"Stored value type does not match pointer operand type!" compiler crash

[LeoNatan]

Describe the bug
The following function crashes the compiler:

func setEnumOverrideIfExists<T: RawRepresentable>(for key: String, in override: [String: Any], target: inout T) where T.RawValue == UInt {
    if let overrideValue = override[key] as? UInt, let overrideValue = T(rawValue: overrideValue) {
        target = overrideValue
    }
}

If, however, I make the following change, there is no crash:

func setEnumOverrideIfExists<T: RawRepresentable>(for key: String, in override: [String: Any], target: inout T) where T.RawValue == UInt {
    if let overrideValue = override[key] as? UInt, let overrideValueEnum = T(rawValue: overrideValue) {
        target = overrideValueEnum
    }
}

To Reproduce
Steps to reproduce the behavior:

1. Add the function above in a Swift file
2. Compile

Expected behavior
Compiler should not crash.

Environment (please complete the following information):

• OS: macOS 12.5 (21G5046c)
• Xcode Version/Tag/Branch: Xcode 13.2

Additional context

Stored value type does not match pointer operand type!
  store i64 %95, i8** %9, align 8, !dbg !393
 i8*in function $s6Panels22PrototypeOverrideModelV07setEnumC8IfExists3for2in0E0ySS_SDySSypGxztSYRzSu8RawValueRtzlF
<unknown>:0: error: fatal error encountered during compilation; please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project
<unknown>:0: note: Broken function found, compilation aborted!
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project and the crash backtrace.
Stack dump:
0.	Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -c /Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Panels/Plugins/Sync/Prototyping/PrototypeOverridesEditors.swift -primary-file /Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Panels/Plugins/Sync/Prototyping/Models/PrototypeOverrideModel.swift /Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Panels/Plugins/Sync/Prototyping/SwiftUIUtils.swift -emit-module-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel~partial.swiftmodule -emit-module-doc-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel~partial.swiftdoc -emit-module-source-info-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel~partial.swiftsourceinfo -emit-dependencies-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel.d -emit-reference-dependencies-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel.swiftdeps -serialize-diagnostics-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel.dia -target x86_64-apple-macos11.0 -enable-objc-interop -stack-check -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.1.sdk -I /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Products/Debug -F /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Products/Debug -enable-testing -g -import-underlying-module -module-cache-path /Users/lnatan/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -swift-version 5 -enforce-exclusivity=checked -Onone -new-driver-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-driver -serialize-debugging-options -Xcc -working-directory -Xcc /Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -enable-anonymous-context-mangled-names -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Panels-generated-files.hmap -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Panels-own-target-headers.hmap -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Panels-all-non-framework-target-headers.hmap -Xcc -ivfsoverlay -Xcc /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/all-product-headers.yaml -Xcc -iquote -Xcc /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Panels-project-headers.hmap -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Products/Debug/include -Xcc -I/Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Pods/Headers/Public -Xcc -I/Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Pods/Headers/Public/CocoaLumberjack -Xcc -I/Users/lnatan/Desktop/Code/craft-manager-mac/Submodules/craft-panels/Panels/Pods/Headers/Public/RNCryptor-objc -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/DerivedSources-normal/x86_64 -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/DerivedSources/x86_64 -Xcc -I/Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/DerivedSources -Xcc -DDEBUG=1 -Xcc -DCURRENT_USER=@\"lnatan\" -Xcc -DCOCOAPODS=1 -Xcc -ivfsoverlay -Xcc /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/unextended-module-overlay.yaml -module-name Panels -target-sdk-version 12.1.0 -o /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Build/Intermediates.noindex/Panels.build/Debug/Panels.build/Objects-normal/x86_64/PrototypeOverrideModel.o -index-store-path /Users/lnatan/Library/Developer/Xcode/DerivedData/Panels-eduudpvkojkgnobxrswznjeogchl/Index/DataStore -index-system-modules
1.	Apple Swift version 5.5.2 (swiftlang-1300.0.47.5 clang-1300.0.29.30)
2.	
3.	Running pass 'Module Verifier' on function '@"$s6Panels22PrototypeOverrideModelV07setEnumC8IfExists3for2in0E0ySS_SDySSypGxztSYRzSu8RawValueRtzlF"'
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010f1d7c27 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 39
1  swift-frontend           0x000000010f1d6bb8 llvm::sys::RunSignalHandlers() + 248
2  swift-frontend           0x000000010f1d8236 SignalHandler(int) + 278
3  libsystem_platform.dylib 0x00007ff80790adfd _sigtramp + 29
4  libsystem_platform.dylib 0x0000000000000003 _sigtramp + 18446603370454012451
5  libsystem_c.dylib        0x00007ff807840d24 abort + 123
6  swift-frontend           0x000000010a2e9502 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*)::$_2::__invoke(void*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) + 978
7  swift-frontend           0x000000010f12169e llvm::report_fatal_error(llvm::Twine const&, bool) + 286
8  swift-frontend           0x000000010f12157b llvm::report_fatal_error(char const*, bool) + 43
9  swift-frontend           0x000000010f0b815f (anonymous namespace)::VerifierLegacyPass::runOnFunction(llvm::Function&) + 111
10 swift-frontend           0x000000010f05236a llvm::FPPassManager::runOnFunction(llvm::Function&) + 1354
11 swift-frontend           0x000000010f051651 llvm::legacy::FunctionPassManagerImpl::run(llvm::Function&) + 113
12 swift-frontend           0x000000010f058b75 llvm::legacy::FunctionPassManager::run(llvm::Function&) + 341
13 swift-frontend           0x000000010a7deb61 swift::performLLVMOptimizations(swift::IRGenOptions const&, llvm::Module*, llvm::TargetMachine*) + 1585
14 swift-frontend           0x000000010a7df9c7 swift::performLLVM(swift::IRGenOptions const&, swift::DiagnosticEngine&, llvm::sys::SmartMutex<false>*, llvm::GlobalVariable*, llvm::Module*, llvm::TargetMachine*, llvm::StringRef, swift::UnifiedStatsReporter*) + 2055
15 swift-frontend           0x000000010a2f4a9d performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 3581
16 swift-frontend           0x000000010a2e6346 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 13830
17 swift-frontend           0x000000010a226b08 main + 1032
18 dyld                     0x000000011c3fa52e start + 462
error: Abort trap: 6 (in target 'Panels' from project 'Panels')

