Not sure what you mean? The positional arg $0 is never used outside the closure whatever the version... No attempt is ever made to save and reuse after withMemoryRebound? Why would I use a separate function?
Are we looking at the same code? 🤓 rédigé sur mon iPhone. > On Sep 3, 2016, at 4:16 PM, Jacob Bandes-Storch <jtban...@gmail.com> wrote: > > Yikes! That's unsafe! When using withMemoryRebound, I think you're only > supposed to use the argument $0 inside the block. Saving it and using it > after withMemoryRebound is probably undefined behavior. But maybe you can > move your ".pointee = x" into a separate function rather than using a closure? > >> On Sat, Sep 3, 2016 at 1:12 PM, Patrice Kouame via swift-users >> <swift-users@swift.org> wrote: >> Finally Success! I’m seeing my pretty little 3D twirling Metal Renderer >> cubes again… Here’s how >> >> Snippet of old sample code which no longer compiles in Xcode 8 beta 6 with >> stricter Swift3 unsafe type casting restrictions >> (in MetalView.swift from # Adopting Metal II: Designing and Implementing a >> Real-World Metal Renderer) >> >> let shadowPtr = >> UnsafeMutablePointer<ShadowPass>(constantBufferForFrame.contents()) >> let mainPtr = UnsafeMutablePointer<MainPass>(shadowPtr.advanced(by: 1)) >> mainPtr.pointee = mainPassFrameData >> var ptr = UnsafeMutablePointer<ObjectData>(mainPtr.advanced(by: 1)) >> >> My conversion attempt that crashes Swift 3 Xcode 8 beta 6 (see RADAR >> 28150447 - Swift 3 UnsafeMutablePointer conversion crashes the compiler and >> IDE) >> >> let shadowPtr = constantBufferForFrame.contents().bindMemory(to: >> ShadowPass.self, capacity: MemoryLayout<shadowPassData>.size) >> let mainPtr : UnsafeMutablePointer<MainPass> = >> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, capacity: 1) { >> $0.pointee = mainPassFrameData >> } >> var ptr : UnsafeMutablePointer<ObjectData> = mainPtr.advanced(by: >> 1).withMemoryRebound(to: ObjectData.self, capacity: MemoryLayout< ObjectData >> >.size) {$0} >> >> Latest conversion that make Xcode and Swift 3 smile again... >> >> let shadowPtr = constantBufferForFrame.contents().bindMemory(to: >> ShadowPass.self, capacity: shadowPassData.count) >> let mainPtr : UnsafeMutablePointer<MainPass> = >> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, capacity: 1) >> {$0} >> mainPtr.pointee = mainPassFrameData >> var ptr : UnsafeMutablePointer<ObjectData> = mainPtr.advanced(by: >> 1).withMemoryRebound(to: ObjectData.self, capacity: objectsToRender) {$0} >> >> Yes… Xcode/Swift3 SIL generation definitely did NOT like my "$0.pointee = >> mainPassFrameData" statement. >> Apparently, reassigning the pointee within the closure makes Swift gag out >> of disgust. Sorry ;-( >> That’s what I get for trying to be fancy… >> And fixed my “capacity” issues thanks to some previous posters. >> >> Hope this helps anyone trying to get the Metal projects to compile again. >> >> At least I got a Radar out of this ;-) Compilers should never burn and crash >> out like this... >> >> Regards to all, Patrice >> >> >>> On Sep 3, 2016, at 1:22 PM, Patrice Kouame via swift-users >>> <swift-users@swift.org> wrote: >>> >>> Gerard- >>> >>> Excellent! Looking forward to seeing your fix (hoping you get your