--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/go/go-lang.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,593 @@
+/* go-lang.c -- Go frontend gcc interface.
+   Copyright (C) 2009-2017 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 "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "target.h"
+#include "tree.h"
+#include "gimple-expr.h"
+#include "diagnostic.h"
+#include "opts.h"
+#include "fold-const.h"
+#include "gimplify.h"
+#include "stor-layout.h"
+#include "debug.h"
+#include "convert.h"
+#include "langhooks.h"
+#include "langhooks-def.h"
+#include "common/common-target.h"
+
+#include <mpfr.h>
+
+#include "go-c.h"
+#include "go-gcc.h"
+
+/* Language-dependent contents of a type.  */
+
+struct GTY(()) lang_type
+{
+  char dummy;
+};
+
+/* Language-dependent contents of a decl.  */
+
+struct GTY(()) lang_decl
+{
+  char dummy;
+};
+
+/* Language-dependent contents of an identifier.  This must include a
+   tree_identifier.  */
+
+struct GTY(()) lang_identifier
+{
+  struct tree_identifier common;
+};
+
+/* The resulting tree type.  */
+
+union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
+	   chain_next ("CODE_CONTAINS_STRUCT (TREE_CODE (&%h.generic), TS_COMMON) ? ((union lang_tree_node *) TREE_CHAIN (&%h.generic)) : NULL")))
+lang_tree_node
+{
+  union tree_node GTY((tag ("0"),
+		       desc ("tree_node_structure (&%h)"))) generic;
+  struct lang_identifier GTY((tag ("1"))) identifier;
+};
+
+/* We don't use language_function.  */
+
+struct GTY(()) language_function
+{
+  int dummy;
+};
+
+/* Option information we need to pass to go_create_gogo.  */
+
+static const char *go_pkgpath = NULL;
+static const char *go_prefix = NULL;
+static const char *go_relative_import_path = NULL;
+static const char *go_c_header = NULL;
+
+/* Language hooks.  */
+
+static bool
+go_langhook_init (void)
+{
+  build_common_tree_nodes (false);
+
+  /* I don't know why this has to be done explicitly.  */
+  void_list_node = build_tree_list (NULL_TREE, void_type_node);
+
+  /* We must create the gogo IR after calling build_common_tree_nodes
+     (because Gogo::define_builtin_function_trees refers indirectly
+     to, e.g., unsigned_char_type_node) but before calling
+     build_common_builtin_nodes (because it calls, indirectly,
+     go_type_for_size).  */
+  struct go_create_gogo_args args;
+  args.int_type_size = INT_TYPE_SIZE;
+  args.pointer_size = POINTER_SIZE;
+  args.pkgpath = go_pkgpath;
+  args.prefix = go_prefix;
+  args.relative_import_path = go_relative_import_path;
+  args.c_header = go_c_header;
+  args.check_divide_by_zero = go_check_divide_zero;
+  args.check_divide_overflow = go_check_divide_overflow;
+  args.compiling_runtime = go_compiling_runtime;
+  args.debug_escape_level = go_debug_escape_level;
+  args.linemap = go_get_linemap();
+  args.backend = go_get_backend();
+  go_create_gogo (&args);
+
+  build_common_builtin_nodes ();
+
+  /* The default precision for floating point numbers.  This is used
+     for floating point constants with abstract type.  This may
+     eventually be controllable by a command line option.  */
+  mpfr_set_default_prec (256);
+
+  /* Go uses exceptions.  */
+  using_eh_for_cleanups ();
+
+  return true;
+}
+
+/* The option mask.  */
+
+static unsigned int
+go_langhook_option_lang_mask (void)
+{
+  return CL_Go;
+}
+
+/* Initialize the options structure.  */
+
+static void
+go_langhook_init_options_struct (struct gcc_options *opts)
+{
+  /* Go says that signed overflow is precisely defined.  */
+  opts->x_flag_wrapv = 1;
+
+  /* We default to using strict aliasing, since Go pointers are safe.
