/* Emit optimization information as JSON files.
   Copyright (C) 2018 Free Software Foundation, Inc.
   Contributed by David Malcolm <dmalcolm@redhat.com>.

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 "config.h"
#include "system.h"
#include "coretypes.h"

#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "diagnostic-core.h"

#include "profile.h"
#include "output.h"
#include "tree-pass.h"

#include "optinfo.h"
#include "optinfo-emit-json.h"
#include "json.h"
#include "pretty-print.h"
#include "tree-pretty-print.h"
#include "gimple-pretty-print.h"
#include "cgraph.h"

#include "langhooks.h"
#include "version.h"
#include "context.h"
#include "pass_manager.h"
#include "selftest.h"
#include "dump-context.h"

/* A class for writing out optimization records in JSON format.  */

class optrecord_json_writer
{
public:
  optrecord_json_writer ();
  ~optrecord_json_writer ();
  void write () const;
  void add_record (const optinfo *optinfo);
  void pop_scope ();

  void add_record (json::object *obj);
  json::object *impl_location_to_json (dump_impl_location_t loc);
  json::object *location_to_json (location_t loc);
  json::object *profile_count_to_json (profile_count count);
  json::string *get_id_value_for_pass (opt_pass *pass);
  json::object *pass_to_json (opt_pass *pass);
  json::value *inlining_chain_to_json (location_t loc);
  json::object *optinfo_to_json (const optinfo *optinfo);
  void add_pass_list (json::array *arr, opt_pass *pass);

private:
  /* The root value for the JSON file.
     Currently the JSON values are stored in memory, and flushed when the
     compiler exits.  It would probably be better to simply write out
     the JSON as we go.  */
  json::array *m_root_tuple;

  /* The currently open scopes, for expressing nested optimization records.  */
  auto_vec<json::array *> m_scopes;
};

/* optrecord_json_writer's ctor.  Populate the top-level parts of the
   in-memory JSON representation.  */

optrecord_json_writer::optrecord_json_writer ()
  : m_root_tuple (NULL), m_scopes ()
{
  m_root_tuple = new json::array ();

  /* Populate with metadata; compare with toplev.c: print_version.  */
  json::object *metadata = new json::object ();
  m_root_tuple->append (metadata);
  metadata->set ("format", new json::string ("1"));
  json::object *generator = new json::object ();
  metadata->set ("generator", generator);
  generator->set ("name", new json::string (lang_hooks.name));
  generator->set ("pkgversion", new json::string (pkgversion_string));
  generator->set ("version", new json::string (version_string));
  /* TARGET_NAME is passed in by the Makefile.  */
  generator->set ("target", new json::string (TARGET_NAME));

  /* TODO: capture command-line?
     see gen_producer_string in dwarf2out.c (currently static).  */

  /* TODO: capture "any plugins?" flag (or the plugins themselves).  */

  json::array *passes = new json::array ();
  m_root_tuple->append (passes);

  /* Call add_pass_list for all of the pass lists.  */
  {
#define DEF_PASS_LIST(LIST) \
    add_pass_list (passes, g->get_passes ()->LIST);
    GCC_PASS_LISTS
#undef DEF_PASS_LIST
  }

  json::array *records = new json::array ();
  m_root_tuple->append (records);

  m_scopes.safe_push (records);
}

/* optrecord_json_writer's ctor.
   Delete the in-memory JSON representation.  */

optrecord_json_writer::~optrecord_json_writer ()
{
  delete m_root_tuple;
}

/* Choose an appropriate filename, and write the saved records to it.  */

void
optrecord_json_writer::write () const
{
  char *filename = concat (dump_base_name, ".opt-record.json", NULL);
  FILE *outfile = fopen (filename, "w");
  if (outfile)
    {
      m_root_tuple->dump (outfile);
      fclose (outfile);
    }
  else
    error_at (UNKNOWN_LOCATION, "unable to write optimization records to %qs",
	      filename); // FIXME: more info?
  free (filename);
}

