From 25e74cb385dc353bcf0e56b35a6f1c7c8b13267e Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Thu, 4 Feb 2016 12:59:06 -0700
Subject: [PATCH] ability to explicitly cast bool to int

---
 src/all_types.hpp    |  1 +
 src/analyze.cpp      | 13 +++++++++++++
 src/codegen.cpp      |  5 +++++
 test/self_hosted.zig | 15 +++++++++++++++
 4 files changed, 34 insertions(+)

diff --git a/src/all_types.hpp b/src/all_types.hpp
index c6baee6a4b8f7dd568b646e048be8f9cdd84ec69..70919f67e72149419aa6fb9c42363ca3057bba83 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -346,6 +346,7 @@ enum CastOp {
     CastOpErrToInt,
     CastOpIntToFloat,
     CastOpFloatToInt,
+    CastOpBoolToInt,
 };
 
 struct AstNodeFnCallExpr {
diff --git a/src/analyze.cpp b/src/analyze.cpp
index 38bc656a1faf677f1b820843e11b868e32baa11c..7e63a43366331e4ddd4f8e84204c9cd9ee2dd25f 100644
--- a/src/analyze.cpp
+++ b/src/analyze.cpp
@@ -3610,6 +3610,10 @@ static void eval_const_expr_implicit_cast(CodeGen *g, AstNode *node, AstNode *ex
             bignum_cast_to_int(&const_val->data.x_bignum, &other_val->data.x_bignum);
             const_val->ok = true;
             break;
+        case CastOpBoolToInt:
+            bignum_init_unsigned(&const_val->data.x_bignum, other_val->data.x_bool ? 1 : 0);
+            const_val->ok = true;
+            break;
     }
 }
 
@@ -3643,6 +3647,15 @@ static TypeTableEntry *analyze_cast_expr(CodeGen *g, ImportTableEntry *import, B
         return wanted_type;
     }
 
+    // explicit cast from bool to int
+    if (wanted_type->id == TypeTableEntryIdInt &&
+        actual_type->id == TypeTableEntryIdBool)
+    {
+        node->data.fn_call_expr.cast_op = CastOpBoolToInt;
+        eval_const_expr_implicit_cast(g, node, expr_node);
+        return wanted_type;
+    }
+
     // explicit cast from pointer to isize or usize
     if ((wanted_type == g->builtin_types.entry_isize || wanted_type == g->builtin_types.entry_usize) &&
         actual_type->id == TypeTableEntryIdPointer)
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 5c07b34097c65ba4f2326d6dfa2c9e46737ef946..e0a2784e95d48d5332bf152e435abd0f7cd13ba4 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -530,6 +530,11 @@ static LLVMValueRef gen_cast_expr(CodeGen *g, AstNode *node) {
                 return LLVMBuildFPToUI(g->builder, expr_val, wanted_type->type_ref, "");
             }
 
+        case CastOpBoolToInt:
+            assert(wanted_type->id == TypeTableEntryIdInt);
+            assert(actual_type->id == TypeTableEntryIdBool);
+            return LLVMBuildZExt(g->builder, expr_val, wanted_type->type_ref, "");
+
     }
     zig_unreachable();
 }
diff --git a/test/self_hosted.zig b/test/self_hosted.zig
index 82f4d553cf6b11d5d34c77b7508f7d0403ac1697..048b820ec95f01edf8f6e5033d6aec97c04963a9 100644
--- a/test/self_hosted.zig
+++ b/test/self_hosted.zig
@@ -82,3 +82,18 @@ fn continue_in_for_loop() {
     }
     if (sum != 6) unreachable{}
 }
+
+
+#attribute("test")
+fn cast_bool_to_int() {
+    const t = true;
+    const f = false;
+    if (i32(t) != i32(1)) unreachable{}
+    if (i32(f) != i32(0)) unreachable{}
+    non_const_cast_bool_to_int(t, f);
+}
+
+fn non_const_cast_bool_to_int(t: bool, f: bool) {
+    if (i32(t) != i32(1)) unreachable{}
+    if (i32(f) != i32(0)) unreachable{}
+}
-- 
2.54.0