book >>> back soon ;-) ) >>> >>> I think Xcode/Swift gags on the last ptr advance to objectData. I recently >>> tried another variant using withUnsafeMutablePointer like this: >>> >>> var ptr : UnsafeMutablePointer<ObjectData> = >>> withUnsafeMutablePointer(to: &mainPtr) { >>> $0.withMemoryRebound(to: ObjectData.self, capacity: >>> objectsToRender) { >>> $0.pointee = renderables[0].objectData >>> } >>> } >>> >>> ..but still crashes with no hints. >>> >>> My bug report also mentions that the Xcode migration/conversion tool is >>> incomplete. >>> It handles the “simpler" UnsafeMutableRawPointer<X> to >>> UnsafeMutablePonter<Y> with bindMemory cases correctly (one still has to >>> mind the capacity value though) >>> In all fairness, migrating/converting automagically in these cases is >>> always a little bit tricky - the proposed Xcode fixes should always be >>> reviewed by a human... >>> >>> Patrice >>> >>>> On Sep 3, 2016, at 1:05 PM, Gerard Iglesias via swift-users >>>> <swift-users@swift.org> wrote: >>>> >>>> Ok >>>> >>>> For the record I succeeded this transformation phase last week >>>> >>>> I remember the tedious stuff to advance pointer from one struct to the >>>> other kind of struct... it worked >>>> >>>> But I don't have my MacBook with me, only the phone, the six :) >>>> >>>> Gérard >>>> >>>>> Le 3 sept. 2016 à 18:22, Patrice Kouame <pkou...@me.com> a écrit : >>>>> >>>>> Indeed. There is a difference between stride and size, but I interpreted >>>>> capacity incorrectly for my purposes. It should indicate the number of >>>>> <T> elements (not their size - right?) and the snippets below should work. >>>>> >>>>> Still, compiler crashes and Xcode IDE is left in inconsistent state. So >>>>> I filed this Apple radar against Developer Tools. >>>>> >>>>> 28150447 - Swift 3 UnsafeMutablePointer conversion crashes the compiler >>>>> and IDE >>>>> Should I file a Swift bug too? Would that be helpful? >>>>> >>>>> Regards, Patrice >>>>> >>>>>> On Sep 3, 2016, at 11:39 AM, Gerard Iglesias via swift-users >>>>>> <swift-users@swift.org> wrote: >>>>>> >>>>>> Hello, >>>>>> >>>>>> I think that it is more secure to use stride in place of size, sometimes >>>>>> it is not the same value. >>>>>> >>>>>> I use it in my own use of raw bindings >>>>>> >>>>>> Regards >>>>>> >>>>>> Gérard >>>>>> >>>>>>> Le 3 sept. 2016 à 10:03, Patrice Kouame via swift-users >>>>>>> <swift-users@swift.org> a écrit : >>>>>>> >>>>>>> Hi Jacob - >>>>>>> >>>>>>> I think you’re right. “capacity” should be the count of type T elements >>>>>>> in my buffer. So in my case that line should read >>>>>>> >>>>>>> let shadowPtr = >>>>>>> constantBufferForFrame.contents().bindMemory(to: ShadowPass.self, >>>>>>> capacity: shadowPassData.count) >>>>>>> >>>>>>> The withMemoryRebound calls need similar adjustments. The pointer to >>>>>>> MainPass is actually a single structure to it should be safe to do this >>>>>>> >>>>>>> let mainPtr : UnsafeMutablePointer<MainPass> = >>>>>>> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, >>>>>>> capacity: 1) { >>>>>>> $0.pointee = mainPassFrameData >>>>>>> } >>>>>>> >>>>>>> Whereas the unsafe pointer to <ObjectData> is actually a buffer of >>>>>>> renderable objects, so this should work: >>>>>>> >>>>>>> var ptr : UnsafeMutablePointer<ObjectData> = >>>>>>> mainPtr.advanced(by: 1).withMemoryRebound(to: ObjectData.self, >>>>>>> capacity: objectsToRender) {_ in >>>>>>> } >>>>>>> >>>>>>> There are surely ways to refactor and simplify this, but I’m trying to >>>>>>> retain as much of the original sample code approach as possible. >>>>>>> >>>>>>> However, the compiler still segs badly. >>>>>>> Xcode also borks an internal error often. Only cleaning or restarting >>>>>>> the project can clear up that state. >>>>>>> Compilers (or Playgrounds for that matter) should never crash, and I’m >>>>>>> not sure where to file this bug : Swift or Apple radar against Xcode or >>>>>>> both? I now Xcode 8 is beta but…it’s been doing this for quite a while >>>>>>> now... >>>>>>> >>>>>>> In both our “close to the metal” (no pun intended) cases, it seems like >>>>>>> a lot of churning for very little gain. Don’t you think? The easier, >>>>>>> but “unsafe” casting afforded previously did the trick with the normal >>>>>>> caveats. >>>>>>> Don’t get me wrong, I love Swift and “get" all the neat type safety >>>>>>> features. Guess we can’t have our cake and eat it too, especially when >>>>>>> interfacing with “unsafe” C APIs. >>>>>>> >>>>>>> Anyway, back to rtfm … maybe some of the Swift Gods can chime in? ;-) >>>>>>> >>>>>>> I must be doing something stupid...Patrice >>>>>>> >>>>>>>> On Sep 3, 2016, at 2:32 AM, Jacob Bandes-Storch <jtban...@gmail.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Hi Patrice, >>>>>>>> I don't have a solution for you, but I just wanted to point out what I >>>>>>>> think may be an error with your use of the new UnsafeRawPointer APIs: >>>>>>>> >>>>>>>> constantBufferForFrame.contents().bindMemory(to: ShadowPass.self, >>>>>>>> capacity: MemoryLayout<ShadowPass>.size) >>>>>>>> >>>>>>>> I believe the `capacity` should actually be the number of ShadowPass >>>>>>>> elements in the buffer, not the size of each element. Using >>>>>>>> `bindMemory(to: ShadowPass.self` already implies that >>>>>>>> MemoryLayout<ShadowPass>.size is the size of each element. >>>>>>>> >>>>>>>> More info at >>>>>>>> https://developer.apple.com/reference/swift/unsaferawpointer/2428875-bindmemory >>>>>>>> >>>>>>>> I just updated a small Metal project of mine to Swift 3. I ran into >>>>>>>> some compiler (playground) crashes, but it does seem to work most of >>>>>>>> the time. Although I only have 1 buffer :-) >>>>>>>> https://github.com/jtbandes/Metalbrot.playground >>>>>>>> >>>>>>>> Jacob >>>>>>>> >>>>>>>>> On Fri, Sep 2, 2016 at 11:00 AM, Patrice Kouame via swift-users >>>>>>>>> <swift-users@swift.org> wrote: >>>>>>>>> Hi all - >>>>>>>>> >>>>>>>>> I’m converting Apple’s Swift Sample "Adopting Metal II: Designing and >>>>>>>>> Implementing a Real-World Metal Renderer” in Xcode 8 beta6 to the >>>>>>>>> latest UnsafeMutablePointer API for untyped memory access. >>>>>>>>> Changes are necessary in MetalView.swift (Apple hasn’t updated their >>>>>>>>> sample code for the latest beta yet…) >>>>>>>>> The Swift Compiler crashes (Segmentation Fault: 11) on the attempt: >>>>>>>>> >>>>>>>>> // Grab a pointer to the constant buffer's data store >>>>>>>>> // Since we are using Swift, it is easier