averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

[Reflection] Hoist computation of error existentials to the reader.

Browse Source 
<rdar://problem/41546568>
This commit is contained in:
Davide Italiano
2018-07-25 18:08:04 -07:00
parent 31f2c75bb7
commit 5dc41566fb
2 changed files with 78 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
include/swift/Reflection/ReflectionContext.h
View File

@@ -77,11 +77,12 @@ class ReflectionContext
public:
using super::getBuilder;
using super::readDemanglingForContextDescriptor;
using super::readIsaMask;
using super::readTypeFromMetadata;
using super::readGenericArgFromMetadata;
using super::readIsaMask;
using super::readMetadataAndValueErrorExistential;
using super::readMetadataAndValueOpaqueExistential;
using super::readMetadataFromInstance;
using super::readTypeFromMetadata;
using typename super::StoredPointer;
explicit ReflectionContext(std::shared_ptr<MemoryReader> reader)
@@ -497,70 +498,21 @@ public:
return true;
}
case RecordKind::ErrorExistential: {
// We have a pointer to an error existential, which is always heap object.
auto MetadataAddress
= readMetadataFromInstance(ExistentialAddress.getAddressData());
if (!MetadataAddress)
auto OptMetaAndValue =
readMetadataAndValueErrorExistential(ExistentialAddress);
if (!OptMetaAndValue)
return false;
bool isObjC = false;
RemoteAddress InstanceMetadataAddress = OptMetaAndValue->first;
RemoteAddress InstanceAddress = OptMetaAndValue->second;
// If we can determine the Objective-C class name, this is probably an
// error existential with NSError-compatible layout.
std::string ObjCClassName;
if (readObjCClassName(*MetadataAddress, ObjCClassName)) {
if (ObjCClassName == "_SwiftNativeNSError")
isObjC = true;
} else {
// Otherwise, we can check to see if this is a class metadata with the
// kind value's least significant bit set, which indicates a pure
// Swift class.
auto Meta = readMetadata(*MetadataAddress);
auto ClassMeta = dyn_cast<TargetClassMetadata<Runtime>>(Meta);
if (!ClassMeta)
return false;
isObjC = ClassMeta->isPureObjC();
}
// In addition to the isa pointer and two 32-bit reference counts, if the
// error existential is layout-compatible with NSError, we also need to
// skip over its three word-sized fields: the error code, the domain,
// and userInfo.
StoredPointer InstanceMetadataAddressAddress
= ExistentialAddress.getAddressData() +
(isObjC ? 5 : 2) * sizeof(StoredPointer);
// We need to get the instance's alignment info so we can get the exact
// offset of the start of its data in the class.
auto InstanceMetadataAddress =
readMetadataFromInstance(InstanceMetadataAddressAddress);
if (!InstanceMetadataAddress)
return false;
auto InstanceTR = readTypeFromMetadata(*InstanceMetadataAddress);
auto InstanceTR =
readTypeFromMetadata(InstanceMetadataAddress.getAddressData());
if (!InstanceTR)
return false;
auto InstanceTI = getTypeInfo(InstanceTR);
if (!InstanceTI)
return false;
// Now we need to skip over the instance metadata pointer and instance's
// conformance pointer for Swift.Error.
StoredPointer InstanceAddress = InstanceMetadataAddressAddress +
2 * sizeof(StoredPointer);
// Round up to alignment, and we have the start address of the
// instance payload.
auto Alignment = InstanceTI->getAlignment();
InstanceAddress += Alignment - InstanceAddress % Alignment;
*OutInstanceTR = InstanceTR;
*OutInstanceAddress = RemoteAddress(InstanceAddress);
return true;
}
default: