[Ada] Clean up support for validity checks in the compiler

This removes old code in the parser that serves no useful purpose and
fixes minor issues in the Validsw package.  No functional changes.

2019-07-04  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* gnat1drv.adb (Adjust_Global_Switches): Use proper interface to
	set the validity settings in CodePeer mode.
	* par-load.adb (Load): Remove all code dealing with validity
	settings.
	* validsw.ads (Validity_Check_Copies): Alphabetize.
	* validsw.adb (Reset_Validity_Check_Options): Set all options to
	off.
	(Save_Validity_Check_Options): Save all options.

From-SVN: r273071

gcc/ada/ChangeLog

+2019-07-04  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat1drv.adb (Adjust_Global_Switches): Use proper interface to
+	set the validity settings in CodePeer mode.
+	* par-load.adb (Load): Remove all code dealing with validity
+	settings.
+	* validsw.ads (Validity_Check_Copies): Alphabetize.
+	* validsw.adb (Reset_Validity_Check_Options): Set all options to
+	off.
+	(Save_Validity_Check_Options): Save all options.
+
 2019-07-04  Hristian Kirtchev  <kirtchev@adacore.com>
 
 	* exp_ch3.adb, exp_ch4.adb, exp_ch4.ads, exp_ch5.adb,

gcc/ada/gnat1drv.adb

@@ -379,8 +379,7 @@ procedure Gnat1drv is
          --  enough useful info.
 
          Reset_Validity_Check_Options;
-         Validity_Check_Default       := True;
-         Validity_Check_Copies        := True;
+         Set_Validity_Check_Options ("dc");
          Check_Validity_Of_Parameters := False;
 
          --  Turn off style check options and ignore any style check pragmas

gcc/ada/par-load.adb

@@ -36,7 +36,6 @@ with Uname;    use Uname;
 with Osint;    use Osint;
 with Sinput.L; use Sinput.L;
 with Stylesw;  use Stylesw;
-with Validsw;  use Validsw;
 
 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
 
@@ -61,10 +60,6 @@ procedure Load is
    Save_Style_Checks : Style_Check_Options;
    --  Save style check so it can be restored later
 
-   Save_Validity_Check  : Boolean;
-   Save_Validity_Checks : Validity_Check_Options;
-   --  Save validity check so it can be restored later
-
    With_Cunit : Node_Id;
    --  Compilation unit node for withed unit
 
@@ -134,9 +129,6 @@ begin
    Save_Style_Check_Options (Save_Style_Checks);
    Save_Style_Check := Opt.Style_Check;
 
-   Save_Validity_Check_Options (Save_Validity_Checks);
-   Save_Validity_Check := Opt.Validity_Checks_On;
-
    --  If main unit, set Main_Unit_Entity (this will get overwritten if
    --  the main unit has a separate spec, that happens later on in Load)
 
@@ -318,11 +310,10 @@ begin
      or else Nkind (Unit (Curunit)) in N_Generic_Instantiation
      or else Nkind (Unit (Curunit)) in N_Renaming_Declaration
    then
-      --  Turn style and validity checks off for parent unit
+      --  Turn style checks off for parent unit
 
       if not GNAT_Mode then
          Reset_Style_Check_Options;
-         Reset_Validity_Check_Options;
       end if;
 
       Spec_Name := Get_Parent_Spec_Name (Unit_Name (Cur_Unum));
@@ -356,11 +347,10 @@ begin
       end if;
    end if;
 
-   --  Now we load with'ed units, with style/validity checks turned off
+   --  Now we load with'ed units, with style checks turned off
 
    if not GNAT_Mode then
       Reset_Style_Check_Options;
-      Reset_Validity_Check_Options;
    end if;
 
    --  Load the context items in two rounds: the first round handles normal
@@ -470,6 +460,4 @@ begin
 
    Set_Style_Check_Options (Save_Style_Checks);
    Opt.Style_Check := Save_Style_Check;
-   Set_Validity_Check_Options (Save_Validity_Checks);
-   Opt.Validity_Checks_On := Save_Validity_Check;
 end Load;

gcc/ada/validsw.adb

@@ -36,11 +36,12 @@ package body Validsw is
    begin
       Validity_Check_Components     := False;
       Validity_Check_Copies         := False;
-      Validity_Check_Default        := True;
+      Validity_Check_Default        := False;
       Validity_Check_Floating_Point := False;
       Validity_Check_In_Out_Params  := False;
       Validity_Check_In_Params      := False;
       Validity_Check_Operands       := False;
+      Validity_Check_Parameters     := False;
       Validity_Check_Returns        := False;
       Validity_Check_Subscripts     := False;
       Validity_Check_Tests          := False;
@@ -73,14 +74,14 @@ package body Validsw is
          Options (K) := ' ';
       end loop;
 
