From 7c80f253c18836ab65da5e807bb0800e9867d260 Mon Sep 17 00:00:00 2001
From: Keno Fischer <keno@juliacomputing.com>
Date: Tue, 18 Apr 2023 01:21:19 +0000
Subject: [PATCH] irverify: Catch invalid use of Goto{IfNot, Node}, ReturnNode

Referencing control flow statements in value position is illegal
and will cause crashes in compilation or interpretation. Add this
to the verifier, so that downstream tooling that checks for valid
IR can catch this before it gets handed off to the compiler.
---
 base/compiler/ssair/verify.jl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/base/compiler/ssair/verify.jl b/base/compiler/ssair/verify.jl
index 66fde426347bd..c281aa4b7786f 100644
--- a/base/compiler/ssair/verify.jl
+++ b/base/compiler/ssair/verify.jl
@@ -43,6 +43,12 @@ function check_op(ir::IRCode, domtree::DomTree, @nospecialize(op), use_bb::Int,
                 error("")
             end
         end
+
+        use_inst = ir[op]
+        if isa(use_inst[:inst], Union{GotoIfNot, GotoNode, ReturnNode})
+            @verify_error "At statement %$use_idx: Invalid use of value statement or terminator %$(op.id)"
+            error("")
+        end
     elseif isa(op, GlobalRef)
         if !isdefined(op.mod, op.name) || !isconst(op.mod, op.name)
             @verify_error "Unbound GlobalRef not allowed in value position"