[LeoNatan]

This also compiles without crashing the compiler:

func setEnumOverrideIfExists<T: RawRepresentable, U>(for key: String, in override: [String: Any], target: inout T) where T.RawValue == U {
    if let overrideValue = override[key] as? U, let overrideValue = T(rawValue: overrideValue) {
        target = overrideValue
    }
}

[AnthonyLatsis]

Could not reproduce with ToT. May I ask that you isolate the following simplification and see whether it crashes in the terminal with swiftc path/to/file.swift -emit-ir?

func foo<T: RawRepresentable>(src: Any, target: inout T) where T.RawValue == UInt {
  if let x = src as? UInt, let x = T(rawValue: x) {
    target = x
  }
}

@xedin do we actually allow this kind of shadowing?

[LeoNatan]

@AnthonyLatsis Reproduced with Xcode 13.2 toolchain:

➜  Desktop swiftc test.swift -emit-ir
Stored value type does not match pointer operand type!
  store i64 %68, i8** %overrideValue.debug, align 8
 i8*in function $s4test23setEnumOverrideIfExists3for2in6targetySS_SDySSypGxztSYRzSu8RawValueRtzlF
<unknown>:0: error: fatal error encountered during compilation; please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project
<unknown>:0: note: Broken function found, compilation aborted!
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project and the crash backtrace.
Stack dump:
0.	Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -emit-ir -primary-file test.swift -target x86_64-apple-macosx12.0 -enable-objc-interop -stack-check -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.1.sdk -color-diagnostics -new-driver-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-driver -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -module-name test -target-sdk-version 12.1.0 -o -
1.	Apple Swift version 5.5.2 (swiftlang-1300.0.47.5 clang-1300.0.29.30)
2.	
3.	Running pass 'Module Verifier' on function '@"$s4test23setEnumOverrideIfExists3for2in6targetySS_SDySSypGxztSYRzSu8RawValueRtzlF"'
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x0000000109c41c27 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 39
1  swift-frontend           0x0000000109c40bb8 llvm::sys::RunSignalHandlers() + 248
2  swift-frontend           0x0000000109c42236 SignalHandler(int) + 278
3  libsystem_platform.dylib 0x00007ff80790adfd _sigtramp + 29
4  libsystem_platform.dylib 000000000000000000 _sigtramp + 18446603370454012448
5  libsystem_c.dylib        0x00007ff807840d24 abort + 123
6  swift-frontend           0x0000000104d53502 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*)::$_2::__invoke(void*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) + 978
7  swift-frontend           0x0000000109b8b69e llvm::report_fatal_error(llvm::Twine const&, bool) + 286
8  swift-frontend           0x0000000109b8b57b llvm::report_fatal_error(char const*, bool) + 43
9  swift-frontend           0x0000000109b2215f (anonymous namespace)::VerifierLegacyPass::runOnFunction(llvm::Function&) + 111
10 swift-frontend           0x0000000109abc36a llvm::FPPassManager::runOnFunction(llvm::Function&) + 1354
11 swift-frontend           0x0000000109abb651 llvm::legacy::FunctionPassManagerImpl::run(llvm::Function&) + 113
12 swift-frontend           0x0000000109ac2b75 llvm::legacy::FunctionPassManager::run(llvm::Function&) + 341
13 swift-frontend           0x0000000105248b61 swift::performLLVMOptimizations(swift::IRGenOptions const&, llvm::Module*, llvm::TargetMachine*) + 1585
14 swift-frontend           0x00000001052499c7 swift::performLLVM(swift::IRGenOptions const&, swift::DiagnosticEngine&, llvm::sys::SmartMutex<false>*, llvm::GlobalVariable*, llvm::Module*, llvm::TargetMachine*, llvm::StringRef, swift::UnifiedStatsReporter*) + 2055
15 swift-frontend           0x0000000104d5ea9d performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 3581
16 swift-frontend           0x0000000104d50346 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 13830
17 swift-frontend           0x0000000104c90b08 main + 1032
18 dyld                     0x000000010dbfb52e start + 462
[1]    47745 abort      swiftc test.swift -emit-ir

[LeoNatan]

Hm, doesn't reproduce with the toolchain in Xcode 14.0 b1. I guess we can close the issue.

➜  Desktop swiftc test.swift -emit-ir
2022-06-20 19:37:24.373 xcodebuild[47889:1008416] [MT] DVTSDK: Warning: SDK path collision for path '<DVTFilePath:0x6000028fa060:'/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.sdk'>': SDK with name 'macosx13.0' being superseded by SDK with 'macosx13.0'.
2022-06-20 19:37:25.581 xcodebuild[47890:1008438] [MT] DVTSDK: Warning: SDK path collision for path '<DVTFilePath:0x600002a64070:'/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.sdk'>': SDK with name 'macosx13.0' being superseded by SDK with 'macosx13.0'.
; ModuleID = '<swift-imported-modules>'
source_filename = "<swift-imported-modules>"
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx12.0.0"

%swift.type = type { i64 }
%swift.full_type = type { i8**, %swift.type }
%swift.bridge = type opaque
%swift.opaque = type opaque
%TSS = type <{ %Ts11_StringGutsV }>
%Ts11_StringGutsV = type <{ %Ts13_StringObjectV }>
%Ts13_StringObjectV = type <{ %Ts6UInt64V, %swift.bridge* }>
%Ts6UInt64V = type <{ i64 }>
%TypSg = type <{ [32 x i8] }>
%TSu = type <{ i64 }>
%swift.metadata_response = type { %swift.type*, i64 }
%swift.vwtable = type { i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i64, i64, i32, i32 }
%TSq = type <{}>
%TSq.0 = type <{}>
%Any = type { [24 x i8], %swift.type* }
%TSq.1 = type <{}>
%__opaque_existential_type_0 = type { [24 x i8], %swift.type* }
%swift.refcounted = type { %swift.type*, i64 }

@"$sSSN" = external global %swift.type, align 8
@"$sypN" = external global %swift.full_type
@"$sSSSHsWP" = external global i8*, align 8
@"$sSuN" = external global %swift.type, align 8
@"\01l_entry_point" = private constant { i32 } { i32 trunc (i64 sub (i64 ptrtoint (i32 (i32, i8**)* @main to i64), i64 ptrtoint ({ i32 }* @"\01l_entry_point" to i64)) to i32) }, section "__TEXT, __swift5_entry, regular, no_dead_strip", align 4
@__swift_reflection_version = linkonce_odr hidden constant i16 3
@llvm.used = appending global [3 x i8*] [i8* bitcast (i32 (i32, i8**)* @main to i8*), i8* bitcast ({ i32 }* @"\01l_entry_point" to i8*), i8* bitcast (i16* @__swift_reflection_version to i8*)], section "llvm.metadata"

define i32 @main(i32 %0, i8** %1) #0 {
entry:
  %2 = bitcast i8** %1 to i8*
  ret i32 0
}

