Parser: recover on unfinished nested modules

src/Compiler/SyntaxTree/LexFilter.fs

@@ -49,7 +49,7 @@ type Context =
     | CtxtTypeDefns of Position    // 'type <here> =', not removed when we find the "="
 
     | CtxtNamespaceHead of Position * token
-    | CtxtModuleHead of Position * token * LexingModuleAttributes
+    | CtxtModuleHead of Position * token * LexingModuleAttributes * isNested: bool
     | CtxtMemberHead of Position
     | CtxtMemberBody of Position
     // If bool is true then this is "whole file"
@@ -68,7 +68,7 @@ type Context =
 
     member c.StartPos =
         match c with
-        | CtxtNamespaceHead (p, _) | CtxtModuleHead (p, _, _) | CtxtException p | CtxtModuleBody (p, _) | CtxtNamespaceBody p
+        | CtxtNamespaceHead (p, _) | CtxtModuleHead (p, _, _, _) | CtxtException p | CtxtModuleBody (p, _) | CtxtNamespaceBody p
         | CtxtLetDecl (_, p) | CtxtDo p | CtxtInterfaceHead p | CtxtTypeDefns p | CtxtParen (_, p) | CtxtMemberHead p | CtxtMemberBody p
         | CtxtWithAsLet p
         | CtxtWithAsAugment p
@@ -1393,6 +1393,9 @@ type LexFilterImpl (
             | CtxtSeqBlock(_, _, AddOneSidedBlockEnd) ->
                 Some (ORIGHT_BLOCK_END(getLastTokenEndRange ()))
 
+            | CtxtModuleHead(isNested = true) ->
+                Some OBLOCKSEP
+
             | _ ->
                 None
 
@@ -1598,11 +1601,11 @@ type LexFilterImpl (
         //  Otherwise it's a 'head' module declaration, so ignore it
 
         //  Here prevToken is either 'module', 'rec', 'global' (invalid), '.', or ident, because we skip attribute tokens and access modifier tokens
-        | _, CtxtModuleHead (moduleTokenPos, prevToken, lexingModuleAttributes) :: rest ->
+        | _, CtxtModuleHead (moduleTokenPos, prevToken, lexingModuleAttributes, isNested) :: rest ->
             match prevToken, token with
             | _, GREATER_RBRACK when lexingModuleAttributes = LexingModuleAttributes
                                      && moduleTokenPos.Column < tokenStartPos.Column ->
-                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, prevToken, NotLexingModuleAttributes))
+                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, prevToken, NotLexingModuleAttributes, isNested))
                 returnToken tokenLexbufState token
             | _ when lexingModuleAttributes = LexingModuleAttributes
                      && moduleTokenPos.Column < tokenStartPos.Column ->
@@ -1612,10 +1615,10 @@ type LexFilterImpl (
             | MODULE, GLOBAL
             | (MODULE | REC | DOT), (REC | IDENT _)
             | IDENT _, DOT when moduleTokenPos.Column < tokenStartPos.Column ->
-                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, token, NotLexingModuleAttributes))
+                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, token, NotLexingModuleAttributes, isNested))
                 returnToken tokenLexbufState token
             | MODULE, LBRACK_LESS when moduleTokenPos.Column < tokenStartPos.Column  ->
-                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, prevToken, LexingModuleAttributes))
+                replaceCtxt tokenTup (CtxtModuleHead (moduleTokenPos, prevToken, LexingModuleAttributes, isNested))
                 returnToken tokenLexbufState token
             | _, (EQUALS | COLON) ->
                 if debug then dprintf "CtxtModuleHead: COLON/EQUALS, pushing CtxtModuleBody and CtxtSeqBlock\n"
@@ -1643,7 +1646,7 @@ type LexFilterImpl (
                     // and we've encountered declarations below
                     if debug then dprintf "CtxtModuleHead: not start of file, popping CtxtModuleHead\n"
                     popCtxt()
-                    reprocessWithoutBlockRule()
+                    insertTokenFromPrevPosToCurrentPos OBLOCKSEP
 
