--vcdz option added,

switched to gcc-4.0.2,
can be compiled with GNAT GPL 2005
ready for ada05 (interface identifier not used anymore)
bug fixes

12 files changed, 3055 insertions, 0 deletions

diff --git a/ortho/gcc/Makefile b/ortho/gcc/Makefile
new file mode 100644
index 000000000..69c99969d
--- /dev/null
+++ b/ortho/gcc/Makefile
@@ -0,0 +1,32 @@
+ortho_srcdir=..
+orthobe_srcdir=$(ortho_srcdir)/gcc
+agcc_objdir=.
+agcc_srcdir=$(ortho_srcdir)/gcc
+AGCC_GCCSRC_DIR:=$(HOME)/dist/gcc-4.0.1
+AGCC_GCCOBJ_DIR:=$(AGCC_GCCSRC_DIR)-objs
+SED=sed
+
+all: $(ortho_exec)
+
+include $(orthobe_srcdir)/Makefile.inc
+
+ORTHO_BASENAME=$(orthobe_srcdir)/ortho_gcc
+ORTHO_PACKAGE=Ortho_Gcc
+
+
+$(ortho_exec): $(AGCC_DEPS) $(ORTHO_BASENAME).ads force
+	gnatmake -m -o $@ -g -aI$(ortho_srcdir) \
+	 -aI$(ortho_srcdir)/gcc $(GNAT_FLAGS) ortho_gcc-main \
+	 -bargs -E -largs $(AGCC_OBJS) #-static
+
+clean: agcc-clean
+	$(RM) -f *.o *.ali ortho_nodes-main
+	$(RM) b~*.ad? *~
+
+distclean: clean agcc-clean
+
+
+force:
+
+.PHONY: force all clean
+
diff --git a/ortho/gcc/Makefile.inc b/ortho/gcc/Makefile.inc
new file mode 100644
index 000000000..33ac0f428
--- /dev/null
+++ b/ortho/gcc/Makefile.inc
@@ -0,0 +1,62 @@
+#  -*- Makefile -*- for the gcc implemantation of ortho.
+#  Copyright (C) 2005 Tristan Gingold
+#
+#  GHDL is free software; you can redistribute it and/or modify it under
+#  the terms of the GNU General Public License as published by the Free
+#  Software Foundation; either version 2, or (at your option) any later
+#  version.
+#
+#  GHDL is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or
+#  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+#  for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with GCC; see the file COPYING.  If not, write to the Free
+#  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+#  02111-1307, USA.
+
+# Variable used:
+# AGCC_GCCSRC_DIR: the gcc source base directory (ie gcc-X.Y.Z-objs/)
+# AGCC_GCCOBJ_DIR: the gcc objects base directory
+# agcc_srcdir: the agcc source directory
+# agcc_objdir: the agcc object directory
+
+AGCC_INC_FLAGS=-I$(AGCC_GCCOBJ_DIR)/gcc -I$(AGCC_GCCSRC_DIR)/include \
+ -I$(AGCC_GCCSRC_DIR)/gcc -I$(AGCC_GCCSRC_DIR)/gcc/config \
+ -I$(AGCC_GCCSRC_DIR)/libcpp/include
+AGCC_CFLAGS=-g -DIN_GCC $(AGCC_INC_FLAGS)
+
+AGCC_LOCAL_OBJS=ortho-lang.o gcc-version.o
+
+AGCC_DEPS := $(AGCC_LOCAL_OBJS)
+AGCC_OBJS := $(AGCC_LOCAL_OBJS) \
+	$(AGCC_GCCOBJ_DIR)/gcc/toplev.o \
+	$(AGCC_GCCOBJ_DIR)/gcc/c-convert.o \
+	$(AGCC_GCCOBJ_DIR)/gcc/libbackend.a \
+	$(AGCC_GCCOBJ_DIR)/libcpp/libcpp.a \
+	$(AGCC_GCCOBJ_DIR)/libiberty/libiberty.a
+
+gcc-version.c: $(AGCC_GCCSRC_DIR)/gcc/version.c
+	-$(RM) -f $@
+	echo '#include "version.h"' > $@
+	sed  -n -e '/version_string/ s/";/ (ghdl)";/p' < $< >> $@
+	echo 'const char bug_report_url[] = "<URL:mailto:ghdl@free.fr>";' >> $@
+
+gcc-version.o: gcc-version.c
+	$(CC) -c -o $@ $< $(AGCC_CFLAGS)
+
+ortho-lang.o: $(agcc_srcdir)/ortho-lang.c \
+ $(AGCC_GCCOBJ_DIR)/gcc/gtype-vhdl.h \
+ $(AGCC_GCCOBJ_DIR)/gcc/gt-vhdl-ortho-lang.h
+	$(CC) -c -o $@ $< $(AGCC_CFLAGS)
+
+agcc-clean: force
+	$(RM) -f $(agcc_objdir)/*.o
+	$(RM) -f $(agcc_srcdir)/*~
+
+agcc-maintainer-clean: force
+	$(RM) -f $(AGCC_DEPS)
+
+
+.PHONY: agcc-clean agcc-maintainer-clean
diff --git a/ortho/gcc/lang.opt b/ortho/gcc/lang.opt
new file mode 100644
index 000000000..2f945266b
--- /dev/null
+++ b/ortho/gcc/lang.opt
@@ -0,0 +1,70 @@
+Language
+vhdl
+
+-std=
+vhdl Joined
+Select the vhdl standard
+
+-compile-standard
+vhdl
+Used during compiler build to compile the std.standard package
+
+-bootstrap
+vhdl
+Used during compiler build to compile std packages
+
+-work=
+vhdl Joined
+Set the name of the work library
+
+-workdir=
+vhdl Joined
+Set the directory of the work library
+
+P
+vhdl Joined
+-P<dir>	Add <dir> to the end of the vhdl library path
+
+-elab
+vhdl Separate
+--elab <name>	Used internally during elaboration of <name>
+
+-anaelab
+vhdl Separate
+--anaelab <name>	Used internally during elaboration of <name>
+
+c
+vhdl Separate
+-c <filename>	Analyze <filename> for --anaelab
+
+v
+vhdl
+Verbose
+
+-warn-
+vhdl Joined
+--warn-<name>	Warn about <name>
+
+-ghdl
+vhdl Joined
+--ghdl-<option>	Pass <option> to vhdl front-end
+
+-expect-failure
+vhdl
+Expect a compiler error (used for testsuite)
+
+-no-vital-checks
+vhdl
+Disable VITAL checks
+
+-vital-checks
+vhdl
+Enable VITAL checks
+
+fexplicit
+vhdl
+Explicit function declarations override implicit one in use
+
+l
+vhdl Joined Separate
+-l<filename>	Put list of files for link in <filename>
diff --git a/ortho/gcc/ortho-lang.c b/ortho/gcc/ortho-lang.c
new file mode 100644
index 000000000..609ec737e
--- /dev/null
+++ b/ortho/gcc/ortho-lang.c
@@ -0,0 +1,2052 @@
+#include <stddef.h>
+#include <math.h>
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "tm_p.h"
+#include "defaults.h"
+#include "ggc.h"
+#include "diagnostic.h"
+#include "langhooks.h"
+#include "langhooks-def.h"
+#include "toplev.h"
+#include "opts.h"
+#include "options.h"
+#include "real.h"
+#include "tree-gimple.h"
+#include "function.h"
+#include "cgraph.h"
+
+const int tree_identifier_size = sizeof (struct tree_identifier);
+
+struct binding_level GTY(())
+{
+  /*  The BIND_EXPR node for this binding.  */
+  tree bind;
+
+  /*  The BLOCK node for this binding.  */
+  tree block;
+
+  /*  If true, stack must be saved (alloca is used).  */
+  int save_stack;
+
+  /*  Parent binding level.  */
+  struct binding_level *prev;
+
+  /*  Decls in this binding.  */