define hidden swiftcc void @"$s4test23setEnumOverrideIfExists3for2in6targetySS_SDySSypGxztSYRzSu8RawValueRtzlF"(i64 %0, %swift.bridge* %1, %swift.bridge* %2, %swift.opaque* nocapture %3, %swift.type* %T, i8** %T.RawRepresentable) #0 {
entry:
  %T1 = alloca %swift.type*, align 8
  %overrideValue.debug = alloca i8*, align 8
  %4 = bitcast i8** %overrideValue.debug to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %4, i8 0, i64 8, i1 false)
  %key.debug = alloca %TSS, align 8
  %5 = bitcast %TSS* %key.debug to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %5, i8 0, i64 16, i1 false)
  %override.debug = alloca %swift.bridge*, align 8
  %6 = bitcast %swift.bridge** %override.debug to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %6, i8 0, i64 8, i1 false)
  %target.debug = alloca %swift.opaque*, align 8
  %7 = bitcast %swift.opaque** %target.debug to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %7, i8 0, i64 8, i1 false)
  %8 = alloca %TypSg, align 8
  %9 = alloca %TSS, align 8
  %overrideValue.debug3 = alloca i64, align 8
  %10 = bitcast i64* %overrideValue.debug3 to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %10, i8 0, i64 8, i1 false)
  %11 = alloca %TSu, align 8
  %12 = alloca %TSu, align 8
  store %swift.type* %T, %swift.type** %T1, align 8
  %13 = call swiftcc %swift.metadata_response @"$sSqMa"(i64 0, %swift.type* %T) #5
  %14 = extractvalue %swift.metadata_response %13, 0
  %15 = bitcast %swift.type* %14 to i8***
  %16 = getelementptr inbounds i8**, i8*** %15, i64 -1
  %.valueWitnesses = load i8**, i8*** %16, align 8, !invariant.load !18, !dereferenceable !19
  %17 = bitcast i8** %.valueWitnesses to %swift.vwtable*
  %18 = getelementptr inbounds %swift.vwtable, %swift.vwtable* %17, i32 0, i32 8
  %size = load i64, i64* %18, align 8, !invariant.load !18
  %19 = alloca i8, i64 %size, align 16
  call void @llvm.lifetime.start.p0i8(i64 -1, i8* %19)
  %20 = bitcast i8* %19 to %TSq*
  %21 = bitcast %swift.type* %T to i8***
  %22 = getelementptr inbounds i8**, i8*** %21, i64 -1
  %T.valueWitnesses = load i8**, i8*** %22, align 8, !invariant.load !18, !dereferenceable !19
  %23 = bitcast i8** %T.valueWitnesses to %swift.vwtable*
  %24 = getelementptr inbounds %swift.vwtable, %swift.vwtable* %23, i32 0, i32 8
  %size2 = load i64, i64* %24, align 8, !invariant.load !18
  %25 = alloca i8, i64 %size2, align 16
  call void @llvm.lifetime.start.p0i8(i64 -1, i8* %25)
  %26 = bitcast i8* %25 to %swift.opaque*
  %27 = alloca i8, i64 %size2, align 16
  call void @llvm.lifetime.start.p0i8(i64 -1, i8* %27)
  %28 = bitcast i8* %27 to %swift.opaque*
  store i8* %27, i8** %overrideValue.debug, align 8
  %29 = bitcast %TSS* %key.debug to i8*
  call void @llvm.lifetime.start.p0i8(i64 16, i8* %29)
  %key.debug._guts = getelementptr inbounds %TSS, %TSS* %key.debug, i32 0, i32 0
  %key.debug._guts._object = getelementptr inbounds %Ts11_StringGutsV, %Ts11_StringGutsV* %key.debug._guts, i32 0, i32 0
  %key.debug._guts._object._countAndFlagsBits = getelementptr inbounds %Ts13_StringObjectV, %Ts13_StringObjectV* %key.debug._guts._object, i32 0, i32 0
  %key.debug._guts._object._countAndFlagsBits._value = getelementptr inbounds %Ts6UInt64V, %Ts6UInt64V* %key.debug._guts._object._countAndFlagsBits, i32 0, i32 0
  store i64 %0, i64* %key.debug._guts._object._countAndFlagsBits._value, align 8
  %key.debug._guts._object._object = getelementptr inbounds %Ts13_StringObjectV, %Ts13_StringObjectV* %key.debug._guts._object, i32 0, i32 1
  store %swift.bridge* %1, %swift.bridge** %key.debug._guts._object._object, align 8
  store %swift.bridge* %2, %swift.bridge** %override.debug, align 8
  store %swift.opaque* %3, %swift.opaque** %target.debug, align 8
  %30 = bitcast %TypSg* %8 to i8*
  call void @llvm.lifetime.start.p0i8(i64 32, i8* %30)
  %31 = call %swift.bridge* @swift_bridgeObjectRetain(%swift.bridge* returned %1) #3
  %32 = bitcast %TSS* %9 to i8*
  call void @llvm.lifetime.start.p0i8(i64 16, i8* %32)
  %._guts = getelementptr inbounds %TSS, %TSS* %9, i32 0, i32 0
  %._guts._object = getelementptr inbounds %Ts11_StringGutsV, %Ts11_StringGutsV* %._guts, i32 0, i32 0
  %._guts._object._countAndFlagsBits = getelementptr inbounds %Ts13_StringObjectV, %Ts13_StringObjectV* %._guts._object, i32 0, i32 0
  %._guts._object._countAndFlagsBits._value = getelementptr inbounds %Ts6UInt64V, %Ts6UInt64V* %._guts._object._countAndFlagsBits, i32 0, i32 0
  store i64 %0, i64* %._guts._object._countAndFlagsBits._value, align 8
  %._guts._object._object = getelementptr inbounds %Ts13_StringObjectV, %Ts13_StringObjectV* %._guts._object, i32 0, i32 1
  store %swift.bridge* %1, %swift.bridge** %._guts._object._object, align 8
  %33 = bitcast %TypSg* %8 to %TSq.0*
  %34 = bitcast %TSS* %9 to %swift.opaque*
  %35 = bitcast %TSq.0* %33 to %swift.opaque*
  call swiftcc void @"$sSDyq_Sgxcig"(%swift.opaque* noalias nocapture sret(%swift.opaque) %35, %swift.opaque* noalias nocapture %34, %swift.bridge* %2, %swift.type* @"$sSSN", %swift.type* getelementptr inbounds (%swift.full_type, %swift.full_type* @"$sypN", i32 0, i32 1), i8** @"$sSSSHsWP")
  %36 = call %TSS* @"$sSSWOh"(%TSS* %9)
  %37 = bitcast %TSS* %9 to i8*
  call void @llvm.lifetime.end.p0i8(i64 16, i8* %37)
  %38 = bitcast %TypSg* %8 to { i64, i64, i64, i64 }*
  %39 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %38, i32 0, i32 0
  %40 = load i64, i64* %39, align 8
  %41 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %38, i32 0, i32 1
  %42 = load i64, i64* %41, align 8
  %43 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %38, i32 0, i32 2
  %44 = load i64, i64* %43, align 8
  %45 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %38, i32 0, i32 3
  %46 = load i64, i64* %45, align 8
  %47 = icmp eq i64 %46, 0
  br i1 %47, label %96, label %48

