Add missing sequence point in lowering of conditional statement (#19336)

src/Compilers/CSharp/Portable/Lowering/LocalRewriter/LocalRewriter_IfStatement.cs

@@ -59,6 +59,7 @@ public override BoundNode VisitIfStatement(BoundIfStatement node)
 
                 builder.Add(new BoundConditionalGoto(rewrittenCondition.Syntax, rewrittenCondition, false, afterif));
                 builder.Add(rewrittenConsequence);
+                builder.Add(new BoundSequencePoint(null, null));
                 builder.Add(new BoundLabelStatement(syntax, afterif));
                 var statements = builder.ToImmutableAndFree();
                 return new BoundStatementList(syntax, statements, hasErrors);
@@ -86,6 +87,7 @@ public override BoundNode VisitIfStatement(BoundIfStatement node)
                 builder.Add(new BoundGotoStatement(syntax, afterif));
                 builder.Add(new BoundLabelStatement(syntax, alt));
                 builder.Add(rewrittenAlternativeOpt);
+                builder.Add(new BoundSequencePoint(null, null));
                 builder.Add(new BoundLabelStatement(syntax, afterif));
                 return new BoundStatementList(syntax, builder.ToImmutableAndFree(), hasErrors);
             }

src/Compilers/CSharp/Portable/Lowering/LocalRewriter/LocalRewriter_ReturnStatement.cs

@@ -28,10 +28,6 @@ public override BoundNode VisitReturnStatement(BoundReturnStatement node)
             {
                 rewritten = _instrumenter.InstrumentReturnStatement(node, rewritten);
             }
-            else if (node.WasCompilerGenerated && _factory.CurrentMethod?.IsAsync == true)
-            {
-                rewritten = new BoundSequencePoint(null, rewritten);
-            }
 
             return rewritten;
         }

src/Compilers/CSharp/Test/Emit/CodeGen/CodeGenLockTests.cs

@@ -57,7 +57,7 @@ .maxstack  2
     IL_0023:  brfalse.s  IL_002b
     IL_0025:  ldloc.0
     IL_0026:  call       ""void System.Threading.Monitor.Exit(object)""
-    IL_002b:  endfinally
+   ~IL_002b:  endfinally
   }
  -IL_002c:  ldstr      ""After""
   IL_0031:  call       ""void System.Console.WriteLine(string)""
@@ -112,7 +112,7 @@ .maxstack  2
     IL_0027:  brfalse.s  IL_002f
     IL_0029:  ldloc.0
     IL_002a:  call       ""void System.Threading.Monitor.Exit(object)""
-    IL_002f:  endfinally
+   ~IL_002f:  endfinally
   }
  -IL_0030:  ldstr      ""After""
   IL_0035:  call       ""void System.Console.WriteLine(string)""
@@ -387,7 +387,7 @@ .maxstack  2
     IL_0027:  brfalse.s  IL_002f
     IL_0029:  ldloc.0
     IL_002a:  call       ""void System.Threading.Monitor.Exit(object)""
-    IL_002f:  endfinally
+   ~IL_002f:  endfinally
   }
  -IL_0030:  ldstr      ""After""
   IL_0035:  call       ""void System.Console.WriteLine(string)""

