[PATCH v2 01/21] libcc1: use templates to unmarshall enums

[Tom Tromey <tom@tromey.com>]

Now that C++11 can be used in GCC, libcc1 can be changed to use
templates and type traits to handle unmarshalling all kinds of enums.

libcc1/ChangeLog
2021-04-27  Tom Tromey  <tom@tromey.com>

	* marshall.hh (cc1_plugin::unmarshall): Use type traits.
	* marshall-cp.hh (cc1_plugin::unmarshall): Remove overloads.
	* marshall-c.hh: Remove.
	* libcc1plugin.cc: Update includes.
	* libcc1.cc: Update includes.
---
 libcc1/ChangeLog       |  8 ++++++
 libcc1/libcc1.cc       |  3 ++-
 libcc1/libcc1plugin.cc |  3 ++-
 libcc1/marshall-c.hh   | 59 ------------------------------------------
 libcc1/marshall-cp.hh  | 40 ----------------------------
 libcc1/marshall.hh     | 26 +++++++++++++++----
 6 files changed, 33 insertions(+), 106 deletions(-)
 delete mode 100644 libcc1/marshall-c.hh

diff --git a/libcc1/libcc1.cc b/libcc1/libcc1.cc
index e4c200c8abd5..68d366a72871 100644
--- a/libcc1/libcc1.cc
+++ b/libcc1/libcc1.cc
@@ -29,7 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include <sys/stat.h>
 #include <stdlib.h>
 #include <sstream>
-#include "marshall-c.hh"
+#include "marshall.hh"
 #include "rpc.hh"
 #include "connection.hh"
 #include "names.hh"
@@ -39,6 +39,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "findcomp.hh"
 #include "compiler-name.hh"
 #include "intl.h"
+#include "gcc-c-interface.h"
 
 struct libcc1;
 
diff --git a/libcc1/libcc1plugin.cc b/libcc1/libcc1plugin.cc
index e80ecd8f4b35..59e4851064a2 100644
--- a/libcc1/libcc1plugin.cc
+++ b/libcc1/libcc1plugin.cc
@@ -63,8 +63,9 @@
 
 #include "callbacks.hh"
 #include "connection.hh"
-#include "marshall-c.hh"
+#include "marshall.hh"
 #include "rpc.hh"
+#include "gcc-c-interface.h"
 
 #ifdef __GNUC__
 #pragma GCC visibility push(default)
diff --git a/libcc1/marshall-c.hh b/libcc1/marshall-c.hh
deleted file mode 100644
index 212603ebb819..000000000000
--- a/libcc1/marshall-c.hh
+++ /dev/null
@@ -1,59 +0,0 @@
-/* Marshalling and unmarshalling of C-specific types.
-   Copyright (C) 2014-2021 Free Software Foundation, Inc.
-
-This file is part of GCC.
-
-GCC is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 3, or (at your option) any later
-version.
-
-GCC is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-for more details.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING3.  If not see
-<http://www.gnu.org/licenses/>.  */
-
-#ifndef CC1_PLUGIN_MARSHALL_C_HH
-#define CC1_PLUGIN_MARSHALL_C_HH
-
-#include "marshall.hh"
-#include "gcc-c-interface.h"
-
-namespace cc1_plugin
-{
-  status
-  unmarshall (connection *conn, enum gcc_c_symbol_kind *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_c_symbol_kind) p;
-    return OK;
-  }
-
-  status
-  unmarshall (connection *conn, enum gcc_c_oracle_request *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_c_oracle_request) p;
-    return OK;
-  }
-
-  status
-  unmarshall (connection *conn, enum gcc_qualifiers *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_qualifiers) p;
-    return OK;
-  }
-}
-
-#endif // CC1_PLUGIN_MARSHALL_C_HH
diff --git a/libcc1/marshall-cp.hh b/libcc1/marshall-cp.hh
index ff80bfe41870..3d6ae4126aee 100644
--- a/libcc1/marshall-cp.hh
+++ b/libcc1/marshall-cp.hh
@@ -25,46 +25,6 @@ along with GCC; see the file COPYING3.  If not see
 
 namespace cc1_plugin
 {
-  status
-  unmarshall (connection *conn, enum gcc_cp_symbol_kind *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_cp_symbol_kind) p;
-    return OK;
-  }
-
-  status
-  unmarshall (connection *conn, enum gcc_cp_oracle_request *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_cp_oracle_request) p;
-    return OK;
-  }
-
-  status
-  unmarshall (connection *conn, enum gcc_cp_qualifiers *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_cp_qualifiers) p;
-    return OK;
-  }
-
-  status
-  unmarshall (connection *conn, enum gcc_cp_ref_qualifiers *result)
-  {
-    protocol_int p;
-    if (!unmarshall_intlike (conn, &p))
-      return FAIL;
-    *result = (enum gcc_cp_ref_qualifiers) p;
-    return OK;
-  }
-
   // Send a gcc_vbase_array marker followed by the array.
   status
   marshall (connection *conn, const gcc_vbase_array *a)
diff --git a/libcc1/marshall.hh b/libcc1/marshall.hh
index 6999c4ff8fd1..8d890eb9b6c7 100644
--- a/libcc1/marshall.hh
+++ b/libcc1/marshall.hh
@@ -20,6 +20,8 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef CC1_PLUGIN_MARSHALL_HH
 #define CC1_PLUGIN_MARSHALL_HH
 
+#include <type_traits>
+
 #include "status.hh"
 #include "gcc-interface.h"
 
@@ -59,17 +61,31 @@ namespace cc1_plugin
   }
 
   // A template function that can handle unmarshalling various integer
-  // objects from the connection.  Note that this can't be
-  // instantiated for enum types.  Note also that there's no way at
-  // the protocol level to distinguish different int types.
+  // objects from the connection.  Note that there's no way at the
+  // protocol level to distinguish different int types.
+  template<typename T>
+  status unmarshall (connection *conn, T *scalar,
+		     typename std::enable_if<std::is_integral<T>::value, T>::type * = 0)
+  {
+    protocol_int result;
+
+    if (!unmarshall_intlike (conn, &result))
+      return FAIL;
+    *scalar = (T) result;
+    return OK;
+  }
+
+  // A template function that can handle unmarshalling various enum
+  // objects from the connection.
   template<typename T>
-  status unmarshall (connection *conn, T *scalar)
+  status unmarshall (connection *conn, T *e_val,
+		     typename std::enable_if<std::is_enum<T>::value, T>::type * = 0)
   {
     protocol_int result;
 
     if (!unmarshall_intlike (conn, &result))
       return FAIL;
-    *scalar = result;
+    *e_val = (T) result;
     return OK;
   }
 
-- 
2.26.2