-      Add ('n', not Validity_Check_Default);
-
-      Add ('c', Validity_Check_Copies);
       Add ('e', Validity_Check_Components);
+      Add ('c', Validity_Check_Copies);
+      Add ('d', Validity_Check_Default);
       Add ('f', Validity_Check_Floating_Point);
       Add ('i', Validity_Check_In_Params);
       Add ('m', Validity_Check_In_Out_Params);
       Add ('o', Validity_Check_Operands);
+      Add ('p', Validity_Check_Parameters);
       Add ('r', Validity_Check_Returns);
       Add ('s', Validity_Check_Subscripts);
       Add ('t', Validity_Check_Tests);

gcc/ada/validsw.ads

@@ -40,33 +40,33 @@ package Validsw is
    --  or in the argument of a Validity_Checks pragma to activate the option.
    --  The corresponding upper case letter deactivates the option.
 
+   Validity_Check_Components : Boolean := False;
+   --  Controls validity checking for assignment to elementary components of
+   --  records. If this switch is set to True using -gnatVe, or an 'e' in the
+   --  argument of Validity_Checks pragma, then the right-hand side of an
+   --  assignment to such a component is checked for validity.
+
    Validity_Check_Copies : Boolean := False;
    --  Controls the validity checking of copies. If this switch is set to
-   --  true using -gnatVc, or a 'c' in the argument of a Validity_Checks
-   --  pragma, then the right side of assignments and also initializing
+   --  True using -gnatVc, or a 'c' in the argument of a Validity_Checks
+   --  pragma, then the right-hand side of assignments and also initializing
    --  expressions in object declarations are checked for validity.
 
-   Validity_Check_Components : Boolean := False;
-   --  Controls validity checking for assignment to elementary components of
-   --  records. If this switch is set true using -gnatVe, or an 'e' in the
-   --  argument of Validity_Checks pragma, then the right hand of an assignment
-   --  to such a component is checked for validity.
-
    Validity_Check_Default : Boolean := True;
    --  Controls default (reference manual) validity checking. If this switch is
    --  set to True using -gnatVd or a 'd' in the argument of a Validity_Checks
-   --  pragma (or the initial default value is used, set True), then left side
-   --  subscripts and case statement arguments are checked for validity. This
-   --  switch is also set by default if no -gnatV switch is used and no
+   --  pragma (or the initial default value is used, set True), then left-hand
+   --  side subscripts and case statement arguments are checked for validity.
+   --  This switch is also set by default if no -gnatV switch is used and no
    --  Validity_Checks pragma is processed.
 
    Validity_Check_Floating_Point : Boolean := False;
-   --  Normally validity checking applies only to discrete values (integer
-   --  and enumeration types). If this switch is set to True using -gnatVf
-   --  or an 'f' in the argument of a Validity_Checks pragma, then floating-
-   --  point values are also checked. The context in which such checks
-   --  occur depends on other flags, e.g. if Validity_Check_Copies is also
-   --  set then floating-point values on the right side of an assignment
+   --  Normally validity checking applies only to discrete values (integer and
+   --  enumeration types). If this switch is set to True using -gnatVf or an
+   --  'f' in the argument of a Validity_Checks pragma, then floating-point
+   --  values are also checked. If the context in which such checks occur
+   --  depends on other flags, e.g. if Validity_Check_Copies is also set,
+   --  then floating-point values on the right-hand side of an assignment
    --  will be validity checked.
 
    Validity_Check_In_Out_Params : Boolean := False;
@@ -103,13 +103,13 @@ package Validsw is
    --  pragma, then the expression in a RETURN statement is validity checked.
 
    Validity_Check_Subscripts : Boolean := False;
-   --  Controls validity checking of subscripts. If this switch is set to
-   --  True using -gnatVs, or an 's' in the argument of a Validity_Checks
-   --  pragma, then all subscripts are checked for validity. Note that left
-   --  side subscript checking is controlled also by Validity_Check_Default.
-   --  If Validity_Check_Subscripts is True, then all subscripts are checked,
-   --  otherwise if Validity_Check_Default is True, then left side subscripts
-   --  are checked, otherwise no subscripts are checked.
+   --  Controls validity checking of subscripts. If this switch is set to True
+   --  using -gnatVs, or an 's' in the argument of a Validity_Checks pragma,
+   --  then all subscripts are checked for validity. Note that left-hand side
+   --  subscript checking is also controlled by Validity_Check_Default. If
+   --  Validity_Check_Subscripts is True, then all subscripts are checked,
+   --  otherwise if Validity_Check_Default is True, then left-hand side
+   --  subscripts are checked; otherwise no subscripts are checked.
 
    Validity_Check_Tests : Boolean := False;
    --  Controls validity checking of tests that occur in conditions (i.e. the