feat: Validate types in math operations (#1300)

Adds a validation to check if a math operation has incompatible types.
For example the following code previously had no validation and as a
consequence would panic during codegen.

```
FUNCTION main : DINT
    VAR
        x1 : ARRAY[0..2] OF TOD;
        x2 : STRING;
    END_VAR

    x1 + x2;
    ADD(x1, x1);
    DIV(x1, x2);
    SUB(x2, x2);
END_FUNCTION
```

Author: volsa

compiler/plc_diagnostics/src/diagnostics/diagnostics_registry.rs

@@ -102,30 +102,30 @@ impl From<&DiagnosticsRegistry> for DiagnosticsConfiguration {
 #[rustfmt::skip]
 lazy_static! {
     pub static ref DIAGNOSTICS: FxHashMap<&'static str, DiagnosticEntry> = add_diagnostic!(
-        E001,   Error,      include_str!("./error_codes/E001.md"), //General Error
-        E002,   Error,      include_str!("./error_codes/E002.md"), //General IO Error
-        E003,   Error,      include_str!("./error_codes/E003.md"), //Parameter Error
-        E004,   Error,      include_str!("./error_codes/E004.md"), //Duplicate Symbol
-        E005,   Error,      include_str!("./error_codes/E005.md"), //Generic LLVM Error
-        E006,   Error,      include_str!("./error_codes/E006.md"), //Missing Token
-        E007,   Error,      include_str!("./error_codes/E007.md"), //Unexpected Token
-        E008,   Error,      include_str!("./error_codes/E008.md"), //Invalid Range
-        E009,   Error,      include_str!("./error_codes/E009.md"), //Mismatched Parantheses
-        E010,   Error,      include_str!("./error_codes/E010.md"), //Invalid Time Literal
-        E011,   Error,      include_str!("./error_codes/E011.md"), //Invalid Number
-        E012,   Error,      include_str!("./error_codes/E012.md"), //Missing Case Condition
-        E013,   Warning,    include_str!("./error_codes/E013.md"), //Keywords shoud contain underscores
-        E014,   Warning,    include_str!("./error_codes/E014.md"), //Wrong parantheses type
-        E015,   Warning,    include_str!("./error_codes/E015.md"), //Pointer is not standard
-        E016,   Warning,    include_str!("./error_codes/E016.md"), //Return types cannot have a default value
-        E017,   Error,      include_str!("./error_codes/E017.md"), //Classes cannot contain implementations
-        E018,   Error,      include_str!("./error_codes/E018.md"), //Duplicate Label
-        E019,   Error,      include_str!("./error_codes/E019.md"), //Classes cannot contain IN_OUT variables
-        E020,   Error,      include_str!("./error_codes/E020.md"), //Classes cannot contain a return type
-        E021,   Error,      include_str!("./error_codes/E021.md"), //POUs cannot be extended
-        E022,   Warning,    include_str!("./error_codes/E022.md"), //Missing action container
-        E023,   Warning,    include_str!("./error_codes/E023.md"), //Statement with no effect
-        E024,   Warning,    include_str!("./error_codes/E024.md"), //Invalid pragma location
+        E001,   Error,      include_str!("./error_codes/E001.md"), // General Error
+        E002,   Error,      include_str!("./error_codes/E002.md"), // General IO Error
+        E003,   Error,      include_str!("./error_codes/E003.md"), // Parameter Error
+        E004,   Error,      include_str!("./error_codes/E004.md"), // Duplicate Symbol
+        E005,   Error,      include_str!("./error_codes/E005.md"), // Generic LLVM Error
+        E006,   Error,      include_str!("./error_codes/E006.md"), // Missing Token
+        E007,   Error,      include_str!("./error_codes/E007.md"), // Unexpected Token
+        E008,   Error,      include_str!("./error_codes/E008.md"), // Invalid Range
+        E009,   Error,      include_str!("./error_codes/E009.md"), // Mismatched Parantheses
+        E010,   Error,      include_str!("./error_codes/E010.md"), // Invalid Time Literal
+        E011,   Error,      include_str!("./error_codes/E011.md"), // Invalid Number
+        E012,   Error,      include_str!("./error_codes/E012.md"), // Missing Case Condition
+        E013,   Warning,    include_str!("./error_codes/E013.md"), // Keywords shoud contain underscores
+        E014,   Warning,    include_str!("./error_codes/E014.md"), // Wrong parantheses type
+        E015,   Warning,    include_str!("./error_codes/E015.md"), // Pointer is not standard
+        E016,   Warning,    include_str!("./error_codes/E016.md"), // Return types cannot have a default value
+        E017,   Error,      include_str!("./error_codes/E017.md"), // Classes cannot contain implementations
+        E018,   Error,      include_str!("./error_codes/E018.md"), // Duplicate Label
+        E019,   Error,      include_str!("./error_codes/E019.md"), // Classes cannot contain IN_OUT variables
+        E020,   Error,      include_str!("./error_codes/E020.md"), // Classes cannot contain a return type
+        E021,   Error,      include_str!("./error_codes/E021.md"), // POUs cannot be extended
+        E022,   Warning,    include_str!("./error_codes/E022.md"), // Missing action container
+        E023,   Warning,    include_str!("./error_codes/E023.md"), // Statement with no effect
+        E024,   Warning,    include_str!("./error_codes/E024.md"), // Invalid pragma location
         E025,   Error,      include_str!("./error_codes/E025.md"), // Missing return type
         E026,   Error,      include_str!("./error_codes/E026.md"),
         E027,   Error,      include_str!("./error_codes/E027.md"),
@@ -139,16 +139,16 @@ lazy_static! {
         E035,   Error,      include_str!("./error_codes/E035.md"),
         E036,   Error,      include_str!("./error_codes/E036.md"),
         E037,   Error,      include_str!("./error_codes/E037.md"),
-        E038,   Error,      include_str!("./error_codes/E038.md"), //Missing type
+        E038,   Error,      include_str!("./error_codes/E038.md"), // Missing type
         E039,   Warning,    include_str!("./error_codes/E039.md"),
         E040,   Error,      include_str!("./error_codes/E040.md"),
         E041,   Error,      include_str!("./error_codes/E041.md"),
-        E042,   Warning,    include_str!("./error_codes/E042.md"), //Assignment to reference
+        E042,   Warning,    include_str!("./error_codes/E042.md"), // Assignment to reference
         E043,   Error,      include_str!("./error_codes/E043.md"),
         E044,   Error,      include_str!("./error_codes/E044.md"),
         E045,   Error,      include_str!("./error_codes/E045.md"),
         E046,   Error,      include_str!("./error_codes/E046.md"),
-        E047,   Warning,    include_str!("./error_codes/E047.md"), //VLAs are always by reference
+        E047,   Warning,    include_str!("./error_codes/E047.md"), // VLAs are always by reference
         E048,   Error,      include_str!("./error_codes/E048.md"),
         E049,   Error,      include_str!("./error_codes/E049.md"),
         E050,   Error,      include_str!("./error_codes/E050.md"),
@@ -161,14 +161,14 @@ lazy_static! {
         E057,   Error,      include_str!("./error_codes/E057.md"),
         E058,   Error,      include_str!("./error_codes/E058.md"),
         E059,   Error,      include_str!("./error_codes/E059.md"),
-        E060,   Info,       include_str!("./error_codes/E060.md"), //Variable direct access with %
+        E060,   Info,       include_str!("./error_codes/E060.md"), // Variable direct access with %
         E061,   Error,      include_str!("./error_codes/E061.md"),
         E062,   Error,      include_str!("./error_codes/E062.md"),
         E063,   Error,      include_str!("./error_codes/E063.md"),
         E064,   Error,      include_str!("./error_codes/E064.md"),
         E065,   Error,      include_str!("./error_codes/E065.md"),
         E066,   Error,      include_str!("./error_codes/E066.md"),
-        E067,   Warning,    include_str!("./error_codes/E067.md"), //Implicit typecast
+        E067,   Warning,    include_str!("./error_codes/E067.md"), // Implicit typecast
         E068,   Error,      include_str!("./error_codes/E068.md"),
         E069,   Error,      include_str!("./error_codes/E069.md"),
         E070,   Error,      include_str!("./error_codes/E070.md"),
@@ -191,17 +191,17 @@ lazy_static! {
         E087,   Error,      include_str!("./error_codes/E087.md"),
         E088,   Error,      include_str!("./error_codes/E088.md"),
         E089,   Error,      include_str!("./error_codes/E089.md"),
-        E090,   Warning,    include_str!("./error_codes/E090.md"), //Incompatible reference Assignment
+        E090,   Warning,    include_str!("./error_codes/E090.md"), // Incompatible reference Assignment
         E091,   Warning,    include_str!("./error_codes/E091.md"),
         E092,   Info,       include_str!("./error_codes/E092.md"),
         E093,   Warning,    include_str!("./error_codes/E093.md"),
         E094,   Error,      include_str!("./error_codes/E094.md"),
-        E095,   Error,      include_str!("./error_codes/E095.md"),  // Action call without `()`
-        E096,   Warning,    include_str!("./error_codes/E096.md"),  // Integer Condition
-        E097,   Error,      include_str!("./error_codes/E097.md"),  // Invalid Array Range
-        E098,   Error,      include_str!("./error_codes/E098.md"),  // Invalid `REF=` assignment
-        E099,   Error,      include_str!("./error_codes/E099.md"),  // Invalid `REFERENCE TO` declaration
-        E100,   Error,      include_str!("./error_codes/E100.md"),  // Immutable variable address
+        E095,   Error,      include_str!("./error_codes/E095.md"), // Action call without `()`
+        E096,   Warning,    include_str!("./error_codes/E096.md"), // Integer Condition
+        E097,   Error,      include_str!("./error_codes/E097.md"), // Invalid Array Range
+        E098,   Error,      include_str!("./error_codes/E098.md"), // Invalid `REF=` assignment
+        E099,   Error,      include_str!("./error_codes/E099.md"), // Invalid `REFERENCE TO` declaration
+        E100,   Error,      include_str!("./error_codes/E100.md"), // Immutable variable address
     );
 }
 

