fixes regressions

changelog.md

@@ -23,6 +23,19 @@
 
 #### Breaking changes in the compiler
 
+- The compiler now implements the "generic symbol prepass" for `when` statements
+  in generics, see bug #8603. This means that code like this does not compile
+  anymore:
+
+```nim
+proc enumToString*(enums: openArray[enum]): string =
+  # typo: 'e' instead 'enums'
+  when e.low.ord >= 0 and e.high.ord < 256:
+    result = newString(enums.len)
+  else:
+    result = newString(enums.len * 2)
+```
+
 ### Library additions
 
 - There is a new stdlib module `editdistance` as a replacement for the

compiler/semtempl.nim

@@ -706,28 +706,26 @@ proc semPatternBody(c: var TemplCtx, n: PNode): PNode =
       elif templToExpand(s):
         return semPatternBody(c, semTemplateExpr(c.c, n, s, {efNoSemCheck}))
 
-    if n.kind == nkInfix and n.sons[0].kind == nkIdent:
+    if n.kind == nkInfix and (let id = considerQuotedIdent(c.c, n[0]); id != nil):
       # we interpret `*` and `|` only as pattern operators if they occur in
       # infix notation, so that '`*`(a, b)' can be used for verbatim matching:
-      let opr = n.sons[0]
+      if id.s == "*" or id.s == "**":
-      if opr.ident.s == "*" or opr.ident.s == "**":
         result = newNodeI(nkPattern, n.info, n.len)
-        result.sons[0] = opr
+        result.sons[0] = newIdentNode(id, n.info)
         result.sons[1] = semPatternBody(c, n.sons[1])
         result.sons[2] = expectParam(c, n.sons[2])
         return
-      elif opr.ident.s == "|":
+      elif id.s == "|":
         result = newNodeI(nkPattern, n.info, n.len)
-        result.sons[0] = opr
+        result.sons[0] = newIdentNode(id, n.info)
         result.sons[1] = semPatternBody(c, n.sons[1])
         result.sons[2] = semPatternBody(c, n.sons[2])
         return
 
-    if n.kind == nkPrefix and n.sons[0].kind == nkIdent:
+    if n.kind == nkPrefix and (let id = considerQuotedIdent(c.c, n[0]); id != nil):
-      let opr = n.sons[0]
+      if id.s == "~":
-      if opr.ident.s == "~":
         result = newNodeI(nkPattern, n.info, n.len)
-        result.sons[0] = opr
+        result.sons[0] = newIdentNode(id, n.info)
         result.sons[1] = semPatternBody(c, n.sons[1])
         return