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, 171 insertions, 0 deletions

diff --git a/libcc1/context.cc b/libcc1/context.cc
new file mode 100644
index 0000000..3d5ff92
--- /dev/null
+++ b/libcc1/context.cc
@@ -0,0 +1,171 @@
+/* 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/>.  */
+
+#include <cc1plugin-config.h>
+
+#undef PACKAGE_NAME
+#undef PACKAGE_STRING
+#undef PACKAGE_TARNAME
+#undef PACKAGE_VERSION
+
+#include "../gcc/config.h"
+
+#undef PACKAGE_NAME
+#undef PACKAGE_STRING
+#undef PACKAGE_TARNAME
+#undef PACKAGE_VERSION
+
+#include "gcc-plugin.h"
+#include "system.h"
+#include "coretypes.h"
+#include "stringpool.h"
+#include "hash-set.h"
+#include "diagnostic.h"
+#include "langhooks.h"
+#include "langhooks-def.h"
+
+#include "gcc-interface.h"
+
+#include "context.hh"
+#include "marshall.hh"
+
+
+
+#ifdef __GNUC__
+#pragma GCC visibility push(default)
+#endif
+int plugin_is_GPL_compatible;
+#ifdef __GNUC__
+#pragma GCC visibility pop
+#endif
+
+cc1_plugin::plugin_context *cc1_plugin::current_context;
+
+
+
+// This is put into the lang hooks when the plugin starts.
+
+static void
+plugin_print_error_function (diagnostic_context *context, const char *file,
+			     diagnostic_info *diagnostic)
+{
+  if (current_function_decl != NULL_TREE
+      && DECL_NAME (current_function_decl) != NULL_TREE
+      && strcmp (IDENTIFIER_POINTER (DECL_NAME (current_function_decl)),
+		 GCC_FE_WRAPPER_FUNCTION) == 0)
+    return;
+  lhd_print_error_function (context, file, diagnostic);
+}
+
+
+
+location_t
+cc1_plugin::plugin_context::get_location_t (const char *filename,
+					    unsigned int line_number)
+{
+  if (filename == NULL)
+    return UNKNOWN_LOCATION;
+
+  filename = intern_filename (filename);
+  linemap_add (line_table, LC_ENTER, false, filename, line_number);
+  location_t loc = linemap_line_start (line_table, line_number, 0);
+  linemap_add (line_table, LC_LEAVE, false, NULL, 0);
+  return loc;
+}
+
+// Add a file name to FILE_NAMES and return the canonical copy.
+const char *
+cc1_plugin::plugin_context::intern_filename (const char *filename)
+{
+  const char **slot = file_names.find_slot (filename, INSERT);
+  if (*slot == NULL)
+    {
+      /* The file name must live as long as the line map, which
+	 effectively means as long as this compilation.  So, we copy
+	 the string here but never free it.  */
+      *slot = xstrdup (filename);
+    }
+  return *slot;
+}
+
+void
+cc1_plugin::plugin_context::mark ()
+{
+  for (const auto &item : address_map)
+    {
+      ggc_mark (item->decl);
+      ggc_mark (item->address);
+    }
+
+  for (const auto &item : preserved)
+    ggc_mark (&item);
+}
+
+
+
+// Perform GC marking.
+
+static void
+gc_mark (void *, void *)
+{
+  if (cc1_plugin::current_context != NULL)
+    cc1_plugin::current_context->mark ();
+}
+
+void
+cc1_plugin::generic_plugin_init (struct plugin_name_args *plugin_info,
+				 unsigned int version)
+{
+  long fd = -1;
+  for (int i = 0; i < plugin_info->argc; ++i)
+    {
+      if (strcmp (plugin_info->argv[i].key, "fd") == 0)
+	{
+	  char *tail;
+	  errno = 0;
+	  fd = strtol (plugin_info->argv[i].value, &tail, 0);
+	  if (*tail != '\0' || errno != 0)
+	    fatal_error (input_location,
+			 "%s: invalid file descriptor argument to plugin",
+			 plugin_info->base_name);
+	  break;
+	}
+    }
+  if (fd == -1)
+    fatal_error (input_location,
+		 "%s: required plugin argument %<fd%> is missing",
+		 plugin_info->base_name);
+
+  current_context = new plugin_context (fd);
+
+  // Handshake.
+  cc1_plugin::protocol_int h_version;
+  if (!current_context->require ('H')
+      || ! ::cc1_plugin::unmarshall (current_context, &h_version))
+    fatal_error (input_location,
+		 "%s: handshake failed", plugin_info->base_name);
+  if (h_version != version)
+    fatal_error (input_location,
+		 "%s: unknown version in handshake", plugin_info->base_name);
+
+  register_callback (plugin_info->base_name, PLUGIN_GGC_MARKING,
+		     gc_mark, NULL);
+
+  lang_hooks.print_error_function = plugin_print_error_function;
+}