added architecture design record for enums

src/tests/adr.rs

@@ -1,2 +1,3 @@
 /// tests for Architecture Design Records (ADR)
+mod enum_adr;
 mod pou_adr;

src/tests/adr/enum_adr.rs

@@ -0,0 +1,144 @@
+use crate::test_utils::tests::codegen;
+
+/// # Architecture Design Record: Enums
+/// An Enum (or Enumeration) is a special datatype in ST. An Enum datatype represents an i32 with a list of
+/// well defined values with dedicated names (e.g. `@red`, `@yellow`, `@green`).
+///
+/// e.g.
+/// ```st
+/// TYPE MyEnum: (element1, element2, element3);
+///     END_TYPE
+/// ```
+#[test]
+fn enums_generate_a_global_constants_for_each_element() {
+    let src = r#"
+        TYPE Color : (red, yellow, green);
+        END_TYPE;
+
+        VAR_GLOBAL
+            myColor : Color;
+        END_VAR"#;
+    insta::assert_snapshot!(codegen(src), @r###"
+    ; ModuleID = 'main'
+    source_filename = "main"
+
+    @myColor = global i32 0
+    @red = unnamed_addr constant i32 0
+    @yellow = unnamed_addr constant i32 1
+    @green = unnamed_addr constant i32 2
+    "###);
+}
+
+/// The values of the enum constants are stored as (enum-local) unique i32 values. They can be
+/// defined by the user via an initialization statement, or automatically assigned by the compiler.
+/// Values that are assigned by the compiler get unique ascending values.
+#[test]
+fn enums_constants_are_automatically_numbered_or_user_defined() {
+    let src = r#"
+        TYPE Color : (red := 1, yellow := 2, green := 4, blue := 8);
+        END_TYPE;
+
+        TYPE State : (open := 1, closed := 4, idle, running);
+        END_TYPE;
+
+        VAR_GLOBAL
+            myColor : Color;
+            myState : State;
+        END_VAR"#;
+
+    insta::assert_snapshot!(codegen(src), @r###"
+    ; ModuleID = 'main'
+    source_filename = "main"
+
+    @myColor = global i32 0
+    @myState = global i32 0
+    @red = unnamed_addr constant i32 1
+    @yellow = unnamed_addr constant i32 2
+    @green = unnamed_addr constant i32 4
+    @blue = unnamed_addr constant i32 8
+    @open = unnamed_addr constant i32 1
+    @closed = unnamed_addr constant i32 4
+    @idle = unnamed_addr constant i32 5
+    @running = unnamed_addr constant i32 6
+    "###);
+}
+
+/// Enum types can be declared as dedicated DataTypes (see above) or direclty as part of a
+/// variable declaration. Note that declaring the same enum twice will result in two distinct
+/// enum-datatypes (and separate constant-variables - e.g. `@red` and `@red.1`).
+#[test]
+fn inline_declaration_of_enum_types() {
+    let src = r#"
+        VAR_GLOBAL
+            frontColor : (red, green, yellow);
+            backColor  : (red, green, yellow);
+        END_VAR"#;
+
+    insta::assert_snapshot!(codegen(src), @r###"
+    ; ModuleID = 'main'
+    source_filename = "main"
+
+    @frontColor = global i32 0
+    @backColor = global i32 0
+    @red = unnamed_addr constant i32 0
+    @green = unnamed_addr constant i32 1
+    @yellow = unnamed_addr constant i32 2
+    @red.1 = unnamed_addr constant i32 0
+    @green.2 = unnamed_addr constant i32 1
+    @yellow.3 = unnamed_addr constant i32 2
+    "###);
+}
+
+/// Enum elements can accessed like global variables. If there are mulitple candidates, one can
+/// pick a specific element by qualifying it with the enum's name (note that this is not possible for inline
+/// enums).
+/// In this example the enum-element `open` is defined in the type `ProcessState` as well as in `Door`. We can now
+/// select a specific element by qualifying it via `ProcessState#closed` or `Door#closed` to access the generated global
+/// variables `@closed` or `@closed.2`.
+#[test]
+fn using_enums() {
+    let src = r#"
+        TYPE ProcessState : (open := 1, closed := 4, idle, running);
+        END_TYPE;
+ 
+        TYPE Door : (open := 8, closed := 16);
+        END_TYPE;
+
+        PROGRAM prg
+            VAR x, y, z : DINT; END_VAR
+
+            x := idle;
+            y := ProcessState#closed;
+            z := Door#closed;
+        END_PROGRAM
+    "#;
+
+    insta::assert_snapshot!(codegen(src), @r###"
+    ; ModuleID = 'main'
+    source_filename = "main"
+
+    %prg_interface = type { i32, i32, i32 }
+
+    @prg_instance = global %prg_interface zeroinitializer
+    @open = unnamed_addr constant i32 1
+    @closed = unnamed_addr constant i32 4
+    @idle = unnamed_addr constant i32 5
+    @running = unnamed_addr constant i32 6
+    @open.1 = unnamed_addr constant i32 8
+    @closed.2 = unnamed_addr constant i32 16
+
+    define void @prg(%prg_interface* %0) {
+    entry:
+      %x = getelementptr inbounds %prg_interface, %prg_interface* %0, i32 0, i32 0
+      %y = getelementptr inbounds %prg_interface, %prg_interface* %0, i32 0, i32 1
+      %z = getelementptr inbounds %prg_interface, %prg_interface* %0, i32 0, i32 2
+      %load_idle = load i32, i32* @idle, align 4
+      store i32 %load_idle, i32* %x, align 4
+      %load_closed = load i32, i32* @closed, align 4
+      store i32 %load_closed, i32* %y, align 4
+      %load_closed1 = load i32, i32* @closed.2, align 4
+      store i32 %load_closed1, i32* %z, align 4
+      ret void
+    }
+    "###);
+}

src/tests/adr/pou_adr.rs

@@ -1,6 +1,6 @@
 use crate::test_utils::tests::{annotate, codegen, index};
 
-/// Architecture Design Record: POUs
+/// # Architecture Design Record: POUs
 ///
 /// POU = Program Organisation Unit
 ///