From c9d14f6c9ec1db8ef85b4c0e837df25921eb4fe7 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Mon, 17 Jun 2019 22:27:13 +0200
Subject: [PATCH] Cause B programs to fail on startup if they detect alignment
 issues.

---
 lang/b/lib/b.h    | 2 ++
 lang/b/lib/main.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/lang/b/lib/b.h b/lang/b/lib/b.h
index 1125452cd..36d9f38fd 100644
--- a/lang/b/lib/b.h
+++ b/lang/b/lib/b.h
@@ -14,6 +14,8 @@
 #error Unsupported EM_PSIZE
 #endif
 
+#define MASK ((1<<SHIFT)-1)
+
 extern FILE* input_unit;
 extern FILE* output_unit;
 
diff --git a/lang/b/lib/main.c b/lang/b/lib/main.c
index 44ea76c9b..1c3ce67a2 100644
--- a/lang/b/lib/main.c
+++ b/lang/b/lib/main.c
@@ -173,6 +173,8 @@ void patch_addresses(uintptr_t** p)
     while (*p)
     {
         uintptr_t* q = *p++;
+		if (*q & MASK)
+			abort();
         *q >>= SHIFT;
     }
 }