From: Marek Polacek <polacek@redhat.com>
Date: Fri, 29 Apr 2022 21:03:41 +0000 (-0400)
Subject: c++: parse error with >= in template argument list [PR105436]
X-Git-Tag: basepoints/gcc-14~7092
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=79a1a01cbd0e4a491d7078783131e3f88ca7158d;p=thirdparty%2Fgcc.git

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 --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();