From 2ebeb0dbf30751cec6fd7cc8578a7aac4cb068ce Mon Sep 17 00:00:00 2001
From: jacob gw <jacoblevgw@gmail.com>
Date: Mon, 1 Mar 2021 09:21:51 -0500
Subject: [PATCH] stage2: remove error number from error set map

This saves memory since it is already stored in module
as well as allowing for better threading.
Part 2 of what is outlined in #8079.
---
 src/Module.zig   | 12 ++++++------
 src/value.zig    |  2 +-
 src/zir_sema.zig |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/Module.zig b/src/Module.zig
index 3a72f1272b..e6d509ace5 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -4083,15 +4083,15 @@ pub fn namedFieldPtr(
             const child_type = try val.toType(scope.arena());
             switch (child_type.zigTypeTag()) {
                 .ErrorSet => {
+                    var name: []const u8 = undefined;
                     // TODO resolve inferred error sets
-                    const entry = if (val.castTag(.error_set)) |payload|
-                        (payload.data.fields.getEntry(field_name) orelse
-                            return mod.fail(scope, src, "no error named '{s}' in '{}'", .{ field_name, child_type })).*
+                    if (val.castTag(.error_set)) |payload|
+                        name = (payload.data.fields.getEntry(field_name) orelse return mod.fail(scope, src, "no error named '{s}' in '{}'", .{ field_name, child_type })).key
                     else
-                        try mod.getErrorValue(field_name);
+                        name = (try mod.getErrorValue(field_name)).key;
 
                     const result_type = if (child_type.tag() == .anyerror)
-                        try Type.Tag.error_set_single.create(scope.arena(), entry.key)
+                        try Type.Tag.error_set_single.create(scope.arena(), name)
                     else
                         child_type;
 
@@ -4100,7 +4100,7 @@ pub fn namedFieldPtr(
                         .val = try Value.Tag.ref_val.create(
                             scope.arena(),
                             try Value.Tag.@"error".create(scope.arena(), .{
-                                .name = entry.key,
+                                .name = name,
                             }),
                         ),
                     });
diff --git a/src/value.zig b/src/value.zig
index ae94e4b424..3fd2889fc8 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -2144,7 +2144,7 @@ pub const Value = extern union {
             base: Payload = .{ .tag = base_tag },
             data: struct {
                 /// TODO revisit this when we have the concept of the error tag type
-                fields: std.StringHashMapUnmanaged(u16),
+                fields: std.StringHashMapUnmanaged(void),
                 decl: *Module.Decl,
             },
         };
diff --git a/src/zir_sema.zig b/src/zir_sema.zig
index c2e01bcaed..6219f10f89 100644
--- a/src/zir_sema.zig
+++ b/src/zir_sema.zig
@@ -1165,7 +1165,7 @@ fn zirErrorSet(mod: *Module, scope: *Scope, inst: *zir.Inst.ErrorSet) InnerError
 
     for (inst.positionals.fields) |field_name| {
         const entry = try mod.getErrorValue(field_name);
-        if (payload.data.fields.fetchPutAssumeCapacity(entry.key, entry.value)) |prev| {
+        if (payload.data.fields.fetchPutAssumeCapacity(entry.key, {})) |_| {
             return mod.fail(scope, inst.base.src, "duplicate error: '{s}'", .{field_name});
         }
     }