[gcc r14-3994] Improve error message for if with an else part while in switch

[Andrew Pinski <pinskia@gcc.gnu.org>]

https://gcc.gnu.org/g:4241415b8817d505e92144175c040a48b1cf2b9f

commit r14-3994-g4241415b8817d505e92144175c040a48b1cf2b9f
Author: Andrew Pinski <apinski@marvell.com>
Date:   Tue Jul 11 22:14:18 2023 -0700

    Improve error message for if with an else part while in switch
    
    While writing some match.pd code, I was trying to figure
    out why I was getting an `expected ), got (` error message
    while writing an if statement with an else clause. For switch
    statements, the if statements cannot have an else clause so
    it would be better to have a decent error message saying that
    explictly.
    
    OK? Bootstrapped and tested on x86_64-linux-gnu.
    
    gcc/ChangeLog:
    
            * genmatch.cc (parser::parse_result): For an else clause
            of an if statement inside a switch, error out explictly.

Diff:
---
 gcc/genmatch.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc
index a1925a747a7..03d325efdf6 100644
--- a/gcc/genmatch.cc
+++ b/gcc/genmatch.cc
@@ -4891,6 +4891,8 @@ parser::parse_result (operand *result, predicate_id *matcher)
 		    ife->trueexpr = parse_result (result, matcher);
 		  else
 		    ife->trueexpr = parse_op ();
+		  if (peek ()->type == CPP_OPEN_PAREN)
+		    fatal_at (peek(), "if inside switch cannot have an else");
 		  eat_token (CPP_CLOSE_PAREN);
 		}
 	      else