From 4cb522fb8ac0150921da4c35a28232e2a6abcafa Mon Sep 17 00:00:00 2001
From: Etan Kissling <etan@status.im>
Date: Mon, 6 Dec 2021 20:38:23 +0100
Subject: [PATCH] allow `HSlice` bounded by constants of distinct types
 (#19219) [backport:1.2]

When creating heterogenous slices of distinct types, the compiler does
not initialize the internal type's `size` before accessing it.
This then leads to this crash message:
```
compiler/int128.nim(594, 11) `false` masking only implemented for 1, 2, 4 and 8 bytes [AssertionError]
```
This patch initializes the `size` properly, fixing the problem.

(cherry picked from commit 0213c7313b2edf8e8ec9d81764685744e874ef84)
---
 compiler/semfold.nim      | 16 ++++++++--------
 tests/slice/tdistinct.nim |  2 ++
 2 files changed, 10 insertions(+), 8 deletions(-)
 create mode 100644 tests/slice/tdistinct.nim

diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index c6bab21c96..5594394d0b 100644
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -164,7 +164,7 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode =
   of mCard: result = newIntNodeT(toInt128(nimsets.cardSet(g.config, a)), n, g)
   of mBitnotI:
     if n.typ.isUnsigned:
-      result = newIntNodeT(bitnot(getInt(a)).maskBytes(int(n.typ.size)), n, g)
+      result = newIntNodeT(bitnot(getInt(a)).maskBytes(int(getSize(g.config, n.typ))), n, g)
     else:
       result = newIntNodeT(bitnot(getInt(a)), n, g)
   of mLengthArray: result = newIntNodeT(lengthOrd(g.config, a.typ), n, g)
@@ -276,23 +276,23 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; g: ModuleGraph): PNode =
   of mBitorI, mOr: result = newIntNodeT(bitor(getInt(a), getInt(b)), n, g)
   of mBitxorI, mXor: result = newIntNodeT(bitxor(getInt(a), getInt(b)), n, g)
   of mAddU:
-    let val = maskBytes(getInt(a) + getInt(b), int(n.typ.size))
+    let val = maskBytes(getInt(a) + getInt(b), int(getSize(g.config, n.typ)))
     result = newIntNodeT(val, n, g)
   of mSubU:
-    let val = maskBytes(getInt(a) - getInt(b), int(n.typ.size))
+    let val = maskBytes(getInt(a) - getInt(b), int(getSize(g.config, n.typ)))
     result = newIntNodeT(val, n, g)
     # echo "subU: ", val, " n: ", n, " result: ", val
   of mMulU:
-    let val = maskBytes(getInt(a) * getInt(b), int(n.typ.size))
+    let val = maskBytes(getInt(a) * getInt(b), int(getSize(g.config, n.typ)))
     result = newIntNodeT(val, n, g)
   of mModU:
-    let argA = maskBytes(getInt(a), int(a.typ.size))
-    let argB = maskBytes(getInt(b), int(a.typ.size))
+    let argA = maskBytes(getInt(a), int(getSize(g.config, a.typ)))
+    let argB = maskBytes(getInt(b), int(getSize(g.config, a.typ)))
     if argB != Zero:
       result = newIntNodeT(argA mod argB, n, g)
   of mDivU:
-    let argA = maskBytes(getInt(a), int(a.typ.size))
-    let argB = maskBytes(getInt(b), int(a.typ.size))
+    let argA = maskBytes(getInt(a), int(getSize(g.config, a.typ)))
+    let argB = maskBytes(getInt(b), int(getSize(g.config, a.typ)))
     if argB != Zero:
       result = newIntNodeT(argA div argB, n, g)
   of mLeSet: result = newIntNodeT(toInt128(ord(containsSets(g.config, a, b))), n, g)
diff --git a/tests/slice/tdistinct.nim b/tests/slice/tdistinct.nim
new file mode 100644
index 0000000000..d99b529a72
--- /dev/null
+++ b/tests/slice/tdistinct.nim
@@ -0,0 +1,2 @@
+type Foo = distinct uint64
+const slice = 0 ..< 42.Foo