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Fix constant reference check in CFA#44762

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DanielRosenwasser merged 5 commits intomainfrom
fixConstantReferenceCheck
Jun 28, 2021
Merged

Fix constant reference check in CFA#44762
DanielRosenwasser merged 5 commits intomainfrom
fixConstantReferenceCheck

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@ahejlsberg ahejlsberg commented Jun 26, 2021

This PR is a follow up fix to #44730. The PR implements a more thorough check to ensure references are non-mutable when they are narrowed by aliased conditional expressions. For example:

function test(obj: { readonly x: string | number }) {
    const isString = typeof obj.x === 'string';
    obj = { x: 42 };
    if (isString) {
        let s: string = obj.x;  // Not narrowed because obj is assigned in function body
    }
}

Previously we'd just check that x is readonly. Now we also check that obj isn't assigned in the function body.

@typescript-bot typescript-bot added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels Jun 26, 2021
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ahejlsberg commented Jun 26, 2021

@typescript-bot perf test this

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typescript-bot commented Jun 26, 2021 •
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Heya @ahejlsberg, I've started to run the perf test suite on this PR at d535af6. You can monitor the build here.

Update: The results are in!

@ahejlsberg ahejlsberg added this to the TypeScript 4.4.1 (RC) milestone Jun 26, 2021
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typescript-bot commented Jun 26, 2021

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The results of the perf run you requested are in!

Here they are:

Comparison Report - main..44762

Metric main 44762 Delta Best Worst
Angular - node (v10.16.3, x64)
Memory used 344,297k (± 0.02%) 344,310k (± 0.01%) +13k (+ 0.00%) 344,207k 344,404k
Parse Time 1.80s (± 0.38%) 1.81s (± 0.50%) +0.01s (+ 0.56%) 1.79s 1.82s
Bind Time 0.85s (± 0.68%) 0.85s (± 0.70%) -0.00s (- 0.12%) 0.83s 0.86s
Check Time 5.44s (± 0.57%) 5.35s (± 0.43%) -0.10s (- 1.76%) 5.31s 5.41s
Emit Time 5.82s (± 0.51%) 5.82s (± 0.67%) -0.00s (- 0.02%) 5.73s 5.91s
Total Time 13.90s (± 0.41%) 13.82s (± 0.45%) -0.09s (- 0.63%) 13.66s 13.98s
Compiler-Unions - node (v10.16.3, x64)
Memory used 201,520k (± 0.03%) 201,510k (± 0.03%) -10k (- 0.01%) 201,347k 201,602k
Parse Time 0.78s (± 0.79%) 0.78s (± 0.74%) +0.00s (+ 0.26%) 0.77s 0.80s
Bind Time 0.53s (± 1.29%) 0.53s (± 1.09%) +0.01s (+ 1.33%) 0.52s 0.54s
Check Time 7.83s (± 0.57%) 7.82s (± 0.67%) -0.01s (- 0.17%) 7.71s 7.92s
Emit Time 2.44s (± 0.80%) 2.45s (± 0.96%) +0.01s (+ 0.49%) 2.40s 2.50s
Total Time 11.58s (± 0.40%) 11.58s (± 0.57%) +0.01s (+ 0.06%) 11.46s 11.74s
Monaco - node (v10.16.3, x64)
Memory used 340,669k (± 0.01%) 340,668k (± 0.03%) -1k (- 0.00%) 340,492k 340,993k
Parse Time 1.45s (± 0.68%) 1.46s (± 0.92%) +0.01s (+ 0.76%) 1.44s 1.49s
Bind Time 0.74s (± 0.80%) 0.75s (± 0.69%) +0.01s (+ 0.67%) 0.74s 0.76s
Check Time 5.44s (± 0.46%) 5.37s (± 0.92%) -0.06s (- 1.14%) 5.23s 5.45s
Emit Time 3.16s (± 0.57%) 3.16s (± 0.72%) -0.01s (- 0.19%) 3.12s 3.21s
Total Time 10.79s (± 0.33%) 10.74s (± 0.53%) -0.05s (- 0.43%) 10.64s 10.86s
TFS - node (v10.16.3, x64)
Memory used 303,980k (± 0.02%) 303,925k (± 0.02%) -54k (- 0.02%) 303,827k 304,160k
Parse Time 1.18s (± 0.80%) 1.19s (± 0.71%) +0.01s (+ 0.76%) 1.17s 1.21s
Bind Time 0.71s (± 0.66%) 0.71s (± 1.02%) +0.00s (+ 0.28%) 0.69s 0.72s
Check Time 4.97s (± 0.51%) 4.89s (± 0.46%) -0.09s (- 1.77%) 4.85s 4.94s
Emit Time 3.34s (± 1.90%) 3.34s (± 1.36%) +0.00s (+ 0.03%) 3.24s 3.47s
Total Time 10.20s (± 0.77%) 10.13s (± 0.59%) -0.08s (- 0.75%) 10.02s 10.28s
material-ui - node (v10.16.3, x64)
Memory used 471,018k (± 0.01%) 470,992k (± 0.02%) -26k (- 0.01%) 470,811k 471,222k
Parse Time 1.72s (± 0.35%) 1.72s (± 0.49%) +0.01s (+ 0.35%) 1.70s 1.74s
Bind Time 0.66s (± 0.74%) 0.67s (± 1.02%) +0.00s (+ 0.30%) 0.65s 0.68s
Check Time 14.17s (± 0.51%) 14.22s (± 0.37%) +0.05s (+ 0.34%) 14.12s 14.34s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 16.55s (± 0.43%) 16.61s (± 0.32%) +0.06s (+ 0.34%) 16.49s 16.72s
Angular - node (v12.1.0, x64)
Memory used 322,582k (± 0.02%) 322,494k (± 0.09%) -88k (- 0.03%) 321,385k 322,841k
Parse Time 1.77s (± 0.54%) 1.79s (± 0.85%) +0.01s (+ 0.73%) 1.75s 1.82s
Bind Time 0.83s (± 1.23%) 0.83s (± 1.21%) +0.01s (+ 0.72%) 0.82s 0.86s
Check Time 5.22s (± 0.58%) 5.16s (± 0.76%) -0.06s (- 1.22%) 5.09s 5.28s
Emit Time 6.01s (± 0.38%) 6.03s (± 0.88%) +0.02s (+ 0.33%) 5.96s 6.19s
Total Time 13.84s (± 0.23%) 13.81s (± 0.65%) -0.02s (- 0.17%) 13.67s 14.09s
Compiler-Unions - node (v12.1.0, x64)
Memory used 188,919k (± 0.11%) 189,190k (± 0.24%) +272k (+ 0.14%) 188,877k 191,003k
Parse Time 0.78s (± 0.88%) 0.78s (± 0.48%) -0.00s (- 0.13%) 0.77s 0.78s
Bind Time 0.53s (± 0.84%) 0.53s (± 0.89%) -0.00s (- 0.38%) 0.52s 0.54s
Check Time 7.34s (± 0.61%) 7.30s (± 0.60%) -0.05s (- 0.64%) 7.19s 7.42s
Emit Time 2.45s (± 1.20%) 2.44s (± 1.17%) -0.01s (- 0.49%) 2.38s 2.52s
Total Time 11.11s (± 0.63%) 11.05s (± 0.63%) -0.06s (- 0.56%) 10.88s 11.25s
Monaco - node (v12.1.0, x64)
Memory used 323,805k (± 0.02%) 323,756k (± 0.01%) -49k (- 0.02%) 323,599k 323,841k
Parse Time 1.41s (± 0.60%) 1.42s (± 0.63%) +0.01s (+ 0.92%) 1.40s 1.44s
Bind Time 0.72s (± 0.66%) 0.73s (± 0.94%) +0.01s (+ 1.26%) 0.71s 0.74s
Check Time 5.30s (± 0.41%) 5.24s (± 0.59%) -0.06s (- 1.17%) 5.17s 5.28s
Emit Time 3.16s (± 1.02%) 3.19s (± 1.08%) +0.03s (+ 0.92%) 3.13s 3.28s
Total Time 10.59s (± 0.41%) 10.58s (± 0.51%) -0.01s (- 0.08%) 10.45s 10.69s
TFS - node (v12.1.0, x64)
Memory used 288,654k (± 0.02%) 288,525k (± 0.01%) -129k (- 0.04%) 288,447k 288,596k
Parse Time 1.19s (± 0.65%) 1.19s (± 0.52%) +0.00s (+ 0.17%) 1.18s 1.20s
