bug#36788: 26.1; ada-mode 6.0.0 should support function expressions returning aggregates directly

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Package: emacs, ada-mode
X-Debbugs-CC: ada-mode-users@nongnu.org
Severity: minor

Hello,

ada_mode_wisi_lr1_parse.exe does not follow AI12-0157[1], which allows
a function expression to return an aggregate directly as opposed to
an aggregate enclosed in an extra pair of parentheses:

package P is
    type T is null record;
    function F return T is (null record);
end P;

ada-mode 6.0 and later (checked with 6.1.1) show red exclamation marks
in the margin at function F.  C-c C-f says:

p.adb:3:51: syntax error: expecting BEGIN, ENTRY, FOR, FUNCTION, 
GENERIC, NOT, OVERRIDING, PACKAGE, PRAGMA, PROCEDURE, PROTECTED, 
SUBTYPE, TASK, TYPE, USE, IDENTIFIER, found 'LEFT_PAREN'

Changing the line to

    function F return T is ((null record));

removes the parsing error.

I know that GNAT Pro has had support for AI12-0157 for at least
a couple of years and I'm pretty sure the latest GNAT GPL Edition
has it too.

[1] 
http://www.ada-auth.org/cgi-bin/cvsweb.cgi/ai12s/ai12-0157-1.txt?rev=1.6

-- 
Ludovic Brenta.