src/Compilers/CSharp/Test/Emit/Emit/EditAndContinue/LocalSlotMappingTests.cs

@@ -349,10 +349,12 @@ static void M()
         <entry offset=""0x12"" startLine=""9"" startColumn=""20"" endLine=""9"" endColumn=""21"" />
         <entry offset=""0x13"" startLine=""9"" startColumn=""22"" endLine=""9"" endColumn=""23"" />
         <entry offset=""0x16"" hidden=""true"" />
+        <entry offset=""0x20"" hidden=""true"" />
         <entry offset=""0x21"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""20"" />
         <entry offset=""0x27"" startLine=""10"" startColumn=""21"" endLine=""10"" endColumn=""22"" />
         <entry offset=""0x28"" startLine=""10"" startColumn=""23"" endLine=""10"" endColumn=""24"" />
         <entry offset=""0x2b"" hidden=""true"" />
+        <entry offset=""0x35"" hidden=""true"" />
         <entry offset=""0x36"" startLine=""11"" startColumn=""5"" endLine=""11"" endColumn=""6"" />
       </sequencePoints>
     </method>
@@ -370,9 +372,11 @@ static void M()
         <entry offset=""0x0"" startLine=""9"" startColumn=""9"" endLine=""9"" endColumn=""19"" />
         <entry offset=""0x10"" startLine=""9"" startColumn=""22"" endLine=""9"" endColumn=""23"" />
         <entry offset=""0x12"" hidden=""true"" />
+        <entry offset=""0x1b"" hidden=""true"" />
         <entry offset=""0x1c"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""20"" />
         <entry offset=""0x22"" startLine=""10"" startColumn=""23"" endLine=""10"" endColumn=""24"" />
         <entry offset=""0x24"" hidden=""true"" />
+        <entry offset=""0x2d"" hidden=""true"" />
         <entry offset=""0x2e"" startLine=""11"" startColumn=""5"" endLine=""11"" endColumn=""6"" />
       </sequencePoints>
     </method>
@@ -559,7 +563,7 @@ .maxstack  2
       IL_002b:  ldloc.2
       IL_002c:  call       ""void System.Threading.Monitor.Exit(object)""
       IL_0031:  nop
-      IL_0032:  endfinally
+     ~IL_0032:  endfinally
     }
    -IL_0033:  nop
     IL_0034:  leave.s    IL_0041
@@ -571,7 +575,7 @@ .maxstack  2
     IL_0039:  ldloc.0
     IL_003a:  call       ""void System.Threading.Monitor.Exit(object)""
     IL_003f:  nop
-    IL_0040:  endfinally
+   ~IL_0040:  endfinally
   }
  -IL_0041:  ret
 }
@@ -1787,7 +1791,7 @@ .maxstack  2
     IL_0010:  ldloc.s    V_6
     IL_0012:  callvirt   ""void System.IDisposable.Dispose()""
     IL_0017:  nop
-    IL_0018:  endfinally
+   ~IL_0018:  endfinally
   }
  -IL_0019:  call       ""object C.F1()""
   IL_001e:  stloc.0
@@ -1810,7 +1814,7 @@ .maxstack  2
     IL_0031:  ldloc.0
     IL_0032:  call       ""void System.Threading.Monitor.Exit(object)""
     IL_0037:  nop
-    IL_0038:  endfinally
+   ~IL_0038:  endfinally
   }
  -IL_0039:  nop
  -IL_003a:  call       ""string C.F2()""

