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Prevent tailcalls when pinning locals; add regression coverage #19148

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Merged
T-Gro merged 7 commits into from
Dec 16, 2025
+44 −59
Merged

Prevent tailcalls when pinning locals; add regression coverage #19148

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6f174da
Initial plan
Copilot Dec 11, 2025
7f259d1
Prevent tailcalls when locals are pinned or address-taken; add regres…
Copilot Dec 11, 2025
27c62a6
Apply patch from /run test-baseline
actions-user Dec 11, 2025
e220776
Adjust tailcall regression scope per feedback
Copilot Dec 12, 2025
f4596cb
Apply patch from /run test-baseline
actions-user Dec 15, 2025
ad1a1d4
Merge branch 'main' into copilot/fix-tail-calls-pinned-locals
T-Gro Dec 15, 2025
3660f11
Update tests/FSharp.Compiler.ComponentTests/EmittedIL/TailCalls.fs
T-Gro Dec 15, 2025
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35 changes: 6 additions & 29 deletions ...nentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOff.il.release.bsl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,16 +16,6 @@

.hash algorithm 0x00008004
.ver 0:0:0:0
}
.mresource public FSharpSignatureCompressedData.assembly
{


}
.mresource public FSharpOptimizationCompressedData.assembly
{


}
.module assembly.exe

Expand Down Expand Up @@ -130,9 +120,7 @@
IL_000c: ret
}

.method public hidebysig virtual final
instance int32 CompareTo(object obj,
class [runtime]System.Collections.IComparer comp) cil managed
.method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -228,9 +216,7 @@
IL_000b: ret
}

.method public hidebysig instance bool
Equals(valuetype floatsanddoubles/Float obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig instance bool Equals(valuetype floatsanddoubles/Float obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand All @@ -249,9 +235,7 @@
IL_0013: ret
}

.method public hidebysig virtual final
instance bool Equals(object obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -451,9 +435,7 @@
IL_000c: ret
}

.method public hidebysig virtual final
instance int32 CompareTo(object obj,
class [runtime]System.Collections.IComparer comp) cil managed
.method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -549,9 +531,7 @@
IL_000b: ret
}

.method public hidebysig instance bool
Equals(valuetype floatsanddoubles/Double obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig instance bool Equals(valuetype floatsanddoubles/Double obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand All @@ -570,9 +550,7 @@
IL_0013: ret
}

.method public hidebysig virtual final
instance bool Equals(object obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -1400,4 +1378,3 @@




35 changes: 6 additions & 29 deletions ...onentTests/EmittedIL/Structure/FloatsAndDoubles.fs.RealInternalSignatureOn.il.release.bsl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,16 +16,6 @@

.hash algorithm 0x00008004
.ver 0:0:0:0
}
.mresource public FSharpSignatureCompressedData.assembly
{


}
.mresource public FSharpOptimizationCompressedData.assembly
{


}
.module assembly.exe

Expand Down Expand Up @@ -130,9 +120,7 @@
IL_000c: ret
}

.method public hidebysig virtual final
instance int32 CompareTo(object obj,
class [runtime]System.Collections.IComparer comp) cil managed
.method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -228,9 +216,7 @@
IL_000b: ret
}

.method public hidebysig instance bool
Equals(valuetype floatsanddoubles/Float obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig instance bool Equals(valuetype floatsanddoubles/Float obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand All @@ -249,9 +235,7 @@
IL_0013: ret
}

.method public hidebysig virtual final
instance bool Equals(object obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -451,9 +435,7 @@
IL_000c: ret
}

.method public hidebysig virtual final
instance int32 CompareTo(object obj,
class [runtime]System.Collections.IComparer comp) cil managed
.method public hidebysig virtual final instance int32 CompareTo(object obj, class [runtime]System.Collections.IComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -549,9 +531,7 @@
IL_000b: ret
}

.method public hidebysig instance bool
Equals(valuetype floatsanddoubles/Double obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig instance bool Equals(valuetype floatsanddoubles/Double obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand All @@ -570,9 +550,7 @@
IL_0013: ret
}

.method public hidebysig virtual final
instance bool Equals(object obj,
class [runtime]System.Collections.IEqualityComparer comp) cil managed
.method public hidebysig virtual final instance bool Equals(object obj, class [runtime]System.Collections.IEqualityComparer comp) cil managed
{
.custom instance void [runtime]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 )

Expand Down Expand Up @@ -1410,4 +1388,3 @@




33 changes: 32 additions & 1 deletion tests/FSharp.Compiler.ComponentTests/EmittedIL/TailCalls.fs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -251,7 +251,7 @@ let run() =
IL_0040: ldc.i4.s 42
IL_0042: ldc.i4.5
IL_0043: call void TailCall06::foo<int32>(int32,
!!0)
!!0)
"""
]

Expand All @@ -276,3 +276,34 @@ let rec countdown n =
"""
]

[<Fact>]
let ``TailCall 08 - No tail call when pinning local byref``() =
FSharp """
module TailCall08

open Microsoft.FSharp.NativeInterop
open System.Runtime.CompilerServices

[<MethodImpl(MethodImplOptions.NoInlining)>]
let bar (pValue: nativeptr<int>) : unit =
let value = NativePtr.read pValue
printfn "value = %A" value

[<MethodImpl(MethodImplOptions.NoInlining)>]
let foo() =
let mutable value = 42
use ptr = fixed &value
bar ptr

[<EntryPoint>]
let main _ =
foo()
0
"""
|> asExe
|> compileWithTailCalls
|> shouldSucceed
|> run
|> shouldSucceed
|> verifyOutput "value = 42\n"

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