Fix #19224 For loops over a hardcoded empty array crash the compiler (#…

…20476) * Fix #11684 For loops over a hardcoded empty array crash the compiler * Update t19224.nim
nim-lang · Oct 1, 2022 · 567c3f0 · 567c3f0
1 parent 0b16505
commit 567c3f0
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 0 deletions.
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
@@ -853,6 +853,9 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
   var iterAfterVarLent = iter.skipTypes({tyGenericInst, tyAlias, tyLent, tyVar})
   # n.len == 3 means that there is one for loop variable
   # and thus no tuple unpacking:
+  if iterAfterVarLent.kind == tyEmpty:
+    localError(c.config, n[^2].info, "cannot infer element type of $1" %
+               renderTree(n[^2], {renderNoComments}))
   if iterAfterVarLent.kind != tyTuple or n.len == 3:
     if n.len == 3:
       if n[0].kind == nkVarTuple:

diff --git a/tests/errmsgs/t19224.nim b/tests/errmsgs/t19224.nim
@@ -0,0 +1,12 @@
+discard """
+cmd: "nim check --hints:off $file"
+errormsg: ""
+nimout: '''
+t19224.nim(10, 10) Error: cannot infer element type of items([])
+t19224.nim(12, 10) Error: cannot infer element type of items(@[])
+'''
+"""
+
+for _ in []: discard
+
+for _ in @[]: discard