From b50844185991a86bac462346413341b87eda14cd Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Wed, 27 Jan 2016 14:49:48 -0700
Subject: [PATCH] fix `%%` prefix operator codegen for simple values

closes #93
---
 src/codegen.cpp    |  3 ++-
 test/run_tests.cpp | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/codegen.cpp b/src/codegen.cpp
index 008ec9b395..78592e4d09 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -916,11 +916,12 @@ static LLVMValueRef gen_prefix_op_expr(CodeGen *g, AstNode *node) {
                 TypeTableEntry *child_type = expr_type->data.error.child_type;
                 // TODO in debug mode, put a panic here if the error is not 0
                 if (child_type->size_in_bits > 0) {
+                    add_debug_source_node(g, node);
                     LLVMValueRef child_val_ptr = LLVMBuildStructGEP(g->builder, expr_val, 1, "");
                     if (handle_is_ptr(child_type)) {
                         return child_val_ptr;
                     } else {
-                        return expr_val;
+                        return LLVMBuildLoad(g->builder, child_val_ptr, "");
                     }
                 } else {
                     return nullptr;
diff --git a/test/run_tests.cpp b/test/run_tests.cpp
index f0834e2ba7..2b80832e8b 100644
--- a/test/run_tests.cpp
+++ b/test/run_tests.cpp
@@ -1329,6 +1329,21 @@ fn f() -> &void {
 pub fn main(args: [][]u8) -> %void {
     const a = f();
     return *a;
+}
+    )SOURCE", "OK\n");
+
+    add_simple_case("unwrap simple value from error", R"SOURCE(
+import "std.zig";
+fn do() -> %isize {
+    13
+}
+
+pub fn main(args: [][]u8) -> %void {
+    const i = %%do();
+    if (i != 13) {
+        %%stdout.printf("BAD\n");
+    }
+    %%stdout.printf("OK\n");
 }
     )SOURCE", "OK\n");
 }