Merge pull request #3724 from AayushSabharwal/as/redundant-codegen

fix: do not unwrap initials in `initializeprobpmap`

Author: ChrisRackauckas

src/systems/problem_utils.jl

@@ -736,6 +736,8 @@ takes a value provider of `srcsys` and a value provider of `dstsys` and returns
 # Keyword Arguments
 - `initials`: Whether to include the `Initial` parameters of `dstsys` among the values
   to be transferred.
+- `unwrap_initials`: Whether initials in `dstsys` corresponding to unknowns in `srcsys` are
+  unwrapped.
 - `p_constructor`: The `p_constructor` argument to `process_SciMLProblem`.
 """
 function get_mtkparameters_reconstructor(srcsys::AbstractSystem, dstsys::AbstractSystem;
@@ -758,7 +760,7 @@ function get_mtkparameters_reconstructor(srcsys::AbstractSystem, dstsys::Abstrac
     end
     initials_getter = if initials && !isempty(syms[2])
         initsyms = Vector{Any}(syms[2])
-        allsyms = Set(all_symbols(srcsys))
+        allsyms = Set(variable_symbols(srcsys))
         if unwrap_initials
             for i in eachindex(initsyms)
                 sym = initsyms[i]

test/code_generation.jl

@@ -110,3 +110,33 @@ end
         @test val[] == 2
     end
 end
+
+@testset "Do not codegen redundant expressions" begin
+    @variables v1(t) = 1
+    @variables v2(t) [guess = 0]
+
+    mutable struct Data
+        count::Int
+    end
+    function update!(d::Data, t)
+        d.count += 1 # Count the number of times the data gets updated.
+    end
+    function (d::Data)(t)
+        update!(d, t)
+        rand(1:10)
+    end
+
+    @parameters (d1::Data)(..) = Data(0)
+    @parameters (d2::Data)(..) = Data(0)
+
+    eqs = [
+        D(v1) ~ d1(t),
+        v2 ~ d2(t) # Some of the data parameters are not actually needed to solve the system.
+    ]
+
+    @mtkbuild sys = System(eqs, t)
+    prob = ODEProblem(sys, [], (0.0, 1.0))
+    sol = solve(prob, Tsit5())
+
+    @test sol.ps[d2].count == 0
+end