Fix SignatureHash to include constant values in hash computation

.gitignore

@@ -137,3 +137,6 @@ positive.exe
 *.bsl.actual
 /src/FSharp.DependencyManager.Nuget/StandardError.txt
 /src/FSharp.DependencyManager.Nuget/StandardOutput.txt
+
+# Test result files
+tests/**/TestResults/*.trx

src/Compiler/Utilities/TypeHashing.fs

@@ -302,6 +302,28 @@ module HashTastMemberOrVals =
 
             combinedHash
 
+    /// Hash a constant value with exhaustive pattern matching over all Const cases
+    let private hashConst (constVal: Const) : Hash =
+        match constVal with
+        | Const.Bool b -> hash b
+        | Const.SByte x -> hash x
+        | Const.Byte x -> hash x
+        | Const.Int16 x -> hash x
+        | Const.UInt16 x -> hash x
+        | Const.Int32 x -> hash x
+        | Const.UInt32 x -> hash x
+        | Const.Int64 x -> hash x
+        | Const.UInt64 x -> hash x
+        | Const.IntPtr x -> hash x
+        | Const.UIntPtr x -> hash x
+        | Const.Single x -> hash x
+        | Const.Double x -> hash x
+        | Const.Char x -> hash x
+        | Const.String x -> hashText x
+        | Const.Decimal x -> hash x
+        | Const.Unit -> 0
+        | Const.Zero -> 0
+
     let private hashNonMemberVal (g: TcGlobals, observer) (tps, v: Val, tau, cxs) =
         if HashAccessibility.isHiddenToObserver v.Accessibility observer then
             0
@@ -313,9 +335,15 @@ module HashTastMemberOrVals =
             let typeHash = hashTopType g argInfos retTy cxs
             let flagsHash = hash v.val_flags.PickledBits
             let attribsHash = hashAttributeList v.Attribs
-
+            
             let combinedHash = nameHash @@ typarHash @@ typeHash @@ flagsHash @@ attribsHash
-            combinedHash
+
+            // Include literal constant value in hash for deterministic builds
+            match v.LiteralValue with
+            | Some constVal -> 
+                let constHash = hashConst constVal
+                combinedHash @@ constHash
+            | None -> combinedHash
 
     let hashValOrMemberNoInst (g, obs) (vref: ValRef) =
         match vref.MemberInfo with

tests/fsharp/Compiler/CodeGen/EmittedIL/DeterministicTests.fs

@@ -333,3 +333,21 @@ let inline myFunc x y = x - y"""
             Assert.Equal(mvid1,mvid2)
         else
             Assert.NotEqual(mvid1,mvid2)
+
+    [<Fact>]
+    let ``Reference assemblies MVID must change when literal constant value changes`` () =
+        let codeWithLiteral42 = """
+module TestModule
+[<Literal>]
+let X = 42
+"""
+
+        let codeWithLiteral43 = """
+module TestModule
+[<Literal>]
+let X = 43
+"""
+
+        let mvid1, mvid2 = calculateRefAssMvids codeWithLiteral42 codeWithLiteral43
+        // Different literal values should produce different MVIDs
+        Assert.NotEqual(mvid1, mvid2)

