Handle more sophisticated switch/case patterns#23
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lucic71 wants to merge 24 commits intoCpp2Rust:masterfrom
Closed
Handle more sophisticated switch/case patterns#23lucic71 wants to merge 24 commits intoCpp2Rust:masterfrom
lucic71 wants to merge 24 commits intoCpp2Rust:masterfrom
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Rename visited_cases to visited_switch_cases_ and move it in class scope. VisitSwitchStmt always resets the set of visited switch cases. The old implementation was buggy because it saved reused SwitchCase pointers across translation units, making contain() return true for switches declared in other TUs.
C++ allows:
switch (x) {
default:
...
case 1:
...
}
In rust, default needs to be always on the last position, otherwise,
all values of x, even 1, will hit the default arm. Hence, the above C++
exmaple becomes:
match x {
1 => ...
_ => ...
}
As such, the algorithm for translating the cases becomes:
for (case: GetTopLevelSwitchCases()) {
if (ChainContainsDefault(case)) {
defer the conversion for the end
}
Convert(case)
Convert(GetSwitchArmBody(case))
}
Convert(deferred default)
ChainContainsDefault traverses the stacked case statements starting from
a top level case. For example:
case 2:
case 3:
default:
...
is deferred for the end of the match arms and is translated as:
_ => {}
i.e., drop the case 2, case 3 from the output, only convert as if it was
only default.
Contributor
Author
|
Will split this into 3 PRs:
|
Merged
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