+     This is turned off for code that imports the "unsafe" package,
+     because using unsafe.pointer violates C style aliasing
+     requirements.  */
+  opts->x_flag_strict_aliasing = 1;
+
+  /* Default to avoiding range issues for complex multiply and
+     divide.  */
+  opts->x_flag_complex_method = 2;
+
+  /* The builtin math functions should not set errno.  */
+  opts->x_flag_errno_math = 0;
+  opts->frontend_set_flag_errno_math = true;
+
+  /* Exceptions are used to handle recovering from panics.  */
+  opts->x_flag_exceptions = 1;
+  opts->x_flag_non_call_exceptions = 1;
+
+  /* We need to keep pointers live for the garbage collector.  */
+  opts->x_flag_keep_gc_roots_live = 1;
+
+  /* Go programs expect runtime.Callers to work, and that uses
+     libbacktrace that uses debug info.  Set the debug info level to 1
+     by default.  In post_options we will set the debug type if the
+     debug info level was not set back to 0 on the command line.  */
+  opts->x_debug_info_level = DINFO_LEVEL_TERSE;
+}
+
+/* Infrastructure for a vector of char * pointers.  */
+
+typedef const char *go_char_p;
+
+/* The list of directories to search after all the Go specific
+   directories have been searched.  */
+
+static vec<go_char_p> go_search_dirs;
+
+/* Handle Go specific options.  Return 0 if we didn't do anything.  */
+
+static bool
+go_langhook_handle_option (
+    size_t scode,
+    const char *arg,
+    int value ATTRIBUTE_UNUSED,
+    int kind ATTRIBUTE_UNUSED,
+    location_t loc ATTRIBUTE_UNUSED,
+    const struct cl_option_handlers *handlers ATTRIBUTE_UNUSED)
+{
+  enum opt_code code = (enum opt_code) scode;
+  bool ret = true;
+
+  switch (code)
+    {
+    case OPT_I:
+      go_add_search_path (arg);
+      break;
+
+    case OPT_L:
+      /* A -L option is assumed to come from the compiler driver.
+	 This is a system directory.  We search the following
+	 directories, if they exist, before this one:
+	   dir/go/VERSION
+	   dir/go/VERSION/MACHINE
+	 This is like include/c++.  */
+      {
+	static const char dir_separator_str[] = { DIR_SEPARATOR, 0 };
+	size_t len;
+	char *p;
+	struct stat st;
+
+	len = strlen (arg);
+	p = XALLOCAVEC (char,
+			(len + sizeof "go" + sizeof DEFAULT_TARGET_VERSION
+			 + sizeof DEFAULT_TARGET_MACHINE + 3));
+	strcpy (p, arg);
+	if (len > 0 && !IS_DIR_SEPARATOR (p[len - 1]))
+	  strcat (p, dir_separator_str);
+	strcat (p, "go");
+	strcat (p, dir_separator_str);
+	strcat (p, DEFAULT_TARGET_VERSION);
+	if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
+	  {
+	    go_add_search_path (p);
+	    strcat (p, dir_separator_str);
+	    strcat (p, DEFAULT_TARGET_MACHINE);
+	    if (stat (p, &st) == 0 && S_ISDIR (st.st_mode))
+	      go_add_search_path (p);
+	  }
+
+	/* Search ARG too, but only after we've searched to Go
+	   specific directories for all -L arguments.  */
+	go_search_dirs.safe_push (arg);
+      }
+      break;
+
+    case OPT_fgo_dump_:
+      ret = go_enable_dump (arg) ? true : false;
+      break;
+
+    case OPT_fgo_optimize_:
+      ret = go_enable_optimize (arg) ? true : false;
+      break;
+
+    case OPT_fgo_pkgpath_:
+      go_pkgpath = arg;
+      break;
+
+    case OPT_fgo_prefix_:
+      go_prefix = arg;
+      break;
+
+    case OPT_fgo_relative_import_path_:
+      go_relative_import_path = arg;
+      break;
+
+    case OPT_fgo_c_header_:
+      go_c_header = arg;
+      break;
+
+    default:
+      /* Just return 1 to indicate that the option is valid.  */
+      break;
+    }
+
+  return ret;
+}
+
+/* Run after parsing options.  */
+
+static bool
+go_langhook_post_options (const char **pfilename ATTRIBUTE_UNUSED)
+{
+  unsigned int ix;
+  const char *dir;
+
+  gcc_assert (num_in_fnames > 0);
+
+  FOR_EACH_VEC_ELT (go_search_dirs, ix, dir)
+    go_add_search_path (dir);
+  go_search_dirs.release ();
+
+  if (flag_excess_precision_cmdline == EXCESS_PRECISION_DEFAULT)
+    flag_excess_precision_cmdline = EXCESS_PRECISION_STANDARD;
+
+  /* Tail call optimizations can confuse uses of runtime.Callers.  */
+  if (!global_options_set.x_flag_optimize_sibling_calls)
+    global_options.x_flag_optimize_sibling_calls = 0;
+
+  /* If the debug info level is still 1, as set in init_options, make
+     sure that some debugging type is selected.  */
+  if (global_options.x_debug_info_level == DINFO_LEVEL_TERSE
+      && global_options.x_write_symbols == NO_DEBUG)
+    global_options.x_write_symbols = PREFERRED_DEBUGGING_TYPE;
+
+  /* We turn on stack splitting if we can.  */
+  if (!global_options_set.x_flag_split_stack
+      && targetm_common.supports_split_stack (false, &global_options))
+    global_options.x_flag_split_stack = 1;
+
+  /* If stack splitting is turned on, and the user did not explicitly
+     request function partitioning, turn off partitioning, as it
+     confuses the linker when trying to handle partitioned split-stack
+     code that calls a non-split-stack function.  */
+  if (global_options.x_flag_split_stack
+      && global_options.x_flag_reorder_blocks_and_partition
+      && !global_options_set.x_flag_reorder_blocks_and_partition)
+    global_options.x_flag_reorder_blocks_and_partition = 0;
+
+  /* Returning false means that the backend should be used.  */
+  return false;
+}
+
+static void
+go_langhook_parse_file (void)
+{
+  go_parse_input_files (in_fnames, num_in_fnames, flag_syntax_only,
+			go_require_return_statement);
+
+  /* Final processing of globals and early debug info generation.  */
+  go_write_globals ();
+}
+
+static tree
+go_langhook_type_for_size (unsigned int bits, int unsignedp)
+{
+  tree type;
+  if (unsignedp)
+    {
+      if (bits == INT_TYPE_SIZE)
+        type = unsigned_type_node;
+      else if (bits == CHAR_TYPE_SIZE)
+        type = unsigned_char_type_node;
+      else if (bits == SHORT_TYPE_SIZE)
+        type = short_unsigned_type_node;
+      else if (bits == LONG_TYPE_SIZE)
+        type = long_unsigned_type_node;
+      else if (bits == LONG_LONG_TYPE_SIZE)
+        type = long_long_unsigned_type_node;
+      else
+        type = make_unsigned_type(bits);
+    }
+  else
+    {
+      if (bits == INT_TYPE_SIZE)
+        type = integer_type_node;
+      else if (bits == CHAR_TYPE_SIZE)
+        type = signed_char_type_node;
+      else if (bits == SHORT_TYPE_SIZE)
+        type = short_integer_type_node;
+      else if (bits == LONG_TYPE_SIZE)
+        type = long_integer_type_node;
+      else if (bits == LONG_LONG_TYPE_SIZE)
+        type = long_long_integer_type_node;
+      else
+        type = make_signed_type(bits);
+    }
+  return type;
+}
+
+static tree
+go_langhook_type_for_mode (machine_mode mode, int unsignedp)
+{
+  tree type;
+  /* Go has no vector types.  Build them here.  FIXME: It does not
+     make sense for the middle-end to ask the frontend for a type
+     which the frontend does not support.  However, at least for now
+     it is required.  See PR 46805.  */
+  if (VECTOR_MODE_P (mode))
+    {
+      tree inner;
+
+      inner = go_langhook_type_for_mode (GET_MODE_INNER (mode), unsignedp);
+      if (inner != NULL_TREE)
+	return build_vector_type_for_mode (inner, mode);
+      return NULL_TREE;
+    }
+
+  scalar_int_mode imode;
+  scalar_float_mode fmode;
+  complex_mode cmode;
+  if (is_int_mode (mode, &imode))
+    return go_langhook_type_for_size (GET_MODE_BITSIZE (imode), unsignedp);
+  else if (is_float_mode (mode, &fmode))
+    {
+      switch (GET_MODE_BITSIZE (fmode))
+	{
+	case 32:
+	  return float_type_node;
+	case 64:
+	  return double_type_node;
+	default:
+	  // We have to check for long double in order to support
+	  // i386 excess precision.
