NoQ created this revision.
NoQ added reviewers: dcoughlin, xazax.hun, a.sidorin, george.karpenkov, szepet.
Herald added subscribers: cfe-commits, rnkovacs.
It is tedious to allocate and then placement-new the construction context, so i
added a tiny variadic template to improve readability.
Repository:
rC Clang
https://reviews.llvm.org/D44725
Files:
lib/Analysis/ConstructionContext.cpp
Index: lib/Analysis/ConstructionContext.cpp
===================================================================
--- lib/Analysis/ConstructionContext.cpp
+++ lib/Analysis/ConstructionContext.cpp
@@ -40,23 +40,29 @@
llvm_unreachable("The above loop can only be terminated via return!");
}
+// A helper - create a construction context in the given bump pointer allocator
+// with given arguments.
+template<typename T, typename... ArgTypes>
+static T *make(BumpVectorContext &C, ArgTypes... Args) {
+ auto *CC = C.getAllocator().Allocate<T>();
+ return new (CC) T(Args...);
+}
+
const ConstructionContext *ConstructionContext::createFromLayers(
BumpVectorContext &C, const ConstructionContextLayer *TopLayer) {
// Before this point all we've had was a stockpile of arbitrary layers.
// Now validate that it is shaped as one of the finite amount of expected
// patterns.
if (const Stmt *S = TopLayer->getTriggerStmt()) {
if (const auto *DS = dyn_cast<DeclStmt>(S)) {
assert(TopLayer->isLast());
- auto *CC =
- C.getAllocator().Allocate<SimpleVariableConstructionContext>();
- return new (CC) SimpleVariableConstructionContext(DS);
- } else if (const auto *NE = dyn_cast<CXXNewExpr>(S)) {
+ return make<SimpleVariableConstructionContext>(C, DS);
+ }
+ if (const auto *NE = dyn_cast<CXXNewExpr>(S)) {
assert(TopLayer->isLast());
- auto *CC =
- C.getAllocator().Allocate<NewAllocatedObjectConstructionContext>();
- return new (CC) NewAllocatedObjectConstructionContext(NE);
- } else if (const auto *BTE = dyn_cast<CXXBindTemporaryExpr>(S)) {
+ return make<NewAllocatedObjectConstructionContext>(C, NE);
+ }
+ if (const auto *BTE = dyn_cast<CXXBindTemporaryExpr>(S)) {
const MaterializeTemporaryExpr *MTE = nullptr;
assert(BTE->getType().getCanonicalType()
->getAsCXXRecordDecl()->hasNonTrivialDestructor());
@@ -68,60 +74,45 @@
ParentLayer->getTriggerStmt()))) {
// A temporary object which has both destruction and
// materialization info.
- auto *CC =
- C.getAllocator().Allocate<TemporaryObjectConstructionContext>();
- return new (CC) TemporaryObjectConstructionContext(BTE, MTE);
+ return make<TemporaryObjectConstructionContext>(C, BTE, MTE);
}
// C++17 *requires* elision of the constructor at the return site
// and at variable initialization site, while previous standards
// were allowing an optional elidable constructor.
if (auto *RS = dyn_cast<ReturnStmt>(ParentLayer->getTriggerStmt())) {
assert(!RS->getRetValue()->getType().getCanonicalType()
->getAsCXXRecordDecl()->hasTrivialDestructor());
- auto *CC =
- C.getAllocator()
- .Allocate<
- CXX17ElidedCopyReturnedValueConstructionContext>();
- return new (CC)
- CXX17ElidedCopyReturnedValueConstructionContext(RS, BTE);
+ return make<CXX17ElidedCopyReturnedValueConstructionContext>(C,
+ RS, BTE);
}
if (auto *DS = dyn_cast<DeclStmt>(ParentLayer->getTriggerStmt())) {
assert(!cast<VarDecl>(DS->getSingleDecl())->getType()
.getCanonicalType()->getAsCXXRecordDecl()
->hasTrivialDestructor());
- auto *CC =
- C.getAllocator()
- .Allocate<CXX17ElidedCopyVariableConstructionContext>();
- return new (CC) CXX17ElidedCopyVariableConstructionContext(DS, BTE);
+ return make<CXX17ElidedCopyVariableConstructionContext>(C, DS, BTE);
}
llvm_unreachable("Unexpected construction context with destructor!");
}
// A temporary object that doesn't require materialization.
- auto *CC =
- C.getAllocator().Allocate<TemporaryObjectConstructionContext>();
- return new (CC)
- TemporaryObjectConstructionContext(BTE, /*MTE=*/nullptr);
- } else if (const auto *MTE = dyn_cast<MaterializeTemporaryExpr>(S)) {
+ return make<TemporaryObjectConstructionContext>(C, BTE, /*MTE=*/nullptr);
+ }
+ if (const auto *MTE = dyn_cast<MaterializeTemporaryExpr>(S)) {
// If the object requires destruction and is not lifetime-extended,
// then it must have a BTE within its MTE.
assert(MTE->getType().getCanonicalType()
->getAsCXXRecordDecl()->hasTrivialDestructor() ||
MTE->getStorageDuration() != SD_FullExpression);
assert(TopLayer->isLast());
- auto *CC =
- C.getAllocator().Allocate<TemporaryObjectConstructionContext>();
- return new (CC) TemporaryObjectConstructionContext(nullptr, MTE);
- } else if (const auto *RS = dyn_cast<ReturnStmt>(S)) {
+ return make<TemporaryObjectConstructionContext>(C, nullptr, MTE);
+ }
+ if (const auto *RS = dyn_cast<ReturnStmt>(S)) {
assert(TopLayer->isLast());
- auto *CC =
- C.getAllocator().Allocate<SimpleReturnedValueConstructionContext>();
- return new (CC) SimpleReturnedValueConstructionContext(RS);
+ return make<SimpleReturnedValueConstructionContext>(C, RS);
}
+ llvm_unreachable("Unexpected construction context with statement!");
} else if (const CXXCtorInitializer *I = TopLayer->getTriggerInit()) {
assert(TopLayer->isLast());
- auto *CC =
- C.getAllocator().Allocate<ConstructorInitializerConstructionContext>();
- return new (CC) ConstructorInitializerConstructionContext(I);
+ return make<ConstructorInitializerConstructionContext>(C, I);
}
llvm_unreachable("Unexpected construction context!");
}
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