Restore missing commit and inline nameof ident check.

src/Compiler/Driver/GraphChecking/DependencyResolution.fs

@@ -1,7 +1,6 @@
 module internal FSharp.Compiler.GraphChecking.DependencyResolution
 
 open FSharp.Compiler.Syntax
-open Internal.Utilities.Library
 
 /// <summary>Find a path from a starting TrieNode and return the end node or None</summary>
 let queryTriePartial (trie: TrieNode) (path: LongIdentifier) : TrieNode option =
@@ -118,6 +117,20 @@ let rec processStateEntry (trie: TrieNode) (state: FileContentQueryState) (entry
             FoundDependencies = foundDependencies
         }
 
+    | ModuleName name ->
+        // We need to check if the module name is a hit in the Trie.
+        let state' =
+            let queryResult = queryTrie trie [ name ]
+            processIdentifier queryResult state
+
+        match state.OwnNamespace with
+        | None -> state'
+        | Some ns ->
+            // If there we currently have our own namespace,
+            // the combination of that namespace + module name should be checked as well.
+            let queryResult = queryTrieDual trie ns [ name ]
+            processIdentifier queryResult state'
+
 /// <summary>
 /// For a given file's content, collect all missing ("ghost") file dependencies that the core resolution algorithm didn't return,
 /// but are required to satisfy the type-checker.

src/Compiler/Driver/GraphChecking/FileContentMapping.fs

@@ -18,6 +18,11 @@ let longIdentToPath (skipLast: bool) (longId: LongIdent) : LongIdentifier =
 let synLongIdentToPath (skipLast: bool) (synLongIdent: SynLongIdent) =
     longIdentToPath skipLast synLongIdent.LongIdent
 
+/// In some rare cases we are interested in the name of a single Ident.
+/// For example `nameof ModuleName` in expressions or patterns.
+let visitIdentAsPotentialModuleName (moduleNameIdent: Ident) =
+    FileContentEntry.ModuleName moduleNameIdent.idText
+
 let visitSynLongIdent (lid: SynLongIdent) : FileContentEntry list = visitLongIdent lid.LongIdent
 
 let visitLongIdent (lid: LongIdent) =
@@ -302,6 +307,10 @@ let visitSynTypeConstraint (tc: SynTypeConstraint) : FileContentEntry list =
     | SynTypeConstraint.WhereTyparIsEnum(typeArgs = typeArgs) -> List.collect visitSynType typeArgs
     | SynTypeConstraint.WhereTyparIsDelegate(typeArgs = typeArgs) -> List.collect visitSynType typeArgs
 
+[<return: Struct>]
+let inline (|NameofIdent|_|) (ident: Ident) =
+    if ident.idText = "nameof" then ValueSome() else ValueNone
+
 /// Special case of `nameof Module` type of expression
 let (|NameofExpr|_|) (e: SynExpr) =
     let rec stripParen (e: SynExpr) =
@@ -310,13 +319,10 @@ let (|NameofExpr|_|) (e: SynExpr) =
         | _ -> e
 
     match e with
-    | SynExpr.App(flag = ExprAtomicFlag.NonAtomic; isInfix = false; funcExpr = SynExpr.Ident nameofIdent; argExpr = moduleNameExpr) ->
-        if nameofIdent.idText <> "nameof" then
-            None
-        else
-            match stripParen moduleNameExpr with
-            | SynExpr.Ident moduleNameIdent -> Some moduleNameIdent
-            | _ -> None
+    | SynExpr.App(flag = ExprAtomicFlag.NonAtomic; isInfix = false; funcExpr = SynExpr.Ident NameofIdent; argExpr = moduleNameExpr) ->
+        match stripParen moduleNameExpr with
+        | SynExpr.Ident moduleNameIdent -> Some moduleNameIdent
+        | _ -> None
     | _ -> None
 
 let visitSynExpr (e: SynExpr) : FileContentEntry list =
@@ -543,18 +549,15 @@ let (|NameofPat|_|) (pat: SynPat) =
         | _ -> p
 
