[SR-2239] `CVaListPointer` does not gets converted to `va_list` on `aarch64`

[gonzalolarralde]

Previous ID	SR-2239
Radar	None
Original Reporter	@gonzalolarralde
Type	Bug

Environment

OS: Ubuntu 16.04 xenial
Kernel: 3.10.65-7-pine64-longsleep #28 SMP PREEMPT Sat Apr 23 20:13:25 CEST 2016 aarch64 aarch64 aarch64 GNU/Linux
CPU: Cortex A53 / ARMv8-A (active state AArch64) @ 1.2Ghz x 4 cores
Board: Pine64

Additional Detail from JIRA

Votes	2
Component/s	Compiler
Labels	Bug, ClangImporter, Linux, aarch64
Assignee	@compnerd
Priority	Medium

md5: 9e146d43940f2f8d25705b8c9685e5fc

is duplicated by:

• SR-5925 non-Darwin aarch64 fails to map va_list to CVaListPointer

Issue Description:

I'm getting an error when trying to compile corelibs-foundation in arm. When the compile process is done with CoreFoundation and gets to the Swift wrappers, it's failing trying to compile NSString.init(format: String: arguments: CVaListPointer) and sibling methods.

cannot convert value of type 'CVaListPointer' to expected argument type 'va_list' (aka '__va_list')

SR-1412 reported problems when trying to resolve the correct va_list in arm. Based on the error message we're getting, and what was the issue at that time, my theory is swift project is resolving va_list and __va_list in a different way as corelibs-foundation does for arm's toolchain. Then the mapped types defined here are failing to work:

// stdarg.h types.
// FIXME: why does this not catch va_list on x86_64?
MAP_STDLIB_TYPE("va_list", VaList, 0, "CVaListPointer", false, DoNothing)
MAP_STDLIB_TYPE("__gnuc_va_list", VaList, 0, "CVaListPointer", false, DoNothing)
MAP_STDLIB_TYPE("__va_list", VaList, 0, "CVaListPointer", false, DoNothing)

https://github.com/apple/swift/blob/621d3b7c666b92b8078624a8d228e1c123f23bca/lib/ClangImporter/MappedTypes.def#L126-L130

Again, is just a theory, I couldn't prove it yet.

Complete compilation call as executed by the build script with the following parameters:

utils/build-script -R --libdispatch 1 --xctest 1 --foundation 1

ubuntu@localhost:~/swift-source/swift-corelibs-foundation$ /home/ubuntu/swift-source/build/Ninja-ReleaseAssert/swift-linux-aarch64/bin/swift -frontend -c Foundation/NSObject.swift Foundation/NSAffineTransform.swift Foundation/NSArray.swift Foundation/NSAttributedString.swift Foundation/NSBundle.swift Foundation/NSByteCountFormatter.swift Foundation/NSCache.swift Foundation/NSCalendar.swift Foundation/NSCFArray.swift Foundation/NSCFDictionary.swift Foundation/NSCFSet.swift Foundation/NSCFString.swift Foundation/NSCharacterSet.swift Foundation/NSCFCharacterSet.swift Foundation/NSCoder.swift Foundation/NSComparisonPredicate.swift Foundation/NSCompoundPredicate.swift Foundation/NSConcreteValue.swift Foundation/NSData.swift Foundation/NSDate.swift Foundation/NSDateComponentsFormatter.swift Foundation/NSDateFormatter.swift Foundation/NSDateIntervalFormatter.swift Foundation/NSDecimal.swift Foundation/NSDecimalNumber.swift Foundation/NSDictionary.swift Foundation/NSEnergyFormatter.swift Foundation/NSEnumerator.swift Foundation/NSError.swift Foundation/NSExpression.swift Foundation/NSFileHandle.swift Foundation/NSFileManager.swift Foundation/NSFormatter.swift Foundation/NSGeometry.swift Foundation/NSHost.swift Foundation/NSHTTPCookie.swift Foundation/NSHTTPCookieStorage.swift Foundation/NSIndexPath.swift Foundation/NSIndexSet.swift Foundation/NSJSONSerialization.swift Foundation/NSKeyedCoderOldStyleArray.swift Foundation/NSKeyedArchiver.swift Foundation/NSKeyedUnarchiver.swift Foundation/NSLengthFormatter.swift Foundation/NSLocale.swift Foundation/NSLock.swift Foundation/NSLog.swift Foundation/NSMassFormatter.swift Foundation/NSNotification.swift Foundation/NSNotificationQueue.swift Foundation/NSNull.swift Foundation/NSNumber.swift Foundation/NSNumberFormatter.swift Foundation/NSObjCRuntime.swift Foundation/NSOperation.swift Foundation/NSOrderedSet.swift Foundation/NSPathUtilities.swift Foundation/NSPersonNameComponents.swift Foundation/NSPersonNameComponentsFormatter.swift Foundation/NSPort.swift Foundation/NSPortMessage.swift Foundation/NSPredicate.swift Foundation/NSProcessInfo.swift Foundation/NSProgress.swift Foundation/NSPropertyList.swift Foundation/NSRange.swift Foundation/NSRegularExpression.swift Foundation/NSRunLoop.swift Foundation/NSScanner.swift Foundation/NSSet.swift Foundation/NSSortDescriptor.swift Foundation/NSSpecialValue.swift Foundation/NSStream.swift -primary-file Foundation/NSString.swift Foundation/String.swift Foundation/NSSwiftRuntime.swift Foundation/NSTask.swift Foundation/NSTextCheckingResult.swift Foundation/NSThread.swift Foundation/NSTimer.swift Foundation/NSTimeZone.swift Foundation/NSURL.swift Foundation/NSURLAuthenticationChallenge.swift Foundation/NSURLCache.swift Foundation/NSURLCredential.swift Foundation/NSURLCredentialStorage.swift Foundation/NSURLError.swift Foundation/NSURLProtectionSpace.swift Foundation/NSURLProtocol.swift Foundation/NSURLRequest.swift Foundation/NSURLResponse.swift Foundation/NSURLSession.swift Foundation/NSUserDefaults.swift Foundation/NSUUID.swift Foundation/NSValue.swift Foundation/NSXMLDocument.swift Foundation/NSXMLDTD.swift Foundation/NSXMLDTDNode.swift Foundation/NSXMLElement.swift Foundation/NSXMLNode.swift Foundation/NSXMLNodeOptions.swift Foundation/NSXMLParser.swift Foundation/FoundationErrors.swift Foundation/URL.swift Foundation/Boxing.swift Foundation/ReferenceConvertible.swift Foundation/Date.swift Foundation/Data.swift Foundation/CharacterSet.swift Foundation/URLRequest.swift Foundation/PersonNameComponents.swift Foundation/Notification.swift Foundation/URLComponents.swift Foundation/DateComponents.swift Foundation/DateInterval.swift Foundation/IndexPath.swift Foundation/IndexSet.swift Foundation/NSStringEncodings.swift Foundation/ExtraStringAPIs.swift Foundation/Measurement.swift Foundation/NSMeasurement.swift Foundation/NSMeasurementFormatter.swift Foundation/Unit.swift -I/home/ubuntu/swift-source/build/Ninja-ReleaseAssert/swift-linux-aarch64/lib/swift/linux -Xcc -fblocks -resource-dir /home/ubuntu/swift-source/build/Ninja-ReleaseAssert/swift-linux-aarch64/lib/swift -target aarch64-unknown-linux   -Ibootstrap/common/usr/include -Ibootstrap/common/usr/local/include   -Ibootstrap/aarch64-linux-gnu/usr/include -Ibootstrap/aarch64-linux-gnu/usr/local/include -O  -I../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation -I../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/usr//lib/swift -I../build/Ninja-ReleaseAssert/foundation-linux-aarch64 -I../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/usr/lib/swift -I/usr/include/libxml2 -I/home/ubuntu/swift-source/build/Ninja-ReleaseAssert/xctest-linux-aarch64 -L/home/ubuntu/swift-source/build/Ninja-ReleaseAssert/xctest-linux-aarch64 -I/usr/include/libxml2 -DDEPLOYMENT_ENABLE_LIBDISPATCH -I/home/ubuntu/swift-source/swift-corelibs-libdispatch -I/home/ubuntu/swift-source/build/Ninja-ReleaseAssert/libdispatch-linux-aarch64/src/swift -Xcc -fblocks -module-name Foundation -module-link-name Foundation -o ../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/Foundation/NSString.swift.o -emit-module-path ../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/Foundation/NSString.swift.o.~partial.swiftmodule -emit-module-doc-path ../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/Foundation/NSString.swift.o.~partial.swiftdoc -emit-dependencies-path ../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/Foundation/NSString.swift.o.d -emit-reference-dependencies-path ../build/Ninja-ReleaseAssert/foundation-linux-aarch64/Foundation/Foundation/NSString.swift.o.swiftdeps -module-cache-path ../build/Ninja-ReleaseAssert/foundation-linux-aarch64
Foundation/NSString.swift:1198:106: error: cannot convert value of type 'CVaListPointer' to expected argument type 'va_list' (aka '__va_list')
        let str = CFStringCreateWithFormatAndArguments(kCFAllocatorSystemDefault, nil, format._cfObject, argList)!
                                                                                                         ^~~~~~~
Foundation/NSString.swift:1206:148: error: cannot convert value of type 'CVaListPointer' to expected argument type 'va_list' (aka '__va_list')
                str = CFStringCreateWithFormatAndArguments(kCFAllocatorSystemDefault, unsafeBitCast(loc, to: CFDictionary.self), format._cfObject, argList)
                                                                                                                                                   ^~~~~~~
Foundation/NSString.swift:1211:106: error: cannot convert value of type 'CVaListPointer' to expected argument type 'va_list' (aka '__va_list')
            str = CFStringCreateWithFormatAndArguments(kCFAllocatorSystemDefault, nil, format._cfObject, argList)
                                                                                                         ^~~~~~~
Foundation/NSString.swift:1218:100: error: cannot convert value of type 'CVaListPointer' to expected argument type 'va_list' (aka '__va_list')
            CFStringCreateWithFormatAndArguments(kCFAllocatorSystemDefault, nil, format._cfObject, vaPtr)
                                                                                                   ^~~~~

