Don't set parent on non-transient symbols in mergeSymbolTable #61560

jakebailey · 2025-04-09T20:38:36Z

This is functionally equivalent to the change made in microsoft/typescript-go#775; this line is stomping on real binder-created AST symbols, which is bad.

jakebailey · 2025-04-09T20:39:23Z

@typescript-bot test it

typescript-bot · 2025-04-09T20:39:28Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`test top400`	✅ Started	✅ Results
`user test this`	✅ Started	✅ Results
`run dt`	✅ Started	✅ Results
`perf test this faster`	✅ Started	👀 Results

typescript-bot · 2025-04-09T21:03:39Z

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

typescript-bot · 2025-04-09T21:12:09Z

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61560/merge:

Everything looks good!

typescript-bot · 2025-04-09T21:27:15Z

@jakebailey
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

_Metric	_baseline	_pr	_Delta	_Best	_Worst	_p-value
_{Compiler-Unions - node (v18.15.0, x64)}
_Errors	₃₄	₃₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,390	_62,390	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,395	_50,395	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{194,137k (± 0.97%)}	_{193,691k (± 0.78%)}	_~	_192,906k	_196,758k	_{p=0.748 n=6}
_{Parse Time}	_{1.30s (± 0.84%)}	_{1.31s (± 0.57%)}	_~	_1.30s	_1.32s	_{p=0.227 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.74s (± 0.44%)}	_{9.74s (± 0.39%)}	_~	_9.69s	_9.80s	_{p=0.936 n=6}
_{Emit Time}	_{2.73s (± 0.30%)}	_{2.73s (± 1.01%)}	_~	_2.70s	_2.77s	_{p=0.805 n=6}
_{Total Time}	_{14.51s (± 0.37%)}	_{14.51s (± 0.38%)}	_~	_14.42s	_14.59s	_{p=0.747 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅₆	₅₆	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_948,670	_948,670	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,947	_410,947	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,224,316k (± 0.00%)}	_{1,224,260k (± 0.00%)}	_~	_1,224,232k	_1,224,317k	_{p=0.092 n=6}
_{Parse Time}	_{6.64s (± 0.81%)}	_{6.66s (± 0.47%)}	_~	_6.60s	_6.68s	_{p=0.142 n=6}
_{Bind Time}	_{1.89s (± 0.62%)}	_{1.88s (± 0.62%)}	_~	_1.86s	_1.89s	_{p=0.187 n=6}
_{Check Time}	_{31.97s (± 0.22%)}	_{31.96s (± 0.37%)}	_~	_31.83s	_32.14s	_{p=0.810 n=6}
_{Emit Time}	_{15.28s (± 0.53%)}	_{15.25s (± 0.59%)}	_~	_15.14s	_15.36s	_{p=0.629 n=6}
_{Total Time}	_{55.78s (± 0.09%)}	_{55.75s (± 0.27%)}	_~	_55.55s	_55.96s	_{p=0.810 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,462,748	_2,462,748	_~	_~	_~	_{p=1.000 n=6}
_Types	_893,580	_893,580	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,312,764k (± 0.00%)}	_{2,312,703k (± 0.00%)}	_~	_2,312,595k	_2,312,774k	_{p=0.261 n=6}
_{Parse Time}	_{9.10s (± 0.20%)}	_{9.09s (± 0.20%)}	_~	_9.08s	_9.12s	_{p=0.243 n=6}
_{Bind Time}	_{2.29s (± 0.53%)}	_{2.29s (± 0.64%)}	_~	_2.27s	_2.30s	_{p=0.867 n=6}
_{Check Time}	_{75.67s (± 0.48%)}	_{75.79s (± 0.50%)}	_~	_75.32s	_76.30s	_{p=0.810 n=6}
_{Emit Time}	_{0.29s (± 1.41%)}	_0.29s	_~	_~	_~	_{p=0.405 n=6}
_{Total Time}	_{87.36s (± 0.42%)}	_{87.46s (± 0.44%)}	_~	_86.96s	_87.99s	_{p=0.810 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,226,719	_1,226,719	_~	_~	_~	_{p=1.000 n=6}
_Types	_266,996	_266,996	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,967,290k (±10.02%)}	_{2,846,187k (±13.21%)}	_~	_2,359,958k	_3,089,705k	_{p=1.000 n=6}
_{Parse Time}	_{6.72s (± 1.33%)}	_{6.66s (± 1.60%)}	_~	_6.52s	_6.78s	_{p=0.230 n=6}
_{Bind Time}	_{2.15s (± 2.59%)}	_{2.16s (± 0.94%)}	_~	_2.13s	_2.19s	_{p=0.748 n=6}
_{Check Time}	_{42.80s (± 0.23%)}	_{42.77s (± 0.38%)}	_~	_42.54s	_43.00s	_{p=1.000 n=6}
_{Emit Time}	_{3.48s (± 2.87%)}	_{3.39s (± 2.18%)}	_~	_3.32s	_3.51s	_{p=0.128 n=6}
_{Total Time}	_{55.15s (± 0.18%)}	_{55.00s (± 0.38%)}	_~	_54.75s	_55.37s	_{p=0.128 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,226,719	_1,226,719	_~	_~	_~	_{p=1.000 n=6}
_Types	_266,996	_266,996	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,424,447k (± 0.01%)}	_{2,424,343k (± 0.02%)}	_~	_2,424,004k	_2,424,842k	_{p=0.810 n=6}
_{Parse Time}	_{5.47s (± 0.48%)}	_{5.49s (± 0.45%)}	_~	_5.45s	_5.51s	_{p=0.335 n=6}
_{Bind Time}	_{1.78s (± 1.15%)}	_{1.80s (± 1.26%)}	_~	_1.77s	_1.82s	_{p=0.252 n=6}