src/builtins.rs

@@ -26,7 +26,7 @@ use crate::{
         AnnotationMap, StatementAnnotation, TypeAnnotator, VisitorContext,
     },
     typesystem::{self, get_bigger_type, get_literal_actual_signed_type_name, DataTypeInformationProvider},
-    validation::{Validator, Validators},
+    validation::{statement::validate_type_compatibility, Validator, Validators},
 };
 
 // Defines a set of functions that are always included in a compiled application
@@ -332,8 +332,9 @@ lazy_static! {
 
                     annotate_arithmetic_function(annotator, statement, operator, params, ctx, Operator::Plus)
                 }),
-                validation:Some(|validator, operator, parameters, _, _| {
-                    validate_builtin_symbol_parameter_count(validator, operator, parameters, Operator::Plus)
+                validation:Some(|validator, operator, parameters, annotations, index| {
+                    validate_types(validator, &parameters, annotations, index);
+                    validate_builtin_symbol_parameter_count(validator, operator, parameters, Operator::Plus);
                 }),
                 generic_name_resolver,
                 code: |_, _, _| {
@@ -357,7 +358,8 @@ lazy_static! {
 
                     annotate_arithmetic_function(annotator, statement, operator, params, ctx, Operator::Multiplication)
                 }),
-                validation: Some(|validator, operator, parameters, _, _| {
+                validation: Some(|validator, operator, parameters, annotations, index| {
+                    validate_types(validator, &parameters, annotations, index);
                     validate_builtin_symbol_parameter_count(validator, operator, parameters, Operator::Multiplication)
                 }),
                 generic_name_resolver,
@@ -382,7 +384,8 @@ lazy_static! {
                     };
                     annotate_arithmetic_function(annotator, statement, operator, params, ctx, Operator::Minus)
                 }),
-                validation:Some(|validator, operator, parameters, _, _| {
+                validation:Some(|validator, operator, parameters, annotations, index| {
+                    validate_types(validator, &parameters, annotations, index);
                     validate_builtin_symbol_parameter_count(validator, operator, parameters, Operator::Minus)
                 }),
                 generic_name_resolver,
@@ -407,7 +410,8 @@ lazy_static! {
                     };
                     annotate_arithmetic_function(annotator, statement, operator, params, ctx, Operator::Division)
                 }),
-                validation:Some(|validator, operator, parameters, _, _| {
+                validation:Some(|validator, operator, parameters, annotations, index| {
+                    validate_types(validator, &parameters, annotations, index);
                     validate_builtin_symbol_parameter_count(validator, operator, parameters, Operator::Division)
                 }),
                 generic_name_resolver,
@@ -565,6 +569,24 @@ lazy_static! {
     ]);
 }
 
+fn validate_types(
+    validator: &mut Validator,
+    parameters: &Option<&AstNode>,
+    annotations: &dyn AnnotationMap,
+    index: &Index,
+) {
+    let Some(params) = parameters else { return };
+
+    let types = flatten_expression_list(params);
+    let mut types = types.iter().peekable();
+
+    while let Some(left) = types.next() {
+        if let Some(right) = types.peek() {
+            validate_type_compatibility(validator, annotations, index, left, right);
+        }
+    }
+}
+
 fn validate_builtin_symbol_parameter_count(
     validator: &mut Validator,
     operator: &AstNode,

src/validation.rs

@@ -9,6 +9,7 @@ use crate::{
         Index, PouIndexEntry,
     },
     resolver::AnnotationMap,
+    typesystem::DataType,
 };
 
 use self::{
@@ -23,7 +24,7 @@ mod array;
 mod global;
 mod pou;
 mod recursive;
-mod statement;
+pub(crate) mod statement;
 mod types;
 mod variable;
 
@@ -129,6 +130,14 @@ impl<'a> Validator<'a> {
         }
     }
 
+    pub fn get_type_name_or_slice(&self, dt: &DataType) -> String {
+        if dt.is_internal() {
+            return dt.get_type_information().get_inner_name().to_string();
+        }
+
+        self.context.slice(&dt.location)
+    }
+
     pub fn diagnostics(&mut self) -> Vec<Diagnostic> {
         let mut all_diagnostics = Vec::new();
         all_diagnostics.append(&mut self.take_diagnostics());