2009-07-22 Robert Dewar <dewar@adacore.com>

	* sem_res.adb (Check_No_Direct_Boolean_Operators): Add check for -gnatyB
	* style.ads, styleg.adb, styleg.ads (Check_Boolean_Operator): New
	procedure.
	* usage.adb, stylesw.ads, stylesw.adb: Add handling of -gnatyB switch
	* gnat_ugn.texi: Add documentation of -gnatyB
	* vms_data.ads: Add entry for -gnatyB (STYLE=BOOLEAN_OPERATORS)



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@149923 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 81 insertions, 0 deletions

diff --git a/gcc/ada/styleg.adb b/gcc/ada/styleg.adb
index c92231d60b3..8bd9f2ee2bd 100644
--- a/gcc/ada/styleg.adb
+++ b/gcc/ada/styleg.adb
@@ -27,11 +27,14 @@
 --  checking rules. For documentation of these rules, see comments on the
 --  individual procedures.
 
+with Atree;    use Atree;
 with Casing;   use Casing;
 with Csets;    use Csets;
+with Einfo;    use Einfo;
 with Err_Vars; use Err_Vars;
 with Opt;      use Opt;
 with Scans;    use Scans;
+with Sinfo;    use Sinfo;
 with Sinput;   use Sinput;
 with Stylesw;  use Stylesw;
 
@@ -166,6 +169,84 @@ package body Styleg is
       end if;
    end Check_Binary_Operator;
 
+   ----------------------------
+   -- Check_Boolean_Operator --
+   ----------------------------
+
+   procedure Check_Boolean_Operator (Node : Node_Id) is
+
+      function OK_Boolean_Operand (N : Node_Id) return Boolean;
+      --  Returns True for simple variable, or "not X1" or "X1 and X2" or
+      --  "X1 or X2" where X1, X2 are recursively OK_Boolean_Operand's.
+
+      ------------------------
+      -- OK_Boolean_Operand --
+      ------------------------
+
+      function OK_Boolean_Operand (N : Node_Id) return Boolean is
+      begin
+         if Nkind_In (N, N_Identifier, N_Expanded_Name) then
+            return True;
+
+         elsif Nkind (N) = N_Op_Not then
+            return OK_Boolean_Operand (Original_Node (Right_Opnd (N)));
+
+         elsif Nkind_In (N, N_Op_And, N_Op_Or) then
+            return OK_Boolean_Operand (Original_Node (Left_Opnd (N)))
+                     and then
+                   OK_Boolean_Operand (Original_Node (Right_Opnd (N)));
+
+         else
+            return False;
+         end if;
+      end OK_Boolean_Operand;
+
+   --  Start of processig for Check_Boolean_Operator
+   begin
+      if Style_Check_Boolean_And_Or
+        and then Comes_From_Source (Node)
+      then
+         declare
+            Orig : constant Node_Id := Original_Node (Node);
+
+         begin
+            if Nkind_In (Orig, N_Op_And, N_Op_Or) then
+               declare
+                  L : constant Node_Id := Original_Node (Left_Opnd  (Orig));
+                  R : constant Node_Id := Original_Node (Right_Opnd (Orig));
+
+               begin
+                  --  First OK case, simple boolean constants/identifiers
+
+                  if OK_Boolean_Operand (L)
+                       and then
+                     OK_Boolean_Operand (R)
+                  then
+                     return;
+
+                  --  Second OK case, modular types
+
+                  elsif Is_Modular_Integer_Type (Etype (Node)) then
+                     return;
+
+                  --  Third OK case, array types
+
+                  elsif Is_Array_Type (Etype (Node)) then
+                     return;
+
+                  --  Otherwise we have an error
+
+                  elsif Nkind (Orig) = N_Op_And then
+                     Error_Msg ("(style) `AND THEN` required", Sloc (Orig));
+                  else
+                     Error_Msg ("(style) `OR ELSE` required", Sloc (Orig));
+                  end if;
+               end;
+            end if;
+         end;
+      end if;
+   end Check_Boolean_Operator;
+
    ---------------
    -- Check_Box --
    ---------------