From 3464351d1e0a1e840d0b1a6267d0a5bf4113cfcc Mon Sep 17 00:00:00 2001
From: Michael Dusan <michael.dusan@gmail.com>
Date: Thu, 10 Oct 2019 04:55:09 -0400
Subject: stage1: fix ir_resolve_str() to return slice

`ir_resolve_str()` bug returns array expression even when when sliced
to a lesser length. Fix is to return array if slice.len == array.len,
otherwise return slice.

Bug report use-case is based on one builtin function. However, at least
the following builtins were exposed to the bug:

    `@byteOffsetOf`
    `@cDefine`
    `@cImport`
    `@cInclude`
    `@cUndef`
    `@compileError`
    `@embedFile`
    `@export`
    `@fieldParentPtr`
    `@hasDecl`
    `@hasField`
    `@import`
    `@unionInit`

closes #3384
---
 src/ir.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

(limited to 'src/ir.cpp')

diff --git a/src/ir.cpp b/src/ir.cpp
index 0e6153ebcd..8fecbf7a18 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -13122,7 +13122,6 @@ static bool ir_resolve_float_mode(IrAnalyze *ira, IrInstruction *value, FloatMod
     return true;
 }
 
-
 static Buf *ir_resolve_str(IrAnalyze *ira, IrInstruction *value) {
     if (type_is_invalid(value->value.type))
         return nullptr;
@@ -13143,11 +13142,11 @@ static Buf *ir_resolve_str(IrAnalyze *ira, IrInstruction *value) {
 
     assert(ptr_field->data.x_ptr.special == ConstPtrSpecialBaseArray);
     ConstExprValue *array_val = ptr_field->data.x_ptr.data.base_array.array_val;
-    if (array_val->data.x_array.special == ConstArraySpecialBuf) {
-        return array_val->data.x_array.data.s_buf;
-    }
     expand_undef_array(ira->codegen, array_val);
     size_t len = bigint_as_usize(&len_field->data.x_bigint);
+    if (array_val->data.x_array.special == ConstArraySpecialBuf && len == buf_len(array_val->data.x_array.data.s_buf)) {
+        return array_val->data.x_array.data.s_buf;
+    }
     Buf *result = buf_alloc();
     buf_resize(result, len);
     for (size_t i = 0; i < len; i += 1) {
-- 
cgit v1.2.3


From 6cbb732b59d1ded92c7272a8b06f645e1c8acfd2 Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Thu, 10 Oct 2019 10:47:59 +0200
Subject: Extern unions should not trigger active field check

Fixes #3378
---
 src/ir.cpp                     |  2 +-
 test/stage1/behavior/union.zig | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

(limited to 'src/ir.cpp')

diff --git a/src/ir.cpp b/src/ir.cpp
index 8fecbf7a18..7dd141423c 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -17951,7 +17951,7 @@ static IrInstruction *ir_analyze_container_field_ptr(IrAnalyze *ira, Buf *field_
                     union_val->special = ConstValSpecialStatic;
                     bigint_init_bigint(&union_val->data.x_union.tag, &field->enum_field->value);
                     union_val->data.x_union.payload = payload_val;
-                } else {
+                } else if (bare_type->data.unionation.layout != ContainerLayoutExtern) {
                     TypeUnionField *actual_field = find_union_field_by_tag(bare_type, &union_val->data.x_union.tag);
                     if (actual_field == nullptr)
                         zig_unreachable();
diff --git a/test/stage1/behavior/union.zig b/test/stage1/behavior/union.zig
index d340a52d1e..f5e9ec09a8 100644
--- a/test/stage1/behavior/union.zig
+++ b/test/stage1/behavior/union.zig
@@ -511,3 +511,13 @@ test "union with comptime_int tag" {
     };
     comptime expect(@TagType(@TagType(Union)) == comptime_int);
 }
+
+test "extern union doesn't trigger field check at comptime" {
+    const U = extern union {
+        x: u32,
+        y: u8,
+    };
+
+    const x = U{ .x = 0x55AAAA55 };
+    comptime expect(x.y == 0x55);
+}
-- 
cgit v1.2.3