stage1: Fix typeInfo generation for arrays w/o sentinel

ZigTypeIdOptional types have a different way of specifying their payload
value depending on whether the child type is a pointer or not (plus some
other special cases).

Fixes #7251

2 files changed, 25 insertions, 13 deletions

diff --git a/src/stage1/ir.cpp b/src/stage1/ir.cpp
index 1f727c1be9..347014f257 100644
--- a/src/stage1/ir.cpp
+++ b/src/stage1/ir.cpp
@@ -25264,12 +25264,12 @@ static Error ir_make_type_info_decls(IrAnalyze *ira, IrInst* source_instr, ZigVa
                         0, 0, 0, false);
                     fn_decl_fields[5]->type = get_optional_type(ira->codegen, get_slice_type(ira->codegen, u8_ptr));
                     if (fn_node->is_extern && fn_node->lib_name != nullptr && buf_len(fn_node->lib_name) > 0) {
-                        fn_decl_fields[5]->data.x_optional = ira->codegen->pass1_arena->create<ZigValue>();
+                        ZigValue *slice_val = ira->codegen->pass1_arena->create<ZigValue>();
                         ZigValue *lib_name = create_const_str_lit(ira->codegen, fn_node->lib_name)->data.x_ptr.data.ref.pointee;
-                        init_const_slice(ira->codegen, fn_decl_fields[5]->data.x_optional, lib_name, 0,
-                                buf_len(fn_node->lib_name), true);
+                        init_const_slice(ira->codegen, slice_val, lib_name, 0, buf_len(fn_node->lib_name), true);
+                        set_optional_payload(fn_decl_fields[5], slice_val);
                     } else {
-                        fn_decl_fields[5]->data.x_optional = nullptr;
+                        set_optional_payload(fn_decl_fields[5], nullptr);
                     }
                     // return_type: type
                     ensure_field_index(fn_decl_val->type, "return_type", 6);
@@ -25549,8 +25549,12 @@ static Error ir_make_type_info_value(IrAnalyze *ira, IrInst* source_instr, ZigTy
                 fields[1]->data.x_type = type_entry->data.array.child_type;
                 // sentinel: anytype
                 fields[2]->special = ConstValSpecialStatic;
-                fields[2]->type = get_optional_type(ira->codegen, type_entry->data.array.child_type);
-                fields[2]->data.x_optional = type_entry->data.array.sentinel;
+                if (type_entry->data.array.child_type != nullptr) {
+                    fields[2]->type = get_optional_type(ira->codegen, type_entry->data.array.child_type);
+                    set_optional_payload(fields[2], type_entry->data.array.sentinel);
+                } else {
+                    fields[2]->type = ira->codegen->builtin_types.entry_null;
+                }
                 break;
             }
         case ZigTypeIdVector: {
diff --git a/test/stage1/behavior/type_info.zig b/test/stage1/behavior/type_info.zig
index fda79e71d2..aa5ac89c94 100644
--- a/test/stage1/behavior/type_info.zig
+++ b/test/stage1/behavior/type_info.zig
@@ -82,9 +82,6 @@ fn testNullTerminatedPtr() void {
     expect(ptr_info.Pointer.sentinel.? == 0);
 
     expect(@typeInfo([:0]u8).Pointer.sentinel != null);
-    expect(@typeInfo([10:0]u8).Array.sentinel != null);
-    expect(@typeInfo([10:0]u8).Array.len == 10);
-    expect(@sizeOf([10:0]u8) == 11);
 }
 
 test "type info: C pointer type info" {
@@ -123,10 +120,21 @@ test "type info: array type info" {
 }
 
 fn testArray() void {
-    const arr_info = @typeInfo([42]bool);
-    expect(arr_info == .Array);
-    expect(arr_info.Array.len == 42);
-    expect(arr_info.Array.child == bool);
+    {
+        const info = @typeInfo([42]u8);
+        expect(info == .Array);
+        expect(info.Array.len == 42);
+        expect(info.Array.child == u8);
+        expect(info.Array.sentinel == null);
+    }
+
+    {
+        const info = @typeInfo([10:0]u8);
+        expect(info.Array.len == 10);
+        expect(info.Array.child == u8);
+        expect(info.Array.sentinel.? == @as(u8, 0));
+        expect(@sizeOf([10:0]u8) == info.Array.len + 1);
+    }
 }
 
 test "type info: optional type info" {