Bind Time 0.69s (± 0.84%) 0.70s (± 1.04%) +0.01s (+ 0.72%) 0.68s 0.71s
Check Time 4.88s (± 0.40%) 4.79s (± 0.40%) -0.09s (- 1.74%) 4.73s 4.83s
Emit Time 3.33s (± 0.81%) 3.33s (± 0.68%) -0.01s (- 0.18%) 3.28s 3.37s
Total Time 10.09s (± 0.37%) 10.01s (± 0.40%) -0.08s (- 0.81%) 9.92s 10.10s
material-ui - node (v12.1.0, x64)
Memory used 449,700k (± 0.06%) 449,688k (± 0.06%) -12k (- 0.00%) 448,681k 449,911k
Parse Time 1.70s (± 0.52%) 1.71s (± 0.55%) +0.01s (+ 0.65%) 1.69s 1.73s
Bind Time 0.65s (± 0.92%) 0.65s (± 0.76%) 0.00s ( 0.00%) 0.64s 0.66s
Check Time 12.77s (± 0.56%) 12.74s (± 1.21%) -0.03s (- 0.27%) 12.53s 13.25s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.12s (± 0.47%) 15.10s (± 1.00%) -0.02s (- 0.11%) 14.89s 15.59s
Angular - node (v14.15.1, x64)
Memory used 321,258k (± 0.01%) 321,181k (± 0.01%) -76k (- 0.02%) 321,116k 321,233k
Parse Time 1.79s (± 0.64%) 1.81s (± 0.51%) +0.02s (+ 1.01%) 1.79s 1.83s
Bind Time 0.88s (± 0.57%) 0.88s (± 0.68%) +0.00s (+ 0.11%) 0.87s 0.89s
Check Time 5.27s (± 0.50%) 5.15s (± 0.48%) -0.12s (- 2.28%) 5.11s 5.22s
Emit Time 6.09s (± 0.85%) 6.14s (± 0.58%) +0.04s (+ 0.74%) 6.06s 6.22s
Total Time 14.02s (± 0.48%) 13.96s (± 0.40%) -0.06s (- 0.42%) 13.87s 14.08s
Compiler-Unions - node (v14.15.1, x64)
Memory used 188,346k (± 0.50%) 187,738k (± 0.02%) -607k (- 0.32%) 187,634k 187,787k
Parse Time 0.80s (± 0.91%) 0.81s (± 0.74%) +0.00s (+ 0.50%) 0.79s 0.82s
Bind Time 0.56s (± 0.61%) 0.57s (± 1.06%) +0.01s (+ 1.44%) 0.55s 0.58s
Check Time 7.48s (± 0.76%) 7.49s (± 0.85%) +0.01s (+ 0.15%) 7.37s 7.65s
Emit Time 2.42s (± 0.84%) 2.44s (± 0.73%) +0.01s (+ 0.58%) 2.41s 2.50s
Total Time 11.26s (± 0.58%) 11.30s (± 0.72%) +0.04s (+ 0.34%) 11.14s 11.53s
Monaco - node (v14.15.1, x64)
Memory used 322,579k (± 0.00%) 322,554k (± 0.00%) -24k (- 0.01%) 322,533k 322,584k
Parse Time 1.48s (± 0.67%) 1.48s (± 0.60%) +0.01s (+ 0.41%) 1.46s 1.50s
Bind Time 0.75s (± 0.63%) 0.75s (± 0.40%) +0.00s (+ 0.27%) 0.75s 0.76s
Check Time 5.25s (± 0.53%) 5.19s (± 0.55%) -0.06s (- 1.09%) 5.13s 5.27s
Emit Time 3.22s (± 0.64%) 3.23s (± 0.67%) +0.01s (+ 0.31%) 3.19s 3.28s
Total Time 10.70s (± 0.44%) 10.66s (± 0.50%) -0.04s (- 0.37%) 10.55s 10.81s
TFS - node (v14.15.1, x64)
Memory used 287,642k (± 0.00%) 287,609k (± 0.00%) -33k (- 0.01%) 287,590k 287,638k
Parse Time 1.26s (± 1.81%) 1.25s (± 1.31%) -0.01s (- 0.87%) 1.20s 1.27s
Bind Time 0.71s (± 0.51%) 0.72s (± 1.03%) +0.01s (+ 1.26%) 0.71s 0.74s
Check Time 4.91s (± 0.54%) 4.83s (± 0.28%) -0.09s (- 1.75%) 4.81s 4.87s
Emit Time 3.42s (± 0.67%) 3.43s (± 0.70%) +0.01s (+ 0.29%) 3.38s 3.50s
Total Time 10.31s (± 0.37%) 10.23s (± 0.22%) -0.08s (- 0.80%) 10.16s 10.28s
material-ui - node (v14.15.1, x64)
Memory used 447,966k (± 0.06%) 448,187k (± 0.01%) +220k (+ 0.05%) 448,123k 448,230k
Parse Time 1.75s (± 0.35%) 1.76s (± 0.71%) +0.01s (+ 0.34%) 1.73s 1.78s
Bind Time 0.69s (± 0.50%) 0.69s (± 0.65%) +0.00s (+ 0.15%) 0.68s 0.70s
Check Time 12.97s (± 0.52%) 12.91s (± 0.46%) -0.07s (- 0.51%) 12.79s 13.10s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.41s (± 0.46%) 15.35s (± 0.36%) -0.06s (- 0.40%) 15.24s 15.52s
System
Machine Namets-ci-ubuntu
Platformlinux 4.4.0-206-generic
Architecturex64
Available Memory16 GB
Available Memory1 GB
CPUs4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
Hosts
  • node (v10.16.3, x64)
  • node (v12.1.0, x64)
  • node (v14.15.1, x64)
Scenarios
  • Angular - node (v10.16.3, x64)
  • Angular - node (v12.1.0, x64)
  • Angular - node (v14.15.1, x64)
  • Compiler-Unions - node (v10.16.3, x64)
  • Compiler-Unions - node (v12.1.0, x64)
  • Compiler-Unions - node (v14.15.1, x64)
  • Monaco - node (v10.16.3, x64)
  • Monaco - node (v12.1.0, x64)
  • Monaco - node (v14.15.1, x64)
  • TFS - node (v10.16.3, x64)
  • TFS - node (v12.1.0, x64)
  • TFS - node (v14.15.1, x64)
  • material-ui - node (v10.16.3, x64)
  • material-ui - node (v12.1.0, x64)
  • material-ui - node (v14.15.1, x64)
Benchmark Name Iterations
Current 44762 10
Baseline main 10

