sema: fix error_return_trace_index handling in zirCondBr

This commit is contained in:
Pavel Verigo 2025-12-05 02:34:51 +01:00
parent ea94ac52c5
commit 49ef28a5f1
2 changed files with 26 additions and 3 deletions

View file

@ -18470,6 +18470,9 @@ fn zirCondbr(
break :blk try sub_block.addTyOp(.unwrap_errunion_err, result_ty, err_operand); break :blk try sub_block.addTyOp(.unwrap_errunion_err, result_ty, err_operand);
}; };
// Reset, this may have been updated by the then block analysis
sub_block.error_return_trace_index = parent_block.error_return_trace_index;
const false_hint: std.builtin.BranchHint = if (err_cond != null and const false_hint: std.builtin.BranchHint = if (err_cond != null and
try sema.maybeErrorUnwrap(&sub_block, else_body, err_cond.?, cond_src, false)) try sema.maybeErrorUnwrap(&sub_block, else_body, err_cond.?, cond_src, false))
h: { h: {
@ -18945,9 +18948,10 @@ fn restoreErrRetIndex(sema: *Sema, start_block: *Block, src: LazySrcLoc, target_
while (true) { while (true) {
if (block.label) |label| { if (block.label) |label| {
if (label.zir_block == zir_block) { if (label.zir_block == zir_block) {
const target_trace_index = if (block.parent) |parent_block| tgt: { const target_trace_index = if (block.parent) |parent_block|
break :tgt parent_block.error_return_trace_index; parent_block.error_return_trace_index
} else sema.error_return_trace_index_on_fn_entry; else
sema.error_return_trace_index_on_fn_entry;
if (start_block.error_return_trace_index != target_trace_index) if (start_block.error_return_trace_index != target_trace_index)
break :b target_trace_index; break :b target_trace_index;

View file

@ -1090,3 +1090,22 @@ test "compare error union to error set" {
try S.doTheTest(0); try S.doTheTest(0);
try comptime S.doTheTest(0); try comptime S.doTheTest(0);
} }
test "'if' ignores error via local while 'else' ignores error directly" {
const S = struct {
/// This function is intentionally fallible despite never returning an
/// error so that it participates in error return tracing.
fn testOne(cond: bool) !void {
if (cond) {
const result = notError();
result catch {};
} else {
notError() catch {};
}
}
fn notError() error{E}!void {}
};
try S.testOne(false);
try S.testOne(true);
}