From 67665286575d406769000b3f3e80d4d03d2cab2b Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 19 Mar 2022 10:58:33 -0700
Subject: [PATCH] stage2: fix crash that could happen if `as` zir fails

Example scenario:

    test {
        const a: i32 = blk: {
            if (false) break :blk 24;
        };
        _ = a;
    }

Prior to this, this would panic the compiler with a source needed error.
This provides the source as `sema.src`. This is not ideal, since the
line it points to is pretty far from the true issue. (One block out)

But, this prevents the compiler from straight up crashing and follows a
pattern used by similar ZIR which don't provide a src loc.
---
 src/Sema.zig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Sema.zig b/src/Sema.zig
index 94db6e80b9..ff33f56c67 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -6362,7 +6362,7 @@ fn zirAs(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst
     defer tracy.end();
 
     const bin_inst = sema.code.instructions.items(.data)[inst].bin;
-    return sema.analyzeAs(block, .unneeded, bin_inst.lhs, bin_inst.rhs);
+    return sema.analyzeAs(block, sema.src, bin_inst.lhs, bin_inst.rhs);
 }
 
 fn zirAsNode(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {