From 03cdca606de86419825dd8499793788f6a1bd7c3 Mon Sep 17 00:00:00 2001
From: ychenfo <yc@m-labs.hk>
Date: Tue, 23 Nov 2021 01:02:42 +0800
Subject: [PATCH] nac3core: check type for default parameter

---
 nac3core/src/toplevel/composer.rs | 19 +++++++++--
 nac3core/src/toplevel/helper.rs   | 56 +++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/nac3core/src/toplevel/composer.rs b/nac3core/src/toplevel/composer.rs
index 232e0c4..677542b 100644
--- a/nac3core/src/toplevel/composer.rs
+++ b/nac3core/src/toplevel/composer.rs
@@ -1135,8 +1135,16 @@ impl TopLevelComposer {
                                     ty,
                                     default_value: match default {
                                         None => None,
-                                        Some(default) =>
-                                            Some(Self::parse_parameter_default_value(default, resolver)?)
+                                        Some(default) => Some({
+                                            let v = Self::parse_parameter_default_value(default, resolver)?;
+                                            Self::check_default_param_type(
+                                                &v,
+                                                &type_annotation,
+                                                primitives_store,
+                                                unifier
+                                            ).map_err(|err| format!("{} at {}", err, x.location))?;
+                                            v
+                                        })
                                     }
                                 })
                             })
@@ -1353,7 +1361,12 @@ impl TopLevelComposer {
                                             if name == "self".into() {
                                                 return Err(format!("`self` parameter cannot take default value at {}", x.location));
                                             }
-                                            Some(Self::parse_parameter_default_value(default, class_resolver)?)
+                                            Some({
+                                                let v = Self::parse_parameter_default_value(default, class_resolver)?;
+                                                Self::check_default_param_type(&v, &type_ann, primitives, unifier)
+                                                    .map_err(|err| format!("{} at {}", err, x.location))?;
+                                                v
+                                            })
                                         }
                                     }
                                 };
diff --git a/nac3core/src/toplevel/helper.rs b/nac3core/src/toplevel/helper.rs
index 2dcb359..5c8b85e 100644
--- a/nac3core/src/toplevel/helper.rs
+++ b/nac3core/src/toplevel/helper.rs
@@ -350,6 +350,62 @@ impl TopLevelComposer {
     pub fn parse_parameter_default_value(default: &ast::Expr, resolver: &(dyn SymbolResolver + Send + Sync)) -> Result<SymbolValue, String> {
         parse_parameter_default_value(default, resolver)
     }
+
+    pub fn check_default_param_type(val: &SymbolValue, ty: &TypeAnnotation, primitive: &PrimitiveStore, unifier: &mut Unifier) -> Result<(), String> {
+        let res = match val {
+            SymbolValue::Bool(..) => {
+                if matches!(ty, TypeAnnotation::Primitive(t) if *t == primitive.bool) {
+                    None
+                } else {
+                    Some("bool".to_string())
+                }
+            }
+            SymbolValue::Double(..) => {
+                if matches!(ty, TypeAnnotation::Primitive(t) if *t == primitive.float) {
+                    None
+                } else {
+                    Some("float".to_string())
+                }
+            }
+            SymbolValue::I32(..) => {
+                if matches!(ty, TypeAnnotation::Primitive(t) if *t == primitive.int32) {
+                    None
+                } else {
+                    Some("int32".to_string())
+                }
+            }
+            SymbolValue::I64(..) => {
+                if matches!(ty, TypeAnnotation::Primitive(t) if *t == primitive.int64) {
+                    None
+                } else {
+                    Some("int64".to_string())
+                }
+            }
+            SymbolValue::Tuple(elts) => {
+                if let TypeAnnotation::Tuple(elts_ty) = ty {
+                    for (e, t) in elts.iter().zip(elts_ty.iter()) {
+                        Self::check_default_param_type(e, t, primitive, unifier)?
+                    }
+                    if elts.len() != elts_ty.len() {
+                        Some(format!("tuple of length {}", elts.len()))
+                    } else {
+                        None
+                    }
+                } else {
+                    Some("tuple".to_string())
+                }
+            }
+        };
+        if let Some(found) = res {
+            Err(format!(
+                "incompatible default parameter type, expect {}, found {}",
+                ty.stringify(unifier),
+                found
+            ))
+        } else {
+            Ok(())
+        }
+    }
 }
 
 pub fn parse_parameter_default_value(default: &ast::Expr, resolver: &(dyn SymbolResolver + Send + Sync)) -> Result<SymbolValue, String> {