         //  Offside rule for SeqBlock.
         //      f x
@@ -1972,7 +1975,8 @@ type LexFilterImpl (
         | MODULE, _ :: _ ->
             insertComingSoonTokens("MODULE", MODULE_COMING_SOON, MODULE_IS_HERE)
             if debug then dprintf "MODULE: entering CtxtModuleHead, awaiting EQUALS to go to CtxtSeqBlock (%a)\n" outputPos tokenStartPos
-            pushCtxt tokenTup (CtxtModuleHead (tokenStartPos, token, NotLexingModuleAttributes))
+            let isNested = match offsideStack with | [ CtxtSeqBlock _ ] -> false | _ -> true
+            pushCtxt tokenTup (CtxtModuleHead (tokenStartPos, token, NotLexingModuleAttributes, isNested))
             pool.Return tokenTup
             hwTokenFetch useBlockRule
 

src/Compiler/pars.fsy

@@ -521,6 +521,12 @@ moduleIntro:
         let mModule = rhs parseState 1
         mModule, $4, $5.LongIdent, $3, $2 }
 
+  | moduleKeyword opt_attributes opt_access opt_rec OBLOCKSEP
+      { if not (isNil $2) then
+            parseState.LexBuffer.CheckLanguageFeatureAndRecover LanguageFeature.AttributesToRightOfModuleKeyword (rhs parseState 4)
+        let mModule = rhs parseState 1
+        mModule, $4, [], $3, $2 }
+
 
 /* The start of a namespace declaration */
 namespaceIntro:

tests/fsharp/typecheck/sigs/neg41.bsl

@@ -1,2 +1,2 @@
 
-neg41.fs(3,1,3,5): parse error FS0010: Unexpected keyword 'type' in definition. Expected '=' or other token.
+neg41.fs(2,20,3,1): parse error FS0010: Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/fsharp/typecheck/sigs/neg42.bsl

@@ -1,2 +1,2 @@
 
-neg42.fsi(3,1,3,5): parse error FS0010: Unexpected keyword 'type' in signature file. Expected ':', '=' or other token.
+neg42.fsi(2,20,3,1): parse error FS0010: Incomplete structured construct at or before this point in signature file. Expected ':', '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 03.fs

@@ -0,0 +1,5 @@
+module Module
+
+module A
+
+()

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 03.fs.bsl

@@ -0,0 +1,20 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 03.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,8)), false, [], false, (3,0--3,8),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None });
+           Expr (Const (Unit, (5,0--5,2)), (5,0--5,2))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--5,2), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,9)-(5,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 04.fs

@@ -0,0 +1,5 @@
+module Module
+
+module
+
+()

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 04.fs.bsl

@@ -0,0 +1,20 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 04.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--5,0)), false, [], false, (3,0--5,0),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None });
+           Expr (Const (Unit, (5,0--5,2)), (5,0--5,2))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--5,2), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,7)-(5,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 05.fs

@@ -0,0 +1,5 @@
+module Module
+
+module rec
+
+()

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 05.fs.bsl

@@ -0,0 +1,20 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 05.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--5,0)), true, [], false, (3,0--5,0),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None });
+           Expr (Const (Unit, (5,0--5,2)), (5,0--5,2))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--5,2), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,11)-(5,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 06.fs

@@ -0,0 +1,5 @@
+module Module
+
+module rec A
+
+()

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 06.fs.bsl

@@ -0,0 +1,20 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 06.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,12)), true, [], false, (3,0--3,12),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None });
+           Expr (Const (Unit, (5,0--5,2)), (5,0--5,2))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--5,2), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,13)-(5,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 07.fs

@@ -0,0 +1,6 @@
+module Module
+
+module A =
+    module
+
+2

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 07.fs.bsl

@@ -0,0 +1,27 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 07.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,8)), false,
+              [NestedModule
+                 (SynComponentInfo
+                    ([], None, [], [],
+                     PreXmlDoc ((4,4), FSharp.Compiler.Xml.XmlDocCollector),
+                     false, None, (4,4--6,0)), false, [], false, (4,4--6,0),
+                  { ModuleKeyword = Some (4,4--4,10)
+                    EqualsRange = None })], false, (3,0--6,0),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = Some (3,9--3,10) });
+           Expr (Const (Int32 2, (6,0--6,1)), (6,0--6,1))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--6,1), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(6,0)-(6,1) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 08.fs