+  tree first_decl;
+  tree last_decl;
+
+  /*  Blocks in this binding.  */
+  tree first_block;
+  tree last_block;
+};
+
+/*  The current binding level.  */
+static GTY(()) struct binding_level *cur_binding_level = NULL;
+
+/*  Chain of unused binding levels.  */
+static GTY(()) struct binding_level *old_binding_levels = NULL;
+
+static tree cur_stmts = NULL_TREE;
+
+static void
+push_binding (void)
+{
+  struct binding_level *res;
+
+  if (old_binding_levels == NULL)
+    res = (struct binding_level *) ggc_alloc (sizeof (struct binding_level));
+  else
+    {
+      res = old_binding_levels;
+      old_binding_levels = res->prev;
+    }
+
+  /* Init.  */
+  res->first_decl = NULL_TREE;
+  res->last_decl = NULL_TREE;
+
+  res->first_block = NULL_TREE;
+  res->last_block = NULL_TREE;
+
+  res->bind = make_node (BIND_EXPR);
+  res->block = make_node (BLOCK);
+  BIND_EXPR_BLOCK (res->bind) = res->block;
+  TREE_SIDE_EFFECTS (res->bind) = 1;
+  TREE_TYPE (res->bind) = void_type_node;
+  TREE_USED (res->block) = 1;
+
+  if (cur_binding_level != NULL)
+    {
+      /* Append the block created.  */
+      if (cur_binding_level->first_block == NULL)
+	cur_binding_level->first_block = res->block;
+      else
+	TREE_CHAIN (cur_binding_level->last_block) = res->block;
+      cur_binding_level->last_block = res->block;
+
+      BLOCK_SUPERCONTEXT (res->block) = cur_binding_level->block;
+    }
+
+  res->prev = cur_binding_level;
+  cur_binding_level = res;
+}
+
+static void
+push_decl (tree decl)
+{
+  DECL_CONTEXT (decl) = current_function_decl;
+
+  if (cur_binding_level->first_decl == NULL)
+    cur_binding_level->first_decl = decl;
+  else
+    TREE_CHAIN (cur_binding_level->last_decl) = decl;
+  cur_binding_level->last_decl = decl;
+}
+
+static tree
+pop_binding (void)
+{
+  tree res;
+  struct binding_level *cur;
+
+  cur = cur_binding_level;
+  res = cur->bind;
+
+  if (cur->save_stack)
+    {
+      tree tmp_var;
+      tree save;
+      tree save_call;
+      tree restore;
+      tree t;
+
+      /* Create an artificial var to save the stack pointer.  */
+      tmp_var = build_decl (VAR_DECL, NULL, ptr_type_node);
+      DECL_ARTIFICIAL (tmp_var) = 1;
+      DECL_IGNORED_P (tmp_var) = 1;
+      TREE_USED (tmp_var) = 1;
+      push_decl (tmp_var);
+
+      /* Create the save stmt.  */
+      save_call = build_function_call_expr
+	(implicit_built_in_decls[BUILT_IN_STACK_SAVE], NULL_TREE);
+      save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
+
+      /* Create the restore stmt.  */
+      restore = build_function_call_expr
+	(implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
+	 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
+
+      /* Build a try-finally block.