/* Add a record for OPTINFO to the queue of records to be written.  */

void
optrecord_json_writer::add_record (const optinfo *optinfo)
{
  json::object *obj = optinfo_to_json (optinfo);

  add_record (obj);

  /* Potentially push the scope.  */
  if (optinfo->get_kind () == OPTINFO_KIND_SCOPE)
    {
      json::array *children = new json::array ();
      obj->set ("children", children);
      m_scopes.safe_push (children);
    }
}

/* Private methods of optrecord_json_writer.  */

/* Add record OBJ to the the innermost scope.  */

void
optrecord_json_writer::add_record (json::object *obj)
{
  /* Add to innermost scope.  */
  gcc_assert (m_scopes.length () > 0);
  m_scopes[m_scopes.length () - 1]->append (obj);
}

/* Pop the innermost scope.  */

void
optrecord_json_writer::pop_scope ()
{
  m_scopes.pop ();
}

/* Create a JSON object representing LOC.  */

json::object *
optrecord_json_writer::impl_location_to_json (dump_impl_location_t loc)
{
  json::object *obj = new json::object ();
  obj->set ("file", new json::string (loc.m_file));
  obj->set ("line", new json::number (loc.m_line));
  if (loc.m_function)
    obj->set ("function", new json::string (loc.m_function));
  return obj;
}

/* Create a JSON object representing LOC.  */

json::object *
optrecord_json_writer::location_to_json (location_t loc)
{
  gcc_assert (LOCATION_LOCUS (loc) != UNKNOWN_LOCATION);
  expanded_location exploc = expand_location (loc);
  json::object *obj = new json::object ();
  obj->set ("file", new json::string (exploc.file));
  obj->set ("line", new json::number (exploc.line));
  obj->set ("column", new json::number (exploc.column));
  return obj;
}

/* Create a JSON object representing COUNT.  */

json::object *
optrecord_json_writer::profile_count_to_json (profile_count count)
{
  json::object *obj = new json::object ();
  obj->set ("value", new json::number (count.to_gcov_type ()));
  obj->set ("quality",
	    new json::string (profile_quality_as_string (count.quality ())));
  return obj;
}

/* Get a string for use when referring to PASS in the saved optimization
   records.  */

json::string *
optrecord_json_writer::get_id_value_for_pass (opt_pass *pass)
{
  pretty_printer pp;
  /* this is host-dependent, but will be consistent for a given host.  */
  pp_pointer (&pp, static_cast<void *> (pass));
  return new json::string (pp_formatted_text (&pp));
}

/* Create a JSON object representing PASS.  */

json::object *
optrecord_json_writer::pass_to_json (opt_pass *pass)
{
  json::object *obj = new json::object ();
  const char *type = NULL;
  switch (pass->type)
    {
    default:
      gcc_unreachable ();
    case GIMPLE_PASS:
      type = "gimple";
      break;
    case RTL_PASS:
      type = "rtl";
      break;
    case SIMPLE_IPA_PASS:
      type = "simple_ipa";
      break;
    case IPA_PASS:
      type = "ipa";
      break;
    }
  obj->set ("id", get_id_value_for_pass (pass));
  obj->set ("type", new json::string (type));
  obj->set ("name", new json::string (pass->name));
  /* Represent the optgroup flags as an array.  */
  {
    json::array *optgroups = new json::array ();
    obj->set ("optgroups", optgroups);
    for (const kv_pair<optgroup_flags_t> *optgroup = optgroup_options;
	 optgroup->name != NULL; optgroup++)
      if (optgroup->value != OPTGROUP_ALL
	  && (pass->optinfo_flags & optgroup->value))
	optgroups->append (new json::string (optgroup->name));
  }
  obj->set ("num", new json::number (pass->static_pass_number));
  return obj;
}

/* Create a JSON array for LOC representing the chain of inlining
   locations.
   Compare with lhd_print_error_function and cp_print_error_function.  */

json::value *
optrecord_json_writer::inlining_chain_to_json (location_t loc)
{
  json::array *array = new json::array ();

  tree abstract_origin = LOCATION_BLOCK (loc);

  while (abstract_origin)
    {
      location_t *locus;
      tree block = abstract_origin;

      locus = &BLOCK_SOURCE_LOCATION (block);
      tree fndecl = NULL;
      block = BLOCK_SUPERCONTEXT (block);
      while (block && TREE_CODE (block) == BLOCK
	     && BLOCK_ABSTRACT_ORIGIN (block))
	{
	  tree ao = BLOCK_ABSTRACT_ORIGIN (block);
	  if (TREE_CODE (ao) == FUNCTION_DECL)
	    {
	      fndecl = ao;
	      break;
	    }
	  else if (TREE_CODE (ao) != BLOCK)
	    break;

	  block = BLOCK_SUPERCONTEXT (block);
	}
      if (fndecl)
	abstract_origin = block;
      else
	{
	  while (block && TREE_CODE (block) == BLOCK)
	    block = BLOCK_SUPERCONTEXT (block);

	  if (block && TREE_CODE (block) == FUNCTION_DECL)
	    fndecl = block;
	  abstract_origin = NULL;
	}
      if (fndecl)
	{
	  json::object *obj = new json::object ();
	  const char *printable_name
	    = lang_hooks.decl_printable_name (fndecl, 2);
	  obj->set ("fndecl", new json::string (printable_name));
	  if (LOCATION_LOCUS (*locus) != UNKNOWN_LOCATION)
	    obj->set ("site", location_to_json (*locus));
	  array->append (obj);
	}
    }

  return array;
}

/* Create a JSON object representing OPTINFO.  */

json::object *
optrecord_json_writer::optinfo_to_json (const optinfo *optinfo)
{
  json::object *obj = new json::object ();

  obj->set ("impl_location",
	    impl_location_to_json (optinfo->get_impl_location ()));

  const char *kind_str = optinfo_kind_to_string (optinfo->get_kind ());
  obj->set ("kind", new json::string (kind_str));
  json::array *message = new json::array ();
  obj->set ("message", message);
  for (unsigned i = 0; i < optinfo->num_items (); i++)
    {
      const optinfo_item *item = optinfo->get_item (i);
      switch (item->get_kind ())
	{
	default:
	  gcc_unreachable ();
	case OPTINFO_ITEM_KIND_TEXT:
	  {
	    message->append (new json::string (item->get_text ()));
	  }
	  break;
	case OPTINFO_ITEM_KIND_TREE:
	  {
	    json::object *json_item = new json::object ();
	    json_item->set ("expr", new json::string (item->get_text ()));

	    /* Capture any location for the node.  */
	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
	      json_item->set ("location",
			      location_to_json (item->get_location ()));

	    message->append (json_item);
	  }
	  break;
	case OPTINFO_ITEM_KIND_GIMPLE:
	  {
	    json::object *json_item = new json::object ();
	    json_item->set ("stmt", new json::string (item->get_text ()));

	    /* Capture any location for the stmt.  */
	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
	      json_item->set ("location",
			      location_to_json (item->get_location ()));

	    message->append (json_item);
	  }
	  break;
	case OPTINFO_ITEM_KIND_SYMTAB_NODE:
	  {
	    json::object *json_item = new json::object ();
	    json_item->set ("symtab_node", new json::string (item->get_text ()));

	    /* Capture any location for the node.  */
	    if (LOCATION_LOCUS (item->get_location ()) != UNKNOWN_LOCATION)
	      json_item->set ("location",
			      location_to_json (item->get_location ()));
	    message->append (json_item);
	  }
	  break;
	}
   }

  if (optinfo->get_pass ())
    obj->set ("pass", get_id_value_for_pass (optinfo->get_pass ()));

  profile_count count = optinfo->get_count ();
  if (count.initialized_p ())
    obj->set ("count", profile_count_to_json (count));

