Go: Update to 1.27

[jketema]

Note that all tests failing here pass on the internal PR.

[owen-mc]

First pass review.

[Copilot]

Pull request overview

Updates CodeQL’s Go support to Go 1.27, including generic method extraction.

Changes:

• Updates SDK, toolchain, CI, and supported-version documentation.
• Handles Go 1.27 generic method type parameters and receivers.
• Adds generic method fixtures and expected results.

Show a summary per file

File	Description
MODULE.bazel	Pins Go SDK 1.27.0.
go/extractor/go.mod	Updates Go and toolchain versions.
go/extractor/extractor.go	Handles instantiated generic method parameters.
go/extractor/trap/labels.go	Resolves originating receiver objects.
go/extractor/autobuilder/build-environment.go	Raises maximum supported Go version.
go/extractor/toolchain/toolchain_test.go	Applies Go 1.27 formatting.
go/actions/test/action.yml	Runs tests with Go 1.27.0.
go/ql/test/library-tests/semmle/go/Function/go.mod	Enables Go 1.27 test syntax.
go/ql/test/library-tests/semmle/go/Function/genericMethods.go	Adds generic method fixtures.
go/ql/test/library-tests/semmle/go/Function/TypeParamType.expected	Updates type-parameter results.
go/ql/test/library-tests/semmle/go/Function/getTypeParameter.expected	Updates declaration results.
go/ql/test/library-tests/semmle/go/Function/getParameter.expected	Updates method parameter results.
go/ql/test/library-tests/semmle/go/Function/GenericFunctionInstantiationExpr.expected	Updates instantiation results.
go/ql/lib/change-notes/2026-06-25-go-1.27.md	Announces Go 1.27 support.
docs/codeql/reusables/supported-versions-compilers.rst	Documents Go 1.27 support.

Review details

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• Files reviewed: 14/15 changed files
• Comments generated: 1
• Review effort level: Balanced

[jketema]

There is indeed an issues here. Consider the following:

type StructWithDependentBound[P any] struct{}

func (*StructWithDependentBound[P]) GenericMethodWithDependentBound[Q ~[]P](x Q) {}

func genericMethodDependentBounds(
	withInt StructWithDependentBound[int],
	withString StructWithDependentBound[string],
) {
	withInt.GenericMethodWithDependentBound([]int{})
	withString.GenericMethodWithDependentBound([]string{})
}

then

from TypeParamType parameter
select parameter.getParamName(), parameter.getConstraint().pp()

produces:

| P | interface { } |
| Q | interface { ~[]P } |
| Q | interface { ~[]int } |
| Q | interface { ~[]string } |

and there are dataset check errors:

[INVALID_KEY_SET] predicate typeparam(@typeparamtype tp, string name, @compositetype bound, @typeparamparentobject parent, int idx, boolean is_from_recv): The key set {parent, idx, is_from_recv} does not functionally determine all fields.
Here is a pair of tuples that agree on the key set but differ at index 2:
Tuple 1 in row 2: (81,"Q",87,52,0,false)
Tuple 2 in row 3: (81,"Q",155,52,0,false)
	Relevant element: tp=81
		Full ID for 81: @"(53),0,false,Q;typeparamtype". The ID may expand to @"{@"{@"{@"(50)"},GenericMethodWithDependentBound;method"}"},0,false,Q;typeparamtype"
	Relevant element: Tuple 1: bound=87
		Full ID for 87: @";(86);interfacetype". The ID may expand to @";{@"{@"~{@"(83)"};typesetliteraltype"}"};interfacetype"
	Relevant element: Tuple 2: bound=155
		Full ID for 155: @";(154);interfacetype". The ID may expand to @";{@"{@"~{@"(147)"};typesetliteraltype"}"};interfacetype"
	Relevant element: parent=52
		Full ID for 52: @"(51),GenericMethodWithDependentBound;method". The ID may expand to @"{@"{@"{@"(47)"};pointertype"}"},GenericMethodWithDependentBound;method"
[INVALID_KEY] predicate typeparam(@typeparamtype tp, string name, @compositetype bound, @typeparamparentobject parent, int idx, boolean is_from_recv): The key set {tp} does not functionally determine all fields.
Here is a pair of tuples that agree on the key set but differ at index 2:
Tuple 1 in row 2: (81,"Q",87,52,0,false)
Tuple 2 in row 3: (81,"Q",155,52,0,false)
	Relevant element: tp=81
		Full ID for 81: @"(53),0,false,Q;typeparamtype". The ID may expand to @"{@"{@"{@"(50)"},GenericMethodWithDependentBound;method"}"},0,false,Q;typeparamtype"
	Relevant element: Tuple 1: bound=87
		Full ID for 87: @";(86);interfacetype". The ID may expand to @";{@"{@"~{@"(83)"};typesetliteraltype"}"};interfacetype"
	Relevant element: Tuple 2: bound=155
		Full ID for 155: @";(154);interfacetype". The ID may expand to @";{@"{@"~{@"(147)"};typesetliteraltype"}"};interfacetype"
	Relevant element: parent=52
		Full ID for 52: @"(51),GenericMethodWithDependentBound;method". The ID may expand to @"{@"{@"{@"(47)"};pointertype"}"},GenericMethodWithDependentBound;method"

Copilot's proposed fix is not near being correct.