+	 The statement list is the block of current statements.  */
+      t = build (TRY_FINALLY_EXPR, void_type_node, cur_stmts, NULL_TREE);
+      TREE_SIDE_EFFECTS (t) = 1;
+
+      /* The finally block is the restore stmt.  */
+      append_to_statement_list (restore, &TREE_OPERAND (t, 1));
+
+      /* The body of the BIND_BLOCK is the save stmt, followed by the
+	 try block.  */
+      BIND_EXPR_BODY (res) = NULL_TREE;
+      append_to_statement_list (save, &BIND_EXPR_BODY (res));
+      append_to_statement_list (t, &BIND_EXPR_BODY (res));
+    }
+  else
+    {
+      /* The body of the BIND_BLOCK is the statement block.  */
+      BIND_EXPR_BODY (res) = cur_stmts;
+    }
+  BIND_EXPR_VARS (res) = cur->first_decl;
+
+  BLOCK_SUBBLOCKS (cur->block) = cur->first_block;
+  BLOCK_VARS (cur->block) = cur->first_decl;
+
+  cur_binding_level = cur->prev;
+  cur->prev = old_binding_levels;
+  old_binding_levels = cur;
+
+  return res;
+}
+
+static void
+append_stmt (tree stmt)
+{
+  if (!EXPR_HAS_LOCATION (stmt))
+    SET_EXPR_LOCATION (stmt, input_location);
+  TREE_SIDE_EFFECTS (stmt) = 1;
+  append_to_statement_list (stmt, &cur_stmts);
+}
+
+static void
+push_stmts (tree stmts)
+{
+  TREE_CHAIN (stmts) = cur_stmts;
+  cur_stmts = stmts;
+}
+
+static void
+pop_stmts (void)
+{
+  tree prev;
+
+  prev = cur_stmts;
+  cur_stmts = TREE_CHAIN (prev);
+  TREE_CHAIN (prev) = NULL_TREE;
+}
+
+static GTY(()) tree top;
+
+static GTY(()) tree stack_alloc_function_ptr;
+extern void ortho_fe_init (void);
+
+static int
+global_bindings_p (void)
+{
+  return cur_binding_level->prev == NULL;
+}
+
+static void
+insert_block (tree b)
+{
+  abort ();
+}
+
+static tree
+pushdecl (tree t)
+{
+  abort ();
+}
+
+static tree
+builtin_function (const char *name,
+		  tree type,
+		  int function_code,
+		  enum built_in_class class,
+		  const char *library_name,
+		  tree attrs ATTRIBUTE_UNUSED);
+
+REAL_VALUE_TYPE fp_const_p5; /* 0.5 */
+REAL_VALUE_TYPE fp_const_m_p5; /* -0.5 */
+REAL_VALUE_TYPE fp_const_zero; /* 0.0 */
+
+static bool
+ortho_init (void)
+{
+  tree n;
+
+  input_location.line = 0;
+
+  /* Create a global binding.  */
+  push_binding ();
+
+  build_common_tree_nodes (0, 0);
+  n = build_decl (TYPE_DECL, get_identifier ("int"), integer_type_node);
+  push_decl (n);
+  n = build_decl (TYPE_DECL, get_identifier ("char"), char_type_node);
+  push_decl (n);
+  size_type_node = unsigned_type_node;
+  set_sizetype (unsigned_type_node);
+  build_common_tree_nodes_2 (0);
+
+  /* Create alloca builtin.  */
+  {
+    tree args_type = tree_cons (NULL_TREE, size_type_node, void_list_node);
+    tree func_type = build_function_type (ptr_type_node, args_type);
+       
+    implicit_built_in_decls[BUILT_IN_ALLOCA] = builtin_function
+      ("__builtin_alloca", func_type,
+       BUILT_IN_ALLOCA, BUILT_IN_NORMAL, NULL, NULL_TREE);
+    
+    stack_alloc_function_ptr = build1
+      (ADDR_EXPR, 
+       build_pointer_type (func_type),
+       implicit_built_in_decls[BUILT_IN_ALLOCA]);
+  }
+
+  {
+    tree ptr_ftype = build_function_type (ptr_type_node, NULL_TREE);
