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[swift-inspect] Add json and summary options to DumpRawMetadata #81186

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Merged
merged 1 commit into from
May 9, 2025
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[swift-inspect] Add json and summary options to DumpRawMetadata #81186

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49 changes: 26 additions & 23 deletions tools/swift-inspect/Sources/swift-inspect/Operations/DumpGenericMetadata.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,18 @@ internal struct Output: TextOutputStream {
}
}

internal func dumpJson(of: (any Encodable), outputFile: String?) throws {
let encoder = JSONEncoder()
encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
let data = try encoder.encode(of)
let jsonOutput = String(data: data, encoding: .utf8)!
if let outputFile = outputFile {
try jsonOutput.write(toFile: outputFile, atomically: true, encoding: .utf8)
} else {
print(jsonOutput)
}
}

internal struct DumpGenericMetadata: ParsableCommand {
static let configuration = CommandConfiguration(
abstract: "Print the target's generic metadata allocations.")
Expand All @@ -99,7 +111,10 @@ internal struct DumpGenericMetadata: ParsableCommand {
var backtraceOptions: BacktraceOptions

@OptionGroup()
var genericMetadataOptions: GenericMetadataOptions
var metadataOptions: MetadataOptions

@Flag(help: "Show allocations in mangled form")
var mangled: Bool = false
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Why has this moved from the metadataOptions group?

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MetadataOptions was previously GenericMetadataOptions and only provided options for swift-inspect --dump-generic-metadata. This PR is proposing that three of the four options from GenericMetadataOptions (json, summary', and outputFile) be added to swift-inspect --dump-raw-metadata. Rather than manually type these options out in [DumpRawMetadata.swift](https://github.com/swiftlang/swift/pull/81186/files#diff-bbb7ba64f4c92e0e341aa925f49f73da14ed9d4aeb92ea4f2e8c50f7c10cc129), I opted to share this set of ParsableArguments`, hence the name change.

However, this PR does not implement the pre-existing mangled option in --dump-raw-metadata. Which is why I chose to remove it from this now more generally used GenericMetadataOptions.


func run() throws {
disableStdErrBuffer()
Expand All @@ -126,7 +141,7 @@ internal struct DumpGenericMetadata: ParsableCommand {

return Metadata(ptr: pointer,
allocation: allocation,
name: process.context.name(type: pointer, mangled: genericMetadataOptions.mangled) ?? "<unknown>",
name: process.context.name(type: pointer, mangled: mangled) ?? "<unknown>",
isArrayOfClass: process.context.isArrayOfClass(pointer),
garbage: garbage,
backtrace: currentBacktrace)
Expand All @@ -146,30 +161,30 @@ internal struct DumpGenericMetadata: ParsableCommand {
}
}

if genericMetadataOptions.json {
if metadataOptions.json {
let processMetadata = ProcessMetadata(name: process.processName,
pid: process.processIdentifier as! ProcessIdentifier,
metadata: generics)
allProcesses.append(processMetadata)
} else if !genericMetadataOptions.summary {
} else if !metadataOptions.summary {
try dumpText(process: process, generics: generics)
}
} // inspect

if genericMetadataOptions.json {
if genericMetadataOptions.summary {
try dumpJson(of: metadataSummary)
if metadataOptions.json {
if metadataOptions.summary {
try dumpJson(of: metadataSummary, outputFile: metadataOptions.outputFile)
} else {
try dumpJson(of: allProcesses)
try dumpJson(of: allProcesses, outputFile: metadataOptions.outputFile)
}
} else if genericMetadataOptions.summary {
} else if metadataOptions.summary {
try dumpTextSummary(of: metadataSummary)
}
}

private func dumpText(process: any RemoteProcess, generics: [Metadata]) throws {
var erroneousMetadata: [(ptr: swift_reflection_ptr_t, name: String)] = []
var output = try Output(genericMetadataOptions.outputFile)
var output = try Output(metadataOptions.outputFile)
print("\(process.processName)(\(process.processIdentifier)):\n", to: &output)
print("Address", "Allocation", "Size", "Offset", "isArrayOfClass", "Name", separator: "\t", to: &output)
generics.forEach {
Expand Down Expand Up @@ -198,20 +213,8 @@ internal struct DumpGenericMetadata: ParsableCommand {
print("", to: &output)
}

private func dumpJson(of: (any Encodable)) throws {
let encoder = JSONEncoder()
encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
let data = try encoder.encode(of)
let jsonOutput = String(data: data, encoding: .utf8)!
if let outputFile = genericMetadataOptions.outputFile {
try jsonOutput.write(toFile: outputFile, atomically: true, encoding: .utf8)
} else {
print(jsonOutput)
}
}

private func dumpTextSummary(of: [String: MetadataSummary]) throws {
var output = try Output(genericMetadataOptions.outputFile)
var output = try Output(metadataOptions.outputFile)
print("Size", "Owners", "Name", separator: "\t", to: &output)
var totalSize = 0
var unknownSize = 0
Expand Down
58 changes: 58 additions & 0 deletions tools/swift-inspect/Sources/swift-inspect/Operations/DumpRawMetadata.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,23 @@