+	  if (fmode == TYPE_MODE(long_double_type_node))
+	    return long_double_type_node;
+	}
+    }
+  else if (is_complex_float_mode (mode, &cmode))
+    {
+      switch (GET_MODE_BITSIZE (cmode))
+	{
+	case 64:
+	  return complex_float_type_node;
+	case 128:
+	  return complex_double_type_node;
+	default:
+	  // We have to check for long double in order to support
+	  // i386 excess precision.
+	  if (cmode == TYPE_MODE(complex_long_double_type_node))
+	    return complex_long_double_type_node;
+	}
+    }
+
+#if HOST_BITS_PER_WIDE_INT >= 64
+  /* The middle-end and some backends rely on TImode being supported
+     for 64-bit HWI.  */
+  if (mode == TImode)
+    {
+      type = build_nonstandard_integer_type (GET_MODE_BITSIZE (TImode),
+					     unsignedp);
+      if (type && TYPE_MODE (type) == TImode)
+	return type;
+    }
+#endif
+  return NULL_TREE;
+}
+
+/* Record a builtin function.  We just ignore builtin functions.  */
+
+static tree
+go_langhook_builtin_function (tree decl)
+{
+  return decl;
+}
+
+/* Return true if we are in the global binding level.  */
+
+static bool
+go_langhook_global_bindings_p (void)
+{
+  return current_function_decl == NULL_TREE;
+}
+
+/* Push a declaration into the current binding level.  We can't
+   usefully implement this since we don't want to convert from tree
+   back to one of our internal data structures.  I think the only way
+   this is used is to record a decl which is to be returned by
+   getdecls, and we could implement it for that purpose if
+   necessary.  */
+
+static tree
+go_langhook_pushdecl (tree decl ATTRIBUTE_UNUSED)
+{
+  gcc_unreachable ();
+}
+
+/* This hook is used to get the current list of declarations as trees.
