Raise error for package referecne before defnition

crates/analyzer/src/analyzer_error.rs

@@ -758,6 +758,21 @@ pub enum AnalyzerError {
         error_location: SourceSpan,
     },
 
+    #[diagnostic(
+        severity(Error),
+        code(referring_package_before_definition),
+        help("change order of package definitions"),
+        url("")
+    )]
+    #[error("pakcakge {identifier} is referred before it is defined.")]
+    ReferringPackageBeforeDefinition {
+        identifier: String,
+        #[source_code]
+        input: NamedSource<String>,
+        #[label("Error location")]
+        error_location: SourceSpan,
+    },
+
     #[diagnostic(
         severity(Error),
         code(unresolvable_generic_argument),
@@ -1569,6 +1584,18 @@ impl AnalyzerError {
         }
     }
 
+    pub fn referring_package_before_definition(
+        identifier: &str,
+        source: &str,
+        token: &TokenRange,
+    ) -> Self {
+        AnalyzerError::ReferringPackageBeforeDefinition {
+            identifier: identifier.to_string(),
+            input: AnalyzerError::named_source(source, token),
+            error_location: token.into(),
+        }
+    }
+
     pub fn unresolvable_generic_argument(
         identifier: &str,
         source: &str,

crates/analyzer/src/handlers/create_reference.rs

@@ -10,7 +10,7 @@ use crate::type_dag::{self, Context, DagError};
 use std::collections::HashMap;
 use veryl_parser::resource_table;
 use veryl_parser::veryl_grammar_trait::*;
-use veryl_parser::veryl_token::{is_anonymous_text, Token, TokenRange};
+use veryl_parser::veryl_token::{is_anonymous_text, Token, TokenRange, TokenSource};
 use veryl_parser::veryl_walker::{Handler, HandlerPoint};
 use veryl_parser::ParolError;
 
@@ -107,6 +107,7 @@ impl<'a> CreateReference<'a> {
 
             match symbol_table::resolve((&base_path, namespace)) {
                 Ok(symbol) => {
+                    self.check_pacakge_reference(&symbol.found, &path.range);
                     symbol_table::add_reference(symbol.found.id, &path.paths[0].base);
 
                     // Check number of arguments
@@ -181,6 +182,31 @@ impl<'a> CreateReference<'a> {
         }
     }
 
+    fn check_pacakge_reference(&mut self, symbol: &Symbol, token_range: &TokenRange) {
+        if !matches!(symbol.kind, SymbolKind::Package(_)) {
+            return;
+        }
+
+        let base_token = token_range.end;
+        let package_token = symbol.token;
+        if let (TokenSource::File(package_file), TokenSource::File(base_file)) =
+            (package_token.source, base_token.source)
+        {
+            let referecne_before_definition = package_file == base_file
+                && (package_token.line > base_token.line
+                    || package_token.line == base_token.line
+                        && package_token.column > base_token.column);
+            if referecne_before_definition {
+                self.errors
+                    .push(AnalyzerError::referring_package_before_definition(
+                        &package_token.to_string(),
+                        self.text,
+                        token_range,
+                    ));
+            }
+        }
+    }
+
     fn insert_declaration_dag_node(&mut self, symbol: &Symbol) -> Option<u32> {
         if let Some(child) = self.insert_dag_node(symbol) {
             if let Some(parent) = self.dag_scope_parent.last().cloned() {

crates/analyzer/src/tests.rs

@@ -1758,6 +1758,67 @@ fn undefined_identifier() {
     ));
 }
 
+#[test]
+fn referring_package_before_definition() {
+    let code = r#"
+    module ModuleA {
+        const A: u32 = PakcageB::B;
+    }
+    package PakcageB {
+        const B: u32 = 0;
+    }
+    "#;
+
+    let errors = analyze(code);
+    assert!(matches!(
+        errors[0],
+        AnalyzerError::ReferringPackageBeforeDefinition { .. }
+    ));
+
+    let code = r#"
+    interface InterfaceA {
+        const A: u32 = PakcageB::B;
+    }
+    package PakcageB {
+        const B: u32 = 0;
+    }
+    "#;
+
+    let errors = analyze(code);
+    assert!(matches!(
+        errors[0],
+        AnalyzerError::ReferringPackageBeforeDefinition { .. }
+    ));
+
+    let code = r#"
+    package PackageA {
+        const A: u32 = PakcageB::B;
+    }
+    package PakcageB {
+        const B: u32 = 0;
+    }
+    "#;
+
+    let errors = analyze(code);
+    assert!(matches!(
+        errors[0],
+        AnalyzerError::ReferringPackageBeforeDefinition { .. }
+    ));
+
+    let code = r#"
+    import PakcageB::B;
+    package PakcageB {
+        const B: u32 = 0;
+    }
+    "#;
+
+    let errors = analyze(code);
+    assert!(matches!(
+        errors[0],
+        AnalyzerError::ReferringPackageBeforeDefinition { .. }
+    ));
+}
+
 #[test]
 fn unknown_attribute() {
     let code = r#"

testcases/sv/19_import_export.sv

@@ -1,6 +1,12 @@
 
 
 
+package veryl_testcase_PackageA;
+    import PackageA::A;
+    import PackageA::*;
+    localparam int unsigned A = 0;
+endpackage
+
 module veryl_testcase_Module19
     import PackageA::A;
     import PackageA::*;
@@ -25,10 +31,4 @@ package veryl_testcase_Package19;
     export A;
     export *::*;
 endpackage
-
-package veryl_testcase_PackageA;
-    import PackageA::A;
-    import PackageA::*;
-    localparam int unsigned A = 0;
-endpackage
 //# sourceMappingURL=../map/testcases/sv/19_import_export.sv.map

testcases/sv/37_package_ref.sv

@@ -1,11 +1,3 @@
-module veryl_testcase_Module37;
-    int unsigned _a;
-    always_comb _a = veryl_testcase_Package37::A;
-    int unsigned _b;
-    always_comb _b = veryl_testcase_Package37::B_C;
-    int unsigned _c;
-    always_comb _c = veryl_testcase_Package37::X();
-endmodule
 package veryl_testcase_Package37;
     localparam int unsigned A = 1;
 
@@ -17,4 +9,13 @@ package veryl_testcase_Package37;
         return 0;
     endfunction
 endpackage
+
+module veryl_testcase_Module37;
+    int unsigned _a;
+    always_comb _a = veryl_testcase_Package37::A;
+    int unsigned _b;
+    always_comb _b = veryl_testcase_Package37::B_C;
+    int unsigned _c;
+    always_comb _c = veryl_testcase_Package37::X();
+endmodule
 //# sourceMappingURL=../map/testcases/sv/37_package_ref.sv.map

testcases/sv/44_import_resolve.sv

@@ -1,3 +1,11 @@
+package veryl_testcase_Package44A;
+    localparam int unsigned z = 0;
+endpackage
+
+package veryl_testcase_Package44B;
+    localparam int unsigned y = 0;
+endpackage
+
 module veryl_testcase_Module44;
     logic [10-1:0] a;
     logic [10-1:0] b;
@@ -10,12 +18,4 @@ module veryl_testcase_Module44;
     always_comb b = z;
     always_comb c = y;
 endmodule
-
-package veryl_testcase_Package44A;
-    localparam int unsigned z = 0;
-endpackage
-
-package veryl_testcase_Package44B;
-    localparam int unsigned y = 0;
-endpackage
 //# sourceMappingURL=../map/testcases/sv/44_import_resolve.sv.map