linq;
-using Microsoft.CodeAnalysis.Test.Utilities;
 using Microsoft.CodeAnalysis.Text;
 using Roslyn.Test.Utilities;
 using Xunit;
@@ -71,6 +71,12 @@ private TextSpan GetSpanIn(SyntaxTree syntaxTree, string textToFind)
             return new TextSpan(index, textToFind.Length);
         }
 
+        private static IEnumerable<string> InspectLineMapping(SyntaxTree tree)
+        {
+            var text = tree.GetText();
+            return tree.GetLineMappings().Select(mapping => $"[|{text.GetSubText(text.Lines.GetTextSpan(mapping.Span))}|] -> {(mapping.IsHidden ? "<hidden>" : mapping.MappedSpan)}");
+        }
+
         [ClrOnlyFact]
         public void TestGetSourceLocationInFile()
         {
@@ -120,7 +126,7 @@ public void TestLineMapping1()
             string sampleProgram = @"using System;
 class X {
 #line 20 ""banana.cs""
-int x; 
+int x;
 int y;
 #line 44
 int z;
@@ -134,7 +140,6 @@ class X {
 #endif
 int a;
 }".NormalizeLineEndings();
-            var resolver = new TestSourceResolver();
 
             SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "goo.cs");
 
@@ -147,6 +152,15 @@ class X {
             AssertMappedSpanEqual(syntaxTree, "w;", "goo.cs", 8, 4, 8, 6, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, "q;\r\nin", "goo.cs", 10, 4, 11, 2, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, "a;", "goo.cs", 15, 4, 15, 6, hasMappedPath: false);
+
+            AssertEx.Equal(new[]
+            {
+                "[|using System;\r\nclass X {\r\n|] -> : (0,0)-(1,11)",
+                "[|int x;\r\nint y;\r\n|] -> banana.cs: (19,0)-(20,8)",
+                "[|int z;\r\n|] -> banana.cs: (43,0)-(43,8)",
+                "[|int w;\r\n|] -> : (8,0)-(8,8)",
+                "[|int q;\r\nint f;\r\n#if false\r\n#line 17 \"d:\\twing.cs\"\r\n#endif\r\nint a;\r\n}|] -> <hidden>"
+            }, InspectLineMapping(syntaxTree));
         }
 
         [Fact]
@@ -165,8 +179,6 @@ class X {
 #line 40
 int v;
 }";
-            var resolver = new TestSourceResolver();
-
             SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "c:\\goo.cs");
 
             AssertMappedSpanEqual(syntaxTree, "int x;", "c:\\goo.cs", 19, 0, 19, 6, hasMappedPath: false);
@@ -183,8 +195,6 @@ public void TestLineMapping_NoSyntaxTreePath()
 #line 20
 class X {}
 ";
-            var resolver = new TestSourceResolver();
-
             AssertMappedSpanEqual(SyntaxFactory.ParseSyntaxTree(sampleProgram, path: ""), "class X {}", "", 19, 0, 19, 10, hasMappedPath: false);
             AssertMappedSpanEqual(SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "   "), "class X {}", "   ", 19, 0, 19, 10, hasMappedPath: false);
         }
@@ -194,32 +204,91 @@ public void TestInvalidLineMapping()
         {
             string sampleProgram = @"using System;
 class X {
-    int q; 
+    int q;
 #line 0 ""firstdirective""
-    int r; 
+    int r;
 #line 20 ""seconddirective""
-    int s; 
-}";
+    int s;
+}".NormalizeLineEndings();
+
             SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "filename.cs");
 
             AssertMappedSpanEqual(syntaxTree, "int q", "filename.cs", 2, 4, 2, 9, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, "int r", "filename.cs", 4, 4, 4, 9, hasMappedPath: false); // invalid #line args
             AssertMappedSpanEqual(syntaxTree, "int s", "seconddirective", 19, 4, 19, 9, hasMappedPath: true);
+
+            AssertEx.Equal(new[]
+            {
+                "[|using System;\r\nclass X {\r\n    int q;\r\n|] -> : (0,0)-(2,12)",
+                "[|    int r;\r\n|] -> : (4,0)-(4,12)",
+                "[|    int s;\r\n}|] -> seconddirective: (19,0)-(20,1)"
+            }, InspectLineMapping(syntaxTree));
         }
 
         [Fact]
         public void TestLineMappingNoDirectives()
         {
             string sampleProgram = @"using System;
 class X {
-int x; 
+int x;
 }";
             SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "c:\\goo.cs");
 
             AssertMappedSpanEqual(syntaxTree, "ing Sy", "c:\\goo.cs", 0, 2, 0, 8, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, "class X", "c:\\goo.cs", 1, 0, 1, 7, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, $"System;{Environment.NewLine}class X", "c:\\goo.cs", 0, 6, 1, 7, hasMappedPath: false);
             AssertMappedSpanEqual(syntaxTree, "x;", "c:\\goo.cs", 2, 4, 2, 6, hasMappedPath: false);
+
+            Assert.Empty(InspectLineMapping(syntaxTree));
+        }
+
+        [Fact]
+        public void TestLineMappingFirstAndLastLineDirectives()
+        {
+            string sampleProgram = @"#line 20
+class X {}
+#line 30".NormalizeLineEndings();
+            var syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "c:\\goo.cs");
+
+            AssertEx.Equal(new[]
+            {
+                "[|class X {}\r\n|] -> : (19,0)-(19,12)",
+            }, InspectLineMapping(syntaxTree));
+        }
+
+        [Fact]
+        public void TestLineMappingLastLineDirectiveFollowedByEmptyLine()
+        {
+            string sampleProgram = @"#line 30
+".NormalizeLineEndings();
+
+            var syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "c:\\goo.cs");
+
+            AssertEx.Equal(new[]
+            {
+                "[||] -> : (29,0)-(29,0)",
+            }, InspectLineMapping(syntaxTree));
+        }
+
+        [Fact]
+        public void TestLineMappingConsecutiveDirectives()
+        {
+            string sampleProgram =
+@"#line hidden
+#line default
+class C {}
+#line 5
+#line 10
+class D {}
+".NormalizeLineEndings();
+
+            var syntaxTree = SyntaxFactory.ParseSyntaxTree(sampleProgram, path: "c:\\goo.cs");
+
+            AssertEx.Equal(new[]
+            {
+                "[|class C {}\r\n|] -> : (2,0)-(2,12)",
+                "[|class D {}\r\n|] -> : (9,0)-(10,0)",
+            }, InspectLineMapping(syntaxTree));
         }
 
         [WorkItem(537005, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/537005")]