================
@@ -4453,12 +4453,35 @@ LogicalResult cir::TryOp::verify() {
if (mlir::isa<cir::UnwindAttr>(typeAttr))
continue;
- // A catch handler region must start with cir.begin_catch, optionally
- // preceded by a single cir.construct_catch_param that performs any
- // pre-begin_catch initialization for the catch parameter.
+ // Nothing may run in a catch handler before cir.begin_catch, so it has to
+ // be the handler region's first operation, with two exceptions.
+ //
+ // When lifetime markers are enabled, the catch parameter's storage can be
+ // marked by a cir.lifetime.start. That parameter is the only variable
+ // whose lifetime begins before the catch is entered, so there is at most
+ // one such marker. Its lifetime-end cleanup has to run after the catch
+ // handler is finished (or exited by an exception unwind), so if there is a
+ // lifetime begin marker, it is followed by a cir.cleanup.scope that
+ // encloses the the rest of the handler with a cir.lifetime.end in its
+ // cleanup region.
+ //
+ // A cir.construct_catch_param may also precede cir.begin_catch, to
+ // perform any pre-begin_catch initialization of the catch parameter.
if (entryBlock.empty())
return emitOpError("catch handler region must not be empty");
+
mlir::Operation *firstOp = &entryBlock.front();
+ if (mlir::isa<cir::LifetimeStartOp>(firstOp)) {
+ mlir::Operation *next = firstOp->getNextNode();
+ auto lifetimeScope =
mlir::dyn_cast_if_present<cir::CleanupScopeOp>(next);
+ if (!lifetimeScope)
+ return emitOpError("'cir.lifetime.start' in a catch handler region "
+ "must be followed by the 'cir.cleanup.scope' of "
+ "its lifetime-end cleanup");
+ mlir::Block &scopeBody = lifetimeScope.getBodyRegion().front();
+ firstOp = scopeBody.empty() ? nullptr : &scopeBody.front();
+ }
+
if (mlir::isa_and_present<cir::ConstructCatchParamOp>(firstOp))
----------------
erichkeane wrote:
Interesting that the `and_present` was done in error, but is now retroactively
correct :D
https://github.com/llvm/llvm-project/pull/219600
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