Merge branch 'topic/133' into 'master'

Rule 'unassigned_out_parameters': also check the subp's decl part.

Closes #133

See merge request eng/libadalang/langkit-query-language!220

Author: Roldak

lkql_checker/doc/gnatcheck_rm/predefined_rules.rst

@@ -8321,17 +8321,17 @@ This rule has the following (mandatory) parameter for the ``+R`` option:
 
 .. index:: Unassigned_OUT_Parameters
 
-Flag procedures' ``out`` parameters that are not assigned.
+Flag subprograms' ``out`` parameters that are not assigned.
 
-An ``out`` parameter is flagged if the *sequence of statements* of
-the procedure body (before the procedure body's exception part, if any)
-contains no assignment to the parameter.
+An ``out`` parameter is flagged if neither the *declarative part* nor the
+*sequence of statements* of the subprogram body (before the subprogram body's
+exception part, if any) contain an assignment to the parameter.
 
 An ``out`` parameter is flagged if an *exception handler* contains neither an
 assignment to the parameter nor a raise statement nor a call to a procedure
 marked No_Return.
 
-Bodies of generic procedures are also considered.
+Bodies of generic subprograms are also considered.
 
 The following are treated as assignments to an ``out`` parameter:
 
@@ -8345,6 +8345,10 @@ The rule has an optional parameter for the ``+R`` option:
   Ignore assignments to subcomponents of an ``out`` parameter when detecting
   if the parameter is assigned.
 
+.. note:: An assignment to a subprogram's parameter can occur in the subprogram
+   body's *declarative part* in the presence of a nested subprogram declaration
+   which itself contains an assignment to the enclosing subprogram's parameter.
+
 .. warning:: This rule only detects the described cases of unassigned variables
    and doesn't provide a full guarantee that there is no uninitialized access.
    It is only a partial replacement for the validity checks provided by

lkql_checker/share/lkql/unassigned_out_parameters.lkql

@@ -1,11 +1,11 @@
-# Flag procedures' out parameters that are not assigned.
-# An out parameter is flagged if the sequence of statements of the procedure
-# body (before the procedure body's exception part, if any) contains no
+# Flag subprogram' out parameters that are not assigned.
+# An out parameter is flagged if the sequence of statements of the subprogram
+# body (before the subprogram body's exception part, if any) contains no
 # assignment to the parameter.
 # An out parameter is also flagged if an exception handler contains neither an
 # assignment to the parameter nor a raise statement nor a call to a procedure
 # marked No_Return.
-# Bodies of generic procedures are also considered.
+# Bodies of generic subprograms are also considered.
 #
 # The following are treated as assignments to an out parameter:
 # - an assignment statement, with the parameter or some component as the target
@@ -51,30 +51,24 @@ fun check_exception_handler(param, name, h, ignore_comp) =
                                     p_has_aspect("No_Return"))) or
     check_stmts(param, name, h, ignore_comp)
 
-fun enclosing_body_stmts(node) =
-   match stdlib.enclosing_body(node)
-   | null         => null
-   | NullSubpDecl => null
-   | p          => p.f_stmts
-
-@unit_check(help="OUT parameters do not get values in procedure bodies",
+@unit_check(help="OUT parameters do not get values in subprogram bodies",
             category="Feature")
 fun unassigned_out_parameters(unit, ignore_component_assignments=false) = [
     {message: "unassigned OUT parameter " & n.f_name.text, loc: n}
     for n in from unit.root
     # Look for out parameters of subprogram bodies only
     select node@DefiningName(parent: DefiningNameList(parent:
-                ParamSpec(f_mode: ModeOut,
-                          parent: ParamSpecList(parent: Params(parent:
-                          SubpSpec(parent: SubpBody))))))
-    when {
-        val f = enclosing_body_stmts(node);
-        val decl = node.p_basic_decl();
-
-        f and not (
-        check_stmts(decl, node.f_name, f.f_stmts, ignore_component_assignments)
-        and not [m for m in (from f.f_exceptions select h@ExceptionHandler
-             when not check_exception_handler(decl, node.f_name, h,
-                                              ignore_component_assignments))
-            ])
-    }]
+                decl@ParamSpec(f_mode: ModeOut,
+                               parent: ParamSpecList(parent: Params(parent:
+                               SubpSpec(parent: body@SubpBody))))))
+    when not (
+        check_stmts(decl, node.f_name, body.f_decls,
+                    ignore_component_assignments)
+        or check_stmts(decl, node.f_name, body.f_stmts.f_stmts,
+                       ignore_component_assignments)
+    ) or stdlib.any([
+        m for m in (from body.f_stmts.f_exceptions select h@ExceptionHandler
+        when not check_exception_handler(decl, node.f_name, h,
+                                         ignore_component_assignments))
+    ])
+]

testsuite/tests/checks/unassigned_out_params/params.adb

@@ -87,6 +87,17 @@ procedure Params is
          raise;
    end;
 
+   function Func_With_Out_Param (X : in out Integer) return Integer is
+   begin
+      X := 1;
+      return 2;
+   end Func_With_Out_Param;
+
+   procedure Proc_Param_Assigned_In_Decl_Part (X : in out Integer) is
+      I : Integer := Func_With_Out_Param (X);
+   begin
+      null;
+   end Proc_Param_Assigned_In_Decl_Part;
 begin
    null;
 end Params;

testsuite/tests/checks/unassigned_out_params_nested_subp/prj.gpr

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

testsuite/tests/checks/unassigned_out_params_nested_subp/test.adb

@@ -0,0 +1,25 @@
+procedure Test is
+   procedure P
+     (A : out Integer;  --  NOFLAG
+      B : out Integer   --  NOFLAG
+      )
+   is
+      procedure Init_A is
+      begin
+         A := 2;
+      end Init_A;
+   begin
+      Init_A;
+
+      declare
+         procedure Init_B is
+         begin
+            B := 2;
+         end Init_B;
+      begin
+         Init_B;
+      end;
+   end P;
+begin
+   null;
+end Test;

testsuite/tests/checks/unassigned_out_params_nested_subp/test.out

@@ -0,0 +1,4 @@
+driver: 'checker'
+rule_name: 'Unassigned_OUT_Parameters'
+project: 'prj.gpr'
+