[lld] [llvm] [DTLTO] Overlap temporary file removal (PR #209423)

[Ben Dunbobbin via llvm-commits]

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@@ -625,6 +625,8 @@ constexpr const char *saveTempsValues[] = {
 
 LinkerDriver::LinkerDriver(Ctx &ctx) : ctx(ctx) {}
 
+void LinkerDriver::cleanupLTO() { lto.reset(); }
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bd1976bris wrote:

Great point. Thanks! I changed this to avoid relying on destruction. `lto::LTO` now has an explicit `cleanupAfterRun()` hook that defaults to a no-op, and DTLTO overrides it to drain the background deletion work. `lld` calls this hook before time-trace write/cleanup.

For non-DTLTO LTO this is just a no-op virtual call when an LTO object exists, and it does not destroy the LTO object.

https://github.com/llvm/llvm-project/pull/209423