48:                                               ; preds = %entry
  %49 = bitcast %TypSg* %8 to %Any*
  %50 = bitcast %TSu* %12 to i8*
  call void @llvm.lifetime.start.p0i8(i64 8, i8* %50)
  %51 = bitcast %TSu* %12 to %swift.opaque*
  %52 = bitcast %Any* %49 to %swift.opaque*
  %53 = call i1 @swift_dynamicCast(%swift.opaque* %51, %swift.opaque* %52, %swift.type* getelementptr inbounds (%swift.full_type, %swift.full_type* @"$sypN", i32 0, i32 1), %swift.type* @"$sSuN", i64 6) #3
  br i1 %53, label %54, label %57

54:                                               ; preds = %48
  %._value4 = getelementptr inbounds %TSu, %TSu* %12, i32 0, i32 0
  %55 = load i64, i64* %._value4, align 8
  %56 = bitcast %TSu* %12 to i8*
  call void @llvm.lifetime.end.p0i8(i64 8, i8* %56)
  br label %59

57:                                               ; preds = %48
  %58 = bitcast %TSu* %12 to i8*
  call void @llvm.lifetime.end.p0i8(i64 8, i8* %58)
  br label %59

59:                                               ; preds = %54, %57
  %60 = phi i64 [ 0, %57 ], [ %55, %54 ]
  %61 = phi i1 [ true, %57 ], [ false, %54 ]
  %62 = bitcast %TypSg* %8 to i8*
  call void @llvm.lifetime.end.p0i8(i64 32, i8* %62)
  br label %63

63:                                               ; preds = %59, %96
  %64 = phi i64 [ 0, %96 ], [ %60, %59 ]
  %65 = phi i1 [ true, %96 ], [ %61, %59 ]
  br i1 %65, label %67, label %66

66:                                               ; preds = %63
  br label %68

67:                                               ; preds = %63
  br label %99

68:                                               ; preds = %66
  %69 = phi i64 [ %64, %66 ]
  store i64 %69, i64* %overrideValue.debug3, align 8
  %70 = bitcast %TSu* %11 to i8*
  call void @llvm.lifetime.start.p0i8(i64 8, i8* %70)
  %._value = getelementptr inbounds %TSu, %TSu* %11, i32 0, i32 0
  store i64 %69, i64* %._value, align 8
  %71 = bitcast %TSq* %20 to %TSq.1*
  %72 = bitcast %TSu* %11 to %swift.opaque*
  %73 = bitcast %TSq.1* %71 to %swift.opaque*
  call swiftcc void @"$sSY8rawValuexSg03RawB0Qz_tcfCTj"(%swift.opaque* noalias nocapture sret(%swift.opaque) %73, %swift.opaque* noalias nocapture %72, %swift.type* swiftself %T, %swift.type* %T, i8** %T.RawRepresentable)
  %74 = bitcast %TSu* %11 to i8*
  call void @llvm.lifetime.end.p0i8(i64 8, i8* %74)
  %75 = bitcast %TSq* %20 to %swift.opaque*
  %76 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 6
  %77 = load i8*, i8** %76, align 8, !invariant.load !18
  %getEnumTagSinglePayload = bitcast i8* %77 to i32 (%swift.opaque*, i32, %swift.type*)*
  %78 = call i32 %getEnumTagSinglePayload(%swift.opaque* noalias %75, i32 1, %swift.type* %T) #6
  %79 = icmp ne i32 %78, 1
  br i1 %79, label %83, label %81

80:                                               ; No predecessors!
  unreachable

81:                                               ; preds = %68
  %82 = call %TSq* @"$sxSgSYRzSu8RawValueRtzlWOh"(%TSq* %20, %swift.type* %T, %swift.type* %14)
  br label %99

