[compiler] Repro for imprecise memo due to closure capturing changes #33180
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Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
This was referenced May 9, 2025
josephsavona
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May 12, 2025
Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. ghstack-source-id: 55efdd1 Pull Request resolved: #33180
josephsavona
commented
May 12, 2025
| t1 = Symbol.for("react.early_return_sentinel"); | ||
| bb0: { | ||
| if (a) { | ||
| keys = Object.keys(Codes); |
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W the changes in this stack, we aren't able to independently memoize this call separately from the keys.map() call below. We infer the callback as mutating its parameter and therefore the callback doesn't meet the "non mutating params" criteria to get independently memoized.
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
This was referenced May 13, 2025
snykgit009
pushed a commit
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May 13, 2025
Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. ghstack-source-id: 55efdd1 Pull Request resolved: facebook/react#33180
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
This was referenced May 27, 2025
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
This was referenced Jun 4, 2025
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
This was referenced Jun 6, 2025
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
…ng changes" Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable. The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation. [ghstack-poisoned]
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Stack from ghstack (oldest at bottom):
Syncing this stack internally there is a small percentage of files that lose memoization, generally for callbacks. The repro here tries to get at the core pattern, where a parameter escapes into a mutable return value. This makes the callback appear mutable, and means that calls like array.map aren't able to optimize as well — even if the array itself is transitively immutable.
The challenge is that we can't really distinguish between just capturing and true mutation right now — AnalyzeFunctions kind of has to pick one, and consider both a mutation.