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

@@ -159,7 +159,7 @@ .maxstack  3
    -IL_00e5:  ldsfld     ""System.Threading.AutoResetEvent Driver.CompletedSignal""
     IL_00ea:  callvirt   ""bool System.Threading.EventWaitHandle.Set()""
     IL_00ef:  pop
-   ~IL_00f0:  leave.s    IL_010c
+    IL_00f0:  leave.s    IL_010c
   }
   catch System.Exception
   {
@@ -288,7 +288,6 @@ .maxstack  3
         <entry offset=""0xcd"" startLine=""18"" startColumn=""24"" endLine=""18"" endColumn=""32"" />
         <entry offset=""0xd9"" startLine=""20"" startColumn=""9"" endLine=""20"" endColumn=""44"" />
         <entry offset=""0xe5"" startLine=""22"" startColumn=""9"" endLine=""22"" endColumn=""38"" />
-        <entry offset=""0xf0"" hidden=""true"" />
         <entry offset=""0xf2"" hidden=""true"" />
         <entry offset=""0x10c"" startLine=""23"" startColumn=""5"" endLine=""23"" endColumn=""6"" />
         <entry offset=""0x114"" hidden=""true"" />
@@ -444,7 +443,6 @@ private Task<int> GetNextInt(Random random)
         <entry offset=""0xe"" startLine=""16"" startColumn=""9"" endLine=""16"" endColumn=""10"" />
         <entry offset=""0xf"" startLine=""17"" startColumn=""13"" endLine=""17"" endColumn=""26"" />
         <entry offset=""0x20"" hidden=""true"" />
-        <entry offset=""0x71"" hidden=""true"" />
         <entry offset=""0x73"" hidden=""true"" />
         <entry offset=""0x8b"" startLine=""18"" startColumn=""9"" endLine=""18"" endColumn=""10"" />
         <entry offset=""0x93"" hidden=""true"" />
@@ -558,7 +556,6 @@ static async void Await(dynamic d)
         <entry offset=""0x11"" startLine=""5"" startColumn=""5"" endLine=""5"" endColumn=""6"" />
         <entry offset=""0x12"" startLine=""6"" startColumn=""9"" endLine=""6"" endColumn=""27"" />
         <entry offset=""0xae"" hidden=""true"" />
-        <entry offset=""0x22c"" hidden=""true"" />
         <entry offset=""0x22e"" hidden=""true"" />
         <entry offset=""0x248"" startLine=""7"" startColumn=""5"" endLine=""7"" endColumn=""6"" />
         <entry offset=""0x250"" hidden=""true"" />
@@ -756,7 +753,6 @@ static async Task M(int b)
         <entry offset=""0x25"" startLine=""13"" startColumn=""9"" endLine=""13"" endColumn=""47"" />
         <entry offset=""0x36"" startLine=""15"" startColumn=""9"" endLine=""15"" endColumn=""31"" />
         <entry offset=""0x55"" hidden=""true"" />
-        <entry offset=""0xa1"" hidden=""true"" />
         <entry offset=""0xa3"" hidden=""true"" />
         <entry offset=""0xba"" startLine=""16"" startColumn=""5"" endLine=""16"" endColumn=""6"" />
         <entry offset=""0xc2"" hidden=""true"" />
@@ -850,7 +846,6 @@ static async Task M(int b)
         <entry offset=""0x41"" startLine=""13"" startColumn=""9"" endLine=""13"" endColumn=""47"" />
         <entry offset=""0x58"" startLine=""15"" startColumn=""9"" endLine=""15"" endColumn=""31"" />
         <entry offset=""0x86"" hidden=""true"" />
-        <entry offset=""0xd7"" hidden=""true"" />
         <entry offset=""0xd9"" hidden=""true"" />
         <entry offset=""0xf1"" startLine=""19"" startColumn=""5"" endLine=""19"" endColumn=""6"" />
         <entry offset=""0xf9"" hidden=""true"" />
@@ -939,7 +934,6 @@ static async Task M(int b)
         <entry offset=""0x4f"" startLine=""15"" startColumn=""9"" endLine=""15"" endColumn=""29"" />
         <entry offset=""0x5b"" hidden=""true"" />
         <entry offset=""0xa7"" startLine=""17"" startColumn=""9"" endLine=""17"" endColumn=""31"" />
-        <entry offset=""0xb7"" hidden=""true"" />
         <entry offset=""0xb9"" hidden=""true"" />
         <entry offset=""0xd0"" startLine=""18"" startColumn=""5"" endLine=""18"" endColumn=""6"" />
         <entry offset=""0xd8"" hidden=""true"" />
@@ -1028,7 +1022,6 @@ static async Task M(int b)
         <entry offset=""0x58"" startLine=""15"" startColumn=""9"" endLine=""15"" endColumn=""29"" />
         <entry offset=""0x64"" hidden=""true"" />
         <entry offset=""0xb5"" startLine=""17"" startColumn=""9"" endLine=""17"" endColumn=""31"" />
-        <entry offset=""0xc6"" hidden=""true"" />
         <entry offset=""0xc8"" hidden=""true"" />
         <entry offset=""0xe0"" startLine=""18"" startColumn=""5"" endLine=""18"" endColumn=""6"" />
         <entry offset=""0xe8"" hidden=""true"" />
@@ -1117,7 +1110,6 @@ static async Task M()
         <entry offset=""0x1b"" startLine=""9"" startColumn=""9"" endLine=""9"" endColumn=""29"" />
         <entry offset=""0x27"" hidden=""true"" />
         <entry offset=""0x7b"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""22"" />
-        <entry offset=""0xd3"" hidden=""true"" />
         <entry offset=""0xd5"" hidden=""true"" />
         <entry offset=""0xed"" startLine=""11"" startColumn=""5"" endLine=""11"" endColumn=""6"" />
         <entry offset=""0xf5"" hidden=""true"" />
@@ -1196,7 +1188,6 @@ static async Task M()
         <entry offset=""0x14"" startLine=""9"" startColumn=""9"" endLine=""9"" endColumn=""22"" />
         <entry offset=""0x64"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""29"" />
         <entry offset=""0x70"" hidden=""true"" />
-        <entry offset=""0xbc"" hidden=""true"" />
         <entry offset=""0xbe"" hidden=""true"" />
         <entry offset=""0xd5"" startLine=""11"" startColumn=""5"" endLine=""11"" endColumn=""6"" />
         <entry offset=""0xdd"" hidden=""true"" />
@@ -1284,7 +1275,6 @@ static async Task M()
         <entry offset=""0x1e"" startLine=""9"" startColumn=""9"" endLine=""9"" endColumn=""22"" />
         <entry offset=""0x76"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""29"" />
         <entry offset=""0x82"" hidden=""true"" />
-        <entry offset=""0xd3"" hidden=""true"" />
         <entry offset=""0xd5"" hidden=""true"" />
         <entry offset=""0xed"" startLine=""14"" startColumn=""5"" endLine=""14"" endColumn=""6"" />
         <entry offset=""0xf5"" hidden=""true"" />
@@ -1731,7 +1721,6 @@ public partial class C
   Document: #1
   IL_0000: <hidden>
   IL_0007: (5, 28) - (5, 29)
-  IL_0008: <hidden>
   IL_000A: <hidden>
   IL_0022: (5, 29) - (5, 30)
   IL_002A: <hidden>