Developer Information:

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ahejlsberg commented Jun 27, 2021

The slight performance improvement is likely from deferring more calls to isParameterAssigned (which can result in an expensive tree walk).

@RyanCavanaugh Would be nice it we could cherry pick this fix into the 4.4 beta.

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DanielRosenwasser commented Jun 28, 2021 •
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If we merge this in, I'll sync the release-4.4 branch and rebuild later this afternoon with @uniqueiniquity since we have 1-2 other PRs that we want in the beta too.

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DanielRosenwasser reviewed Jun 28, 2021
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src/compiler/checker.ts
return isConstVariable(symbol) || !!symbol.valueDeclaration && getRootDeclaration(symbol.valueDeclaration).kind === SyntaxKind.Parameter && !isParameterAssigned(symbol);
case SyntaxKind.PropertyAccessExpression:
case SyntaxKind.ElementAccessExpression:
// The resolvedSymbol property is initialized by checkPropertyAccess or checkElementAccess before we get here.
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Would be nice if there was a way to assert this easily.

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DanielRosenwasser commented Jun 28, 2021

I added the tests case I mentioned in 3b12c04

Kind of surprised we don't narrow this.x, but not worth blocking on.

@DanielRosenwasser DanielRosenwasser merged commit 5f8a9e5 into main Jun 28, 2021
@DanielRosenwasser DanielRosenwasser deleted the fixConstantReferenceCheck branch June 28, 2021 23:41
@mkubilayk mkubilayk mentioned this pull request Jul 20, 2021
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@RyanCavanaugh RyanCavanaugh Awaiting requested review from RyanCavanaugh

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