From a459570d94d8e803d9d6d9f35e06f92f1402865d Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Tue, 30 Oct 2018 15:54:02 +0100
Subject: [PATCH] wasm: execute an 'unreachable' trap inst on panic

This already happened when directly calling panic() but not with some
runtime panics like accessing a slice out of bounds.
---
 src/runtime/panic.go        | 5 +++++
 src/runtime/runtime_wasm.go | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index cac51733a..c7d3d14cc 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -1,5 +1,10 @@
 package runtime
 
+// trap is a compiler hint that this function cannot be executed. It is
+// translated into either a trap instruction or a call to abort().
+//go:linkname trap llvm.trap
+func trap()
+
 // Builtin function panic(msg), used as a compiler intrinsic.
 func _panic(message interface{}) {
 	printstring("panic: ")
diff --git a/src/runtime/runtime_wasm.go b/src/runtime/runtime_wasm.go
index cf4eca693..8e58eec5d 100644
--- a/src/runtime/runtime_wasm.go
+++ b/src/runtime/runtime_wasm.go
@@ -49,6 +49,7 @@ func align(ptr uintptr) uintptr {
 	return (ptr + 3) &^ 3
 }
 
+// Abort executes the wasm 'unreachable' instruction.
 func abort() {
-	// TODO
+	trap()
 }