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

@@ -403,6 +403,7 @@ static void Main()
         <entry offset=""0x18"" startLine=""23"" startColumn=""13"" endLine=""23"" endColumn=""41"" />
         <entry offset=""0x1d"" startLine=""21"" startColumn=""24"" endLine=""21"" endColumn=""26"" />
         <entry offset=""0x27"" hidden=""true"" />
+        <entry offset=""0x30"" hidden=""true"" />
         <entry offset=""0x31"" startLine=""25"" startColumn=""5"" endLine=""25"" endColumn=""6"" />
       </sequencePoints>
       <scope startOffset=""0x0"" endOffset=""0x32"">
@@ -555,6 +556,7 @@ public static void Main()
         <entry offset=""0x17"" startLine=""46"" startColumn=""49"" endLine=""46"" endColumn=""50"" />
         <entry offset=""0x18"" startLine=""46"" startColumn=""24"" endLine=""46"" endColumn=""26"" />
         <entry offset=""0x22"" hidden=""true"" />
+        <entry offset=""0x2c"" hidden=""true"" />
         <entry offset=""0x2d"" startLine=""47"" startColumn=""5"" endLine=""47"" endColumn=""6"" />
       </sequencePoints>
       <scope startOffset=""0x0"" endOffset=""0x2e"">

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

@@ -1314,8 +1314,10 @@ static void F()
         <entry offset=""0x4f"" startLine=""18"" startColumn=""13"" endLine=""18"" endColumn=""25"" />
         <entry offset=""0x61"" startLine=""19"" startColumn=""9"" endLine=""19"" endColumn=""10"" />
         <entry offset=""0x64"" hidden=""true"" />
+        <entry offset=""0x78"" hidden=""true"" />
         <entry offset=""0x79"" hidden=""true"" />
         <entry offset=""0x7b"" hidden=""true"" />
+        <entry offset=""0x8f"" hidden=""true"" />
         <entry offset=""0x90"" startLine=""20"" startColumn=""5"" endLine=""20"" endColumn=""6"" />
       </sequencePoints>
       <scope startOffset=""0x0"" endOffset=""0x91"">

