From aa0bd20c466216ba3d74d7c307274e6421f805fb Mon Sep 17 00:00:00 2001
From: g-w1 <jacoblevgw@gmail.com>
Date: Wed, 23 Dec 2020 15:47:41 -0500
Subject: [PATCH] few small things before moving error set widening from
 Module.coerce -> Module.resolvePeerTypes

* make Type.eql for errors not reach unreachable
* use global_error_set instead of getErrorValue
* use value in analyzeInstCmp instead of type and use the u16 error
  value field instead of the name so that we don't need mem.eql
---
 src/Module.zig   |  5 +++++
 src/type.zig     |  2 ++
 src/zir_sema.zig | 19 ++++++++-----------
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/Module.zig b/src/Module.zig
index 87cf84d4428d..805d20f6c416 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -2731,6 +2731,11 @@ pub fn resolvePeerTypes(self: *Module, scope: *Scope, instructions: []*Inst) !Ty
             chosen = candidate;
             continue;
         }
+
+        // error set widening
+        // TODO remove: dest is chosen, cur is canditade
+        if (chosen.ty.zigTypeTag() == .ErrorSet and candidate.ty.zigTypeTag() == .ErrorSet) {}
+
         if (chosen.ty.isInt() and
             candidate.ty.isInt() and
             chosen.ty.isSignedInt() == candidate.ty.isSignedInt())
diff --git a/src/type.zig b/src/type.zig
index 3bb0a2c64d3b..333b38a0cf7b 100644
--- a/src/type.zig
+++ b/src/type.zig
@@ -232,6 +232,8 @@ pub const Type = extern union {
                         return true
                     else
                         return false;
+                } else if (b.tag() == .anyerror) {
+                    return false;
                 }
 
                 if (a.tag() == .error_set_single and b.tag() == .error_set_single) {
diff --git a/src/zir_sema.zig b/src/zir_sema.zig
index e765e7bd6c53..6203b96215fe 100644
--- a/src/zir_sema.zig
+++ b/src/zir_sema.zig
@@ -873,8 +873,8 @@ fn analyzeInstMergeErrorSets(mod: *Module, scope: *Scope, inst: *zir.Inst.BinOp)
 
     switch (lhs_fields) {
         .err_single => |name| {
-            const entry = mod.global_error_set.get(name).?;
-            payload.fields.putAssumeCapacity(name, entry);
+            const num = mod.global_error_set.get(name).?;
+            payload.fields.putAssumeCapacity(name, num);
         },
         .multiple => |multiple| {
             var it = multiple.iterator();
@@ -887,8 +887,8 @@ fn analyzeInstMergeErrorSets(mod: *Module, scope: *Scope, inst: *zir.Inst.BinOp)
 
     switch (rhs_fields) {
         .err_single => |name| {
-            const entry = try mod.getErrorValue(name);
-            payload.fields.putAssumeCapacity(entry.key, entry.value);
+            const num = mod.global_error_set.get(name).?;
+            payload.fields.putAssumeCapacity(name, num);
         },
         .multiple => |multiple| {
             var it = multiple.iterator();
@@ -1751,13 +1751,10 @@ fn analyzeInstCmp(
         if (!is_equality_cmp) {
             return mod.fail(scope, inst.base.src, "{} operator not allowed for errors", .{@tagName(op)});
         }
-        const lhs_comptime = lhs.ty.cast(Type.Payload.ErrorSetSingle);
-        const rhs_comptime = rhs.ty.cast(Type.Payload.ErrorSetSingle);
-        if (lhs_comptime != null and rhs_comptime != null) {
-            if (op == .eq)
-                return mod.constBool(scope, inst.base.src, !std.mem.eql(u8, lhs_comptime.?.name, rhs_comptime.?.name))
-            else
-                return mod.constBool(scope, inst.base.src, std.mem.eql(u8, lhs_comptime.?.name, rhs_comptime.?.name));
+        const lhs_val = lhs.value();
+        const rhs_val = rhs.value();
+        if (lhs_val != null and rhs_val != null) {
+            return mod.constBool(scope, inst.base.src, !(lhs_val.?.cast(Value.Payload.Error).?.value == rhs_val.?.cast(Value.Payload.Error).?.value) == (op == .eq));
         }
         return mod.fail(scope, inst.base.src, "TODO runtime error comparison", .{});
     } else if (lhs.ty.isNumeric() and rhs.ty.isNumeric()) {