to cast the pointer >>>>>>>>> to the ShadowPass type to fill the constant buffer >>>>>>>>> // We need to make a copy of these so the block captures the >>>>>>>>> correct data >>>>>>>>> >>>>>>>>> // let shadowPtr = >>>>>>>>> UnsafeMutablePointer<ShadowPass>(constantBufferForFrame.contents()) >>>>>>>>> let shadowPtr = >>>>>>>>> constantBufferForFrame.contents().bindMemory(to: ShadowPass.self, >>>>>>>>> capacity: MemoryLayout<ShadowPass>.size) >>>>>>>>> shadowPtr.pointee = shadowPassData[0] >>>>>>>>> >>>>>>>>> //More Swift specific stuff - advance pointer and cast to >>>>>>>>> MainPass >>>>>>>>> >>>>>>>>> // let mainPtr = >>>>>>>>> UnsafeMutablePointer<MainPass>(shadowPtr.advanced(by: 1)) >>>>>>>>> // mainPtr.pointee = mainPassFrameData >>>>>>>>> let mainPtr : UnsafeMutablePointer<MainPass> = >>>>>>>>> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, >>>>>>>>> capacity: MemoryLayout<MainPass>.size) { >>>>>>>>> $0.pointee = mainPassFrameData >>>>>>>>> } >>>>>>>>> >>>>>>>>> //Advance and cast to ObjectData >>>>>>>>> >>>>>>>>> // var ptr = >>>>>>>>> UnsafeMutablePointer<ObjectData>(mainPtr.advanced(by: 1)) >>>>>>>>> var ptr : UnsafeMutablePointer<ObjectData> = >>>>>>>>> mainPtr.advanced(by: 1).withMemoryRebound(to: ObjectData.self, >>>>>>>>> capacity: MemoryLayout<ObjectData>.size) {_ in >>>>>>>>> } >>>>>>>>> >>>>>>>>> let shadowOffset = 0 >>>>>>>>> let mainPassOffset = MemoryLayout<ShadowPass>.size + >>>>>>>>> shadowOffset >>>>>>>>> let objectDataOffset = MemoryLayout<MainPass>.size + >>>>>>>>> mainPassOffset >>>>>>>>> >>>>>>>>> // Update position of all the objects >>>>>>>>> if multithreadedUpdate { >>>>>>>>> DispatchQueue.concurrentPerform(iterations: >>>>>>>>> objectsToRender) { i in >>>>>>>>> let thisPtr = ptr.advanced(by: i) >>>>>>>>> _ = self.renderables[i].UpdateData(ptr, deltaTime: >>>>>>>>> 1.0/60.0) >>>>>>>>> } >>>>>>>>> } >>>>>>>>> else { >>>>>>>>> for index in 0..<objectsToRender { >>>>>>>>> ptr = renderables[index].UpdateData(ptr, deltaTime: >>>>>>>>> 1.0/60.0) >>>>>>>>> } >>>>>>>>> } >>>>>>>>> >>>>>>>>> ptr = ptr.advanced(by: objectsToRender) >>>>>>>>> >>>>>>>>> _ = groundPlane!.UpdateData(ptr, deltaTime: 1.0/60.0) >>>>>>>>> >>>>>>>>> Any help is appreciated. I have the latest Xcode log handy if >>>>>>>>> necessary. Here’s a clip of the stack trace. >>>>>>>>> >>>>>>>>> 0 swift 0x000000010714a99d >>>>>>>>> PrintStackTraceSignalHandler(void*) + 45 >>>>>>>>> 1 swift 0x000000010714a3e6 SignalHandler(int) + >>>>>>>>> 470 >>>>>>>>> 2 libsystem_platform.dylib 0x00007fff91461bba _sigtramp + 26 >>>>>>>>> 3 libsystem_platform.dylib 000000000000000000 _sigtramp + 1857676384 >>>>>>>>> 4 swift 0x00000001047207b3 (anonymous >>>>>>>>> namespace)::SILGenApply::visitExpr(swift::Expr*) + 51 >>>>>>>>> 5 swift 0x0000000104723ace (anonymous >>>>>>>>> namespace)::SILGenApply::visitApplyExpr(swift::ApplyExpr*) + 5182 >>>>>>>>> 6 swift 0x0000000104711cc1 >>>>>>>>> prepareApplyExpr(swift::Lowering::SILGenFunction&, swift::Expr*) + 273 >>>>>>>>> 7 swift 0x00000001047624e7 >>>>>>>>> swift::ASTVisitor<(anonymous namespace)::RValueEmitter, >>>>>>>>> swift::Lowering::RValue, void, void, void, void, void, >>>>>>>>> swift::Lowering::SGFContext>::visit(swift::Expr*, >>>>>>>>> swift::Lowering::SGFContext) + 