Merge branch 'topic/kp_20227' into 'master'

Add detector for KP 20227

Closes #590

See merge request eng/libadalang/langkit-query-language!590

Author: HugoGGuerrier

lkql_checker/share/lkql/kp/kp_20227.lkql

@@ -0,0 +1,5 @@
+@check(help="possible occurrence of KP 20227",
+       message="possible occurrence of KP 20227")
+fun kp_20227(node) =
+    |" Flags unchecked union types.
+    node is BaseTypeDecl(p_has_aspect("unchecked_union"): true)

testsuite/tests/checks/KP-20227/main.adb

@@ -0,0 +1,39 @@
+procedure Main is
+   type R_1 (B : Boolean) is record  --  FLAG
+      case B is
+         when True =>
+            I : Integer;
+
+         when False =>
+            C : Character;
+      end case;
+   end record;
+
+   pragma Unchecked_Union (R_1);
+
+   type R_2 (B : Boolean) is record  --  FLAG
+      case B is
+         when True =>
+            I : Integer;
+
+         when False =>
+            C : Character;
+      end case;
+   end record
+   with Unchecked_Union;
+
+   type R_3 (B : Boolean) is record  --  NOFLAG
+      case B is
+         when True =>
+            I : Integer;
+
+         when False =>
+            C : Character;
+      end case;
+   end record;
+
+   subtype S_R_1 is R_1;   --  FLAG
+   type D_R_1 is new R_1;  --  FLAG
+begin
+   null;
+end Main;

testsuite/tests/checks/KP-20227/prj.gpr

@@ -0,0 +1,2 @@
+project Prj is
+end Prj;

testsuite/tests/checks/KP-20227/test.out

@@ -0,0 +1,16 @@
+main.adb:2:9: rule violation: possible occurrence of KP 20227
+2 |    type R_1 (B : Boolean) is record  --  FLAG
+  |         ^^^
+
+main.adb:14:9: rule violation: possible occurrence of KP 20227
+14 |    type R_2 (B : Boolean) is record  --  FLAG
+   |         ^^^
+
+main.adb:35:12: rule violation: possible occurrence of KP 20227
+35 |    subtype S_R_1 is R_1;   --  FLAG
+   |            ^^^^^
+
+main.adb:36:9: rule violation: possible occurrence of KP 20227
+36 |    type D_R_1 is new R_1;  --  FLAG
+   |         ^^^^^
+

testsuite/tests/checks/KP-20227/test.yaml

@@ -0,0 +1,3 @@
+driver: checker
+rule_name: kp_20227
+project: prj.gpr

testsuite/tests/gnatcheck/xml_help/test.out

@@ -101,6 +101,7 @@ testsuite_driver: No output file generated by gnatcheck
       <check switch="+Rkp_20112" label="possible occurrence of KP 20112"/>
       <check switch="+Rkp_20113" label="possible occurrence of KP 20113"/>
       <check switch="+Rkp_20186" label="possible occurrence of KP 20186"/>
+      <check switch="+Rkp_20227" label="possible occurrence of KP 20227"/>
       <check switch="+Rkp_ob03_009" label="possible occurrence of KP OB03-009"/>
       <check switch="+Rkp_p226_024" label="possible occurrence of KP P226-024 - global analysis required"/>
       <check switch="+Rkp_q309_014" label="possible occurrence of KP Q309-014"/>
@@ -627,6 +628,7 @@ testsuite_driver: No output file generated by gnatcheck
       <check switch="+Rkp_20112" label="possible occurrence of KP 20112"/>
       <check switch="+Rkp_20113" label="possible occurrence of KP 20113"/>
       <check switch="+Rkp_20186" label="possible occurrence of KP 20186"/>
+      <check switch="+Rkp_20227" label="possible occurrence of KP 20227"/>
       <check switch="+Rkp_ob03_009" label="possible occurrence of KP OB03-009"/>
       <check switch="+Rkp_p226_024" label="possible occurrence of KP P226-024 - global analysis required"/>
       <check switch="+Rkp_q309_014" label="possible occurrence of KP Q309-014"/>