fixes #23422; card regression (#23437)

fixes #23422

ref https://github.com/nim-lang/Nim/issues/20997
https://github.com/nim-lang/Nim/pull/21165

The function `cardSet` is used for large sets that are stored in the
form of arrays. It shouldn't be passed as a pointer

compiler/ccgexprs.nim

@@ -2088,7 +2088,7 @@ proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
     of mExcl: binaryStmtInExcl(p, e, d, "$1[(NU)($2)>>3] &= ~(1U<<($2&7U));$n")
     of mCard:
       var a: TLoc = initLocExpr(p, e[1])
-      putIntoDest(p, d, e, ropecg(p.module, "#cardSet($1, $2)", [addrLoc(p.config, a), size]))
+      putIntoDest(p, d, e, ropecg(p.module, "#cardSet($1, $2)", [rdCharLoc(a), size]))
     of mLtSet, mLeSet:
       i = getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt)) # our counter
       a = initLocExpr(p, e[1])

tests/sets/tsets.nim

@@ -1,3 +1,7 @@
+discard """
+  target: "c cpp"
+"""
+
 # Test builtin sets
 
 # xxx these tests are not very good, this should be revisited.
@@ -93,3 +97,37 @@ block:
 
   doAssert k99 notin s1
   doAssert k99 notin s2
+
+block: # bug #23422
+  block:
+    var a: set[uint8] = {1'u8}
+
+    proc printLen(x: set[uint8]): int =
+      doAssert x.len == card(x)
+      result = card(x)
+
+    proc printLenVar(x: var set[uint8]): int =
+      doAssert x.len == card(x)
+      result = card(x)
+
+    doAssert a.len == 1
+    doAssert printLen(a) == 1
+    doAssert printLenVar(a) == card(a)
+
+  block:
+    type Fruit = enum
+      Apple, Banana, Melon
+
+    var a: set[Fruit] = {Apple}
+
+    proc printLen(x: set[Fruit]): int =
+      doAssert x.len == card(x)
+      result = card(x)
+
+    proc printLenVar(x: var set[Fruit]): int =
+      doAssert x.len == card(x)
+      result = card(x)
+
+    doAssert a.len == 1
+    doAssert printLen(a) == 1
+    doAssert printLenVar(a) == card(a)