     match pat with
-    | SynPat.LongIdent(longDotId = SynLongIdent(id = [ nameofIdent ]); typarDecls = None; argPats = SynArgPats.Pats [ moduleNamePat ]) ->
-        if nameofIdent.idText <> "nameof" then
-            None
-        else
-            match stripPats moduleNamePat with
-            | SynPat.LongIdent(
-                longDotId = SynLongIdent.SynLongIdent(id = [ moduleNameIdent ]; dotRanges = []; trivia = [ None ])
-                extraId = None
-                typarDecls = None
-                argPats = SynArgPats.Pats []
-                accessibility = None) -> Some moduleNameIdent
-            | _ -> None
+    | SynPat.LongIdent(longDotId = SynLongIdent(id = [ NameofIdent ]); typarDecls = None; argPats = SynArgPats.Pats [ moduleNamePat ]) ->
+        match stripPats moduleNamePat with
+        | SynPat.LongIdent(
+            longDotId = SynLongIdent.SynLongIdent(id = [ moduleNameIdent ]; dotRanges = []; trivia = [ None ])
+            extraId = None
+            typarDecls = None
+            argPats = SynArgPats.Pats []
+            accessibility = None) -> Some moduleNameIdent
+        | _ -> None
     | _ -> None
 
 let visitPat (p: SynPat) : FileContentEntry list =

src/Compiler/Driver/GraphChecking/Types.fs

@@ -73,6 +73,9 @@ type internal FileContentEntry =
     /// Being explicit about nested modules allows for easier reasoning what namespaces (paths) are open.
     /// We can scope an `OpenStatement` to the everything that is happening inside the nested module.
     | NestedModule of name: string * nestedContent: FileContentEntry list
+    /// A single identifier that could be the name of a module.
+    /// Example use-case: `let x = nameof Foo` where `Foo` is a module.
+    | ModuleName of name: Identifier
 
 type internal FileContent =
     {

src/Compiler/Driver/GraphChecking/Types.fsi

@@ -67,6 +67,9 @@ type internal FileContentEntry =
     /// Being explicit about nested modules allows for easier reasoning what namespaces (paths) are open.
     /// For example we can limit the scope of an `OpenStatement` to symbols defined inside the nested module.
     | NestedModule of name: string * nestedContent: FileContentEntry list
+    /// A single identifier that could be the name of a module.
+    /// Example use-case: `let x = nameof Foo` where `Foo` is a module.
+    | ModuleName of name: Identifier
 
 /// File identifiers and its content extract for dependency resolution
 type internal FileContent =

tests/FSharp.Compiler.ComponentTests/TypeChecks/Graph/Scenarios.fs

@@ -800,6 +800,86 @@ printfn "Hello"
 """
                     Set.empty
             ]
+        scenario
+            "Nameof module with namespace"
+            [
+                sourceFile
+                    "A.fs"
+                    """
+namespace X.Y.Z
+
+module Foo =
+    let x = 2
+"""
+                    Set.empty
+                sourceFile
+                    "B.fs"
+                    """
+namespace X.Y.Z
+
+module Point =
+    let y = nameof Foo
+"""
+                    (set [| 0 |])
+            ]
+        scenario
+            "Nameof module without namespace"
+            [
+                sourceFile
+                    "A.fs"
+                    """
+module Foo
+
+let x = 2
+"""
+                    Set.empty
+                sourceFile
+                    "B.fs"
+                    """
+module Point
+
+let y = nameof Foo
+"""
+                    (set [| 0 |])
+            ]
+        scenario
+            "Single module name should always be checked, regardless of own namespace"
+            [
+                sourceFile "X.fs" "namespace X.Y" Set.empty
+                sourceFile
+                    "A.fs"
+                    """
+module Foo
+
+let x = 2
+"""
+                    Set.empty
+                sourceFile
+                    "B.fs"
+                    """
+namespace X.Y
+
+type T() =
+    let _ = nameof Foo
+"""
+                    (set [| 1 |])
+            ]
+        scenario
+            "nameof pattern"
+            [
+                sourceFile "A.fs" "module Foo" Set.empty
+                sourceFile
+                    "B.fs"
+                    """
+module Bar
+
+do
+    match "" with
+    | nameof Foo -> ()
+    | _ -> ()
+"""
+                    (set [| 0 |])
+            ]
         scenario
             "parentheses around module name in nameof pattern"
             [