This patch fixes a bug in which pragma Ignore_Pragma(Interface); is illegal,
except in Ada 83 mode. It should be legal in all modes.
The following test should compile quietly.
-- gnat.adc
pragma Ignore_Pragma(Interface);
-- legal_interface.ads
package Legal_Interface is
procedure Interface_Or_Not;
pragma Interface (Esperanto, Interface_Or_Not);
-- The pragma should be ignored, so the body of Interface_Or_Not is legal,
-- and the fact that Esperanto is not a supported language is irrelevant.
end Legal_Interface;
-- legal_interface.adb
package body Legal_Interface is
procedure Interface_Or_Not is
begin
null;
end Interface_Or_Not;
end Legal_Interface;
Tested on x86_64-pc-linux-gnu, committed on trunk
2017-04-25 Bob Duff <d...@adacore.com>
* par-ch2.adb, scans.ads, scn.adb: Do not give an error for
reserved words inside pragmas. This is necessary to allow the
pragma name Interface to be used in pragma Ignore_Pragma.
* par.adb: Minor comment fix.
Index: par-ch2.adb
===================================================================
--- par-ch2.adb (revision 247135)
+++ par-ch2.adb (working copy)
@@ -268,6 +268,7 @@
-- Start of processing for P_Pragma
begin
+ Inside_Pragma := True;
Prag_Node := New_Node (N_Pragma, Token_Ptr);
Scan; -- past PRAGMA
Prag_Name := Token_Name;
@@ -362,9 +363,10 @@
Semicolon_Loc := Token_Ptr;
- -- Cancel indication of being within Depends pragm. Can be done
- -- unconditionally, since quicker than doing a test.
+ -- Cancel indication of being within a pragma or in particular a Depends
+ -- pragma.
+ Inside_Pragma := False;
Inside_Depends := False;
-- Now we have two tasks left, we need to scan out the semicolon
@@ -388,12 +390,11 @@
Skip_Pragma_Semicolon;
return Par.Prag (Prag_Node, Semicolon_Loc);
end if;
-
exception
when Error_Resync =>
Resync_Past_Semicolon;
+ Inside_Pragma := False;
return Error;
-
end P_Pragma;
-- This routine is called if a pragma is encountered in an inappropriate
Index: scans.ads
===================================================================
--- scans.ads (revision 247135)
+++ scans.ads (working copy)
@@ -484,9 +484,13 @@
-- Is it really right for this to be a Name rather than a String, what
-- about the case of Wide_Wide_Characters???
+ Inside_Pragma : Boolean := False;
+ -- True within a pragma. Used to avoid complaining about reserved words
+ -- within pragmas (see Scan_Reserved_Identifier).
+
Inside_Depends : Boolean := False;
- -- Flag set True for parsing the argument of a Depends pragma or aspect
- -- (used to allow/require non-standard style rules for =>+ with -gnatyt).
+ -- True while parsing the argument of a Depends pragma or aspect (used to
+ -- allow/require non-standard style rules for =>+ with -gnatyt).
Inside_If_Expression : Nat := 0;
-- This is a counter that is set non-zero while scanning out an if
Index: par.adb
===================================================================
--- par.adb (revision 247146)
+++ par.adb (working copy)
@@ -70,8 +70,8 @@
-- Par.Ch5.Get_Loop_Block_Name).
Inside_Record_Definition : Boolean := False;
- -- Flag set True within a record definition. Used to control warning
- -- for redefinition of standard entities (not issued for field names).
+ -- True within a record definition. Used to control warning for
+ -- redefinition of standard entities (not issued for field names).
--------------------
-- Error Recovery --
Index: scn.adb
===================================================================
--- scn.adb (revision 247135)
+++ scn.adb (working copy)
@@ -255,9 +255,7 @@
-- Clear flags for reserved words used as identifiers
- for J in Token_Type loop
- Used_As_Identifier (J) := False;
- end loop;
+ Used_As_Identifier := (others => False);
end Initialize_Scanner;
---------------
@@ -380,8 +378,8 @@
------------------------------
procedure Scan_Reserved_Identifier (Force_Msg : Boolean) is
- Token_Chars : constant String := Token_Type'Image (Token);
-
+ Token_Chars : String := Token_Type'Image (Token);
+ Len : Natural := 0;
begin
-- AI12-0125 : '@' denotes the target_name, i.e. serves as an
-- abbreviation for the LHS of an assignment.
@@ -394,16 +392,24 @@
-- We have in Token_Chars the image of the Token name, i.e. Tok_xxx.
-- This code extracts the xxx and makes an identifier out of it.
- Name_Len := 0;
-
for J in 5 .. Token_Chars'Length loop
- Name_Len := Name_Len + 1;
- Name_Buffer (Name_Len) := Fold_Lower (Token_Chars (J));
+ Len := Len + 1;
+ Token_Chars (Len) := Fold_Lower (Token_Chars (J));
end loop;
- Token_Name := Name_Find;
+ Token_Name := Name_Find (Token_Chars (1 .. Len));
- if not Used_As_Identifier (Token) or else Force_Msg then
+ -- If Inside_Pragma is True, we don't give an error. This is to allow
+ -- things like "pragma Ignore_Pragma (Interface)", where "Interface" is
+ -- a reserved word. There is no danger of missing errors, because any
+ -- misuse must have been preceded by an illegal declaration. For
+ -- example, in "pragma Pack (Begin);", either Begin is not declared,
+ -- which is an error, or it is declared, which will be an error on that
+ -- declaration.
+
+ if (not Used_As_Identifier (Token) or else Force_Msg)
+ and then not Inside_Pragma
+ then
Error_Msg_Name_1 := Token_Name;
Error_Msg_SC ("reserved word* cannot be used as identifier!");
Used_As_Identifier (Token) := True;
