[gcc r13-115] c++: parse error with >= in template argument list [PR105436]

[gcc r13-115] c++: parse error with >= in template argument list [PR105436]

[Marek Polacek]

https://gcc.gnu.org/g:79a1a01cbd0e4a491d7078783131e3f88ca7158d

commit r13-115-g79a1a01cbd0e4a491d7078783131e3f88ca7158d
Author: Marek Polacek <polacek@redhat.com>
Date:   Fri Apr 29 17:03:41 2022 -0400

    c++: parse error with >= in template argument list [PR105436]
    
    This patch fixes an oversight whereby we treated >= as the end of
    a template argument.  This causes problems in C++14, because in
    cp_parser_template_argument we go different ways for C++14 and C++17:
    
      /* It must be a non-type argument.  In C++17 any constant-expression is
         allowed.  */
      if (cxx_dialect > cxx14)
        goto general_expr;
    
    so in this testcase in C++14 we get "N" as the template argument but in
    C++17 it is the whole "N >= 5" expression.  So in C++14 the remaining
    ">= 5" triggered the newly-added diagnostic.
    
            PR c++/105436
    
    gcc/cp/ChangeLog:
    
            * parser.cc (cp_parser_next_token_ends_template_argument_p): Don't
            return true for CPP_GREATER_EQ.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/parse/template31.C: New test.

Diff:
---
 gcc/cp/parser.cc                        | 1 -
 gcc/testsuite/g++.dg/parse/template31.C | 4 ++++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index a5cbb3e896f..5fa743b5a8e 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -33224,7 +33224,6 @@ cp_parser_next_token_ends_template_argument_p (cp_parser *parser)
 	  || ((cxx_dialect != cxx98) && token->type == CPP_RSHIFT)
 	  /* For better diagnostics, treat >>= like that too, that
 	     shouldn't appear non-nested in template arguments.  */
-	  || token->type == CPP_GREATER_EQ
 	  || token->type == CPP_RSHIFT_EQ);
 }
 
diff --git a/gcc/testsuite/g++.dg/parse/template31.C b/gcc/testsuite/g++.dg/parse/template31.C
new file mode 100644
index 00000000000..a5693e851f7
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/template31.C
@@ -0,0 +1,4 @@
+// PR c++/105436
+
+template<bool> struct A;
+template<int N> A<N >= 5> f();