lkql check: add a warning when different LKQL files declare checkers with identical name

Author: thvnx

lkql_jit/language/src/main/java/com/adacore/lkql_jit/checker/BaseChecker.java

@@ -118,6 +118,11 @@ public void setAlias(String alias) {
     /** Create a deep copy of the current checker and return it. */
     public abstract BaseChecker copy();
 
+    /** Get the checker path name. */
+    public String getPath() {
+        return function.rootNode.getBody().getSourceSection().getSource().getPath();
+    }
+
     // ----- Inner classes -----
 
     /** This enum represents the valid remediation levels */

lkql_jit/language/src/main/java/com/adacore/lkql_jit/runtime/GlobalScope.java

@@ -86,7 +86,19 @@ public Map<String, BaseChecker> getCheckers() {
      */
     @CompilerDirectives.TruffleBoundary
     public void addChecker(String name, BaseChecker checker) {
-        this.checkers.put(name, checker);
+        BaseChecker previousValue = this.checkers.put(name, checker);
+
+        if (previousValue != null) {
+            System.err.println(
+                "Warning: a checker named \"" +
+                name +
+                "\" from: " +
+                previousValue.getPath() +
+                ", has been replaced by the one from: " +
+                checker.getPath() +
+                ". Note: checkers should have unique names."
+            );
+        }
     }
 
     /**

testsuite/tests/checks/same_check_name/rule1.lkql

@@ -0,0 +1,3 @@
+@check(message="Rule1")
+fun my_rule(node) =
+    node is DefiningName

testsuite/tests/checks/same_check_name/rule2.lkql

@@ -0,0 +1,3 @@
+@check(message="Rule2")
+fun my_rule(node) =
+    node is NullStmt

testsuite/tests/checks/same_check_name/rule3.lkql

@@ -0,0 +1,3 @@
+@check(message="Rule3")
+fun my_rule(node) =
+    node is DefiningName

testsuite/tests/checks/same_check_name/test.adb

@@ -0,0 +1,4 @@
+procedure P is  --  FLAG
+begin
+   null;
+end P;

testsuite/tests/checks/same_check_name/test.out

@@ -0,0 +1,6 @@
+Warning: a checker named "my_rule" from: <test-dir>/rule1.lkql, has been replaced by the one from: <test-dir>/rule2.lkql. Note: checkers should have unique names.
+Warning: a checker named "my_rule" from: <test-dir>/rule2.lkql, has been replaced by the one from: <test-dir>/rule3.lkql. Note: checkers should have unique names.
+test.adb:1:11: rule violation: Rule3
+1 | procedure P is  --  FLAG
+  |           ^
+

testsuite/tests/checks/same_check_name/test.yaml

@@ -0,0 +1,3 @@
+driver: 'checker'
+rule_name: My_Rule
+input_sources: [test.adb]