Reapply r183721, reverted in r183776, with a fix for a bug in the former (we
were lacking ExprWithCleanups nodes in some cases where the new approach to
lifetime extension needed them).
Original commit message:
Rework IR emission for lifetime-extended temporaries. Instead of trying to walk
into the expression and dig out a single lifetime-extended entity and manually
pull its cleanup outside the expression, instead keep a list of the cleanups
which we'll need to emit when we get to the end of the full-expression. Also
emit those cleanups early, as EH-only cleanups, to cover the case that the
full-expression does not terminate normally. This allows IR generation to
properly model temporary lifetime when multiple temporaries are extended by the
same declaration.
We have a pre-existing bug where an exception thrown from a temporary's
destructor does not clean up lifetime-extended temporaries created in the same
expression and extended to automatic storage duration; that is not fixed by
this patch.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183859 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 427f8f4..b678f91 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -5272,6 +5272,9 @@
Init = const_cast<Expr *>(
Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
+ if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
+ Init = BTE->getSubExpr();
+
if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
if (ILE->initializesStdInitializerList() || ILE->getType()->isArrayType()) {
// FIXME: If this is an InitListExpr which creates a std::initializer_list
@@ -5567,16 +5570,21 @@
performLifetimeExtension(CurInit.get(), ExtendingDecl);
// Materialize the temporary into memory.
- CurInit = new (S.Context) MaterializeTemporaryExpr(
+ MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr(
Entity.getType().getNonReferenceType(), CurInit.get(),
Entity.getType()->isLValueReferenceType(), ExtendingDecl);
// If we're binding to an Objective-C object that has lifetime, we
- // need cleanups.
- if (S.getLangOpts().ObjCAutoRefCount &&
- CurInit.get()->getType()->isObjCLifetimeType())
+ // need cleanups. Likewise if we're extending this temporary to automatic
+ // storage duration -- we need to register its cleanup during the
+ // full-expression's cleanups.
+ if ((S.getLangOpts().ObjCAutoRefCount &&
+ MTE->getType()->isObjCLifetimeType()) ||
+ (MTE->getStorageDuration() == SD_Automatic &&
+ MTE->getType().isDestructedType()))
S.ExprNeedsCleanups = true;
-
+
+ CurInit = S.Owned(MTE);
break;
}