zig

commit 36faf76fe1eeb3aafcc4de94fc83fd8ca3b18b25 (tree)
parent d4cac43d308ffa930cd7174567be7c1fe18e29fb
Author: Pavel Verigo <paul.verigo@gmail.com>
Date:   Tue, 10 Mar 2026 08:38:12 +0100

AstGen: add missing addRestoreErrRetIndex calls when handling for/while expr

Fixes #30912

Diffstat:
M
lib/std/zig/AstGen.zig
 | 
16
++++++++++++++++
M
test/error_traces.zig
 | 
126
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 142 insertions(+), 0 deletions(-)
diff --git a/lib/std/zig/AstGen.zig b/lib/std/zig/AstGen.zig
@@ -6656,9 +6656,16 @@ fn whileExpr(
                 .operand = undefined,
             } },
         });
+        if (!continue_scope.is_comptime) {
+            _ = try continue_scope.addRestoreErrRetIndex(.{ .block = continue_block }, .always, then_node);
+        }
         _ = try continue_scope.addBreak(break_tag, continue_block, .void_value);
     }
     try continue_scope.setBlockBody(continue_block);
+    if (!then_scope.is_comptime) {
+        const cont_node = while_full.ast.cont_expr.unwrap() orelse then_node;
+        _ = try then_scope.addRestoreErrRetIndex(.{ .block = cond_block }, .always, cont_node);
+    }
     _ = try then_scope.addBreak(break_tag, cond_block, .void_value);
 
     var else_scope = parent_gz.makeSubBlock(&cond_scope.base);
@@ -6703,6 +6710,9 @@ fn whileExpr(
 
         try checkUsed(parent_gz, &else_scope.base, sub_scope);
         if (!else_scope.endsWithNoReturn()) {
+            if (!else_scope.is_comptime) {
+                _ = try else_scope.addRestoreErrRetIndex(.{ .block = loop_block }, .always, else_node);
+            }
             _ = try else_scope.addBreakWithSrcNode(break_tag, loop_block, else_result, else_node);
         }
     } else {
@@ -6973,6 +6983,9 @@ fn forExpr(
     });
 
     const break_tag: Zir.Inst.Tag = if (is_inline) .break_inline else .@"break";
+    if (!then_scope.is_comptime) {
+        _ = try then_scope.addRestoreErrRetIndex(.{ .block = cond_block }, .always, then_node);
+    }
     _ = try then_scope.addBreak(break_tag, cond_block, .void_value);
 
     var else_scope = parent_gz.makeSubBlock(&cond_scope.base);
@@ -6990,6 +7003,9 @@ fn forExpr(
             _ = try addEnsureResult(&else_scope, else_result, else_node);
         }
         if (!else_scope.endsWithNoReturn()) {
+            if (!else_scope.is_comptime) {
+                _ = try else_scope.addRestoreErrRetIndex(.{ .block = loop_block }, .always, else_node);
+            }
             _ = try else_scope.addBreakWithSrcNode(break_tag, loop_block, else_result, else_node);
         }
     } else {
diff --git a/test/error_traces.zig b/test/error_traces.zig
@@ -93,6 +93,132 @@ pub fn addCases(cases: *@import("tests.zig").ErrorTracesContext, os: std.Target.
     });
 
     cases.addCase(.{
+        .name = "for loop pops error return trace",
+        .source =
+        \\fn foo() !void { return error.FooError; }
+        \\
+        \\pub fn main() !void {
+        \\    for (0..2) |_| {
+        \\        const f = foo();
+        \\        f catch {};
+        \\    } else {
+        \\        const f = foo();
+        \\        f catch {};
+        \\    }
+        \\    return error.Stop;
+        \\}
+        ,
+        .expect_error = "Stop",
+        .expect_trace =
+        \\source.zig:11:5: [address] in main
+        \\    return error.Stop;
+        \\    ^
+        ,
+        .disable_trace_optimized = &.{
+            .{ .x86_64, .windows },
+            .{ .x86, .windows },
+            .{ .x86_64, .macos },
+            .{ .aarch64, .macos },
+        },
+    });
+
+    cases.addCase(.{
+        .name = "implicit continue in for loop pops stale error return trace",
+        .source =
+        \\fn foo() !void { return error.FooError; }
+        \\
+        \\pub fn main() !void {
+        \\    for (0..2) |i| {
+        \\        const f = foo();
+        \\        f catch {};
+        \\
+        \\        if (i == 1) return error.Stop;
+        \\    }
+        \\}
+        ,
+        .expect_error = "Stop",
+        .expect_trace =
+        \\source.zig:1:18: [address] in foo
+        \\fn foo() !void { return error.FooError; }
+        \\                 ^
+        \\source.zig:8:21: [address] in main
+        \\        if (i == 1) return error.Stop;
+        \\                    ^
+        ,
+        .disable_trace_optimized = &.{
+            .{ .x86_64, .windows },
+            .{ .x86, .windows },
+            .{ .x86_64, .macos },
+            .{ .aarch64, .macos },
+        },
+    });
+
+    cases.addCase(.{
+        .name = "while loop pops error return trace",
+        .source =
+        \\fn foo() !void { return error.FooError; }
+        \\
+        \\pub fn main() !void {
+        \\    var i: usize = 0;
+        \\    while (i < 2) {
+        \\        const f = foo();
+        \\        f catch {};
+        \\        i += 1;
+        \\    } else {
+        \\        const f = foo();
+        \\        f catch {};
+        \\    }
+        \\    return error.Stop;
+        \\}
+        ,
+        .expect_error = "Stop",
+        .expect_trace =
+        \\source.zig:13:5: [address] in main
+        \\    return error.Stop;
+        \\    ^
+        ,
+        .disable_trace_optimized = &.{
+            .{ .x86_64, .windows },
+            .{ .x86, .windows },
+            .{ .x86_64, .macos },
+            .{ .aarch64, .macos },
+        },
+    });
+
+    cases.addCase(.{
+        .name = "implicit continue in while loop pops stale error return trace",
+        .source =
+        \\fn foo() !void { return error.FooError; }
+        \\
+        \\pub fn main() !void {
+        \\    var i: usize = 0;
+        \\    while (i < 2) {
+        \\        const f = foo();
+        \\        f catch {};
+        \\
+        \\        if (i == 1) return error.Stop;
+        \\        i += 1;
+        \\    }
+        \\}
+        ,
+        .expect_error = "Stop",
+        .expect_trace =
+        \\source.zig:1:18: [address] in foo
+        \\fn foo() !void { return error.FooError; }
+        \\                 ^
+        \\source.zig:9:21: [address] in main
+        \\        if (i == 1) return error.Stop;
+        \\                    ^
+        ,
+        .disable_trace_optimized = &.{
+            .{ .x86_64, .windows },
+            .{ .x86, .windows },
+            .{ .x86_64, .macos },
+            .{ .aarch64, .macos },
+        },
+    });
+
+    cases.addCase(.{
         .name = "try return + handled catch/if-else",
         .source =
         \\fn foo() !void {