compiler: include the scope in the type code name #5183

dgryski · 2026-01-16T21:30:11Z

compiler/interface.go

niaow · 2026-01-16T22:17:32Z

Maybe add this to the compiler frontend tests (compiler/testdata/interface.*)

dgryski · 2026-01-16T22:47:14Z

I don't think I can put it in the golden compiler/testdata/*.ll files since the pointer address will change between runs. It does have a test in the main testdata/ directory though.

niaow · 2026-01-16T22:49:21Z

Oh, we should not be using the pointer address for this.

dgryski · 2026-01-16T22:51:32Z

There doesn't appear to be anything else aside from pointer addresses to allow us to differentiate scopes. Even the String() representation of a scope includes the pointer address. I'd love a more stable suggestion. I asked in #tools on Slack for advice.

dgryski · 2026-01-16T22:52:30Z

Note also this the pointer address of the scope in the compiler, not the pointer at runtime on the device.

niaow · 2026-01-16T22:55:13Z

If that is the case then we could loop through the SSA and assign numbers to them? Non-deterministic compilation is not acceptable.

dgryski · 2026-01-16T23:00:34Z

Ok. I'll see what I can come up with.

dgryski · 2026-01-17T00:51:41Z

PTAL

dgryski · 2026-01-19T17:27:06Z

(Oops, hadn't actually pushed my changes.... 🤦 )

Fixes tinygo-org#5180

niaow · 2026-01-19T18:49:46Z

compiler/interface.go

+	for scope != pkg {
+		parent := scope.Parent()
+		for i := range parent.NumChildren() {
+			if parent.Child(i) == scope {


This can result in O(n^2) overhead. Maybe build a map with everything in the package once and then look up from it?

This code only runs for types declared in a local scope. I'll add a scope -> name cache for this function but walking the entire list of scopes looking for named types before we need them seems like overkill.

You still have not fixed this issue. You are still iterating over every child of every parent for every child. This index is what you should be caching.

Do you want the id cached for only the matching child (so I don't need to iterate next time), or for every child? (I'm concerned the "every child" case will just bloat the cache with entries that will never be queried. This is already only walking up the scopes from the scope the type is defined in up to the parent scope, so we're only looking at the children of parent nodes on the path to the root.)

Commit e56e3e5 caches the index of each scope that we encounter on the path to the root. We might have to double scan a particular parent if there are multiple scopes with types defined in them. (I'm going to run this over the test corpus and see if I can quantify the loops -- the numbers we're dealing with are pretty small..)

or for every child?

Yes. The cache does not actually solve anything unless you do this.

I added some logging to getScopeID and this is the output for running the compiler over the entire test corpus (180 packages, ~1.5 million lines of Go code):

~/go/src/github.com/dgryski/tinygo-test-corpus $ rg === corpus.out |sed 's/.*===//' scopeIdx: id=46:10: loops=58 scopeIdx: id=46:10: loops=0 scopeIdx: id=46:10: loops=0 scopeIdx: id=25:4: loops=31 scopeIdx: id=25:4: loops=0 scopeIdx: id=25:4: loops=0 scopeIdx: id=25:4: loops=0 scopeIdx: id=25:4: loops=0 scopeIdx: id=25:4: loops=0 scopeIdx: id=4:1: loops=7 scopeIdx: id=4:1: loops=0 scopeIdx: id=4:1: loops=0 scopeIdx: id=4:1: loops=0 scopeIdx: id=0:3: loops=5 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=5 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=0:3: loops=0 scopeIdx: id=8:0: loops=10 scopeIdx: id=8:0: loops=0 scopeIdx: id=8:0: loops=0 scopeIdx: id=10:0: loops=11 scopeIdx: id=10:0: loops=0 scopeIdx: id=10:0: loops=0 scopeIdx: id=0:9:0:5:1:0: loops=21 scopeIdx: id=0:9:0:5:1:0: loops=0 scopeIdx: id=0:9:0:5:1:0: loops=0

Even only adding in the matching child, the number of iterations is very small, and this code just isn't called that frequently. Adding in all the children will just increase the memory usage for no benefit, since none of them are likely to have named types in them that we're going to query.

niaow · 2026-01-19T18:49:59Z

This is better

niaow

And again, this needs to be in the compiler testdata.

niaow · 2026-01-20T12:47:14Z

compiler/interface.go

+	scopeid map[*types.Scope]string
+}{
+	sync.Mutex{},
+	make(map[*types.Scope]string),


Move this into the compiler context to get rid of the lock and the memory leak.

niaow · 2026-01-20T12:48:12Z

compiler/interface.go

+	for scope != pkg {
+		parent := scope.Parent()
+		for i := range parent.NumChildren() {
+			if parent.Child(i) == scope {


You still have not fixed this issue. You are still iterating over every child of every parent for every child. This index is what you should be caching.

niaow · 2026-01-20T20:12:18Z

Actually I just thought of a much simpler solution to this that I can try in a bit

dgryski requested review from aykevl and niaow January 16, 2026 21:30

dgryski force-pushed the dgryski/named-type-scope branch from cec236b to 4fd15a3 Compare January 16, 2026 21:40

niaow reviewed Jan 16, 2026

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compiler/interface.go Show resolved Hide resolved

dgryski force-pushed the dgryski/named-type-scope branch from 4fd15a3 to 91c1d8a Compare January 16, 2026 22:46

dgryski force-pushed the dgryski/named-type-scope branch from 91c1d8a to b6aa203 Compare January 19, 2026 17:26

dgryski force-pushed the dgryski/named-type-scope branch 2 times, most recently from f6cd265 to f087248 Compare January 19, 2026 18:30

compiler: include the scope in the type code name

7b86f95

Fixes tinygo-org#5180

dgryski force-pushed the dgryski/named-type-scope branch from f087248 to 7b86f95 Compare January 19, 2026 18:42

niaow reviewed Jan 19, 2026

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compiler: add scopeID cache

332e2b9

niaow requested changes Jan 20, 2026

View reviewed changes

dgryski added 2 commits January 20, 2026 07:43

compiler/testdata: add .ll test for scope id changes

d91670c

compiler: move scope id cache to compilerContext

e56e3e5

compiler: include the scope in the type code name #5183

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compiler: include the scope in the type code name #5183

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