Debug: fix if and match condition sequence points (#19932)

Author: auduchinok

docs/release-notes/.FSharp.Compiler.Service/11.0.100.md

@@ -94,6 +94,7 @@
 * Add `#version;;` directive to F# Interactive to display version and environment information. ([Issue #13307](https://github.com/dotnet/fsharp/issues/13307), [PR #19332](https://github.com/dotnet/fsharp/pull/19332))
 * Debug: rework for expressions stepping ([PR #19894](https://github.com/dotnet/fsharp/pull/19894))
 * Debug: rework conditional erasure, fix stepping over literals ([PR #19897](https://github.com/dotnet/fsharp/pull/19897))
+* Debug: fix if and match condition sequence points ([PR #19932](https://github.com/dotnet/fsharp/pull/19932))
 
 ### Changed
 

src/Compiler/CodeGen/IlxGen.fs

@@ -3723,19 +3723,6 @@ and GenLinearExpr cenv cgbuf eenv expr sequel preSteps (contf: FakeUnit -> FakeU
 
                          //assert(cgbuf.GetCurrentStack() = stackAfterJoin)  // REVIEW: Since gen_dtree* now sets stack, stack should be stackAfterJoin at this point...
                          CG.SetStack cgbuf stackAfterJoin
-                         // If any values are left on the stack after the join then we're certainly going to do something with them
-                         // For example, we may be about to execute a 'stloc' for
-                         //
-                         //   let y2 = if System.DateTime.Now.Year < 2000 then 1 else 2
-                         //
-                         // or a 'stelem' for
-                         //
-                         //   arr.[0] <- if System.DateTime.Now.Year > 2000 then 1 else 2
-                         //
-                         // In both cases, any instructions that come after this point will be falsely associated with the last branch of the control
-                         // prior to the join point. This is base, e.g. see FSharp 1.0 bug 5155
-                         cgbuf.EmitStartOfHiddenCode()
-
                          GenSequel cenv eenv.cloc cgbuf sequelAfterJoin
                          Fake))
 
@@ -7952,8 +7939,6 @@ and GenDecisionTreeSwitch
     let m = e.Range
     cgbuf.SetMarkToHereIfNecessary inplabOpt
 
-    cgbuf.EmitStartOfHiddenCode()
-
     match cases with
     // optimize a test against a boolean value, i.e. the all-important if-then-else
     | TCase(DecisionTreeTest.Const(Const.Bool b), successTree) :: _ ->

tests/AheadOfTime/Trimming/check.ps1

@@ -63,10 +63,10 @@ function CheckTrim($root, $tfm, $outputfile, $expected_len, $callerLineNumber) {
 $allErrors = @()
 
 # Check net9.0 trimmed assemblies
-$allErrors += CheckTrim -root "SelfContained_Trimming_Test" -tfm "net9.0" -outputfile "FSharp.Core.dll" -expected_len 311808 -callerLineNumber 66
+$allErrors += CheckTrim -root "SelfContained_Trimming_Test" -tfm "net9.0" -outputfile "FSharp.Core.dll" -expected_len 310272 -callerLineNumber 66
 
 # Check net9.0 trimmed assemblies with static linked FSharpCore
-$allErrors += CheckTrim -root "StaticLinkedFSharpCore_Trimming_Test" -tfm "net9.0" -outputfile "StaticLinkedFSharpCore_Trimming_Test.dll" -expected_len 9169408 -callerLineNumber 69
+$allErrors += CheckTrim -root "StaticLinkedFSharpCore_Trimming_Test" -tfm "net9.0" -outputfile "StaticLinkedFSharpCore_Trimming_Test.dll" -expected_len 9168896 -callerLineNumber 69
 
 # Check net9.0 trimmed assemblies with F# metadata resources removed
 $allErrors += CheckTrim -root "FSharpMetadataResource_Trimming_Test" -tfm "net9.0" -outputfile "FSharpMetadataResource_Trimming_Test.dll" -expected_len 7609344 -callerLineNumber 72

tests/FSharp.Compiler.ComponentTests/Debugger/MatchEndSequencePoint.fs

@@ -181,26 +181,3 @@ let dispatch (cmd: Cmd) (active: bool) (count: int) =
             (Line 29)
 
     // ---- Instrumentation: verify FeeFee IS emitted at match join points ----
-
-    [<Fact>]
-    let ``Match in statement position emits hidden point at join`` () =
-        // #12052: The fix emits EmitStartOfHiddenCode unconditionally.
-        // Verify hidden (FeeFee) points are present — proving the fix emits them.
-        verifyAllSequencePoints
-            "
-module TestModuleHidden
-
-let funcE (x: int) =
-    match x with
-    | 1 -> System.Console.WriteLine(\"one\")
-    | _ -> System.Console.WriteLine(\"other\")
-    System.Console.WriteLine(\"done\")
-            " [
-                (Line 5, Col 5, Line 5, Col 17)
-                (Line 6, Col 12, Line 6, Col 43)
-                (Line 7, Col 12, Line 7, Col 45)
-                (Line 8, Col 5, Line 8, Col 37)
-                (Line 16707566, Col 0, Line 16707566, Col 0)
-                (Line 16707566, Col 0, Line 16707566, Col 0)
-                (Line 16707566, Col 0, Line 16707566, Col 0)
-            ]