closure complain (#1154)

Author: Araq

src/nimony/derefs.nim

@@ -350,7 +350,7 @@ proc trProcPragmas(c: var Context; n: var Cursor) =
     takeParRi c, n
 
 proc trProcDecl(c: var Context; n: var Cursor) =
-  c.typeCache.openScope()
+  c.typeCache.openScope(ProcScope)
   takeToken c, n
   let symId = n.symId
   var isGeneric = false
@@ -714,7 +714,15 @@ proc trFor(c: var Context; n: var Cursor) =
 proc tr(c: var Context; n: var Cursor; e: Expects) =
   case n.kind
   of Symbol:
-    trLocation c, n, e
+    let localInfo = c.typeCache.getLocalInfo(n.symId)
+    if localInfo.crossedProc:
+      let info = n.info
+      c.dest.buildTree ErrT, info:
+        c.dest.addSubtree n
+        c.dest.add strToken(pool.strings.getOrIncl("cannot access local variable `" & asNimCode(n) & "` from another routine; closures are not supported"), info)
+      skip n
+    else:
+      trLocation c, n, e
   of IntLit, UIntLit, FloatLit, CharLit, StringLit:
     if e.wantMutable:
       # Consider `fvar(returnsVar(someLet))`: We must not allow this.

src/nimony/typenav.nim

@@ -31,10 +31,14 @@ proc isGeneratedType*(s: string): bool =
 type
   LocalInfo* = object
     kind*: SymKind
+    crossedProc*: bool
     typ*: Cursor
+  ScopeKind* = enum
+    OtherScope, ProcScope, UnusedScope
   TypeScope* {.acyclic.} = ref object
     locals: Table[SymId, LocalInfo]
     parent: TypeScope
+    kind: ScopeKind
 
   TypeCache* = object
     builtins*: BuiltinTypes
@@ -47,8 +51,8 @@ proc createTypeCache*(): TypeCache =
 proc registerLocal*(c: var TypeCache; s: SymId; kind: SymKind; typ: Cursor) =
   c.current.locals[s] = LocalInfo(kind: kind, typ: typ)
 
-proc openScope*(c: var TypeCache) =
-  c.current = TypeScope(locals: initTable[SymId, LocalInfo](), parent: c.current)
+proc openScope*(c: var TypeCache; kind = OtherScope) =
+  c.current = TypeScope(locals: initTable[SymId, LocalInfo](), parent: c.current, kind: kind)
 
 proc closeScope*(c: var TypeCache) =
   c.current = c.current.parent
@@ -87,11 +91,17 @@ proc getInitValueImpl(c: var TypeCache; s: SymId): Cursor =
 
 proc getLocalInfo*(c: var TypeCache; s: SymId): LocalInfo =
   var it {.cursor.} = c.current
+  var crossedProc = false
+  var compareTo = UnusedScope
   while it != nil:
     var res = it.locals.getOrDefault(s)
+    if it.kind == compareTo:
+      crossedProc = true
     if res.kind != NoSym:
+      res.crossedProc = crossedProc
       return res
     it = it.parent
+    compareTo = ProcScope
   return default(LocalInfo)
 
 proc getInitValue*(c: var TypeCache; s: SymId): Cursor =