83:                                               ; preds = %68
  %84 = bitcast %TSq* %20 to %swift.opaque*
  %85 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 4
  %86 = load i8*, i8** %85, align 8, !invariant.load !18
  %initializeWithTake = bitcast i8* %86 to %swift.opaque* (%swift.opaque*, %swift.opaque*, %swift.type*)*
  %87 = call %swift.opaque* %initializeWithTake(%swift.opaque* noalias %28, %swift.opaque* noalias %84, %swift.type* %T) #3
  %88 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 2
  %89 = load i8*, i8** %88, align 8, !invariant.load !18
  %initializeWithCopy = bitcast i8* %89 to %swift.opaque* (%swift.opaque*, %swift.opaque*, %swift.type*)*
  %90 = call %swift.opaque* %initializeWithCopy(%swift.opaque* noalias %26, %swift.opaque* noalias %28, %swift.type* %T) #3
  %91 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 5
  %92 = load i8*, i8** %91, align 8, !invariant.load !18
  %assignWithTake = bitcast i8* %92 to %swift.opaque* (%swift.opaque*, %swift.opaque*, %swift.type*)*
  %93 = call %swift.opaque* %assignWithTake(%swift.opaque* noalias %3, %swift.opaque* noalias %26, %swift.type* %T) #3
  %94 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 1
  %95 = load i8*, i8** %94, align 8, !invariant.load !18
  %destroy = bitcast i8* %95 to void (%swift.opaque*, %swift.type*)*
  call void %destroy(%swift.opaque* noalias %28, %swift.type* %T) #3
  br label %99

96:                                               ; preds = %entry
  %97 = call %TypSg* @"$sypSgWOh"(%TypSg* %8)
  %98 = bitcast %TypSg* %8 to i8*
  call void @llvm.lifetime.end.p0i8(i64 32, i8* %98)
  br label %63

99:                                               ; preds = %83, %81, %67
  %100 = bitcast %swift.opaque* %28 to i8*
  call void @llvm.lifetime.end.p0i8(i64 -1, i8* %100)
  %101 = bitcast %swift.opaque* %26 to i8*
  call void @llvm.lifetime.end.p0i8(i64 -1, i8* %101)
  %102 = bitcast %TSq* %20 to i8*
  call void @llvm.lifetime.end.p0i8(i64 -1, i8* %102)
  ret void
}

declare swiftcc %swift.metadata_response @"$sSqMa"(i64, %swift.type*) #0

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1

; Function Attrs: argmemonly nofree nounwind willreturn writeonly
declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #2

; Function Attrs: nounwind
declare %swift.bridge* @swift_bridgeObjectRetain(%swift.bridge* returned) #3

declare swiftcc void @"$sSDyq_Sgxcig"(%swift.opaque* noalias nocapture sret(%swift.opaque), %swift.opaque* noalias nocapture, %swift.bridge*, %swift.type*, %swift.type*, i8**) #0

; Function Attrs: noinline nounwind
define linkonce_odr hidden %TSS* @"$sSSWOh"(%TSS* %0) #4 {
entry:
  %._guts = getelementptr inbounds %TSS, %TSS* %0, i32 0, i32 0
  %._guts._object = getelementptr inbounds %Ts11_StringGutsV, %Ts11_StringGutsV* %._guts, i32 0, i32 0
  %._guts._object._object = getelementptr inbounds %Ts13_StringObjectV, %Ts13_StringObjectV* %._guts._object, i32 0, i32 1
  %toDestroy = load %swift.bridge*, %swift.bridge** %._guts._object._object, align 8
  call void @swift_bridgeObjectRelease(%swift.bridge* %toDestroy) #3
  ret %TSS* %0
}

; Function Attrs: nounwind
declare void @swift_bridgeObjectRelease(%swift.bridge*) #3

; Function Attrs: argmemonly nofree nosync nounwind willreturn
declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1

; Function Attrs: noinline nounwind
define linkonce_odr hidden %TypSg* @"$sypSgWOh"(%TypSg* %0) #4 {
entry:
  %1 = bitcast %TypSg* %0 to { i64, i64, i64, i64 }*
  %2 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %1, i32 0, i32 0
  %3 = load i64, i64* %2, align 8
  %4 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %1, i32 0, i32 1
  %5 = load i64, i64* %4, align 8
  %6 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %1, i32 0, i32 2
  %7 = load i64, i64* %6, align 8
  %8 = getelementptr inbounds { i64, i64, i64, i64 }, { i64, i64, i64, i64 }* %1, i32 0, i32 3
  %9 = load i64, i64* %8, align 8
  %10 = icmp eq i64 %9, 0
  br i1 %10, label %14, label %11

11:                                               ; preds = %entry
  %12 = bitcast %TypSg* %0 to %Any*
  %13 = bitcast %Any* %12 to %__opaque_existential_type_0*
  call void @__swift_destroy_boxed_opaque_existential_0(%__opaque_existential_type_0* %13) #3
  br label %14

14:                                               ; preds = %11, %entry
  ret %TypSg* %0
}