_{Check Time}	_{35.35s (± 0.23%)}	_{35.35s (± 0.22%)}	_~	_35.26s	_35.47s	_{p=0.936 n=6}
_{Emit Time}	_{3.06s (± 1.22%)}	_{3.06s (± 1.16%)}	_~	_3.01s	_3.09s	_{p=1.000 n=6}
_{Total Time}	_{45.69s (± 0.17%)}	_{45.72s (± 0.17%)}	_~	_45.60s	_45.80s	_{p=0.748 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,674	_262,674	_~	_~	_~	_{p=1.000 n=6}
_Types	_106,849	_106,849	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{440,427k (± 0.02%)}	_{440,445k (± 0.02%)}	_~	_440,324k	_440,508k	_{p=0.630 n=6}
_{Parse Time}	_{3.53s (± 1.27%)}	_{3.53s (± 0.86%)}	_~	_3.49s	_3.58s	_{p=0.935 n=6}
_{Bind Time}	_{1.31s (± 1.08%)}	_{1.32s (± 0.91%)}	_~	_1.31s	_1.34s	_{p=0.139 n=6}
_{Check Time}	_{18.98s (± 0.55%)}	_{18.95s (± 0.45%)}	_~	_18.80s	_19.01s	_{p=0.872 n=6}
_{Emit Time}	_{1.51s (± 0.68%)}	_{1.52s (± 1.25%)}	_~	_1.49s	_1.55s	_{p=0.094 n=6}
_{Total Time}	_{25.32s (± 0.46%)}	_{25.32s (± 0.44%)}	_~	_25.15s	_25.41s	_{p=0.936 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₁	₇₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,981	_225,981	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,356	_94,356	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,236k (± 0.04%)}	_{371,221k (± 0.02%)}	_~	_371,125k	_371,333k	_{p=0.575 n=6}
_{Parse Time}	_{2.88s (± 0.56%)}	_{2.91s (± 0.73%)}	_{+0.03s (+ 1.04%)}	_2.88s	_2.94s	_{p=0.034 n=6}
_{Bind Time}	_{1.59s (± 0.65%)}	_{1.61s (± 1.41%)}	_~	_1.58s	_1.64s	_{p=0.217 n=6}
_{Check Time}	_{16.52s (± 0.39%)}	_{16.53s (± 0.30%)}	_~	_16.48s	_16.62s	_{p=0.936 n=6}
_{Emit Time}	_{0.00s (±244.70%)}	_0.00s	_~	_~	_~	_{p=0.405 n=6}
_{Total Time}	_{21.00s (± 0.37%)}	_{21.05s (± 0.30%)}	_~	_20.98s	_21.15s	_{p=0.170 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₄	₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,344,528	_3,344,528	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,133,660	_1,133,660	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,404,018k (± 0.01%)}	_{3,403,860k (± 0.00%)}	_~	_3,403,629k	_3,404,141k	_{p=0.128 n=6}
_{Parse Time}	_{14.72s (± 0.62%)}	_{14.73s (± 0.33%)}	_~	_14.67s	_14.79s	_{p=0.936 n=6}
_{Bind Time}	_{4.69s (± 0.60%)}	_{4.74s (± 2.01%)}	_~	_4.68s	_4.93s	_{p=0.294 n=6}
_{Check Time}	_{92.41s (± 1.52%)}	_{91.20s (± 0.45%)}	_~	_90.52s	_91.67s	_{p=0.054 n=6}
_{Emit Time}	_{29.61s (± 1.68%)}	_{29.75s (± 2.23%)}	_~	_29.32s	_31.04s	_{p=0.936 n=6}
_{Total Time}	_{141.43s (± 0.87%)}	_{140.40s (± 0.42%)}	_~	_139.85s	_141.22s	_{p=0.093 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₂	₂	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_312,525	_312,525	_~	_~	_~	_{p=1.000 n=6}
_Types	_137,826	_137,826	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{467,643k (± 0.02%)}	_{467,593k (± 0.03%)}	_~	_467,436k	_467,760k	_{p=0.378 n=6}
_{Parse Time}	_{5.14s (± 1.15%)}	_{5.12s (± 1.13%)}	_~	_5.07s	_5.23s	_{p=0.683 n=6}
_{Bind Time}	_{2.27s (± 0.72%)}	_{2.25s (± 1.42%)}	_~	_2.21s	_2.30s	_{p=0.126 n=6}
_{Check Time}	_{25.59s (± 0.20%)}	_{25.51s (± 0.21%)}	_{-0.08s (- 0.32%)}	_25.44s	_25.58s	_{p=0.030 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{33.01s (± 0.28%)}	_{32.89s (± 0.27%)}	_~	_32.78s	_33.00s	_{p=0.066 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_568,548	_568,548	_~	_~	_~	_{p=1.000 n=6}
_Types	_190,459	_190,459	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{498,525k (± 0.01%)}	_{498,465k (± 0.01%)}	_~	_498,414k	_498,558k	_{p=0.093 n=6}
_{Parse Time}	_{3.37s (± 0.83%)}	_{3.36s (± 0.83%)}	_~	_3.31s	_3.38s	_{p=0.936 n=6}
_{Bind Time}	_{1.20s (± 0.86%)}	_{1.21s (± 1.10%)}	_~	_1.19s	_1.23s	_{p=0.506 n=6}
_{Check Time}	_{20.00s (± 0.35%)}	_{20.03s (± 0.31%)}	_~	_19.97s	_20.11s	_{p=0.296 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.57s (± 0.32%)}	_{24.60s (± 0.30%)}	_~	_24.49s	_24.70s	_{p=0.470 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Compiler-Unions - node (v18.15.0, x64)
angular-1 - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-build-src-public-api - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
ts-pre-modules - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate-main - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

