This is my funny version… I succeeded and I didn’t come back to find an other
way…
// 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().assumingMemoryBound(to:
ShadowPass.self)
shadowPtr.pointee = shadowPassData[0]
//More Swift specific stuff - advance pointer and cast to MainPass
//let mainPtr = UnsafeMutablePointer<MainPass>(shadowPtr.advanced(by: 1))
let mainPtr = constantBufferForFrame.contents().advanced(by:
MemoryLayout<ShadowPass>.size).assumingMemoryBound(to: MainPass.self)
mainPtr.pointee = mainPassFrameData
//Advance and cast to ObjectData
//var ptr = UnsafeMutablePointer<ObjectData>(mainPtr.advanced(by: 1))
var ptr = constantBufferForFrame.contents().advanced(by:
MemoryLayout<ShadowPass>.size +
MemoryLayout<MainPass>.size).assumingMemoryBound(to: ObjectData.self)
> On 3 Sep 2016, at 19:22, Patrice Kouame <pkou...@me.com> 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 <mailto: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
>> <mailto: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 <mailto: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 <mailto: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
>>>>>> <mailto: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
>>>>>>
>>>>>> <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
>>>>>> <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 <mailto: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 <mailto:swift-users@swift.org>
>>>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>>>> <https://lists.swift.org/mailman/listinfo/swift-users>
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> swift-users mailing list
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>>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>>> <https://lists.swift.org/mailman/listinfo/swift-users>
>>>> _______________________________________________
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>>>> <https://lists.swift.org/mailman/listinfo/swift-users>
>>>
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>
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