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[Backtracing] Fix out-of-process async backtraces. #64178

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Merged
merged 2 commits into from
Mar 9, 2023
Merged

[Backtracing] Fix out-of-process async backtraces. #64178

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43375e7
[Backtracing] Fix out-of-process async backtraces.
al45tair Mar 7, 2023
9061d4e
[Backtracing][Tests] Don't demangle in CrashAsync.
al45tair Mar 8, 2023
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11 changes: 10 additions & 1 deletion stdlib/public/Backtracing/BacktraceFormatter.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -654,7 +654,16 @@ public struct BacktraceFormatter {
// sourceLocation.column is an index in UTF-8 code units in
// `untabified`. We should point at the grapheme cluster that
// contains that UTF-8 index.
let adjustedColumn = max(sourceLocation.column, 1)
let adjustedColumn: Int
if sourceLocation.column > 0 {
adjustedColumn = sourceLocation.column
} else {
if let ndx = code.firstIndex(where: { $0 != " " }) {
adjustedColumn = code.distance(from: code.startIndex, to: ndx) + 1
} else {
adjustedColumn = 1
}
}
let utf8Ndx
= untabified.utf8.index(untabified.utf8.startIndex,
offsetBy: adjustedColumn,
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6 changes: 1 addition & 5 deletions stdlib/public/Backtracing/FramePointerUnwinder.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -16,10 +16,6 @@

import Swift

// @available(SwiftStdlib 5.1, *)
@_silgen_name("swift_task_getCurrent")
func _getCurrentAsyncTask() -> UnsafeRawPointer?

@_spi(Unwinders)
public struct FramePointerUnwinder<C: Context, M: MemoryReader>: Sequence, IteratorProtocol {
public typealias Context = C
Expand Down Expand Up @@ -47,7 +43,7 @@ public struct FramePointerUnwinder<C: Context, M: MemoryReader>: Sequence, Itera
#if (os(macOS) || os(iOS) || os(watchOS)) && (arch(arm64) || arch(arm64_32) || arch(x86_64))
// On Darwin, we borrow a bit of the frame pointer to indicate async
// stack frames
return (storedFp & (1 << 60)) != 0 && _getCurrentAsyncTask() != nil
return (storedFp & (1 << 60)) != 0
#else
return false
#endif
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12 changes: 9 additions & 3 deletions stdlib/public/Backtracing/SymbolicatedBacktrace.swift
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Expand Up @@ -148,11 +148,17 @@ public struct SymbolicatedBacktrace: CustomStringConvertible {
if rawName == "start" && imageName == "dyld" {
return true
}
if let location = sourceLocation,
location.line == 0 && location.column == 0 {
if rawName.hasSuffix("5$mainyyFZ")
|| rawName.hasSuffix("5$mainyyYaFZTQ0_")
|| rawName == "_async_MainTQ0_" {
return true
}
if rawName == "__ZL23completeTaskWithClosurePN5swift12AsyncContextEPNS_10SwiftErrorE" && imageName == "libswift_Concurrency.dylib" {
return true
}
if rawName.hasSuffix("5$mainyyFZ") {
if let location = sourceLocation,
location.line == 0 && location.column == 0
&& !_swift_isThunkFunction(rawName) {
return true
}
#endif
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99 changes: 99 additions & 0 deletions test/Backtracing/CrashAsync.swift
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@@ -0,0 +1,99 @@
// RUN: %empty-directory(%t)
// RUN: %target-build-swift %s -parse-as-library -Onone -g -o %t/CrashAsync
// RUN: %target-codesign %t/CrashAsync

// Demangling is disabled for now because older macOS can't demangle async
// function names. We test demangling elsewhere, so this is no big deal.

// RUN: (env SWIFT_BACKTRACE=enable=yes,demangle=no,cache=no %target-run %t/CrashAsync || true) | %FileCheck %s
// RUN: (env SWIFT_BACKTRACE=preset=friendly,enable=yes,demangle=no,cache=no %target-run %t/CrashAsync || true) | %FileCheck %s --check-prefix FRIENDLY

// UNSUPPORTED: use_os_stdlib
// UNSUPPORTED: back_deployment_runtime
// REQUIRES: executable_test
// REQUIRES: backtracing
// REQUIRES: OS=macosx

@available(SwiftStdlib 5.1, *)
func crash() {
let ptr = UnsafeMutablePointer<Int>(bitPattern: 4)!
ptr.pointee = 42
}

@available(SwiftStdlib 5.1, *)
func level(_ n: Int) async {
if n < 5 {
await level(n + 1)
} else {
crash()
}
}

@available(SwiftStdlib 5.1, *)
@main
struct CrashAsync {
static func main() async {
await level(1)
}
}

// CHECK: *** Program crashed: Bad pointer dereference at 0x{{0+}}4 ***

// CHECK: Thread {{[0-9]+}} crashed:

