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fix break inside of for loops that use next (#1436) #1441

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fix break inside of for loops that use next (#1436) #1441

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e5f3f97
Add _for_break variable when we break inside of nested do/while(false…
Nov 29, 2025
51f0bb8
Changes in regression-tests adding _for_break variable (#1436)
Nov 29, 2025
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Add _for_break variable when we break inside of nested do/while(false… 
…) loop (#1436)
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Kevin Egan committed Nov 29, 2025
commit e5f3f978a6fbccfb0dae438a0a8f108ce7db1e5d
19 changes: 12 additions & 7 deletions source/to_cpp1.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2409,18 +2409,17 @@ class cppfront
printer.print_extra("{");
}

// If there's a next-expression, smuggle it in via a nested do/while(false) loop
// (nested "continue" will work, but "break" won't until we do extra work to implement
// that using a flag and implementing "break" as "_for_break = true; continue;")
// If there's a next-expression, smuggle it in via a nested do/while(false) loop.
// We implement break as "_for_break = true; continue;")
if (n.next_expression) {
printer.print_cpp2(" { do ", n.position());
printer.print_cpp2(" { bool _for_break = false; do ", n.position());
}

assert(n.body);
emit(*n.body);

if (n.next_expression) {
printer.print_cpp2(" while (false); ", n.position());
printer.print_cpp2(" while (false); if (_for_break) { break; } ", n.position());
emit(*n.next_expression);
printer.print_cpp2("; }", n.position());
}
Expand Down Expand Up @@ -2684,8 +2683,14 @@ class cppfront
);
}
else {
emit(*n.keyword);
printer.print_cpp2(";", n.position());
if (*n.keyword == "break" && iteration_statements.back().stmt->next_expression
&& *(iteration_statements.back().stmt->identifier) == "for") {
// if we have a next expression there is an nested "do/while(false) loop
printer.print_cpp2("_for_break = true; continue;", n.position());
} else {
emit(*n.keyword);
printer.print_cpp2(";", n.position());
}
}
}

Expand Down