feat: support referencing local variables in pointer initialization

src/codegen/generators/expression_generator.rs

@@ -684,7 +684,7 @@ impl<'ink, 'b> ExpressionCodeGenerator<'ink, 'b> {
             } else {
                 // TODO: using the global context we could get a slice here; currently not possible because the
                 //       global context isn't passed into codegen
-                Err(Diagnostic::new(&format!("{element:?} not a direct access"))
+                Err(Diagnostic::new(format!("{element:?} not a direct access"))
                     .with_error_code("E055")
                     .with_location(element.get_location()))
             }?;

src/codegen/generators/pou_generator.rs

@@ -772,6 +772,20 @@ impl<'ink, 'cg> PouGenerator<'ink, 'cg> {
                         variable.source_location.get_column(),
                     );
                 }
+
+                if self
+                    .index
+                    .find_effective_type_by_name(variable.get_type_name())
+                    .map(|it| it.get_type_information())
+                    .is_some_and(|it| it.is_reference_to() || it.is_alias())
+                {
+                    // aliases and reference to variables have special handling for initialization. initialize with a nullpointer
+                    self.llvm.builder.build_store(
+                        left,
+                        left.get_type().get_element_type().into_pointer_type().const_null(),
+                    );
+                    continue;
+                };
                 let right_stmt =
                     self.index.get_const_expressions().maybe_get_constant_statement(&variable.initial_value);
                 self.generate_variable_initializer(variable, left, right_stmt, &exp_gen)?;

