Instruments Trace Viewer

3. Symbolicate if Needed

When stack traces show addresses instead of function names:

xctrace symbolicate --input recording.trace --dsym /path/to/MyApp.dSYM

dSYM locations: ~/Library/Developer/Xcode/Archives/, DerivedData/<project>/Build/Products/

Essential Commands

TOC Structure

<trace-toc>
  <run number="1">
    <data>
      <table schema="time-sample" />
      <table schema="allocation" />
    </data>
    <processes>
      <process name="MyApp" pid="12345">
        <binary name="MyApp" UUID="..." />
      </process>
    </processes>
  </run>
</trace-toc>

XPath Patterns

# All data from a table
--xpath '/trace-toc/run[@number="1"]/data/table[@schema="<schema>"]'

# Process binaries
--xpath '/trace-toc/run[@number="1"]/processes/process[@name="MyApp"]/binary'

# All runs
--xpath '/trace-toc/run/data/table[@schema="time-sample"]'

Template-Specific References

Consult these for detailed XPath patterns and output interpretation:

• Time Profiler: references/time-profiler.md
• Allocations: references/allocations.md
• Leaks: references/leaks.md
• SwiftUI: references/swiftui.md
• App Launch: references/app-launch.md
• Network: references/network.md
• File Activity: references/file-activity.md
• Metal System Trace: references/metal-system-trace.md
• CPU Counters: references/cpu-counters.md
• Signposts & Points of Interest: references/signposts-poi.md

Troubleshooting

• Empty output: Schema may not exist—export TOC first to verify available schemas
• Unsymbolicated after symbolication: Verify dSYM UUID matches binary UUID with dwarfdump --uuid MyApp.dSYM
• XPath returns nothing: Check run number exists and schema name is case-sensitive exact match