typescript-bot · 2025-04-09T22:11:40Z

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61560/merge:

Everything looks good!

Copilot

Pull Request Overview

This PR fixes an issue where mergeSymbolTable was incorrectly setting the parent property on non-transient symbols, which overwrites proper binder-created AST symbols. The change adds a guard to only set the parent on transient symbols.

Copilot · 2025-09-11T00:11:51Z

src/compiler/checker.ts

+                if (merged.flags & SymbolFlags.Transient) {
+                    merged.parent = mergedParent;
+                }


The condition should use bitwise AND with proper parentheses for clarity. Consider writing if ((merged.flags & SymbolFlags.Transient) !== 0) to make the intent more explicit that you're checking for the presence of the flag.

Suggested change

if (merged.flags & SymbolFlags.Transient) {

merged.parent = mergedParent;

}

if ((merged.flags & SymbolFlags.Transient) !== 0) {

merged.parent = mergedParent;

}

Don't set parent on non-transient symbols in mergeSymbolTable

0efb559

github-project-automation bot added this to PR Backlog Apr 9, 2025

github-project-automation bot moved this to Not started in PR Backlog Apr 9, 2025

typescript-bot assigned jakebailey Apr 9, 2025

typescript-bot added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Apr 9, 2025

jakebailey requested review from DanielRosenwasser and ahejlsberg June 30, 2025 23:34

Merge branch 'main' into transient-symbol-merge

e2105d5

Copilot AI review requested due to automatic review settings September 11, 2025 00:11

Copilot AI reviewed Sep 11, 2025

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Don't set parent on non-transient symbols in mergeSymbolTable #61560

Don't set parent on non-transient symbols in mergeSymbolTable #61560

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Don't set parent on non-transient symbols in mergeSymbolTable #61560

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Don't set parent on non-transient symbols in mergeSymbolTable #61560

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