[gonzalolarralde]

I think it worths to be said that the exact same codebase checked out at the same time in a x86_64 linux 16.04 emulator worked fine. This seems to be an arm only issue.

[swift-ci]

Comment by Neon (JIRA)

I just learned that arm aarch64 != apple arm64.

The arm aarch64 ABI defines __va_list as:

struct __va_list
   {
     void *__stack;
     void *__gr_top;
     void *__vr_top;
     int   __gr_offs;
     int   __vr_offs;
   };

but for apple arm64 it is char*.

Is it possible that swift is only working with apple arm64 but clang has arm aarch64 implemented?

[modocache]

Is this issue related to https://bugs.swift.org/browse/SR-3429 ?

[compnerd]

@modocache, unlikely that they are related. This would need to work before that can even occur as this issue prevents the definition of `CVaListPointer` entirely.

[compnerd]

Partial WIP patch at apple/swift#12623. The ClangImporter still needs adjustment and _VaListBuilder needs to be completed.

[compnerd]

The only bit that remains is fixing the _VaListBuilder which seems to not be getting interpreted properly.

[futurejones]

We now have a fix for this issue.

apple/swift#15174

This fix has been tested on a variety of arm64/aarch64 devices, from small SBC's like the RaspberryPi and Rock64, to high end Cavium ThunderX servers.

We need this issue resolved urgently as it is blocking successful builds on the new AArch64 CI - https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-aarch64/

[swift-ci]

Comment by Ed Vielmetti (JIRA)

@compnerd please take a look? We have a new CI system ready to go, blocked at the moment on this bug.