Import: share assembly CCUs between projects

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

@@ -178,6 +178,7 @@
 
 * IL: cache C# extension methods per CCU ([PR #20256](https://github.com/dotnet/fsharp/pull/20256))
 * Nullness warning FS3261 on dotted method or property access (e.g. `x.Member`) now underlines the receiver expression and includes the member name and (when known) the binding name in the message. ([Issue #19658](https://github.com/dotnet/fsharp/issues/19658), [PR #19814](https://github.com/dotnet/fsharp/pull/19814))
+* Import: share assembly CCUs between projects ([PR #20296](https://github.com/dotnet/fsharp/pull/20296))
 * IL: share the pickled references ([PR #20301](https://github.com/dotnet/fsharp/pull/20301))
 * Direct delegate construction ([PR ##19993](https://github.com/dotnet/fsharp/pull/19993))
 * IL: add `ILPreNamespace`, make `ILPreTypeDef` creation lazy ([PR #20092](https://github.com/dotnet/fsharp/pull/20092))

src/Compiler/Driver/CompilerConfig.fs

@@ -445,6 +445,13 @@ type TypeCheckingConfig =
         DumpGraph: bool
     }
 
+[<RequireQualifiedAccess>]
+type ImportReuseKey =
+    {
+        LangVersion: decimal
+        CheckNullness: bool
+    }
+
 [<NoEquality; NoComparison>]
 type TcConfigBuilder =
     {
@@ -645,6 +652,8 @@ type TcConfigBuilder =
 
         mutable parallelReferenceResolution: ParallelReferenceResolution
 
+        mutable shareImportedAssemblies: bool
+
         mutable captureIdentifiersWhenParsing: bool
 
         mutable typeCheckingConfig: TypeCheckingConfig
@@ -844,6 +853,7 @@ type TcConfigBuilder =
             xmlDocInfoLoader = None
             exiter = QuitProcessExiter
             parallelReferenceResolution = ParallelReferenceResolution.On
+            shareImportedAssemblies = true
             captureIdentifiersWhenParsing = false
             typeCheckingConfig =
                 {
@@ -1397,8 +1407,16 @@ type TcConfig private (data: TcConfigBuilder, validate: bool) =
     member _.xmlDocInfoLoader = data.xmlDocInfoLoader
     member _.exiter = data.exiter
     member _.parallelReferenceResolution = data.parallelReferenceResolution
+    member _.shareImportedAssemblies = data.shareImportedAssemblies
     member _.captureIdentifiersWhenParsing = data.captureIdentifiersWhenParsing
     member _.typeCheckingConfig = data.typeCheckingConfig
+
+    member _.importReuseKey =
+        {
+            ImportReuseKey.LangVersion = data.langVersion.SpecifiedVersion
+            ImportReuseKey.CheckNullness = data.checkNullness
+        }
+
     member _.dumpSignatureData = data.dumpSignatureData
     member _.realsig = data.realsig
     member _.compilationMode = data.compilationMode

src/Compiler/Driver/CompilerConfig.fsi

@@ -225,6 +225,12 @@ type TypeCheckingConfig =
         DumpGraph: bool
     }
 
+/// A field belongs here when two projects differing in it cannot reuse one imported form
+[<RequireQualifiedAccess>]
+type ImportReuseKey =
+    { LangVersion: decimal
+      CheckNullness: bool }
+
 [<NoEquality; NoComparison>]
 type TcConfigBuilder =
     {
@@ -515,6 +521,8 @@ type TcConfigBuilder =
 
         mutable parallelReferenceResolution: ParallelReferenceResolution
 
+        mutable shareImportedAssemblies: bool
+
         mutable captureIdentifiersWhenParsing: bool
 
         mutable typeCheckingConfig: TypeCheckingConfig
@@ -888,10 +896,14 @@ type TcConfig =
 
     member parallelReferenceResolution: ParallelReferenceResolution
 
+    member shareImportedAssemblies: bool
+
     member captureIdentifiersWhenParsing: bool
 
     member typeCheckingConfig: TypeCheckingConfig
 
+    member importReuseKey: ImportReuseKey
+
     member dumpSignatureData: bool
 
     member realsig: bool