Add AutomaticDifferentiationBackend (#2386)

Author: odow

docs/src/manual/models.md

@@ -78,6 +78,7 @@ The following attributes are available:
  * [`ObjectiveFunction`](@ref)
  * [`ObjectiveFunctionType`](@ref)
  * [`ObjectiveSense`](@ref)
+
 ## AbstractOptimizer API
 
 The following attributes are available:
@@ -104,3 +105,4 @@ The following attributes are available:
  * [`TimeLimitSec`](@ref)
  * [`ObjectiveLimit`](@ref)
  * [`SolutionLimit`](@ref)
+ * [`AutomaticDifferentiationBackend`](@ref)

docs/src/reference/models.md

@@ -86,6 +86,7 @@ NumberOfThreads
 RawSolver
 AbsoluteGapTolerance
 RelativeGapTolerance
+AutomaticDifferentiationBackend
 ```
 
 List of attributes useful for optimizers

src/attributes.jl

@@ -2119,6 +2119,20 @@ struct ListOfSupportedNonlinearOperators <: AbstractOptimizerAttribute end
     OTHER_ERROR,
 )
 
+"""
+    AutomaticDifferentiationBackend() <: AbstractOptimizerAttribute
+
+An [`AbstractOptimizerAttribute`](@ref) for setting the automatic differentiation
+backend used by the solver.
+
+The value must be a subtype of [`Nonlinear.AbstractAutomaticDifferentiation`](@ref).
+"""
+struct AutomaticDifferentiationBackend <: AbstractOptimizerAttribute end
+
+function attribute_value_type(::AutomaticDifferentiationBackend)
+    return Nonlinear.AbstractAutomaticDifferentiation
+end
+
 """
     TerminationStatus()
 

test/attributes.jl

@@ -310,6 +310,12 @@ function test_scalar_nonlinear_function_set_objective()
     return
 end
 
+function test_attributes_AutomaticDifferentiationBackend()
+    @test MOI.attribute_value_type(MOI.AutomaticDifferentiationBackend()) ==
+          MOI.Nonlinear.AbstractAutomaticDifferentiation
+    return
+end
+
 function runtests()
     for name in names(@__MODULE__; all = true)
         if startswith("$name", "test_")