; Function Attrs: noinline nounwind
define linkonce_odr hidden void @__swift_destroy_boxed_opaque_existential_0(%__opaque_existential_type_0* %0) #4 {
entry:
  %1 = getelementptr inbounds %__opaque_existential_type_0, %__opaque_existential_type_0* %0, i32 0, i32 1
  %2 = load %swift.type*, %swift.type** %1, align 8
  %3 = getelementptr inbounds %__opaque_existential_type_0, %__opaque_existential_type_0* %0, i32 0, i32 0
  %4 = bitcast %swift.type* %2 to i8***
  %5 = getelementptr inbounds i8**, i8*** %4, i64 -1
  %.valueWitnesses = load i8**, i8*** %5, align 8, !invariant.load !18, !dereferenceable !19
  %6 = bitcast i8** %.valueWitnesses to %swift.vwtable*
  %7 = getelementptr inbounds %swift.vwtable, %swift.vwtable* %6, i32 0, i32 10
  %flags = load i32, i32* %7, align 8, !invariant.load !18
  %8 = and i32 %flags, 131072
  %flags.isInline = icmp eq i32 %8, 0
  br i1 %flags.isInline, label %inline, label %outline

inline:                                           ; preds = %entry
  %9 = bitcast [24 x i8]* %3 to %swift.opaque*
  %10 = bitcast %swift.type* %2 to i8***
  %11 = getelementptr inbounds i8**, i8*** %10, i64 -1
  %.valueWitnesses1 = load i8**, i8*** %11, align 8, !invariant.load !18, !dereferenceable !19
  %12 = getelementptr inbounds i8*, i8** %.valueWitnesses1, i32 1
  %13 = load i8*, i8** %12, align 8, !invariant.load !18
  %destroy = bitcast i8* %13 to void (%swift.opaque*, %swift.type*)*
  call void %destroy(%swift.opaque* noalias %9, %swift.type* %2) #3
  ret void

outline:                                          ; preds = %entry
  %14 = bitcast [24 x i8]* %3 to %swift.refcounted**
  %15 = load %swift.refcounted*, %swift.refcounted** %14, align 8
  call void @swift_release(%swift.refcounted* %15) #3
  ret void
}

; Function Attrs: nounwind
declare void @swift_release(%swift.refcounted*) #3

declare swiftcc void @"$sSY8rawValuexSg03RawB0Qz_tcfCTj"(%swift.opaque* noalias nocapture sret(%swift.opaque), %swift.opaque* noalias nocapture, %swift.type* swiftself, %swift.type*, i8**) #0

; Function Attrs: noinline nounwind
define linkonce_odr hidden %TSq* @"$sxSgSYRzSu8RawValueRtzlWOh"(%TSq* %0, %swift.type* %T, %swift.type* %"Optional<T>") #4 {
entry:
  %T1 = alloca %swift.type*, align 8
  store %swift.type* %T, %swift.type** %T1, align 8
  %1 = bitcast %TSq* %0 to %swift.opaque*
  %2 = bitcast %swift.type* %T to i8***
  %3 = getelementptr inbounds i8**, i8*** %2, i64 -1
  %T.valueWitnesses = load i8**, i8*** %3, align 8, !invariant.load !18, !dereferenceable !19
  %4 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 6
  %5 = load i8*, i8** %4, align 8, !invariant.load !18
  %getEnumTagSinglePayload = bitcast i8* %5 to i32 (%swift.opaque*, i32, %swift.type*)*
  %6 = call i32 %getEnumTagSinglePayload(%swift.opaque* noalias %1, i32 1, %swift.type* %T) #6
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %8, label %12

8:                                                ; preds = %entry
  %9 = bitcast %TSq* %0 to %swift.opaque*
  %10 = getelementptr inbounds i8*, i8** %T.valueWitnesses, i32 1
  %11 = load i8*, i8** %10, align 8, !invariant.load !18
  %destroy = bitcast i8* %11 to void (%swift.opaque*, %swift.type*)*
  call void %destroy(%swift.opaque* noalias %9, %swift.type* %T) #3
  br label %12

12:                                               ; preds = %8, %entry
  ret %TSq* %0
}

; Function Attrs: nounwind
declare zeroext i1 @swift_dynamicCast(%swift.opaque*, %swift.opaque*, %swift.type*, %swift.type*, i64) #3

attributes #0 = { "frame-pointer"="all" "no-trapping-math"="true" "probe-stack"="__chkstk_darwin" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="generic" }
attributes #1 = { argmemonly nofree nosync nounwind willreturn }
attributes #2 = { argmemonly nofree nounwind willreturn writeonly }
attributes #3 = { nounwind }
attributes #4 = { noinline nounwind "frame-pointer"="all" "no-trapping-math"="true" "probe-stack"="__chkstk_darwin" "stack-protector-buffer-size"="8" "target-cpu"="penryn" "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87" "tune-cpu"="generic" }
attributes #5 = { nounwind readnone }
attributes #6 = { nounwind readonly }

!llvm.module.flags = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11}
!swift.module.flags = !{!12}
!llvm.linker.options = !{!13, !14, !15, !16, !17}