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

@@ -2649,6 +2649,7 @@ static void Main(string[] args)
         <entry offset=""0x3c"" startLine=""26"" startColumn=""13"" endLine=""26"" endColumn=""14"" />
         <entry offset=""0x3d"" startLine=""12"" startColumn=""28"" endLine=""12"" endColumn=""30"" />
         <entry offset=""0x47"" hidden=""true"" />
+        <entry offset=""0x51"" hidden=""true"" />
         <entry offset=""0x52"" startLine=""27"" startColumn=""9"" endLine=""27"" endColumn=""10"" />
       </sequencePoints>
       <scope startOffset=""0x0"" endOffset=""0x53"">
@@ -4486,16 +4487,20 @@ static void Main()
         <entry offset=""0xc"" startLine=""22"" startColumn=""62"" endLine=""22"" endColumn=""90"" />
         <entry offset=""0x17"" startLine=""23"" startColumn=""13"" endLine=""23"" endColumn=""47"" />
         <entry offset=""0x24"" hidden=""true"" />
+        <entry offset=""0x2e"" hidden=""true"" />
         <entry offset=""0x2f"" hidden=""true"" />
         <entry offset=""0x31"" hidden=""true"" />
+        <entry offset=""0x3b"" hidden=""true"" />
         <entry offset=""0x3c"" startLine=""25"" startColumn=""16"" endLine=""25"" endColumn=""60"" />
         <entry offset=""0x47"" startLine=""25"" startColumn=""62"" endLine=""25"" endColumn=""90"" />
         <entry offset=""0x52"" startLine=""26"" startColumn=""9"" endLine=""26"" endColumn=""10"" />
         <entry offset=""0x53"" startLine=""27"" startColumn=""13"" endLine=""27"" endColumn=""48"" />
         <entry offset=""0x5e"" startLine=""28"" startColumn=""9"" endLine=""28"" endColumn=""10"" />
         <entry offset=""0x61"" hidden=""true"" />
+        <entry offset=""0x6b"" hidden=""true"" />
         <entry offset=""0x6c"" hidden=""true"" />
         <entry offset=""0x6e"" hidden=""true"" />
+        <entry offset=""0x78"" hidden=""true"" />
         <entry offset=""0x79"" startLine=""31"" startColumn=""9"" endLine=""31"" endColumn=""10"" />
         <entry offset=""0x7a"" startLine=""33"" startColumn=""9"" endLine=""33"" endColumn=""10"" />
         <entry offset=""0x7b"" startLine=""34"" startColumn=""5"" endLine=""34"" endColumn=""6"" />
@@ -4515,8 +4520,8 @@ static void Main()
 </symbols>");
         }
 
-        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/18844"), WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
-        public void UsingStatement_Embedded()
+        [Fact, WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
+        public void UsingStatement_EmbeddedConditional()
         {
             var source = @"
 class C
@@ -4590,6 +4595,7 @@ .maxstack  1
     IL_001d:  ldloc.2
     IL_001e:  callvirt   ""void System.IDisposable.Dispose()""
     IL_0023:  nop
+    // sequence point: <hidden>
     IL_0024:  endfinally
   }
   // sequence point: return value;
@@ -4603,6 +4609,302 @@ .maxstack  1
 ", sequencePoints: "C.F", source: source);
         }
 
