fix: Return of aggregate values in function pointer calls

Adjusted the AggregateTypeLowerer for function pointer calls

Author: volsa

src/codegen/tests/function_pointer_tests.rs

@@ -145,7 +145,7 @@ fn function_pointer_method_with_input_output_inout() {
       store i16 0, i16* %localInOutVariable, align 2
       store void (%FbA*, i16, i16*, i16*)* @FbA__foo, void (%FbA*, i16, i16*, i16*)** %fnPtr, align 8
       %1 = load void (%FbA*, i16, i16*, i16*)*, void (%FbA*, i16, i16*, i16*)** %fnPtr, align 8
-      call void %1(%FbA* %instanceFbA, i32 12345, i16* %localOutVariable, i16* %localInOutVariable)
+      call void %1(%FbA* %instanceFbA, i16 12345, i16* %localOutVariable, i16* %localInOutVariable)
       %2 = load void (%FbA*, i16, i16*, i16*)*, void (%FbA*, i16, i16*, i16*)** %fnPtr, align 8
       %load_localInVariable = load i16, i16* %localInVariable, align 2
       call void %2(%FbA* %instanceFbA, i16 %load_localInVariable, i16* %localOutVariable, i16* %localInOutVariable)
@@ -591,3 +591,90 @@ fn user_defined_virtual_table_calls() {
     attributes #0 = { argmemonly nofree nounwind willreturn }
     "#);
 }
+
+#[test]
+fn function_pointer_aggregate_return() {
+    let result = codegen(
+        r"
+        FUNCTION_BLOCK FbA
+            METHOD foo: STRING
+                foo := 'aaaaa';
+            END_METHOD
+        END_FUNCTION_BLOCK
+
+        FUNCTION main
+            VAR
+                instanceFbA: FbA;
+                fooPtr: POINTER TO FbA.foo;
+                result: STRING;
+            END_VAR
+
+            result := fooPtr^(instanceFbA);
+        END_FUNCTION
+        ",
+    );
+
+    filtered_assert_snapshot!(result, @r#"
+    ; ModuleID = '<internal>'
+    source_filename = "<internal>"
+    target datalayout = "[filtered]"
+    target triple = "[filtered]"
+
+    %FbA = type {}
+
+    @__FbA__init = unnamed_addr constant %FbA zeroinitializer
+    @utf08_literal_0 = private unnamed_addr constant [6 x i8] c"aaaaa\00"
+
+    define void @FbA(%FbA* %0) {
+    entry:
+      %this = alloca %FbA*, align 8
+      store %FbA* %0, %FbA** %this, align 8
+      ret void
+    }
+
+    define void @FbA__foo(%FbA* %0, i8* %1) {
+    entry:
+      %this = alloca %FbA*, align 8
+      store %FbA* %0, %FbA** %this, align 8
+      %foo = alloca i8*, align 8
+      store i8* %1, i8** %foo, align 8
+      %deref = load i8*, i8** %foo, align 8
+      call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 %deref, i8* align 1 getelementptr inbounds ([6 x i8], [6 x i8]* @utf08_literal_0, i32 0, i32 0), i32 6, i1 false)
+      ret void
+    }
+
+    define void @main() {
+    entry:
+      %instanceFbA = alloca %FbA, align 8
+      %fooPtr = alloca void (%FbA*, [81 x i8]*)*, align 8
+      %result = alloca [81 x i8], align 1
+      %0 = bitcast %FbA* %instanceFbA to i8*
+      call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 1 %0, i8* align 1 bitcast (%FbA* @__FbA__init to i8*), i64 ptrtoint (%FbA* getelementptr (%FbA, %FbA* null, i32 1) to i64), i1 false)
+      store void (%FbA*, [81 x i8]*)* null, void (%FbA*, [81 x i8]*)** %fooPtr, align 8
+      %1 = bitcast [81 x i8]* %result to i8*
+      call void @llvm.memset.p0i8.i64(i8* align 1 %1, i8 0, i64 ptrtoint ([81 x i8]* getelementptr ([81 x i8], [81 x i8]* null, i32 1) to i64), i1 false)
+      %__0 = alloca [81 x i8], align 1
+      %2 = bitcast [81 x i8]* %__0 to i8*
+      call void @llvm.memset.p0i8.i64(i8* align 1 %2, i8 0, i64 ptrtoint ([81 x i8]* getelementptr ([81 x i8], [81 x i8]* null, i32 1) to i64), i1 false)
+      %3 = load void (%FbA*, [81 x i8]*)*, void (%FbA*, [81 x i8]*)** %fooPtr, align 8
+      %4 = bitcast [81 x i8]* %__0 to i8*
+      call void %3(%FbA* %instanceFbA, i8* %4)
+      %5 = bitcast [81 x i8]* %result to i8*
+      %6 = bitcast [81 x i8]* %__0 to i8*
+      call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 %5, i8* align 1 %6, i32 80, i1 false)
+      ret void
+    }
+
+    ; Function Attrs: argmemonly nofree nounwind willreturn
+    declare void @llvm.memcpy.p0i8.p0i8.i32(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i32, i1 immarg) #0
+
+    ; Function Attrs: argmemonly nofree nounwind willreturn
+    declare void @llvm.memcpy.p0i8.p0i8.i64(i8* noalias nocapture writeonly, i8* noalias nocapture readonly, i64, i1 immarg) #0
+
+    ; Function Attrs: argmemonly nofree nounwind willreturn writeonly
+    declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #1
+
+    attributes #0 = { argmemonly nofree nounwind willreturn }
+    attributes #1 = { argmemonly nofree nounwind willreturn writeonly }
+    "#);
+}