From 5a9c6980f5469133100200f47cb880e6e691923d Mon Sep 17 00:00:00 2001
From: Daniel Wennberg <daniel.wennberg@gmail.com>
Date: Thu, 3 Oct 2024 12:43:50 -0700
Subject: [PATCH] Fix justActive condition

Closes #1935
---
 src/compiler.jl  |  2 +-
 test/runtests.jl | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/compiler.jl b/src/compiler.jl
index 16d54481cf..a38aae7ad8 100644
--- a/src/compiler.jl
+++ b/src/compiler.jl
@@ -467,7 +467,7 @@ end
 
     subT = fieldtype(T, f)
 
-    if justActive && !allocatedinline(subT)
+    if justActive && ismutabletype(subT)
         return Val(AnyState)
     end
 
diff --git a/test/runtests.jl b/test/runtests.jl
index 902b9e4f65..e85f1afae4 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -144,6 +144,17 @@ end
     @test Enzyme.Compiler.active_reg_inner(Tuple, (), nothing) == Enzyme.Compiler.DupState
     @test Enzyme.Compiler.active_reg_inner(Tuple, (), nothing, #=justactive=#Val(false), #=unionsret=#Val(false), #=abstractismixed=#Val(true)) == Enzyme.Compiler.MixedState
     @test Enzyme.Compiler.active_reg_inner(Tuple{A,A} where A, (), nothing, #=justactive=#Val(false), #=unionsret=#Val(false), #=abstractismixed=#Val(true)) == Enzyme.Compiler.MixedState
+
+    # issue #1935
+    struct Incomplete
+        x::Float64
+        y
+        Incomplete(x) = new(x)
+        # incomplete constructor & non-bitstype field => !Base.allocatedinline(Incomplete)
+    end
+    @test Enzyme.Compiler.active_reg_inner(Tuple{Incomplete}, (), nothing, #=justActive=#Val(false)) == Enzyme.Compiler.MixedState
+    @test Enzyme.Compiler.active_reg_inner(Tuple{Incomplete}, (), nothing, #=justActive=#Val(true)) == Enzyme.Compiler.ActiveState
+
     world = codegen_world_age(typeof(f0), Tuple{Float64})
     thunk_a = Enzyme.Compiler.thunk(Val(world), Const{typeof(f0)}, Active, Tuple{Active{Float64}}, Val(API.DEM_ReverseModeCombined), Val(1), Val((false, false)), Val(false), Val(false), DefaultABI, Val(false), Val(false))
     thunk_b = Enzyme.Compiler.thunk(Val(world), Const{typeof(f0)}, Const, Tuple{Const{Float64}}, Val(API.DEM_ReverseModeCombined), Val(1), Val((false, false)), Val(false), Val(false), DefaultABI, Val(false), Val(false))