stage2: error_set_merged type equality

This implements type equality for error sets. This is done
through element-wise error set comparison.

Inferred error sets are always distinct types and other error sets are
always sorted. See #11022.

4 files changed, 113 insertions, 36 deletions

diff --git a/test/behavior/cast.zig b/test/behavior/cast.zig
index 6f300773ae..1f92a0214f 100644
--- a/test/behavior/cast.zig
+++ b/test/behavior/cast.zig
@@ -669,8 +669,8 @@ test "peer type resolution: disjoint error sets" {
         try expect(error_set_info == .ErrorSet);
         try expect(error_set_info.ErrorSet.?.len == 3);
         try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "One"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Two"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Three"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Three"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Two"));
     }
 
     {
@@ -678,8 +678,8 @@ test "peer type resolution: disjoint error sets" {
         const error_set_info = @typeInfo(ty);
         try expect(error_set_info == .ErrorSet);
         try expect(error_set_info.ErrorSet.?.len == 3);
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "Three"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "One"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "One"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Three"));
         try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Two"));
     }
 }
@@ -704,8 +704,8 @@ test "peer type resolution: error union and error set" {
 
         const error_set_info = @typeInfo(info.ErrorUnion.error_set);
         try expect(error_set_info.ErrorSet.?.len == 3);
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "Three"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "One"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "One"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Three"));
         try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Two"));
     }
 
@@ -717,8 +717,8 @@ test "peer type resolution: error union and error set" {
         const error_set_info = @typeInfo(info.ErrorUnion.error_set);
         try expect(error_set_info.ErrorSet.?.len == 3);
         try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "One"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Two"));
-        try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Three"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Three"));
+        try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Two"));
     }
 }
 
diff --git a/test/behavior/error.zig b/test/behavior/error.zig
index 7dd0d44e01..8541c7defd 100644
--- a/test/behavior/error.zig
+++ b/test/behavior/error.zig
@@ -330,7 +330,11 @@ fn intLiteral(str: []const u8) !?i64 {
 }
 
 test "nested error union function call in optional unwrap" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const S = struct {
         const Foo = struct {
@@ -375,7 +379,11 @@ test "nested error union function call in optional unwrap" {
 }
 
 test "return function call to error set from error union function" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const S = struct {
         fn errorable() anyerror!i32 {
@@ -404,7 +412,11 @@ test "optional error set is the same size as error set" {
 }
 
 test "nested catch" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const S = struct {
         fn entry() !void {
@@ -428,11 +440,18 @@ test "nested catch" {
 }
 
 test "function pointer with return type that is error union with payload which is pointer of parent struct" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    // This test uses the stage2 const fn pointer
+    if (builtin.zig_backend == .stage1) return error.SkipZigTest;
+
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const S = struct {
         const Foo = struct {
-            fun: fn (a: i32) (anyerror!*Foo),
+            fun: *const fn (a: i32) (anyerror!*Foo),
         };
 
         const Err = error{UnspecifiedErr};
@@ -480,7 +499,11 @@ test "return result loc as peer result loc in inferred error set function" {
 }
 
 test "error payload type is correctly resolved" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const MyIntWrapper = struct {
         const Self = @This();
@@ -496,7 +519,11 @@ test "error payload type is correctly resolved" {
 }
 
 test "error union comptime caching" {
-    if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
 
     const S = struct {
         fn quux(comptime arg: anytype) void {
@@ -539,3 +566,69 @@ test "@errorName sentinel length matches slice length" {
 pub fn testBuiltinErrorName(err: anyerror) [:0]const u8 {
     return @errorName(err);
 }
+
+test "error set equality" {
+    // This tests using stage2 logic (#11022)
+    if (builtin.zig_backend == .stage1) return error.SkipZigTest;
+
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+
+    const a = error{One};
+    const b = error{One};
+
+    try expect(a == a);
+    try expect(a == b);
+    try expect(a == error{One});
+
+    // should treat as a set
+    const c = error{ One, Two };
+    const d = error{ Two, One };
+
+    try expect(c == d);
+}
+
+test "inferred error set equality" {
+    if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+
+    const S = struct {
+        fn foo() !void {
+            return @This().bar();
+        }
+
+        fn bar() !void {
+            return error.Bad;
+        }
+
+        fn baz() !void {
+            return quux();
+        }
+
+        fn quux() anyerror!void {}
+    };
+
+    const FooError = @typeInfo(@typeInfo(@TypeOf(S.foo)).Fn.return_type.?).ErrorUnion.error_set;
+    const BarError = @typeInfo(@typeInfo(@TypeOf(S.bar)).Fn.return_type.?).ErrorUnion.error_set;
+    const BazError = @typeInfo(@typeInfo(@TypeOf(S.baz)).Fn.return_type.?).ErrorUnion.error_set;
+
+    try expect(BarError != error{Bad});
+
+    try expect(FooError != anyerror);
+    try expect(BarError != anyerror);
+    try expect(BazError != anyerror);
+
+    try expect(FooError != BarError);
+    try expect(FooError != BazError);
+    try expect(BarError != BazError);
+
+    try expect(FooError == FooError);
+    try expect(BarError == BarError);
+    try expect(BazError == BazError);
+}
diff --git a/test/behavior/type_info.zig b/test/behavior/type_info.zig
index ad8fe03c15..8b917ad5e1 100644
--- a/test/behavior/type_info.zig
+++ b/test/behavior/type_info.zig
@@ -205,6 +205,9 @@ test "type info: error set single value" {
 }
 
 test "type info: error set merged" {
+    // #11022 forces ordering of error sets in stage2
+    if (builtin.zig_backend == .stage1) return error.SkipZigTest;
+
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -217,8 +220,8 @@ test "type info: error set merged" {
     try expect(error_set_info == .ErrorSet);
     try expect(error_set_info.ErrorSet.?.len == 3);
     try expect(mem.eql(u8, error_set_info.ErrorSet.?[0].name, "One"));
-    try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Two"));
-    try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Three"));
+    try expect(mem.eql(u8, error_set_info.ErrorSet.?[1].name, "Three"));
+    try expect(mem.eql(u8, error_set_info.ErrorSet.?[2].name, "Two"));
 }
 
 test "type info: enum info" {
diff --git a/test/stage2/x86_64.zig b/test/stage2/x86_64.zig
index aeed29bf43..458289e06e 100644
--- a/test/stage2/x86_64.zig
+++ b/test/stage2/x86_64.zig
@@ -1413,25 +1413,6 @@ pub fn addCases(ctx: *TestContext) !void {
         }
 
         {
-            var case = ctx.exe("error set equality", target);
-
-            case.addCompareOutput(
-                \\pub fn main() void {
-                \\    assert(@TypeOf(error.Foo) == @TypeOf(error.Foo));
-                \\    assert(@TypeOf(error.Bar) != @TypeOf(error.Foo));
-                \\    assert(anyerror == anyerror);
-                \\    assert(error{Foo} != error{Foo});
-                \\    // TODO put inferred error sets here when @typeInfo works
-                \\}
-                \\fn assert(b: bool) void {
-                \\    if (!b) unreachable;
-                \\}
-            ,
-                "",
-            );
-        }
-
-        {
             var case = ctx.exe("comptime var", target);
 
             case.addError(