libcc1: share basic context code

Both plugins in libcc1 share a fair amount of boilerplate.  They both
share error-emission code, context management code, and tree GC code.
This patch unifies these two bodies of code, avoiding needless
duplication.

libcc1

	* libcc1plugin.cc: Move code to context.cc.
	* libcp1plugin.cc: Move code to context.cc.
	* context.hh: New file.
	* context.cc: New file.
	* Makefile.in: Rebuild.
	* Makefile.am (AM_CPPFLAGS): Add more gcc flags.
	(CPPFLAGS_FOR_C, CPPFLAGS_FOR_CXX): Update.
	(libcc1plugin_la_SOURCES): Add context.hh, context.cc.
	(libcp1plugin_la_SOURCES): Likewise.

1 files changed, 121 insertions, 0 deletions

diff --git a/libcc1/context.hh b/libcc1/context.hh
new file mode 100644
index 0000000..21a8262
--- /dev/null
+++ b/libcc1/context.hh
@@ -0,0 +1,121 @@
+/* Generic plugin context
+   Copyright (C) 2020 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_CONTEXT_HH
+#define CC1_PLUGIN_CONTEXT_HH
+
+#include "system.h"
+#include "coretypes.h"
+#include "tree.h"
+
+#include "connection.hh"
+
+namespace cc1_plugin
+{
+  static inline unsigned long long
+  convert_out (tree t)
+  {
+    return (unsigned long long) (uintptr_t) t;
+  }
+
+  static inline tree
+  convert_in (unsigned long long v)
+  {
+    return (tree) (uintptr_t) v;
+  }
+
+  struct decl_addr_value
+  {
+    tree decl;
+    tree address;
+  };
+
+  struct decl_addr_hasher : free_ptr_hash<decl_addr_value>
+  {
+    static hashval_t hash (const decl_addr_value *e)
+    {
+      return DECL_UID (e->decl);
+    }
+
+    static bool equal (const decl_addr_value *p1,
+		       const decl_addr_value *p2)
+    {
+      return p1->decl == p2->decl;
+    }
+  };
+
+  struct string_hasher : nofree_ptr_hash<const char>
+  {
+    static inline hashval_t hash (const char *s)
+    {
+      return htab_hash_string (s);
+    }
+
+    static inline bool equal (const char *p1, const char *p2)
+    {
+      return strcmp (p1, p2) == 0;
+    }
+  };
+
+  struct plugin_context : public cc1_plugin::connection
+  {
+    plugin_context (int fd)
+      : cc1_plugin::connection (fd),
+	address_map (30),
+	preserved (30),
+	file_names (30)
+    {
+    }
+
+    // Map decls to addresses.
+    hash_table<decl_addr_hasher> address_map;
+
+    // A collection of trees that are preserved for the GC.
+    hash_table< nofree_ptr_hash<tree_node> > preserved;
+
+    // File name cache.
+    hash_table<string_hasher> file_names;
+
+    // Perform GC marking.
+    void mark ();
+
+    // Preserve a tree during the plugin's operation.
+    tree preserve (tree t)
+    {
+      tree_node **slot = preserved.find_slot (t, INSERT);
+      *slot = t;
+      return t;
+    }
+
+    location_t get_location_t (const char *filename,
+			       unsigned int line_number);
+
+  private:
+
+    // Add a file name to FILE_NAMES and return the canonical copy.
+    const char *intern_filename (const char *filename);
+  };
+
+  extern plugin_context *current_context;
+
+  void generic_plugin_init (struct plugin_name_args *plugin_info,
+			    unsigned int version);
+}
+
+#endif // CC1_PLUGIN_CONTEXT_HH