From caf77196512fd866663b216486c3ae317c20a2bf Mon Sep 17 00:00:00 2001
From: Tom Tromey <tom@tromey.com>
Date: Sun, 23 Feb 2025 15:34:40 -0700
Subject: [PATCH] Handle ">>" in cp-name-parser.y

I noticed that a certain name didn't work correctly when trying to
remove the parameters.  I put this into lookup_name_info-selftests.c.

I tracked this down to the fact that cp-name-parser.y doesn't handle
">>" to end templates.  This patch fixes this in a simple way --
accepting the "RSH" token where appropriate and then un-pushing a ">".
---
 gdb/cp-name-parser.y                       | 21 +++++++++++++++++++++
 gdb/unittests/lookup_name_info-selftests.c |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/gdb/cp-name-parser.y b/gdb/cp-name-parser.y
index 14ee6cfb9fc..6c36abea4b0 100644
--- a/gdb/cp-name-parser.y
+++ b/gdb/cp-name-parser.y
@@ -81,6 +81,14 @@ struct cpname_state
       demangle_info (info)
   { }
 
+  /* Un-push a character into the lexer.  This can only un-push the
+     previous character in the input string.  */
+  void unpush (char c)
+  {
+    gdb_assert (lexptr[-1] == c);
+    --lexptr;
+  }
+
   /* LEXPTR is the current pointer into our lex buffer.  PREV_LEXPTR
      is the start of the last token lexed, only used for diagnostics.
      ERROR_LEXPTR is the first place an error occurred.  GLOBAL_ERRMSG
@@ -515,6 +523,11 @@ conversion_op_name
 unqualified_name:	oper
 		|	oper '<' template_params '>'
 			{ $$ = state->fill_comp (DEMANGLE_COMPONENT_TEMPLATE, $1, $3.comp); }
+		|	oper '<' template_params RSH
+			{
+			  $$ = state->fill_comp (DEMANGLE_COMPONENT_TEMPLATE, $1, $3.comp);
+			  state->unpush ('>');
+			}
 		|	'~' NAME
 			{ $$ = state->make_dtor (gnu_v3_complete_object_dtor, $2); }
 		;
@@ -580,6 +593,11 @@ nested_name	:	NAME COLONCOLON
 /* DEMANGLE_COMPONENT_TEMPLATE_ARGLIST */
 templ	:	NAME '<' template_params '>'
 			{ $$ = state->fill_comp (DEMANGLE_COMPONENT_TEMPLATE, $1, $3.comp); }
+		| NAME '<' template_params RSH
+			{
+			  $$ = state->fill_comp (DEMANGLE_COMPONENT_TEMPLATE, $1, $3.comp);
+			  state->unpush ('>');
+			}
 		;
 
 template_params	:	template_arg
@@ -2085,6 +2103,9 @@ canonicalize_tests ()
   should_be_the_same ("something<void ()>", "something<void (void)>");
 
   should_parse ("void whatever::operator<=><int, int>");
+
+  should_be_the_same ("Foozle<int>::fogey<Empty<int> > (Empty<int>)",
+		      "Foozle<int>::fogey<Empty<int>> (Empty<int>)");
 }
 
 #endif
diff --git a/gdb/unittests/lookup_name_info-selftests.c b/gdb/unittests/lookup_name_info-selftests.c
index a6b50851cc9..fb4be2133cb 100644
--- a/gdb/unittests/lookup_name_info-selftests.c
+++ b/gdb/unittests/lookup_name_info-selftests.c
@@ -96,6 +96,9 @@ run_tests ()
   CHECK (language_cplus, "A::B::C()", "A::B::C");
   CHECK (language_cplus, "A::B::C", "A::B::C");
 
+  CHECK (language_cplus, "Foozle<int>::fogey<Empty<int>> (Empty<int>)",
+	 "Foozle<int>::fogey<Empty<int> >");
+
 #undef CHECK
 #undef CHECK_INCOMPL
 }
-- 
2.39.5