Forbid use of static threads

src/linting/extended_checks.jl

@@ -211,6 +211,7 @@ struct StringInterpolation_Extension <: ViolationExtendedRule end
 struct RelPathAPIUsage_Extension <: ViolationExtendedRule end
 struct NonFrontShapeAPIUsage_Extension <: ViolationExtendedRule end
 struct InterpolationInSafeLog_Extension <: RecommendationExtendedRule end
+struct UseOfStaticThreads <: ViolationExtendedRule end
 
 
 const all_extended_rule_types = Ref{Any}(
@@ -568,3 +569,9 @@ end
 function check(t::InterpolationInSafeLog_Extension, x::EXPR)
     generic_check(t, x, "@warnv_safe_to_log hole_variable \"LINT_STRING_WITH_INTERPOLATION\"", "Safe warning log has interpolation.")
 end
+
+function check(t::UseOfStaticThreads, x::EXPR)
+    msg = "Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`. Static threads must not be used as generated tasks will not be able to migrate across threads."
+    generic_check(t, x, "@threads :static hole_variable_star", msg)
+    generic_check(t, x, "Threads.@threads :static hole_variable_star", msg)
+end

test/rai_rules_tests.jl

@@ -1937,3 +1937,23 @@ end
     @test lint_test(source, "Line 7, column 9: Safe warning log has interpolation.")
     @test lint_test(source, "Line 10, column 17: Safe warning log has interpolation.")
 end
+
+@testset "Use of static threads" begin
+    source = raw"""
+    function f()
+        Threads.@threads :static for _ in 1:10
+            println("foo")
+        end
+
+        @threads :static for _ in 1:10
+            println("foo")
+        end
+
+        Threads.@threads :dynamic for _ in 1:10
+            println("foo")
+        end
+    end
+    """
+    @test lint_test(source, "Line 2, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
+    @test lint_test(source, "Line 6, column 5: Use `Threads.@threads :dynamic` instead of `Threads.@threads :static`.")
+end