!0 = !{i32 2, !"SDK Version", [2 x i32] [i32 13, i32 0]}
!1 = !{i32 1, !"Objective-C Version", i32 2}
!2 = !{i32 1, !"Objective-C Image Info Version", i32 0}
!3 = !{i32 1, !"Objective-C Image Info Section", !"__DATA,__objc_imageinfo,regular,no_dead_strip"}
!4 = !{i32 4, !"Objective-C Garbage Collection", i32 84346624}
!5 = !{i32 1, !"Objective-C Class Properties", i32 64}
!6 = !{i32 1, !"Objective-C Enforce ClassRO Pointer Signing", i8 0}
!7 = !{i32 1, !"wchar_size", i32 4}
!8 = !{i32 7, !"PIC Level", i32 2}
!9 = !{i32 7, !"uwtable", i32 1}
!10 = !{i32 7, !"frame-pointer", i32 2}
!11 = !{i32 1, !"Swift Version", i32 7}
!12 = !{!"standard-library", i1 false}
!13 = !{!"-lswiftSwiftOnoneSupport"}
!14 = !{!"-lswiftCore"}
!15 = !{!"-lswift_Concurrency"}
!16 = !{!"-lswift_StringProcessing"}
!17 = !{!"-lobjc"}
!18 = !{}
!19 = !{i64 88}

[AnthonyLatsis]

Reproduced with Xcode 13.2 toolchain

Was this the original example or the one I provided?

---

I would like to add a regression test and confirm that the shadowing is supported before we close this for good—we don't want this to suddenly reemerge in a future release.

[LeoNatan]

Not sure what I ran before, but this is with your x code:

➜  Desktop swiftc test.swift -emit-ir
Stored value type does not match pointer operand type!
  store i64 %41, i8** %x.debug, align 8
 i8*in function $s4test3foo3src6targetyyp_xztSYRzSu8RawValueRtzlF
<unknown>:0: error: fatal error encountered during compilation; please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project
<unknown>:0: note: Broken function found, compilation aborted!
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the project and the crash backtrace.
Stack dump:
0.	Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend -frontend -emit-ir -primary-file test.swift -target x86_64-apple-macosx12.0 -enable-objc-interop -stack-check -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.1.sdk -color-diagnostics -new-driver-path /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-driver -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift -module-name test -target-sdk-version 12.1.0 -o -
1.	Apple Swift version 5.5.2 (swiftlang-1300.0.47.5 clang-1300.0.29.30)
2.	
3.	Running pass 'Module Verifier' on function '@"$s4test3foo3src6targetyyp_xztSYRzSu8RawValueRtzlF"'
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010b8fdc27 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 39
1  swift-frontend           0x000000010b8fcbb8 llvm::sys::RunSignalHandlers() + 248
2  swift-frontend           0x000000010b8fe236 SignalHandler(int) + 278
3  libsystem_platform.dylib 0x00007ff80790adfd _sigtramp + 29
4  libsystem_platform.dylib 000000000000000000 _sigtramp + 18446603370454012448
5  libsystem_c.dylib        0x00007ff807840d24 abort + 123
6  swift-frontend           0x0000000106a0f502 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*)::$_2::__invoke(void*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, bool) + 978
7  swift-frontend           0x000000010b84769e llvm::report_fatal_error(llvm::Twine const&, bool) + 286
8  swift-frontend           0x000000010b84757b llvm::report_fatal_error(char const*, bool) + 43
9  swift-frontend           0x000000010b7de15f (anonymous namespace)::VerifierLegacyPass::runOnFunction(llvm::Function&) + 111
10 swift-frontend           0x000000010b77836a llvm::FPPassManager::runOnFunction(llvm::Function&) + 1354
11 swift-frontend           0x000000010b777651 llvm::legacy::FunctionPassManagerImpl::run(llvm::Function&) + 113
12 swift-frontend           0x000000010b77eb75 llvm::legacy::FunctionPassManager::run(llvm::Function&) + 341
13 swift-frontend           0x0000000106f04b61 swift::performLLVMOptimizations(swift::IRGenOptions const&, llvm::Module*, llvm::TargetMachine*) + 1585
14 swift-frontend           0x0000000106f059c7 swift::performLLVM(swift::IRGenOptions const&, swift::DiagnosticEngine&, llvm::sys::SmartMutex<false>*, llvm::GlobalVariable*, llvm::Module*, llvm::TargetMachine*, llvm::StringRef, swift::UnifiedStatsReporter*) + 2055
15 swift-frontend           0x0000000106a1aa9d performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> >, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 3581
16 swift-frontend           0x0000000106a0c346 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 13830
17 swift-frontend           0x000000010694cb08 main + 1032
18 dyld                     0x00000001185ec52e start + 462
[1]    49512 abort      swiftc test.swift -emit-ir

test.swift.zip

[AnthonyLatsis]

Great to know we have a reduced reproducer, thanks!

[LeoNatan]

It might be fixed, the compiler doesn’t crash with the Xcode 14 beta toolchain.

[AnthonyLatsis]

It no longer crashes, but the rebinding of x looks a bit fishy; I am unaware that we allow this kind of shadowing.

[LeoNatan]

Well, everywhere else this works as expected. I don’t see why this shadowing wouldn’t be allowed, while shadowing in general is allowed. There is nothing special here.

[AnthonyLatsis]

There are very few occasions where we allow shadowing within the same lexical scope. This could be one of them, except we seem to lack the test coverage.