From 39ee14d25346aa82e75e9818e92e3c43571c6757 Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Mon, 25 Jul 2022 11:18:34 +0000
Subject: [PATCH] Error when trying to define variadic functions

They aren't yet supported by Cranelift
---
 src/abi/mod.rs        |  9 +++++++++
 src/intrinsics/mod.rs | 14 ++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/src/abi/mod.rs b/src/abi/mod.rs
index 6f12d9ca531..815450f689e 100644
--- a/src/abi/mod.rs
+++ b/src/abi/mod.rs
@@ -193,6 +193,15 @@ pub(crate) fn codegen_fn_prelude<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, start_
     }
 
     let fn_abi = fx.fn_abi.take().unwrap();
+
+    // FIXME implement variadics in cranelift
+    if fn_abi.c_variadic {
+        fx.tcx.sess.span_fatal(
+            fx.mir.span,
+            "Defining variadic functions is not yet supported by Cranelift",
+        );
+    }
+
     let mut arg_abis_iter = fn_abi.args.iter();
 
     let func_params = fx
diff --git a/src/intrinsics/mod.rs b/src/intrinsics/mod.rs
index 4b2207f3758..eb58cfbb356 100644
--- a/src/intrinsics/mod.rs
+++ b/src/intrinsics/mod.rs
@@ -1135,6 +1135,20 @@ fn codegen_regular_intrinsic_call<'tcx>(
             // FIXME implement black_box semantics
             ret.write_cvalue(fx, a);
         };
+
+        // FIXME implement variadics in cranelift
+        va_copy, (o _dest, o _src) {
+            fx.tcx.sess.span_fatal(
+                source_info.span,
+                "Defining variadic functions is not yet supported by Cranelift",
+            );
+        };
+        va_arg | va_end, (o _valist) {
+            fx.tcx.sess.span_fatal(
+                source_info.span,
+                "Defining variadic functions is not yet supported by Cranelift",
+            );
+        };
     }
 
     let ret_block = fx.get_block(destination.unwrap());