Support for retain sections

compiler/plc_ast/src/ast.rs

@@ -637,10 +637,16 @@ impl Default for VariableBlock {
 
 impl Debug for VariableBlock {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("VariableBlock")
-            .field("variables", &self.variables)
-            .field("variable_block_type", &self.kind)
-            .finish()
+        let mut result = f.debug_struct("VariableBlock");
+        result.field("variables", &self.variables).field("variable_block_type", &self.kind);
+
+        if self.constant {
+            result.field("constant", &self.constant);
+        }
+        if self.retain {
+            result.field("retain", &self.retain);
+        }
+        result.finish()
     }
 }
 

compiler/plc_driver/src/pipelines.rs

@@ -42,7 +42,7 @@ use plc_header_generator::{
     GenerateHeaderOptions,
 };
 use plc_index::GlobalContext;
-use plc_lowering::inheritance::InheritanceLowerer;
+use plc_lowering::{inheritance::InheritanceLowerer, retain::RetainParticipant};
 use project::{
     object::Object,
     project::{LibraryInformation, Project},
@@ -301,6 +301,7 @@ impl<T: SourceContainer> BuildPipeline<T> {
                 self.context.should_generate_external_constructors(),
             )),
             Box::new(PropertyLowerer::new(self.context.provider())),
+            Box::new(RetainParticipant::new(self.context.provider())),
             Box::new(AggregateTypeLowerer::new(self.context.provider())),
             Box::new(InheritanceLowerer::new(self.context.provider())),
             Box::new(InitParticipant::new(

compiler/plc_driver/src/pipelines/participant.rs

@@ -20,7 +20,10 @@ use plc::{
     ConfigFormat, OnlineChange, Target,
 };
 use plc_diagnostics::diagnostics::Diagnostic;
-use plc_lowering::{inheritance::InheritanceLowerer, initializer::Initializer};
+use plc_lowering::{
+    retain::RetainParticipant,
+    {inheritance::InheritanceLowerer, initializer::Initializer},
+};
 use project::{object::Object, project::LibraryInformation};
 use source_code::SourceContainer;
 
@@ -307,3 +310,12 @@ impl PipelineParticipantMut for PolymorphismLowerer {
         project.index(self.ids.clone()).annotate(self.ids.clone())
     }
 }
+
+impl PipelineParticipantMut for RetainParticipant {
+    fn post_index(&mut self, indexed_project: IndexedProject) -> IndexedProject {
+        let IndexedProject { mut project, index, .. } = indexed_project;
+        self.lower_retain(&mut project.units, index);
+        //Re-index
+        project.index(self.ids.clone())
+    }
+}

compiler/plc_lowering/src/lib.rs

@@ -6,6 +6,7 @@ use plc_ast::{ast::AstNode, provider::IdProvider};
 
 pub mod inheritance;
 pub mod initializer;
+pub mod retain;
 #[cfg(test)]
 mod tests;