gnat_rm.texi: Document Reason argument for pragma Warnings.

2013-04-25  Robert Dewar  <dewar@adacore.com>

	* gnat_rm.texi: Document Reason argument for pragma Warnings.
	* par-prag.adb: Handle Reason parameter for pragma Warnings.
	* sem_prag.adb (Analyze_Pragma, case Warnings): Allow Reason argument.
	* snames.ads-tmpl (Name_Reason): New name entry.

From-SVN: r198295
This commit is contained in:
Robert Dewar 2013-04-25 10:49:26 +00:00 committed by Arnaud Charlet
parent 2995860f56
commit bbee5cc4b0
5 changed files with 71 additions and 23 deletions

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@ -1,3 +1,10 @@
2013-04-25 Robert Dewar <dewar@adacore.com>
* gnat_rm.texi: Document Reason argument for pragma Warnings.
* par-prag.adb: Handle Reason parameter for pragma Warnings.
* sem_prag.adb (Analyze_Pragma, case Warnings): Allow Reason argument.
* snames.ads-tmpl (Name_Reason): New name entry.
2013-04-25 Yannick Moy <moy@adacore.com>
* exp_spark.adb (Expand_SPARK_N_In): Remove procedure.

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@ -6520,10 +6520,12 @@ implementation in DEC Ada 83.
Syntax:
@smallexample @c ada
pragma Warnings (On | Off);
pragma Warnings (On | Off, LOCAL_NAME);
pragma Warnings (static_string_EXPRESSION);
pragma Warnings (On | Off, static_string_EXPRESSION);
pragma Warnings (On | Off [,REASON]);
pragma Warnings (On | Off, LOCAL_NAME [,REASON]);
pragma Warnings (static_string_EXPRESSION [,REASON]);
pragma Warnings (On | Off, static_string_EXPRESSION [,REASON]);
REASON ::= Reason => static_string_EXPRESSION
@end smallexample
@noindent
@ -6531,17 +6533,28 @@ Normally warnings are enabled, with the output being controlled by
the command line switch. Warnings (@code{Off}) turns off generation of
warnings until a Warnings (@code{On}) is encountered or the end of the
current unit. If generation of warnings is turned off using this
pragma, then no warning messages are output, regardless of the
setting of the command line switches.
pragma, then some or all of the warning messages are suppressed,
regardless of the setting of the command line switches.
The form with a single argument may be used as a configuration pragma.
The @code{Reason} parameter may optionally appear as the last argument
in any of the forms of this pragma. It is intended purely for the
purposes of documenting the reason for the @code{Warnings} pragma.
The compiler will check that the argument is a static string but
otherwise ignore this argument. Other tools may provide specialized
processing for this string.
The form with a single argument (or two arguments if Reason present),
where the first argument is @code{ON} or @code{OFF}
may be used as a configuration pragma.
If the @var{LOCAL_NAME} parameter is present, warnings are suppressed for
the specified entity. This suppression is effective from the point where
it occurs till the end of the extended scope of the variable (similar to
the scope of @code{Suppress}).
the scope of @code{Suppress}). This form cannot be used as a configuration
pragma.
The form with a single static_string_EXPRESSION argument provides more precise
The form with a single static_string_EXPRESSION argument (and possible
reason) provides more precise
control over which warnings are active. The string is a list of letters
specifying which warnings are to be activated and which deactivated. The
code for these letters is the same as the string used in the command
@ -6549,7 +6562,7 @@ line switch controlling warnings. For a brief summary, use the gnatmake
command with no arguments, which will generate usage information containing
the list of warnings switches supported. For
full details see @ref{Warning Message Control,,, gnat_ugn, @value{EDITION}
User's Guide}.
User's Guide}. This form can also be used as a configuration pragma.
@noindent
The warnings controlled by the `-gnatw' switch are generated by the front end

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@ -17,7 +17,7 @@
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- War --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
@ -1027,8 +1027,15 @@ begin
-- set well before any semantic analysis is performed. Note that we
-- ignore this pragma if debug flag -gnatd.i is set.
-- Also note that the "one argument" case may have two arguments if the
-- second one is a reason argument.
when Pragma_Warnings =>
if Arg_Count = 1 and then not Debug_Flag_Dot_I then
if not Debug_Flag_Dot_I
and then (Arg_Count = 1
or else (Arg_Count = 2
and then Chars (Arg2) = Name_Reason))
then
Check_No_Identifier (Arg1);
declare

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@ -3310,13 +3310,11 @@ package body Sem_Prag is
procedure Check_No_Identifiers is
Arg_Node : Node_Id;
begin
if Arg_Count > 0 then
Arg_Node := Arg1;
while Present (Arg_Node) loop
Check_No_Identifier (Arg_Node);
Next (Arg_Node);
end loop;
end if;
Arg_Node := Arg1;
for J in 1 .. Arg_Count loop
Check_No_Identifier (Arg_Node);
Next (Arg_Node);
end loop;
end Check_No_Identifiers;
------------------------
@ -17477,14 +17475,36 @@ package body Sem_Prag is
-- Warnings --
--------------
-- pragma Warnings (On | Off);
-- pragma Warnings (On | Off, LOCAL_NAME);
-- pragma Warnings (static_string_EXPRESSION);
-- pragma Warnings (On | Off, STRING_LITERAL);
-- pragma Warnings (On | Off [,REASON]);
-- pragma Warnings (On | Off, LOCAL_NAME [,REASON]);
-- pragma Warnings (static_string_EXPRESSION [,REASON]);
-- pragma Warnings (On | Off, STRING_LITERAL [,REASON]);
-- REASON ::= Reason => Static_String_Expression
when Pragma_Warnings => Warnings : begin
GNAT_Pragma;
Check_At_Least_N_Arguments (1);
-- See if last argument is labeled Reason. If so, make sure we
-- have a static string expression, but otherwise just ignore
-- the REASON argument by decreasing Num_Args by 1 (all the
-- remaining tests look only at the first Num_Args arguments).
declare
Last_Arg : constant Node_Id :=
Last (Pragma_Argument_Associations (N));
begin
if Nkind (Last_Arg) = N_Pragma_Argument_Association
and then Chars (Last_Arg) = Name_Reason
then
Check_Arg_Is_Static_Expression (Last_Arg, Standard_String);
Arg_Count := Arg_Count - 1;
end if;
end;
-- Now proceed with REASON taken care of and eliminated
Check_No_Identifiers;
-- If debug flag -gnatd.i is set, pragma is ignored

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@ -746,6 +746,7 @@ package Snames is
Name_Optional : constant Name_Id := N + $;
Name_Policy : constant Name_Id := N + $;
Name_Parameter_Types : constant Name_Id := N + $;
Name_Reason : constant Name_Id := N + $;
Name_Reference : constant Name_Id := N + $;
Name_Requires : constant Name_Id := N + $;
Name_Restricted : constant Name_Id := N + $;