From d067a037cce906d600851e9b88df251451f9a93e Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Mon, 19 Aug 2019 15:58:31 -0400
Subject: [PATCH] fix void array as a local variable initializer

Related: #1767
---
 src/ir.cpp                    | 12 ++++++++++--
 test/stage1/behavior/void.zig |  5 +++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/ir.cpp b/src/ir.cpp
index 3b855b374f4c16f5d3900f61242c38bf75219925..ccdd34f893868b9f70beffcbc225e4dc30c85f2c 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -13940,8 +13940,7 @@ static IrInstruction *ir_analyze_array_mult(IrAnalyze *ira, IrInstructionBinOp *
     uint64_t old_array_len = array_type->data.array.len;
     uint64_t new_array_len;
 
-    if (mul_u64_overflow(old_array_len, mult_amt, &new_array_len))
-    {
+    if (mul_u64_overflow(old_array_len, mult_amt, &new_array_len)) {
         ir_add_error(ira, &instruction->base, buf_sprintf("operation results in overflow"));
         return ira->codegen->invalid_instruction;
     }
@@ -13956,6 +13955,15 @@ static IrInstruction *ir_analyze_array_mult(IrAnalyze *ira, IrInstructionBinOp *
         return result;
     }
 
+    switch (type_has_one_possible_value(ira->codegen, result->value.type)) {
+        case OnePossibleValueInvalid:
+            return ira->codegen->invalid_instruction;
+        case OnePossibleValueYes:
+            return result;
+        case OnePossibleValueNo:
+            break;
+    }
+
     // TODO optimize the buf case
     expand_undef_array(ira->codegen, array_val);
     out_val->data.x_array.data.s_none.elements = create_const_vals(new_array_len);
diff --git a/test/stage1/behavior/void.zig b/test/stage1/behavior/void.zig
index 972279194689fa120c70f4cb4fa41cf6e4dc97c3..19e879d1570d328fd146a15a7ff3a619e90808dc 100644
--- a/test/stage1/behavior/void.zig
+++ b/test/stage1/behavior/void.zig
@@ -33,3 +33,8 @@ test "void optional" {
     var x: ?void = {};
     expect(x != null);
 }
+
+test "void array as a local variable initializer" {
+    var x = [_]void{{}} ** 1004;
+    var y = x[0];
+}
-- 
2.54.0