+
+    implicit_built_in_decls[BUILT_IN_STACK_SAVE] = builtin_function
+      ("__builtin_stack_save", ptr_ftype,
+       BUILT_IN_STACK_SAVE, BUILT_IN_NORMAL, NULL, NULL_TREE);
+  }
+
+  {
+    tree ftype_ptr;
+
+    ftype_ptr = build_function_type
+      (void_type_node,
+       tree_cons (NULL_TREE, ptr_type_node, NULL_TREE));
+
+    implicit_built_in_decls[BUILT_IN_STACK_RESTORE] = builtin_function
+      ("__builtin_stack_restore", ftype_ptr,
+       BUILT_IN_STACK_RESTORE, BUILT_IN_NORMAL, NULL, NULL_TREE);
+  }
+
+  {
+    REAL_VALUE_TYPE v;
+    
+    REAL_VALUE_FROM_INT (v, 1, 0, DFmode);
+    real_ldexp (&fp_const_p5, &v, -1);
+    
+    REAL_VALUE_FROM_INT (v, -1, -1, DFmode);
+    real_ldexp (&fp_const_m_p5, &v, -1);
+    
+    REAL_VALUE_FROM_INT (fp_const_zero, 0, 0, DFmode);
+  }
+
+  ortho_fe_init ();
+
+  return true;
+}
+
+static void
+ortho_finish (void)
+{
+}
+
+static unsigned int
+ortho_init_options (unsigned int argc, const char **argv)
+{
+  return CL_vhdl;
+}
+
+static bool
+ortho_post_options (const char **pfilename)
+{
+  if (*pfilename == NULL || strcmp (*pfilename, "-") == 0)
+    *pfilename = "*stdin*";
+
+  /* Run the back-end.  */
+  return false;
+}
+
+extern int lang_handle_option (const char *opt, const char *arg);
+
+static int
+ortho_handle_option (size_t code, const char *arg, int value)
+{
+  const char *opt;
+
+  opt = cl_options[code].opt_text;
+
+  switch (code)
+    {
+    case OPT__elab:
+    case OPT_l:
+    case OPT_c:
+    case OPT__anaelab:
+      /* Only a few options have a real arguments.  */
+      return lang_handle_option (opt, arg);
+    default:
+      /* The other options must have a joint argument.  */
+      if (arg != NULL)
+	{
+	  size_t len1;
+	  size_t len2;
+	  char *nopt;
+	  
+	  len1 = strlen (opt);
+	  len2 = strlen (arg);
+	  nopt = alloca (len1 + len2 + 1);
+	  memcpy (nopt, opt, len1);
+	  memcpy (nopt + len1, arg, len2);
+	  nopt[len1 + len2] = 0;
+	  opt = nopt;
+	}
+      return lang_handle_option (opt, NULL);
+    }
+}
+
+#if 0
+void
+linemap_init (void *s)
+{
+}
+#endif
+
+extern int lang_parse_file (const char *filename);
+
+static void
+ortho_parse_file (int debug)
+{
+  const char *filename;
+
+  if (num_in_fnames == 0)
+    filename = NULL;
+  else
+    filename = in_fnames[0];
+
+  if (!lang_parse_file (filename))
+    errorcount++;
+  else
+    {
+      cgraph_finalize_compilation_unit ();
+      cgraph_optimize ();
+    }
+}
+
+static void
+ortho_expand_function (tree fndecl)
+{
+  if (DECL_CONTEXT (fndecl) != NULL_TREE)
+    {
+      push_function_context ();
+      tree_rest_of_compilation (fndecl);
+      pop_function_context ();
+    }
+  else
+      tree_rest_of_compilation (fndecl);
+}
+
+/*  Called by the back-end or by the front-end when the address of EXP
+    must be taken.
+    This function should found the base object (if any), and mark it as
+    addressable (via TREE_ADDRESSABLE).  It may emit a warning if this
+    object cannot be addressable (front-end restriction).
+    Returns TRUE in case of success, FALSE in case of failure.
