Files
swift-mirror/stdlib/public/RuntimeModule/PDBCache.swift
Alastair Houghton acdaeef626 [Backtracing][PDB] Add PDB code and SymbolLocator.
Added the PDB reading code and also a `SymbolLocator` type that
allows us to locate symbols for a given image.

rdar://168454023
2026-02-17 10:50:55 +00:00

99 lines
2.7 KiB
Swift

//===--- PDBCache.swift - PDB support for Swift ---------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2024 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Provides a per-thread PDB cache that improves efficiency when taking
// multiple backtraces by avoiding loading PDBs multiple times.
//
//===----------------------------------------------------------------------===//
import Swift
#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
internal import Darwin
#elseif os(Windows)
internal import WinSDK
#elseif canImport(Glibc)
internal import Glibc
#elseif canImport(Musl)
internal import Musl
#endif
/// Provides a per-thread image cache for PDB processing. This means
/// if you take multiple backtraces from a thread, you won't load the same
/// image multiple times.
final class PDBCache {
var cache: [String: PDBFile] = [:]
func purge() {
cache = [:]
}
func lookup(path: String?) -> PDBFile? {
guard let path = path else {
return nil
}
if let image = cache[path] {
return image
}
if let image = PDBFile(path: path) {
cache[path] = image
return image
}
return nil
}
#if os(Windows)
private static var dwTlsIndex: DWORD = {
let dwNdx = TlsAlloc()
if dwNdx == TLS_OUT_OF_INDEXES {
fatalError("Unable to allocate TSD for PDBCache")
}
return dwNdx
}()
#else
private static var key: pthread_key_t = {
var theKey = pthread_key_t()
let err = pthread_key_create(
&theKey,
{ rawPtr in
let ptr = Unmanaged<PDBCache>.fromOpaque(
notMutable(notOptional(rawPtr))
)
ptr.release()
}
)
if err != 0 {
fatalError("Unable to create TSD key for PDBCache")
}
return theKey
}()
#endif
static var threadLocal: PDBCache {
#if os(Windows)
guard let rawPtr = TlsGetValue(dwTlsIndex) else {
let cache = Unmanaged<PDBCache>.passRetained(PDBCache())
TlsSetValue(dwTlsIndex, cache.toOpaque())
return cache.takeUnretainedValue()
}
#else
guard let rawPtr = pthread_getspecific(key) else {
let cache = Unmanaged<PDBCache>.passRetained(PDBCache())
pthread_setspecific(key, cache.toOpaque())
return cache.takeUnretainedValue()
}
#endif
let cache = Unmanaged<PDBCache>.fromOpaque(rawPtr)
return cache.takeUnretainedValue()
}
}