src/codegen/tests/initialization_test/complex_initializers.rs

@@ -1368,3 +1368,275 @@ fn var_external_blocks_are_ignored_in_init_functions() {
     }
     "###)
 }
+
+#[test]
+fn ref_to_local_member() {
+    let res = codegen(
+        r"
+    FUNCTION_BLOCK foo
+    VAR
+        s  : STRING;
+        ptr : REF_TO STRING := REF(s);
+        alias AT s : STRING;
+        reference_to : REFERENCE TO STRING REF= s;
+    END_VAR
+    END_FUNCTION_BLOCK
+        ",
+    );
+
+    insta::assert_snapshot!(res, @r#"
+    ; ModuleID = '<internal>'
+    source_filename = "<internal>"
+
+    %foo = type { [81 x i8], [81 x i8]*, [81 x i8]*, [81 x i8]* }
+
+    @__foo__init = unnamed_addr constant %foo zeroinitializer
+
+    define void @foo(%foo* %0) {
+    entry:
+      %s = getelementptr inbounds %foo, %foo* %0, i32 0, i32 0
+      %ptr = getelementptr inbounds %foo, %foo* %0, i32 0, i32 1
+      %alias = getelementptr inbounds %foo, %foo* %0, i32 0, i32 2
+      %reference_to = getelementptr inbounds %foo, %foo* %0, i32 0, i32 3
+      ret void
+    }
+    ; ModuleID = '__initializers'
+    source_filename = "__initializers"
+
+    %foo = type { [81 x i8], [81 x i8]*, [81 x i8]*, [81 x i8]* }
+
+    @__foo__init = external global %foo
+
+    define void @__init_foo(%foo* %0) {
+    entry:
+      %self = alloca %foo*, align 8
+      store %foo* %0, %foo** %self, align 8
+      %deref = load %foo*, %foo** %self, align 8
+      %ptr = getelementptr inbounds %foo, %foo* %deref, i32 0, i32 1
+      %deref1 = load %foo*, %foo** %self, align 8
+      %s = getelementptr inbounds %foo, %foo* %deref1, i32 0, i32 0
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      %deref2 = load %foo*, %foo** %self, align 8
+      %alias = getelementptr inbounds %foo, %foo* %deref2, i32 0, i32 2
+      %deref3 = load %foo*, %foo** %self, align 8
+      %s4 = getelementptr inbounds %foo, %foo* %deref3, i32 0, i32 0
+      store [81 x i8]* %s4, [81 x i8]** %alias, align 8
+      %deref5 = load %foo*, %foo** %self, align 8
+      %reference_to = getelementptr inbounds %foo, %foo* %deref5, i32 0, i32 3
+      %deref6 = load %foo*, %foo** %self, align 8
+      %s7 = getelementptr inbounds %foo, %foo* %deref6, i32 0, i32 0
+      store [81 x i8]* %s7, [81 x i8]** %reference_to, align 8
+      ret void
+    }
+
+    declare void @foo(%foo*)
+    ; ModuleID = '__init___testproject'
+    source_filename = "__init___testproject"
+
+    @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* @__init___testproject, i8* null }]
+
+    define void @__init___testproject() {
+    entry:
+      ret void
+    }
+    "#)
+}
+
+#[test]
+fn ref_to_local_member_shadows_global() {
+    let res = codegen(
+        r"
+    VAR_GLOBAL
+        s : STRING;
+    END_VAR
+
+    FUNCTION_BLOCK foo
+    VAR
+        s : STRING;
+        ptr : REF_TO STRING := REF(s);
+        alias AT s : STRING;
+        reference_to : REFERENCE TO STRING REF= s;
+    END_VAR
+    END_FUNCTION_BLOCK
+        ",
+    );
+
+    insta::assert_snapshot!(res, @r#"
+    ; ModuleID = '<internal>'
+    source_filename = "<internal>"
+
+    %foo = type { [81 x i8], [81 x i8]*, [81 x i8]*, [81 x i8]* }
+
+    @s = global [81 x i8] zeroinitializer
+    @__foo__init = unnamed_addr constant %foo zeroinitializer
+
+    define void @foo(%foo* %0) {
+    entry:
+      %s = getelementptr inbounds %foo, %foo* %0, i32 0, i32 0
+      %ptr = getelementptr inbounds %foo, %foo* %0, i32 0, i32 1
+      %alias = getelementptr inbounds %foo, %foo* %0, i32 0, i32 2
+      %reference_to = getelementptr inbounds %foo, %foo* %0, i32 0, i32 3
+      ret void
+    }
+    ; ModuleID = '__initializers'
+    source_filename = "__initializers"
+
+    %foo = type { [81 x i8], [81 x i8]*, [81 x i8]*, [81 x i8]* }
+
+    @__foo__init = external global %foo
+
+    define void @__init_foo(%foo* %0) {
+    entry:
+      %self = alloca %foo*, align 8
+      store %foo* %0, %foo** %self, align 8
+      %deref = load %foo*, %foo** %self, align 8
+      %ptr = getelementptr inbounds %foo, %foo* %deref, i32 0, i32 1
+      %deref1 = load %foo*, %foo** %self, align 8
+      %s = getelementptr inbounds %foo, %foo* %deref1, i32 0, i32 0
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      %deref2 = load %foo*, %foo** %self, align 8
+      %alias = getelementptr inbounds %foo, %foo* %deref2, i32 0, i32 2
+      %deref3 = load %foo*, %foo** %self, align 8
+      %s4 = getelementptr inbounds %foo, %foo* %deref3, i32 0, i32 0
+      store [81 x i8]* %s4, [81 x i8]** %alias, align 8
+      %deref5 = load %foo*, %foo** %self, align 8
+      %reference_to = getelementptr inbounds %foo, %foo* %deref5, i32 0, i32 3
+      %deref6 = load %foo*, %foo** %self, align 8
+      %s7 = getelementptr inbounds %foo, %foo* %deref6, i32 0, i32 0
+      store [81 x i8]* %s7, [81 x i8]** %reference_to, align 8
+      ret void
+    }
+
+    declare void @foo(%foo*)
+    ; ModuleID = '__init___testproject'
+    source_filename = "__init___testproject"
+
+    @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* @__init___testproject, i8* null }]
+
+    define void @__init___testproject() {
+    entry:
+      ret void
+    }
+    "#)
+}
+
+#[test]
+fn temporary_variable_ref_to_local_member() {
+    let res = codegen(
+        r"
+    FUNCTION_BLOCK foo
+    VAR
+        s  : STRING;
+    END_VAR
+    VAR_TEMP
+        ptr : REF_TO STRING := REF(s);
+        alias AT s : STRING;
+        reference_to : REFERENCE TO STRING REF= s;
+    END_VAR
+    END_FUNCTION_BLOCK
+        ",
+    );
+
+    insta::assert_snapshot!(res, @r#"
+    ; ModuleID = '<internal>'
+    source_filename = "<internal>"
+
+    %foo = type { [81 x i8] }
+
+    @__foo__init = unnamed_addr constant %foo zeroinitializer
+
+    define void @foo(%foo* %0) {
+    entry:
+      %s = getelementptr inbounds %foo, %foo* %0, i32 0, i32 0
+      %ptr = alloca [81 x i8]*, align 8
+      %alias = alloca [81 x i8]*, align 8
+      %reference_to = alloca [81 x i8]*, align 8
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      store [81 x i8]* null, [81 x i8]** %alias, align 8
+      store [81 x i8]* null, [81 x i8]** %reference_to, align 8
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      store [81 x i8]* %s, [81 x i8]** %alias, align 8
+      store [81 x i8]* %s, [81 x i8]** %reference_to, align 8
+      ret void
+    }
+    ; ModuleID = '__initializers'
+    source_filename = "__initializers"
+
+    %foo = type { [81 x i8] }
+
+    @__foo__init = external global %foo
+
+    define void @__init_foo(%foo* %0) {
+    entry:
+      %self = alloca %foo*, align 8
+      store %foo* %0, %foo** %self, align 8
+      ret void
+    }
+
+    declare void @foo(%foo*)
+    ; ModuleID = '__init___testproject'
+    source_filename = "__init___testproject"
+
+    @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* @__init___testproject, i8* null }]
+
+    define void @__init___testproject() {
+    entry:
+      ret void
+    }
+    "#)
+}
+
+#[test]
+fn temporary_variable_ref_to_temporary_variable() {
+    let res = codegen(
+        r"
+    FUNCTION foo
+    VAR
+        ptr : REF_TO STRING := REF(s);
+        alias AT s : STRING;
+    END_VAR
+    VAR_TEMP
+        s  : STRING;
+        reference_to : REFERENCE TO STRING REF= alias;
+    END_VAR
+    FUNCTION
+        ",
+    );
+
+    insta::assert_snapshot!(res, @r##"
+    ; ModuleID = '<internal>'
+    source_filename = "<internal>"
+
+    define void @foo() {
+    entry:
+      %ptr = alloca [81 x i8]*, align 8
+      %alias = alloca [81 x i8]*, align 8
+      %s = alloca [81 x i8], align 1
+      %reference_to = alloca [81 x i8]*, align 8
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      store [81 x i8]* null, [81 x i8]** %alias, align 8
+      %0 = bitcast [81 x i8]* %s to i8*
+      call void @llvm.memset.p0i8.i64(i8* align 1 %0, i8 0, i64 ptrtoint ([81 x i8]* getelementptr ([81 x i8], [81 x i8]* null, i32 1) to i64), i1 false)
+      store [81 x i8]* null, [81 x i8]** %reference_to, align 8
+      store [81 x i8]* %s, [81 x i8]** %ptr, align 8
+      store [81 x i8]* %s, [81 x i8]** %alias, align 8
+      %deref = load [81 x i8]*, [81 x i8]** %alias, align 8
+      store [81 x i8]* %deref, [81 x i8]** %reference_to, align 8
+      ret void
+    }
+
+    ; Function Attrs: argmemonly nofree nounwind willreturn writeonly
+    declare void @llvm.memset.p0i8.i64(i8* nocapture writeonly, i8, i64, i1 immarg) #0
+
+    attributes #0 = { argmemonly nofree nounwind willreturn writeonly }
+    ; ModuleID = '__init___testproject'
+    source_filename = "__init___testproject"
+
+    @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* @__init___testproject, i8* null }]
+
+    define void @__init___testproject() {
+    entry:
+      ret void
+    }
+    "##)
+}