+   We don't support that; instead we use the write_globals hook.  This
+   can't simply crash because it is called by -gstabs.  */
+
+static tree
+go_langhook_getdecls (void)
+{
+  return NULL;
+}
+
+/* Go specific gimplification.  We need to gimplify
+   CALL_EXPR_STATIC_CHAIN, because the gimplifier doesn't handle
+   it.  */
+
+static int
+go_langhook_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
+{
+  if (TREE_CODE (*expr_p) == CALL_EXPR
+      && CALL_EXPR_STATIC_CHAIN (*expr_p) != NULL_TREE)
+    gimplify_expr (&CALL_EXPR_STATIC_CHAIN (*expr_p), pre_p, post_p,
+		   is_gimple_val, fb_rvalue);
+  return GS_UNHANDLED;
+}
+
+/* Return a decl for the exception personality function.  The function
+   itself is implemented in libgo/runtime/go-unwind.c.  */
+
+static tree
+go_langhook_eh_personality (void)
+{
+  static tree personality_decl;
+  if (personality_decl == NULL_TREE)
+    {
+      personality_decl = build_personality_function ("gccgo");
+      go_preserve_from_gc (personality_decl);
+    }
+  return personality_decl;
+}
+
+/* Functions called directly by the generic backend.  */
+
+tree
+convert (tree type, tree expr)
+{
+  if (type == error_mark_node
+      || expr == error_mark_node
+      || TREE_TYPE (expr) == error_mark_node)
+    return error_mark_node;
+
+  if (type == TREE_TYPE (expr))
+    return expr;
+
+  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (expr)))
+    return fold_convert (type, expr);
+
+  switch (TREE_CODE (type))
+    {
+    case VOID_TYPE:
+    case BOOLEAN_TYPE:
+      return fold_convert (type, expr);
+    case INTEGER_TYPE:
+      return fold (convert_to_integer (type, expr));
+    case POINTER_TYPE:
+      return fold (convert_to_pointer (type, expr));
+    case REAL_TYPE:
+      return fold (convert_to_real (type, expr));
+    case COMPLEX_TYPE:
+      return fold (convert_to_complex (type, expr));
+    default:
+      break;
+    }
+
+  gcc_unreachable ();
+}
+
+/* FIXME: This is a hack to preserve trees that we create from the
+   garbage collector.  */
+
+static GTY(()) tree go_gc_root;
+
+void
+go_preserve_from_gc (tree t)
+{
+  go_gc_root = tree_cons (NULL_TREE, t, go_gc_root);
+}
+
+/* Convert an identifier for use in an error message.  */
+
+const char *
+go_localize_identifier (const char *ident)
+{
+  return identifier_to_locale (ident);
+}
+
+#undef LANG_HOOKS_NAME
+#undef LANG_HOOKS_INIT
+#undef LANG_HOOKS_OPTION_LANG_MASK
+#undef LANG_HOOKS_INIT_OPTIONS_STRUCT
+#undef LANG_HOOKS_HANDLE_OPTION
+#undef LANG_HOOKS_POST_OPTIONS
+#undef LANG_HOOKS_PARSE_FILE
+#undef LANG_HOOKS_TYPE_FOR_MODE
+#undef LANG_HOOKS_TYPE_FOR_SIZE
+#undef LANG_HOOKS_BUILTIN_FUNCTION
+#undef LANG_HOOKS_GLOBAL_BINDINGS_P
+#undef LANG_HOOKS_PUSHDECL
+#undef LANG_HOOKS_GETDECLS
+#undef LANG_HOOKS_GIMPLIFY_EXPR
+#undef LANG_HOOKS_EH_PERSONALITY
+
+#define LANG_HOOKS_NAME			"GNU Go"
+#define LANG_HOOKS_INIT			go_langhook_init
+#define LANG_HOOKS_OPTION_LANG_MASK	go_langhook_option_lang_mask
+#define LANG_HOOKS_INIT_OPTIONS_STRUCT	go_langhook_init_options_struct
+#define LANG_HOOKS_HANDLE_OPTION	go_langhook_handle_option
+#define LANG_HOOKS_POST_OPTIONS		go_langhook_post_options
+#define LANG_HOOKS_PARSE_FILE		go_langhook_parse_file
+#define LANG_HOOKS_TYPE_FOR_MODE	go_langhook_type_for_mode
+#define LANG_HOOKS_TYPE_FOR_SIZE	go_langhook_type_for_size
+#define LANG_HOOKS_BUILTIN_FUNCTION	go_langhook_builtin_function
+#define LANG_HOOKS_GLOBAL_BINDINGS_P	go_langhook_global_bindings_p
+#define LANG_HOOKS_PUSHDECL		go_langhook_pushdecl
+#define LANG_HOOKS_GETDECLS		go_langhook_getdecls
+#define LANG_HOOKS_GIMPLIFY_EXPR	go_langhook_gimplify_expr
+#define LANG_HOOKS_EH_PERSONALITY	go_langhook_eh_personality
+
+struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
+
+#include "gt-go-go-lang.h"
+#include "gtype-go.h"