sem_prag.adb, [...]: Minor code clean up.

2015-02-05  Yannick Moy  <moy@adacore.com>

	* sem_prag.adb, par-prag.adb: Minor code clean up.

From-SVN: r220448

gcc/ada/ChangeLog

 2015-02-05  Yannick Moy  <moy@adacore.com>
 
+	* sem_prag.adb, par-prag.adb: Minor code clean up.
+
+2015-02-05  Yannick Moy  <moy@adacore.com>
+
 	* par-prag.adb (Pragma_Warnings): Update for extended form
 	of pragma Warnings. The "one" argument case may now have 2 or
 	3 arguments.

gcc/ada/par-prag.adb

@@ -1047,14 +1047,21 @@ begin
       -- Warnings (GNAT) --
       ---------------------
 
-      --  pragma Warnings ([TOOL_NAME,] On | Off [,REASON]);
-      --  pragma Warnings ([TOOL_NAME,] On | Off, LOCAL_NAME [,REASON]);
-      --  pragma Warnings ([TOOL_NAME,] static_string_EXPRESSION [,REASON]);
-      --  pragma Warnings ([TOOL_NAME,] On | Off,
-      --                                static_string_EXPRESSION [,REASON]);
+      --  pragma Warnings ([TOOL_NAME,] DETAILS [, REASON]);
+
+      --  DETAILS ::= On | Off
+      --  DETAILS ::= On | Off, local_NAME
+      --  DETAILS ::= static_string_EXPRESSION
+      --  DETAILS ::= On | Off, static_string_EXPRESSION
+
+      --  TOOL_NAME ::= GNAT | GNATProve
 
       --  REASON ::= Reason => STRING_LITERAL {& STRING_LITERAL}
 
+      --  Note: If the first argument matches an allowed tool name, it is
+      --  always considered to be a tool name, even if there is a string
+      --  variable of that name.
+
       --  The one argument ON/OFF case is processed by the parser, since it may
       --  control parser warnings as well as semantic warnings, and in any case
       --  we want to be absolutely sure that the range in the warnings table is
@@ -1065,8 +1072,6 @@ begin
       --  arguments if the first one is a tool name, and/or the last one is a
       --  reason argument.
 
-      --  Need documentation and syntax for TOOL_NAME ???
-
       when Pragma_Warnings => Warnings : declare
          function First_Arg_Is_Matching_Tool_Name return Boolean;
          --  Returns True if the first argument is a tool name matching the
@@ -1087,14 +1092,20 @@ begin
          -- First_Arg_Is_Matching_Tool_Name --
          -------------------------------------
 
-         --  Comments needed for these complex conditionals ???
-
          function First_Arg_Is_Matching_Tool_Name return Boolean is
          begin
             return Nkind (Arg1) = N_Identifier
+
+              --  Return True if the tool name is GNAT, and we're not in
+              --  GNATprove or CodePeer or ASIS mode...
+
               and then ((Chars (Arg1) = Name_Gnat
                           and then not
                             (CodePeer_Mode or GNATprove_Mode or ASIS_Mode))
+
+              --  or if the tool name is GNATprove, and we're in GNATprove
+              --  mode.
+
                         or else
                         (Chars (Arg1) = Name_Gnatprove
                           and then GNATprove_Mode));

gcc/ada/sem_prag.adb

@@ -3109,7 +3109,9 @@ package body Sem_Prag is
       --  Analyzes the argument, and determines if it is a static string
       --  expression, returns True if so, False if non-static or not String.
       --  A special case is that a string literal returns True in Ada 83 mode
-      --  (which has no such thing as static string expressions).
+      --  (which has no such thing as static string expressions). Note that
+      --  the call analyzes its argument, so this cannot be used for the case
+      --  where an identifier might not be declared.
 
       procedure Pragma_Misplaced;
       pragma No_Return (Pragma_Misplaced);
@@ -21323,18 +21325,20 @@ package body Sem_Prag is
          -- Warnings --
          --------------
 
-         --  pragma Warnings ([TOOL_NAME,] On | Off [,REASON]);
-         --  pragma Warnings ([TOOL_NAME,] On | Off, LOCAL_NAME [,REASON]);
-         --  pragma Warnings ([TOOL_NAME,] static_string_EXPRESSION [,REASON]);
-         --  pragma Warnings ([TOOL_NAME,] On | Off,
-         --                                static_string_EXPRESSION [,REASON]);
+         --  pragma Warnings ([TOOL_NAME,] DETAILS [, REASON]);
+
+         --  DETAILS ::= On | Off
+         --  DETAILS ::= On | Off, local_NAME
+         --  DETAILS ::= static_string_EXPRESSION
+         --  DETAILS ::= On | Off, static_string_EXPRESSION
+
+         --  TOOL_NAME ::= GNAT | GNATProve
 
          --  REASON ::= Reason => STRING_LITERAL {& STRING_LITERAL}
 
-         --  If present, TOOL_NAME refers to a tool, currently either GNAT
-         --  or GNATprove. If an identifier is a static string expression,
-         --  the form of pragma Warnings that starts with a static string
-         --  expression is used.
+         --  Note: If the first argument matches an allowed tool name, it is
+         --  always considered to be a tool name, even if there is a string
+         --  variable of that name.
 
          when Pragma_Warnings => Warnings : declare
             Reason : String_Id;
@@ -21396,9 +21400,7 @@ package body Sem_Prag is
                --  was given otherwise, by shifting the arguments.
 
                if Nkind (Argx) = N_Identifier
-                 and then not Nam_In (Chars (Argx), Name_On, Name_Off)
-                 and then not Is_Static_String_Expression (Arg1)
-                 --  How can this possibly work e.g. for GNATprove???
+                 and then Nam_In (Chars (Argx), Name_Gnat, Name_Gnatprove)
                then
                   if Chars (Argx) = Name_Gnat then
                      if CodePeer_Mode or GNATprove_Mode or ASIS_Mode then
@@ -21415,9 +21417,7 @@ package body Sem_Prag is
                      end if;
 
                   else
-                     Error_Pragma_Arg
-                       ("argument of pragma% must be On/Off or tool name "
-                        & "or static string expression", Arg1);
+                     raise Program_Error;
                   end if;
 
                   --  At this point, the pragma Warnings applies to the tool,