103 >>>>>>>>> 8 swift 0x0000000104762313 >>>>>>>>> swift::Lowering::SILGenFunction::emitExprInto(swift::Expr*, >>>>>>>>> swift::Lowering::Initialization*) + 195 >>>>>>>>> 9 swift 0x000000010474fbc3 >>>>>>>>> swift::Lowering::SILGenFunction::emitPatternBinding(swift::PatternBindingDecl*, >>>>>>>>> unsigned int) + 195 >>>>>>>>> 10 swift 0x00000001047077bd >>>>>>>>> swift::ASTVisitor<swift::Lowering::SILGenFunction, void, void, void, >>>>>>>>> void, void, void>::visit(swift::Decl*) + 125 >>>>>>>>> 11 swift 0x00000001047c0019 >>>>>>>>> swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, >>>>>>>>> void, void, void, void>::visit(swift::Stmt*) + 4169 >>>>>>>>> 12 swift 0x00000001047809ba >>>>>>>>> swift::Lowering::SILGenFunction::emitFunction(swift::FuncDecl*) + 314 >>>>>>>>> 13 swift 0x00000001046fd775 >>>>>>>>> swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*)::$_1::operator()(swift::SILFunction*) >>>>>>>>> const + 1877 >>>>>>>>> 14 swift 0x00000001046fc322 >>>>>>>>> swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 626 >>>>>>>>> 15 swift 0x00000001047c7007 (anonymous >>>>>>>>> namespace)::SILGenType::emitType() + 1271 >>>>>>>>> 16 swift 0x00000001047c6a9e >>>>>>>>> swift::Lowering::SILGenModule::visitNominalTypeDecl(swift::NominalTypeDecl*) >>>>>>>>> + 30 >>>>>>>>> 17 swift 0x0000000104709093 >>>>>>>>> swift::Lowering::SILGenModule::emitSourceFile(swift::SourceFile*, >>>>>>>>> unsigned int) + 1795 >>>>>>>>> 18 swift 0x000000010470ad4d >>>>>>>>> swift::SILModule::constructSIL(swift::ModuleDecl*, >>>>>>>>> swift::SILOptions&, swift::FileUnit*, llvm::Optional<unsigned int>, >>>>>>>>> bool, bool) + 1629 >>>>>>>>> 19 swift 0x00000001045621bf >>>>>>>>> performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, >>>>>>>>> llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*) + 19487 >>>>>>>>> 20 swift 0x000000010455b2c5 >>>>>>>>> swift::performFrontend(llvm::ArrayRef<char const*>, char const*, >>>>>>>>> void*, swift::FrontendObserver*) + 17029 >>>>>>>>> 21 swift 0x000000010451888d main + 8685 >>>>>>>>> 22 libdyld.dylib 0x00007fff91255255 start + 1 >>>>>>>>> >>>>>>>>> >>>>>>>>> Patrice >>>>>>>>> >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> swift-users mailing list >>>>>>>>> swift-users@swift.org >>>>>>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>>>>> >>>>>>> _______________________________________________ >>>>>>> swift-users mailing list >>>>>>> swift-users@swift.org >>>>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>>>> _______________________________________________ >>>>>> swift-users mailing list >>>>>> swift-users@swift.org >>>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>> _______________________________________________ >>>> swift-users mailing list >>>> swift-users@swift.org >>>> https://lists.swift.org/mailman/listinfo/swift-users >>> >>> _______________________________________________ >>> swift-users mailing list >>> swift-users@swift.org >>> https://lists.swift.org/mailman/listinfo/swift-users >> >> >> _______________________________________________ >> swift-users mailing list >> swift-users@swift.org >> https://lists.swift.org/mailman/listinfo/swift-users >
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