@@ -0,0 +1,6 @@
+module Module
+
+module A =
+    module B
+
+    2

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 08.fs.bsl

@@ -0,0 +1,27 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 08.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,8)), false,
+              [NestedModule
+                 (SynComponentInfo
+                    ([], None, [], [B],
+                     PreXmlDoc ((4,4), FSharp.Compiler.Xml.XmlDocCollector),
+                     false, None, (4,4--4,12)), false, [], false, (4,4--4,12),
+                  { ModuleKeyword = Some (4,4--4,10)
+                    EqualsRange = None });
+               Expr (Const (Int32 2, (6,4--6,5)), (6,4--6,5))], false,
+              (3,0--6,5), { ModuleKeyword = Some (3,0--3,6)
+                            EqualsRange = Some (3,9--3,10) })],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--6,5), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,13)-(6,4) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 09.fs

@@ -0,0 +1,6 @@
+module Module
+
+module A =
+    module B =
+
+    2

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 09.fs.bsl

@@ -0,0 +1,28 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 09.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,8)), false,
+              [NestedModule
+                 (SynComponentInfo
+                    ([], None, [], [B],
+                     PreXmlDoc ((4,4), FSharp.Compiler.Xml.XmlDocCollector),
+                     false, None, (4,4--4,12)), false, [], false, (4,4--4,14),
+                  { ModuleKeyword = Some (4,4--4,10)
+                    EqualsRange = Some (4,13--4,14) });
+               Expr (Const (Int32 2, (6,4--6,5)), (6,4--6,5))], false,
+              (3,0--6,5), { ModuleKeyword = Some (3,0--3,6)
+                            EqualsRange = Some (3,9--3,10) })],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--6,5), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(6,4)-(6,5) parse error Possible incorrect indentation: this token is offside of context started at position (4:5). Try indenting this token further or using standard formatting conventions.
+(6,4)-(6,5) parse error Incomplete structured construct at or before this point in definition

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 10.fs

@@ -0,0 +1,6 @@
+module Module
+
+module A =
+    module
+
+    2

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 10.fs.bsl

@@ -0,0 +1,27 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 10.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [A],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--3,8)), false,
+              [NestedModule
+                 (SynComponentInfo
+                    ([], None, [], [],
+                     PreXmlDoc ((4,4), FSharp.Compiler.Xml.XmlDocCollector),
+                     false, None, (4,4--6,4)), false, [], false, (4,4--6,4),
+                  { ModuleKeyword = Some (4,4--4,10)
+                    EqualsRange = None });
+               Expr (Const (Int32 2, (6,4--6,5)), (6,4--6,5))], false,
+              (3,0--6,5), { ModuleKeyword = Some (3,0--3,6)
+                            EqualsRange = Some (3,9--3,10) })],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--6,5), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,11)-(6,4) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 11.fs

@@ -0,0 +1,5 @@
+module Module
+
+module
+
+A

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 11.fs.bsl

@@ -0,0 +1,19 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 11.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--5,0)), false, [], false, (3,0--5,0),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None }); Expr (Ident A, (5,0--5,1))],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--5,1), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(3,7)-(5,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 12.fs

@@ -0,0 +1,3 @@
+module Module
+
+module

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 12.fs.bsl

@@ -0,0 +1,19 @@
+ImplFile
+  (ParsedImplFileInput
+     ("/root/ModuleOrNamespace/Nested module 12.fs", false,
+      QualifiedNameOfFile Module, [], [],
+      [SynModuleOrNamespace
+         ([Module], false, NamedModule,
+          [NestedModule
+             (SynComponentInfo
+                ([], None, [], [],
+                 PreXmlDoc ((3,0), FSharp.Compiler.Xml.XmlDocCollector), false,
+                 None, (3,0--4,0)), false, [], false, (3,0--4,0),
+              { ModuleKeyword = Some (3,0--3,6)
+                EqualsRange = None })],
+          PreXmlDoc ((1,0), FSharp.Compiler.Xml.XmlDocCollector), [], None,
+          (1,0--4,0), { LeadingKeyword = Module (1,0--1,6) })], (true, true),
+      { ConditionalDirectives = []
+        CodeComments = [] }, set []))
+
+(4,0)-(4,0) parse error Incomplete structured construct at or before this point in definition. Expected '=' or other token.

tests/service/data/SyntaxTree/ModuleOrNamespace/Nested module 13.fs

@@ -0,0 +1,3 @@
+module Module
+
+module A