+        [Fact, WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
+        public void UsingStatement_EmbeddedConditional2()
+        {
+            var source = @"
+class C
+{
+    bool F()
+    {
+        bool x = true;
+        bool value = false;
+        using (var stream = new System.IO.MemoryStream())
+            if (x)
+            {
+                value = true;
+            }
+            else
+            {
+                value = false;
+            }
+
+        return value;
+    }
+}
+";
+
+            var c = CreateCompilationWithMscorlibAndSystemCore(source, options: TestOptions.DebugDll);
+            var v = CompileAndVerify(c);
+            v.VerifyIL("C.F", @"
+{
+  // Code size       47 (0x2f)
+  .maxstack  1
+  .locals init (bool V_0, //x
+                bool V_1, //value
+                System.IO.MemoryStream V_2, //stream
+                bool V_3,
+                bool V_4)
+  // sequence point: {
+  IL_0000:  nop
+  // sequence point: bool x = true;
+  IL_0001:  ldc.i4.1
+  IL_0002:  stloc.0
+  // sequence point: bool value = false;
+  IL_0003:  ldc.i4.0
+  IL_0004:  stloc.1
+  // sequence point: var stream = new System.IO.MemoryStream()
+  IL_0005:  newobj     ""System.IO.MemoryStream..ctor()""
+  IL_000a:  stloc.2
+  .try
+  {
+    // sequence point: if (x)
+    IL_000b:  ldloc.0
+    IL_000c:  stloc.3
+    // sequence point: <hidden>
+    IL_000d:  ldloc.3
+    IL_000e:  brfalse.s  IL_0016
+    // sequence point: {
+    IL_0010:  nop
+    // sequence point: value = true;
+    IL_0011:  ldc.i4.1
+    IL_0012:  stloc.1
+    // sequence point: }
+    IL_0013:  nop
+    IL_0014:  br.s       IL_001a
+    // sequence point: {
+    IL_0016:  nop
+    // sequence point: value = false;
+    IL_0017:  ldc.i4.0
+    IL_0018:  stloc.1
+    // sequence point: }
+    IL_0019:  nop
+    // sequence point: <hidden>
+    IL_001a:  leave.s    IL_0027
+  }
+  finally
+  {
+    // sequence point: <hidden>
+    IL_001c:  ldloc.2
+    IL_001d:  brfalse.s  IL_0026
+    IL_001f:  ldloc.2
+    IL_0020:  callvirt   ""void System.IDisposable.Dispose()""
+    IL_0025:  nop
+    // sequence point: <hidden>
+    IL_0026:  endfinally
+  }
+  // sequence point: return value;
+  IL_0027:  ldloc.1
+  IL_0028:  stloc.s    V_4
+  IL_002a:  br.s       IL_002c
+  // sequence point: }
+  IL_002c:  ldloc.s    V_4
+  IL_002e:  ret
+}
+", sequencePoints: "C.F", source: source);
+        }
+
+        [Fact, WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
+        public void UsingStatement_EmbeddedWhile()
+        {
+            var source = @"
+class C
+{
+    void F(bool x)
+    {
+        using (var stream = new System.IO.MemoryStream())
+            while (x)
+                x = false;
+    }
+}
+";
+
+            var c = CreateCompilationWithMscorlibAndSystemCore(source, options: TestOptions.DebugDll);
+            var v = CompileAndVerify(c);
+            v.VerifyIL("C.F", @"
+{
+  // Code size       31 (0x1f)
+  .maxstack  1
+  .locals init (System.IO.MemoryStream V_0, //stream
+                bool V_1)
+  // sequence point: {
+  IL_0000:  nop
+  // sequence point: var stream = new System.IO.MemoryStream()
+  IL_0001:  newobj     ""System.IO.MemoryStream..ctor()""
+  IL_0006:  stloc.0
+  .try
+  {
+    // sequence point: <hidden>
+    IL_0007:  br.s       IL_000c
+    // sequence point: x = false;
+    IL_0009:  ldc.i4.0
+    IL_000a:  starg.s    V_1
+    // sequence point: while (x)
+    IL_000c:  ldarg.1
+    IL_000d:  stloc.1
+    // sequence point: <hidden>
+    IL_000e:  ldloc.1
+    IL_000f:  brtrue.s   IL_0009
+    IL_0011:  leave.s    IL_001e
+  }
+  finally
+  {
+    // sequence point: <hidden>
+    IL_0013:  ldloc.0
+    IL_0014:  brfalse.s  IL_001d
+    IL_0016:  ldloc.0
+    IL_0017:  callvirt   ""void System.IDisposable.Dispose()""
+    IL_001c:  nop
+    // sequence point: <hidden>
+    IL_001d:  endfinally