src/codegen/tests/statement_codegen_test.rs

@@ -297,7 +297,6 @@ fn reference_to_string_assignment() {
             VAR
                 a : REF_TO STRING;
             END_VAR
-
             a^ := 'hello';
         END_FUNCTION
         "#,
@@ -351,16 +350,15 @@ fn local_alias() {
         "#,
     );
 
-    assert_snapshot!(content, @r###"
+    assert_snapshot!(content, @r#"
     ; ModuleID = '<internal>'
     source_filename = "<internal>"
 
     define void @main() {
     entry:
       %foo = alloca i32*, align 8
       %bar = alloca i32, align 4
-      %load_bar = load i32, i32* %bar, align 4
-      store i32 %load_bar, i32** %foo, align 4
+      store i32* null, i32** %foo, align 8
       store i32 0, i32* %bar, align 4
       store i32* %bar, i32** %foo, align 8
       ret void
@@ -374,7 +372,7 @@ fn local_alias() {
     entry:
       ret void
     }
-    "###);
+    "#);
 }
 
 #[test]
@@ -390,16 +388,15 @@ fn local_string_alias() {
         "#,
     );
 
-    assert_snapshot!(content, @r###"
+    assert_snapshot!(content, @r##"
     ; ModuleID = '<internal>'
     source_filename = "<internal>"
 
     define void @main() {
     entry:
       %foo = alloca [81 x i8]*, align 8
       %bar = alloca [81 x i8], align 1
-      %load_bar = load [81 x i8], [81 x i8]* %bar, align 1
-      store [81 x i8] %load_bar, [81 x i8]** %foo, align 1
+      store [81 x i8]* null, [81 x i8]** %foo, align 8
       %0 = bitcast [81 x i8]* %bar to i8*
       call void @llvm.memset.p0i8.i64(i8* align 1 %0, i8 0, i64 ptrtoint ([81 x i8]* getelementptr ([81 x i8], [81 x i8]* null, i32 1) to i64), i1 false)
       store [81 x i8]* %bar, [81 x i8]** %foo, align 8
@@ -419,7 +416,7 @@ fn local_string_alias() {
     entry:
       ret void
     }
-    "###);
+    "##);
 }
 
 #[test]