tests/fsharp/TestResults/_pkrvmq0rgcvqdmg_2025-07-21_15_41_19.trx

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TestRun id="b040ce9d-5754-42d1-8a68-cffa0613fca0" name="@pkrvmq0rgcvqdmg 2025-07-21 15:41:19" xmlns="http://microsoft.com/schemas/VisualStudio/TeamTest/2010">
+  <Times creation="2025-07-21T15:41:19.2821401+00:00" queuing="2025-07-21T15:41:19.2821402+00:00" start="2025-07-21T15:41:17.7511294+00:00" finish="2025-07-21T15:41:19.2827881+00:00" />
+  <TestSettings name="default" id="2a232d4b-5d63-4bdd-8dab-ced2eacd7dda">
+    <Deployment runDeploymentRoot="_pkrvmq0rgcvqdmg_2025-07-21_15_41_19" />
+  </TestSettings>
+  <TestLists>
+    <TestList name="Results Not in a List" id="8c84fa94-04c1-424b-9868-57a2d4851a1d" />
+    <TestList name="All Loaded Results" id="19431567-8539-422a-85d7-44ee4e166bda" />
+  </TestLists>
+  <ResultSummary outcome="Failed">
+    <Counters total="0" executed="0" passed="0" failed="0" error="0" timeout="0" aborted="0" inconclusive="0" passedButRunAborted="0" notRunnable="0" notExecuted="0" disconnected="0" warning="0" completed="0" inProgress="0" pending="0" />
+    <Output>
+      <StdOut>[xUnit.net 00:00:00.00] xUnit.net VSTest Adapter v2.8.2+699d445a1a (64-bit .NET 10.0.0-preview.6.25315.102)
+[xUnit.net 00:00:00.15]   Discovering: FSharpSuite.Tests
+[xUnit.net 00:00:00.32]   Discovered:  FSharpSuite.Tests
+[xUnit.net 00:00:00.34]   Starting:    FSharpSuite.Tests
+</StdOut>
+    </Output>
+    <RunInfos>
+      <RunInfo computerName="pkrvmq0rgcvqdmg" outcome="Error" timestamp="2025-07-21T15:41:19.1924271+00:00">
+        <Text>[xUnit.net 00:00:00.43] FSharpSuite.Tests: Catastrophic failure: System.TypeInitializationException: The type initializer for '&lt;StartupCode$FSharp-Test-Utilities&gt;.$TestFramework' threw an exception.
+ ---&gt; System.Exception: Couldn't find "FSharp.Compiler.Interactive.Settings/Debug/netstandard2.0/FSharp.Compiler.Interactive.Settings.dll" on the following paths: "/home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/../../artifacts/bin/FSharp.Compiler.Interactive.Settings/Debug/netstandard2.0/FSharp.Compiler.Interactive.Settings.dll", "/home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/../../artifacts/bin/fsharp.compiler.interactive.settings/debug/netstandard2.0/fsharp.compiler.interactive.settings.dll". Running 'build test' once might solve this issue
+   at TestFramework.requireFile(String dir, String path) in /home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/TestFramework.fs:line 296
+   at TestFramework.requireArtifact@326.Invoke(String path)
+   at TestFramework.config(String configurationName, FSharpMap`2 envVars) in /home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/TestFramework.fs:line 337
+   at &lt;StartupCode$FSharp-Test-Utilities&gt;.$TestFramework..cctor() in /home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/TestFramework.fs:line 460
+   --- End of inner exception stack trace ---
+   at TestFramework.get_initialConfig()
+   at &lt;StartupCode$FSharp-Test-Utilities&gt;.$XunitHelpers.CreateExecutor@198.RunTestCases(IEnumerable`1 testCases, IMessageSink executionMessageSink, ITestFrameworkExecutionOptions executionOptions) in /home/runner/work/fsharp/fsharp/tests/FSharp.Test.Utilities/XunitHelpers.fs:line 216
+   at Xunit.Sdk.TestFrameworkExecutor`1.RunTests(IEnumerable`1 testCases, IMessageSink executionMessageSink, ITestFrameworkExecutionOptions executionOptions) in /_/src/xunit.execution/Sdk/Frameworks/TestFrameworkExecutor.cs:line 100
+   at Xunit.Xunit2.RunTests(IEnumerable`1 testCases, IMessageSink messageSink, ITestFrameworkExecutionOptions executionOptions) in /_/src/xunit.runner.utility/Frameworks/v2/Xunit2.cs:line 110
+   at Xunit.XunitFrontController.RunTests(IEnumerable`1 testMethods, IMessageSink messageSink, ITestFrameworkExecutionOptions executionOptions) in /_/src/xunit.runner.utility/Frameworks/XunitFrontController.cs:line 185
+   at TestFrameworkExtensions.RunTests(ITestFrameworkExecutor executor, IEnumerable`1 testCases, IMessageSinkWithTypes executionMessageSink, ITestFrameworkExecutionOptions executionOptions) in /_/src/xunit.runner.utility/Extensions/TestFrameworkExtensions.cs:line 69
+   at Xunit.Runner.VisualStudio.VsTestRunner.RunTestsInAssembly(IRunContext runContext, IFrameworkHandle frameworkHandle, LoggerHelper logger, TestPlatformContext testPlatformContext, RunSettings runSettings, IMessageSinkWithTypes reporterMessageHandler, AssemblyRunInfo runInfo) in /_/src/xunit.runner.visualstudio/VsTestRunner.cs:line 555</Text>
+      </RunInfo>
+      <RunInfo computerName="pkrvmq0rgcvqdmg" outcome="Warning" timestamp="2025-07-21T15:41:19.1975217+00:00">
+        <Text>No test matches the given testcase filter `Simple assembly should be deterministic` in /home/runner/work/fsharp/fsharp/artifacts/bin/FSharpSuite.Tests/Debug/net9.0/FSharpSuite.Tests.dll</Text>
+      </RunInfo>
+    </RunInfos>
+  </ResultSummary>
+</TestRun>