+  }
+  // sequence point: }
+  IL_001e:  ret
+}
+", sequencePoints: "C.F", source: source);
+        }
+
+        [Fact, WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
+        public void UsingStatement_EmbeddedFor()
+        {
+            var source = @"
+class C
+{
+    void F(bool x)
+    {
+        using (var stream = new System.IO.MemoryStream())
+            for ( ; x == true; )
+                x = false;
+    }
+}
+";
+
+            var c = CreateCompilationWithMscorlibAndSystemCore(source, options: TestOptions.DebugDll);
+            var v = CompileAndVerify(c);
+            v.VerifyIL("C.F", @"
+{
+  // Code size       31 (0x1f)
+  .maxstack  1
+  .locals init (System.IO.MemoryStream V_0, //stream
+                bool V_1)
+  // sequence point: {
+  IL_0000:  nop
+  // sequence point: var stream = new System.IO.MemoryStream()
+  IL_0001:  newobj     ""System.IO.MemoryStream..ctor()""
+  IL_0006:  stloc.0
+  .try
+  {
+    // sequence point: <hidden>
+    IL_0007:  br.s       IL_000c
+    // sequence point: x = false;
+    IL_0009:  ldc.i4.0
+    IL_000a:  starg.s    V_1
+    // sequence point: x == true
+    IL_000c:  ldarg.1
+    IL_000d:  stloc.1
+    // sequence point: <hidden>
+    IL_000e:  ldloc.1
+    IL_000f:  brtrue.s   IL_0009
+    IL_0011:  leave.s    IL_001e
+  }
+  finally
+  {
+    // sequence point: <hidden>
+    IL_0013:  ldloc.0
+    IL_0014:  brfalse.s  IL_001d
+    IL_0016:  ldloc.0
+    IL_0017:  callvirt   ""void System.IDisposable.Dispose()""
+    IL_001c:  nop
+    // sequence point: <hidden>
+    IL_001d:  endfinally
+  }
+  // sequence point: }
+  IL_001e:  ret
+}
+", sequencePoints: "C.F", source: source);
+        }
+
+        [Fact, WorkItem(18844, "https://github.com/dotnet/roslyn/issues/18844")]
+        public void LockStatement_EmbeddedIf()
+        {
+            var source = @"
+class C
+{
+    void F(bool x)
+    {
+        string y = """";
+        lock (y)
+            if (!x)
+                System.Console.Write(1);
+            else
+                System.Console.Write(2);
+    }
+}
+";
+
+            var c = CreateCompilationWithMscorlibAndSystemCore(source, options: TestOptions.DebugDll);
+            var v = CompileAndVerify(c);
+            v.VerifyIL("C.F", @"
+{
+  // Code size       58 (0x3a)
+  .maxstack  2
+  .locals init (string V_0, //y
+                string V_1,
+                bool V_2,
+                bool V_3)
+  // sequence point: {
+  IL_0000:  nop
+  // sequence point: string y = """";
+  IL_0001:  ldstr      """"
+  IL_0006:  stloc.0
+  // sequence point: lock (y)
+  IL_0007:  ldloc.0
+  IL_0008:  stloc.1
+  IL_0009:  ldc.i4.0
+  IL_000a:  stloc.2
+  .try
+  {
+    IL_000b:  ldloc.1
+    IL_000c:  ldloca.s   V_2
+    IL_000e:  call       ""void System.Threading.Monitor.Enter(object, ref bool)""
+    IL_0013:  nop
+    // sequence point: if (!x)
+    IL_0014:  ldarg.1
+    IL_0015:  ldc.i4.0
+    IL_0016:  ceq
+    IL_0018:  stloc.3
+    // sequence point: <hidden>
+    IL_0019:  ldloc.3
+    IL_001a:  brfalse.s  IL_0025
+    // sequence point: System.Console.Write(1);
+    IL_001c:  ldc.i4.1
+    IL_001d:  call       ""void System.Console.Write(int)""
+    IL_0022:  nop
+    IL_0023:  br.s       IL_002c
+    // sequence point: System.Console.Write(2);
+    IL_0025:  ldc.i4.2
+    IL_0026:  call       ""void System.Console.Write(int)""
+    IL_002b:  nop
+    // sequence point: <hidden>
+    IL_002c:  leave.s    IL_0039
+  }
+  finally
+  {
+    // sequence point: <hidden>
+    IL_002e:  ldloc.2
+    IL_002f:  brfalse.s  IL_0038
+    IL_0031:  ldloc.1
+    IL_0032:  call       ""void System.Threading.Monitor.Exit(object)""
+    IL_0037:  nop
+    // sequence point: <hidden>
+    IL_0038:  endfinally
+  }
+  // sequence point: }
+  IL_0039:  ret
+}
+", sequencePoints: "C.F", source: source);
+        }
+
         #endregion
 