  /* Record any location, handling the case where of an UNKNOWN_LOCATION
     within an inlined block.  */
  location_t loc = optinfo->get_location_t ();
  if (get_pure_location (line_table, loc) != UNKNOWN_LOCATION)
    {
      // TOOD: record the location (just caret for now)
      // TODO: start/finish also?
      obj->set ("location", location_to_json (loc));
    }

  if (current_function_decl)
    {
      const char *fnname = get_fnname_from_decl (current_function_decl);
      obj->set ("function", new json::string (fnname));
    }

  if (loc != UNKNOWN_LOCATION)
    obj->set ("inlining_chain", inlining_chain_to_json (loc));

  return obj;
}

/* Add a json description of PASS and its siblings to ARR, recursing into
   child passes (adding their descriptions within a "children" array).  */

void
optrecord_json_writer::add_pass_list (json::array *arr, opt_pass *pass)
{
  do
    {
      json::object *pass_obj = pass_to_json (pass);
      arr->append (pass_obj);
      if (pass->sub)
	{
	  json::array *sub = new json::array ();
	  pass_obj->set ("children", sub);
	  add_pass_list (sub, pass->sub);
	}
      pass = pass->next;
    }
  while (pass);
}

/* File-level interface to rest of compiler (to avoid exposing
   class optrecord_json_writer outside of this file).  */

static optrecord_json_writer *the_json_writer;

/* Perform startup activity for -fsave-optimization-record.  */

void
optimization_records_start ()
{
  /* Bail if recording not enabled.  */
  if (!flag_save_optimization_record)
    return;

  the_json_writer = new optrecord_json_writer ();
}

/* Perform cleanup activity for -fsave-optimization-record.

   Currently, the file is written out here in one go, before cleaning
   up.  */

void
optimization_records_finish ()
{
  /* Bail if recording not enabled.  */
  if (!the_json_writer)
    return;

  the_json_writer->write ();

  delete the_json_writer;
  the_json_writer = NULL;
}

/* Did the user request optimization records to be written out?  */

bool
optimization_records_enabled_p ()
{
  return the_json_writer != NULL;
}

/* If optimization records were requested, then add a record for OPTINFO
   to the queue of records to be written.  */

void
optimization_records_maybe_record_optinfo (const optinfo *optinfo)
{
  /* Bail if recording not enabled.  */
  if (!the_json_writer)
    return;

  the_json_writer->add_record (optinfo);
}

/* Handling for the end of a dump scope for the
   optimization records sink.  */

void
optimization_records_maybe_pop_dump_scope ()
{
  /* Bail if recording not enabled.  */
  if (!the_json_writer)
    return;

  the_json_writer->pop_scope ();
}

#if CHECKING_P

namespace selftest {

/* Verify that we can build a JSON optimization record from dump_*
   calls.  */

static void
test_building_json_from_dump_calls ()
{
  temp_dump_context tmp (true, true, MSG_NOTE);
  dump_location_t loc;
  dump_printf_loc (MSG_NOTE, loc, "test of tree: ");
  dump_generic_expr (MSG_NOTE, TDF_SLIM, integer_zero_node);
  optinfo *info = tmp.get_pending_optinfo ();
  ASSERT_TRUE (info != NULL);
  ASSERT_EQ (info->num_items (), 2);

  optrecord_json_writer writer;
  json::object *json_obj = writer.optinfo_to_json (info);
  ASSERT_TRUE (json_obj != NULL);

  /* Verify that the json is sane.  */
  pretty_printer pp;
  json_obj->print (&pp);
  const char *json_str = pp_formatted_text (&pp);
  ASSERT_STR_CONTAINS (json_str, "impl_location");
  ASSERT_STR_CONTAINS (json_str, "\"kind\": \"note\"");
  ASSERT_STR_CONTAINS (json_str,
		       "\"message\": [\"test of tree: \", {\"expr\": \"0\"}]");
  delete json_obj;
}

/* Run all of the selftests within this file.  */

void
optinfo_emit_json_cc_tests ()
{
  test_building_json_from_dump_calls ();
}

} // namespace selftest

#endif /* CHECKING_P */