import ArgumentParser
import SwiftRemoteMirror
import Foundation

private struct AllocatorTagTotal: Encodable {
let name: String
let tag: Int
var totalBytes: Int
}

private struct Summary: Encodable {
let totalBytesAllocated: Int
let allocatorTags: [AllocatorTagTotal]
}

private struct RawMetadataOutput: Encodable {
let allocationList: [swift_metadata_allocation_t]?
let summary: Summary?
}

internal struct DumpRawMetadata: ParsableCommand {
static let configuration = CommandConfiguration(
Expand All @@ -22,8 +39,15 @@ internal struct DumpRawMetadata: ParsableCommand {

@OptionGroup()
var backtraceOptions: BacktraceOptions

@OptionGroup()
var metadataOptions: MetadataOptions

func run() throws {
var allocatorTagTotals = [Int: AllocatorTagTotal]()
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Let's drop AllocatorTagTotal, as we really only need the number of bytes allocated. We can get the name later by calling name(allocation:) in the summary output loop (it's cheap) and the the tag is already in the dictionary key. And a minor style thing, it's a bit nicer to initialize this with the empty dictionary literal like var allocatorTagTotals: [Int: Int] = [:], like allocationList's declaration just below.

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@jabrylg jabrylg May 1, 2025 •
edited
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Ah realized we can't easily get name(allocation:) outside of the closure because we need process.context to call it. Also can't throw the summary into the closure because it would break --all.

var total: Int = 0
var allocationList: [swift_metadata_allocation_t] = []

try inspect(options: options) { process in
let stacks: [swift_reflection_ptr_t:[swift_reflection_ptr_t]]? =
backtraceOptions.style == nil
Expand All @@ -33,6 +57,18 @@ internal struct DumpRawMetadata: ParsableCommand {
try process.context.allocations.forEach { allocation in
let name: String = process.context.name(allocation: allocation.tag) ?? "<unknown>"
print("Metadata allocation at: \(hex: allocation.ptr) size: \(allocation.size) tag: \(allocation.tag) (\(name))")

if metadataOptions.summary {
if var allocatorTagTotal = allocatorTagTotals[Int(allocation.tag)] {
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There's a fun shorthand way to write this. Assuming this dictionary is now typed [swift_metadata_allocation_tag_t: Int] like I mentioned above, you can do this add-or-insert thing in a single line:

allocatorTagTotals[allocation.tag, default: 0] += allocation.size

allocatorTagTotal.totalBytes += allocation.size
allocatorTagTotals[Int(allocation.tag)] = allocatorTagTotal
} else {
allocatorTagTotals[Int(allocation.tag)] = AllocatorTagTotal(name: name, tag: Int(allocation.tag), totalBytes: allocation.size)
}

total += allocation.size
}
allocationList.append(allocation)
if let style = backtraceOptions.style {
if let stack = stacks?[allocation.ptr] {
print(backtrace(stack, style: style, process.symbolicate))
Expand All @@ -42,5 +78,27 @@ internal struct DumpRawMetadata: ParsableCommand {
}
}
}

if metadataOptions.json {
let jsonStruct: RawMetadataOutput
let allocatorTagArray = Array(allocatorTagTotals.values).sorted(by: {$0.totalBytes > $1.totalBytes})
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If you change the dictionary as suggested above, then you can grab the keys and values together and sort them like:

let tagSizes = allocatorTagTotals.sorted(by: { $0.1 > $1.1 })

Then you can iterate like:

for (tag, size) in tagSizes {


if metadataOptions.summary {
let summaryStruct = Summary(totalBytesAllocated: total, allocatorTags: allocatorTagArray)
jsonStruct = RawMetadataOutput(allocationList: allocationList, summary: summaryStruct)
} else {
jsonStruct = RawMetadataOutput(allocationList: allocationList, summary: nil)
}
try dumpJson(of: jsonStruct, outputFile: metadataOptions.outputFile)
} else if metadataOptions.summary {
let allocatorTagArray = Array(allocatorTagTotals.values).sorted(by: {$0.totalBytes > $1.totalBytes})

print("Metadata allocation summary:")
for tag in allocatorTagArray {
print("Tag: \(tag.tag) (\(tag.name)) Size: \(tag.totalBytes) bytes")
}

print("\nTotal bytes allocated: \(total)")
}
}
}
5 changes: 1 addition & 4 deletions tools/swift-inspect/Sources/swift-inspect/main.swift
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Expand Up @@ -62,10 +62,7 @@ internal struct BacktraceOptions: ParsableArguments {
}
}

internal struct GenericMetadataOptions: ParsableArguments {
@Flag(help: "Show allocations in mangled form")
var mangled: Bool = false

internal struct MetadataOptions: ParsableArguments {
@Flag(help: "Output JSON")
var json: Bool = false

Expand Down