         // LockStatement tested in CodeGenLock
@@ -5986,7 +6288,6 @@ static async Task F()
         <entry offset=""0x7"" startLine=""6"" startColumn=""5"" endLine=""6"" endColumn=""6"" />
         <entry offset=""0x8"" startLine=""7"" startColumn=""9"" endLine=""7"" endColumn=""35"" />
         <entry offset=""0x1f"" startLine=""8"" startColumn=""9"" endLine=""8"" endColumn=""26"" />
-        <entry offset=""0x4a"" hidden=""true"" />
         <entry offset=""0x4c"" hidden=""true"" />
         <entry offset=""0x64"" startLine=""9"" startColumn=""5"" endLine=""9"" endColumn=""6"" />
         <entry offset=""0x6c"" hidden=""true"" />
@@ -6049,7 +6350,6 @@ static void M()
         <entry offset=""0x7"" startLine=""7"" startColumn=""9"" endLine=""7"" endColumn=""10"" />
         <entry offset=""0x8"" startLine=""8"" startColumn=""13"" endLine=""8"" endColumn=""39"" />
         <entry offset=""0x1f"" startLine=""9"" startColumn=""13"" endLine=""9"" endColumn=""30"" />
-        <entry offset=""0x4a"" hidden=""true"" />
         <entry offset=""0x4c"" hidden=""true"" />
         <entry offset=""0x64"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""10"" />
         <entry offset=""0x6c"" hidden=""true"" />
@@ -6367,7 +6667,6 @@ public async void M1()
       <sequencePoints>
         <entry offset=""0x0"" hidden=""true"" document=""1"" />
         <entry offset=""0x7"" startLine=""8"" startColumn=""5"" endLine=""8"" endColumn=""6"" document=""1"" />
-        <entry offset=""0x8"" hidden=""true"" document=""1"" />
         <entry offset=""0xa"" hidden=""true"" document=""1"" />
         <entry offset=""0x22"" startLine=""9"" startColumn=""5"" endLine=""9"" endColumn=""6"" document=""1"" />
         <entry offset=""0x2a"" hidden=""true"" document=""1"" />
@@ -6743,7 +7042,6 @@ .maxstack  2
     IL_001a:  br.s       IL_001e
     // sequence point: break;
     IL_001c:  br.s       IL_001e
-    // sequence point: <hidden>
     IL_001e:  leave.s    IL_0038
   }
   catch System.Exception
@@ -6826,7 +7124,6 @@ .maxstack  2
     // sequence point: <hidden>
     IL_0021:  ldloc.1
     IL_0022:  brtrue.s   IL_0011
-    // sequence point: <hidden>
     IL_0024:  leave.s    IL_003e
   }
   catch System.Exception
@@ -6918,7 +7215,6 @@ .maxstack  3
     // sequence point: <hidden>
     IL_0031:  ldloc.2
     IL_0032:  brtrue.s   IL_0011
-    // sequence point: <hidden>
     IL_0034:  leave.s    IL_004e
   }
   catch System.Exception
@@ -7013,7 +7309,6 @@ .maxstack  3
     // sequence point: <hidden>
     IL_003b:  ldloc.2
     IL_003c:  brtrue.s   IL_001b
-    // sequence point: <hidden>
     IL_003e:  leave.s    IL_0058
   }
   catch System.Exception

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

@@ -251,6 +251,7 @@ static void F(System.Collections.Generic.IEnumerable<(int a, int b)> ie)
         <entry offset=""0x21"" startLine=""10"" startColumn=""9"" endLine=""10"" endColumn=""10"" />
         <entry offset=""0x22"" startLine=""7"" startColumn=""13"" endLine=""7"" endColumn=""15"" />
         <entry offset=""0x2c"" hidden=""true"" />
+        <entry offset=""0x36"" hidden=""true"" />
         <entry offset=""0x37"" startLine=""11"" startColumn=""5"" endLine=""11"" endColumn=""6"" />
       </sequencePoints>
       <scope startOffset=""0x0"" endOffset=""0x38"">

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

@@ -1734,7 +1734,7 @@ .locals init (Test V_0)
     IL_000e:  ldloc.0
     IL_000f:  callvirt   ""void System.IDisposable.Dispose()""
     IL_0014:  nop
-    IL_0015:  endfinally
+   ~IL_0015:  endfinally
   }
  -IL_0016:  ret
 }", sequencePoints: "Test.Main");