From 1b2154dfe2f9b5030f487e7c4be8c706ce6e59b5 Mon Sep 17 00:00:00 2001
From: Tadeo Kondrak <me@tadeo.ca>
Date: Tue, 1 Sep 2020 18:55:36 -0600
Subject: [PATCH] builtin: Add TypeInfo.StructField.is_comptime

---
 lib/std/builtin.zig                | 1 +
 lib/std/meta/trailer_flags.zig     | 1 +
 src/ir.cpp                         | 6 ++++++
 test/stage1/behavior/type_info.zig | 6 ++++++
 4 files changed, 14 insertions(+)

diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index 3d103d6d06..911a0eb15c 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -261,6 +261,7 @@ pub const TypeInfo = union(enum) {
         name: []const u8,
         field_type: type,
         default_value: anytype,
+        is_comptime: bool,
     };
 
     /// This data structure is used by the Zig language code generation and
diff --git a/lib/std/meta/trailer_flags.zig b/lib/std/meta/trailer_flags.zig
index 19f6ee2e80..c8c1323686 100644
--- a/lib/std/meta/trailer_flags.zig
+++ b/lib/std/meta/trailer_flags.zig
@@ -46,6 +46,7 @@ pub fn TrailerFlags(comptime Fields: type) type {
                         ??struct_field.field_type,
                         @as(?struct_field.field_type, null),
                     ),
+                    .is_comptime = false,
                 };
             }
             break :blk @Type(.{
diff --git a/src/ir.cpp b/src/ir.cpp
index 692dd392e1..124c1feb06 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -25683,6 +25683,10 @@ static Error ir_make_type_info_value(IrAnalyze *ira, IrInst* source_instr, ZigTy
                     }
                     set_optional_payload(inner_fields[2], struct_field->init_val);
 
+                    inner_fields[3]->special = ConstValSpecialStatic;
+                    inner_fields[3]->type = ira->codegen->builtin_types.entry_bool;
+                    inner_fields[3]->data.x_bool = struct_field->is_comptime;
+
                     ZigValue *name = create_const_str_lit(ira->codegen, struct_field->name)->data.x_ptr.data.ref.pointee;
                     init_const_slice(ira->codegen, inner_fields[0], name, 0, buf_len(struct_field->name), true);
 
@@ -26291,6 +26295,8 @@ static ZigType *type_info_to_type(IrAnalyze *ira, IrInst *source_instr, ZigTypeI
                             buf_ptr(&field->type_entry->name), buf_ptr(&field->type_entry->name)));
                     return ira->codegen->invalid_inst_gen->value->type;
                 }
+                if ((err = get_const_field_bool(ira, source_instr->source_node, field_value, "is_comptime", 3, &field->is_comptime)))
+                    return ira->codegen->invalid_inst_gen->value->type;
             }
 
             return entry;
diff --git a/test/stage1/behavior/type_info.zig b/test/stage1/behavior/type_info.zig
index d0da8815f7..409993a741 100644
--- a/test/stage1/behavior/type_info.zig
+++ b/test/stage1/behavior/type_info.zig
@@ -418,3 +418,9 @@ test "Struct.is_tuple" {
     expect(@typeInfo(@TypeOf(.{0})).Struct.is_tuple);
     expect(!@typeInfo(@TypeOf(.{ .a = 0 })).Struct.is_tuple);
 }
+
+test "StructField.is_comptime" {
+    const info = @typeInfo(struct { x: u8 = 3, comptime y: u32 = 5 }).Struct;
+    expect(!info.fields[0].is_comptime);
+    expect(info.fields[1].is_comptime);
+}