From 8878f085dccaf9efe89a04b458205fddc215e095 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Tue, 1 Mar 2022 15:26:31 -0700
Subject: [PATCH] Sema: correct implementation of comptimeOnly for tuples

This makes formatted printing work when mixing comptime and runtime
fields.
---
 src/Sema.zig            | 5 +++--
 src/type.zig            | 5 +++--
 test/behavior/tuple.zig | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/Sema.zig b/src/Sema.zig
index 5bceb60aa0..e58fdef4a7 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -19585,8 +19585,9 @@ fn typeRequiresComptime(sema: *Sema, block: *Block, src: LazySrcLoc, ty: Type) C
 
         .tuple => {
             const tuple = ty.castTag(.tuple).?.data;
-            for (tuple.types) |field_ty| {
-                if (try sema.typeRequiresComptime(block, src, field_ty)) {
+            for (tuple.types) |field_ty, i| {
+                const have_comptime_val = tuple.values[i].tag() != .unreachable_value;
+                if (!have_comptime_val and try sema.typeRequiresComptime(block, src, field_ty)) {
                     return true;
                 }
             }
diff --git a/src/type.zig b/src/type.zig
index 40700f28af..90e79a8eed 100644
--- a/src/type.zig
+++ b/src/type.zig
@@ -4050,8 +4050,9 @@ pub const Type = extern union {
 
             .tuple => {
                 const tuple = ty.castTag(.tuple).?.data;
-                for (tuple.types) |field_ty| {
-                    if (field_ty.comptimeOnly()) return true;
+                for (tuple.types) |field_ty, i| {
+                    const have_comptime_val = tuple.values[i].tag() != .unreachable_value;
+                    if (!have_comptime_val and field_ty.comptimeOnly()) return true;
                 }
                 return false;
             },
diff --git a/test/behavior/tuple.zig b/test/behavior/tuple.zig
index 2f4b85d0bc..4c13668dbd 100644
--- a/test/behavior/tuple.zig
+++ b/test/behavior/tuple.zig
@@ -45,7 +45,7 @@ test "tuple multiplication" {
     comptime try S.doTheTest();
 }
 
-test "tuple concatenation" {
+test "more tuple concatenation" {
     if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
 
     const T = struct {