From 348e1a4297656e969a44a3cfc0632da8aa9726a3 Mon Sep 17 00:00:00 2001
From: German Nikolishin <german.nikolishin@gmail.com>
Date: Sat, 24 Feb 2024 14:58:49 +0000
Subject: [PATCH] resolve fields

---
 crates/semantics/src/ast.rs      | 14 -----------
 crates/semantics/src/contract.rs | 10 +++++---
 crates/semantics/src/lib.rs      |  1 +
 crates/semantics/src/types.rs    | 42 +++++++++++++++++++++++++++++---
 4 files changed, 46 insertions(+), 21 deletions(-)

diff --git a/crates/semantics/src/ast.rs b/crates/semantics/src/ast.rs
index 862e01c..d4b220e 100644
--- a/crates/semantics/src/ast.rs
+++ b/crates/semantics/src/ast.rs
@@ -47,20 +47,6 @@ impl Type {
                 set
             }
             TypeVariant::Struct(s) => HashSet::from([s.i]),
-            TypeVariant::Model(s) => {
-                contract.diagnostics.push(Report::semantic_error(
-                    s.loc.clone(),
-                    String::from("Cannot use model as a type here,"),
-                ));
-                HashSet::new()
-            }
-            TypeVariant::State(s) => {
-                contract.diagnostics.push(Report::semantic_error(
-                    s.loc.clone(),
-                    String::from("Cannot use state as a type here,"),
-                ));
-                HashSet::new()
-            }
             _ => HashSet::new(),
         }
     }
diff --git a/crates/semantics/src/contract.rs b/crates/semantics/src/contract.rs
index 34480b5..97ed390 100644
--- a/crates/semantics/src/contract.rs
+++ b/crates/semantics/src/contract.rs
@@ -11,7 +11,7 @@ use crate::ast::{
 };
 use crate::decls::DelayedDeclaration;
 use crate::global_symbol::SymbolInfo;
-use crate::types::map_type;
+use crate::types::{find_user_type_recursion, map_type, validate_fields};
 use crate::{decls::DelayedDeclarations, global_symbol::GlobalSymbol};
 
 /// Arbitrary limit of a max number of topic.
@@ -73,6 +73,9 @@ impl ContractDefinition {
     }
 
     /// Resolves fields during the second pass.
+    /// - Discover fields for structs, models, and states.
+    /// - Detect any cycles and report them.
+    /// - Ensure that no fields have types of any state or model.
     pub fn resolve_fields(&mut self, delay: &DelayedDeclarations) {
         // Update fields of the models and structs together.
         for (s, m) in delay.structs.iter().zip(delay.models.iter()) {
@@ -115,8 +118,9 @@ impl ContractDefinition {
 
             self.states[state.i].body = body;
         }
-        // todo: check for cycles.
-        // todo: check for valid types.
+
+        find_user_type_recursion(self);
+        validate_fields(self);
     }
 
     /// Resolve fields of declarations.
diff --git a/crates/semantics/src/lib.rs b/crates/semantics/src/lib.rs
index a472313..bf90ecd 100644
--- a/crates/semantics/src/lib.rs
+++ b/crates/semantics/src/lib.rs
@@ -18,6 +18,7 @@ mod tests;
 pub fn resolve_semantics(source: &Source) -> ContractDefinition {
     let mut definition = ContractDefinition::default();
     let delay = definition.resolve_declarations(source);
+    definition.resolve_fields(&delay);
 
     definition
 }
diff --git a/crates/semantics/src/types.rs b/crates/semantics/src/types.rs
index 41b7d47..2691a75 100644
--- a/crates/semantics/src/types.rs
+++ b/crates/semantics/src/types.rs
@@ -1,6 +1,6 @@
 use std::collections::HashSet;
 
-use crate::ast::{List, Mapping, Param, Set, Type, TypeVariant};
+use crate::ast::{List, Mapping, Param, Set, StateBody, Type, TypeVariant};
 use crate::contract::ContractDefinition;
 use crate::global_symbol::{GlobalSymbol, SymbolInfo};
 use folidity_diagnostics::Report;
@@ -81,7 +81,7 @@ pub fn map_type(contract: &mut ContractDefinition, ty: &parsed_ast::Type) -> Res
 /// Licensed as Apache 2.0
 //todo: rewrite.
 //TODO: support finite size recursive types.
-pub fn find_user_type_recursion(contract: &mut ContractDefinition) -> Result<(), Span> {
+pub fn find_user_type_recursion(contract: &mut ContractDefinition) {
     let mut edges = HashSet::new();
     for n in 0..contract.structs.len() {
         collect_edges(
@@ -111,8 +111,6 @@ pub fn find_user_type_recursion(contract: &mut ContractDefinition) -> Result<(),
             ));
         }
     }
-
-    Ok(())
 }
 
 /// Collect field dependencies into the graph edges.
@@ -145,3 +143,39 @@ fn check_for_recursive_types(node: usize, graph: &FieldGraph, contract: &mut Con
         }
     }
 }
+
+pub fn validate_fields(contract: &mut ContractDefinition) {
+    let mut validate = |fields: &[Param]| {
+        for field in fields.iter() {
+            match &field.ty.ty {
+                TypeVariant::Function(_) => contract.diagnostics.push(Report::semantic_error(
+                    field.loc.clone(),
+                    String::from("Function cannot be used as a field type."),
+                )),
+                TypeVariant::Model(_) => contract.diagnostics.push(Report::semantic_error(
+                    field.loc.clone(),
+                    String::from("Model cannot be used as a field type."),
+                )),
+                TypeVariant::State(_) => contract.diagnostics.push(Report::semantic_error(
+                    field.loc.clone(),
+                    String::from("State cannot be used as a field type."),
+                )),
+                _ => {}
+            }
+        }
+    };
+
+    for s in &contract.structs {
+        validate(&s.fields);
+    }
+
+    for s in &contract.states {
+        if let Some(StateBody::Raw(fields)) = &s.body {
+            validate(fields);
+        }
+    }
+
+    for m in &contract.models {
+        validate(&m.fields);
+    }
+}