// CHECK: 0 0x{{[0-9a-f]+}} _$s10CrashAsync5crashyyF + {{[0-9]+}} in CrashAsync at {{.*}}/CrashAsync.swift:20:15
// CHECK-NEXT: 1 [ra] 0x{{[0-9a-f]+}} _$s10CrashAsync5levelyySiYaFTY0_ + {{[0-9]+}} in CrashAsync at {{.*}}/CrashAsync.swift:28:5
// CHECK-NEXT: 2 [async] 0x{{[0-9a-f]+}} _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}/CrashAsync.swift:26
// CHECK-NEXT: 3 [async] 0x{{[0-9a-f]+}} _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}/CrashAsync.swift:26
// CHECK-NEXT: 4 [async] 0x{{[0-9a-f]+}} _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}/CrashAsync.swift:26
// CHECK-NEXT: 5 [async] 0x{{[0-9a-f]+}} _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}/CrashAsync.swift:26
// CHECK-NEXT: 6 [async] 0x{{[0-9a-f]+}} _$s10CrashAsyncAAV4mainyyYaFZTQ0_ in CrashAsync at {{.*}}/CrashAsync.swift:36
// CHECK-NEXT: 7 [async] [system] 0x{{[0-9a-f]+}} _$s10CrashAsyncAAV5$mainyyYaFZTQ0_ in CrashAsync at {{.*}}/<compiler-generated>
// CHECK-NEXT: 8 [async] [system] 0x{{[0-9a-f]+}} _async_MainTQ0_ in CrashAsync at {{.*}}/<compiler-generated>
// CHECK-NEXT: 9 [async] [thunk] 0x{{[0-9a-f]+}} _$sIetH_yts5Error_pIegHrzo_TRTQ0_ in CrashAsync at {{.*}}/<compiler-generated>
// CHECK-NEXT: 10 [async] [thunk] 0x{{[0-9a-f]+}} _$sIetH_yts5Error_pIegHrzo_TRTATQ0_ in CrashAsync at {{.*}}/<compiler-generated>
// CHECK-NEXT: 11 [async] [system] 0x{{[0-9a-f]+}} __ZL23completeTaskWithClosurePN5swift12AsyncContextEPNS_10SwiftErrorE in libswift_Concurrency.dylib at {{.*}}/Task.cpp:463

// FRIENDLY: *** Program crashed: Bad pointer dereference at 0x{{0+}}4 ***

// FRIENDLY: Thread {{[0-9]+}} crashed:

// FRIENDLY: 0 _$s10CrashAsync5crashyyF + {{[0-9]+}} in CrashAsync at {{.*}}CrashAsync.swift:20:15

// FRIENDLY: 18| func crash() {
// FRIENDLY-NEXT: 19| let ptr = UnsafeMutablePointer<Int>(bitPattern: 4)!
// FRIENDLY-NEXT: * 20| ptr.pointee = 42
// FRIENDLY-NEXT: | ^
// FRIENDLY-NEXT: 21| }
// FRIENDLY-NEXT: 22|

// FRIENDLY: 1 _$s10CrashAsync5levelyySiYaFTY0_ + {{[0-9]+}} in CrashAsync at {{.*}}CrashAsync.swift:28:5

// FRIENDLY: 26| await level(n + 1)
// FRIENDLY-NEXT: 27| } else {
// FRIENDLY-NEXT: * 28| crash()
// FRIENDLY-NEXT: | ^
// FRIENDLY-NEXT: 29| }
// FRIENDLY-NEXT: 30| }

// FRIENDLY:2 _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}CrashAsync.swift:26

// FRIENDLY: 24| func level(_ n: Int) async {
// FRIENDLY-NEXT: 25| if n < 5 {
// FRIENDLY-NEXT: * 26| await level(n + 1)
// FRIENDLY-NEXT: | ^
// FRIENDLY-NEXT: 27| } else {
// FRIENDLY-NEXT: 28| crash()

// FRIENDLY: 3 _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}CrashAsync.swift:26
// FRIENDLY: 4 _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}CrashAsync.swift:26
// FRIENDLY: 5 _$s10CrashAsync5levelyySiYaFTQ1_ in CrashAsync at {{.*}}CrashAsync.swift:26
// FRIENDLY: 6 _$s10CrashAsyncAAV4mainyyYaFZTQ0_ in CrashAsync at {{.*}}CrashAsync.swift:36

// FRIENDLY: 34| struct CrashAsync {
// FRIENDLY-NEXT: 35| static func main() async {
// FRIENDLY-NEXT: * 36| await level(1)
// FRIENDLY-NEXT: | ^
// FRIENDLY-NEXT: 37| }
// FRIENDLY-NEXT: 38| }

10 changes: 5 additions & 5 deletions test/Backtracing/CrashWithThunk.swift
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Expand Up @@ -33,11 +33,11 @@ struct CrashWithThunk {

// CHECK: Thread 0 crashed:

// CHECK: 0 0x{{[0-9a-f]+}} crash() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:20:15
// CHECK-NEXT: 1 [ra] [thunk] [system] 0x{{[0-9a-f]+}} thunk for @escaping @callee_guaranteed () -> () + {{[0-9]+}} in CrashWithThunk at {{.*}}/Backtracing/<compiler-generated>
// CHECK-NEXT: 2 [ra] 0x{{[0-9a-f]+}} static CrashWithThunk.main() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:28:9
// CHECK-NEXT: 3 [ra] [system] 0x{{[0-9a-f]+}} static CrashWithThunk.$main() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:23:1
// CHECK-NEXT: 4 [ra] [system] 0x{{[0-9a-f]+}} main + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift
// CHECK: 0 0x{{[0-9a-f]+}} crash() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:20:15
// CHECK-NEXT: 1 [ra] [thunk] 0x{{[0-9a-f]+}} thunk for @escaping @callee_guaranteed () -> () + {{[0-9]+}} in CrashWithThunk at {{.*}}/Backtracing/<compiler-generated>
// CHECK-NEXT: 2 [ra] 0x{{[0-9a-f]+}} static CrashWithThunk.main() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:28:9
// CHECK-NEXT: 3 [ra] [system] 0x{{[0-9a-f]+}} static CrashWithThunk.$main() + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift:23:1
// CHECK-NEXT: 4 [ra] [system] 0x{{[0-9a-f]+}} main + {{[0-9]+}} in CrashWithThunk at {{.*}}/CrashWithThunk.swift

// CHECK: Registers:

Expand Down