+    Note that the status is never checked by the back-end.  */
+static bool
+ortho_mark_addressable (tree exp)
+{
+  tree n;
+
+  n = exp;
+
+  while (1)
+    switch (TREE_CODE (n))
+      {
+      case VAR_DECL:
+      case CONST_DECL:
+      case PARM_DECL:
+      case RESULT_DECL:
+	TREE_ADDRESSABLE (n) = 1;
+	return true;
+
+      case COMPONENT_REF:
+      case ARRAY_REF:
+	n = TREE_OPERAND (n, 0);
+	break;
+
+      case FUNCTION_DECL:
+      case CONSTRUCTOR:
+	TREE_ADDRESSABLE (n) = 1;
+	return true;
+
+      case INDIRECT_REF:
+	return true;
+
+      default:
+	abort ();
+      }
+}
+
+static tree
+ortho_truthvalue_conversion (tree expr)
+{
+  tree expr_type;
+  tree t;
+  tree f;
+
+  expr_type = TREE_TYPE (expr);
+  if (TREE_CODE (expr_type) != BOOLEAN_TYPE)
+    {
+      t = integer_one_node;
+      f = integer_zero_node;
+    }
+  else
+    {
+      f = TYPE_MIN_VALUE (expr_type);
+      t = TYPE_MAX_VALUE (expr_type);
+    }
+
+
+  switch (TREE_CODE (expr))
+    {
+    case EQ_EXPR:
+    case NE_EXPR:
+    case LE_EXPR:
+    case GE_EXPR:
+    case LT_EXPR:
+    case GT_EXPR:
+    case TRUTH_ANDIF_EXPR:
+    case TRUTH_ORIF_EXPR:
+    case TRUTH_AND_EXPR:
+    case TRUTH_OR_EXPR:
+    case ERROR_MARK:
+      return expr;
+
+    case INTEGER_CST:
+      /* Not 0 is true.  */
+      return integer_zerop (expr) ? f : t;
+
+    case REAL_CST:
+      return real_zerop (expr) ? f : t;
+
+    default:
+      abort ();
+    }
+}
+
+/* Return a definition for a builtin function named NAME and whose data type
+   is TYPE.  TYPE should be a function type with argument types.
+   FUNCTION_CODE tells later passes how to compile calls to this function.
+   See tree.h for its possible values.
+
+   If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME,
+   the name to be called if we can't opencode the function.  If
+   ATTRS is nonzero, use that for the function's attribute list.  */
+static tree
+builtin_function (const char *name,
+		  tree type,
+		  int function_code,
+		  enum built_in_class class,
+		  const char *library_name,
+		  tree attrs ATTRIBUTE_UNUSED)
+{
+  tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type);
+  DECL_EXTERNAL (decl) = 1;
+  TREE_PUBLIC (decl) = 1;
+  if (library_name)
+    SET_DECL_ASSEMBLER_NAME (decl, get_identifier (library_name));
+  make_decl_rtl (decl);
+  DECL_BUILT_IN_CLASS (decl) = class;
+  DECL_FUNCTION_CODE (decl) = function_code;
+  return decl;
+}
+
+/*  This variable keeps a table for types for each precision so that we only
+    allocate each of them once. Signed and unsigned types are kept separate. 
+ */
+static GTY(()) tree signed_and_unsigned_types[MAX_BITS_PER_WORD + 1][2];
+
+/*  Return an integer type with the number of bits of precision given by
+    PRECISION.  UNSIGNEDP is nonzero if the type is unsigned; otherwise
+    it is a signed type.  */
+static tree
+type_for_size (unsigned int precision, int unsignedp)
+{
+  tree t;
+
+  if (precision <= MAX_BITS_PER_WORD
+      && signed_and_unsigned_types[precision][unsignedp] != NULL_TREE)
+    return signed_and_unsigned_types[precision][unsignedp];
+
+  if (unsignedp) 
+    t = make_unsigned_type (precision);
+  else
+    t = make_signed_type (precision);
+
+  if (precision <= MAX_BITS_PER_WORD)
+    signed_and_unsigned_types[precision][unsignedp] = t;
+
+  return t;
+}
+
+/*  Return a data type that has machine mode MODE.  UNSIGNEDP selects
+    an unsigned type; otherwise a signed type is returned.  */
+static tree
+type_for_mode (enum machine_mode mode, int unsignedp)
+{
+  return type_for_size (GET_MODE_BITSIZE (mode), unsignedp);
+}
+
+/*  Return the unsigned version of a TYPE_NODE, a scalar type.  */
+static tree
+unsigned_type (tree type)
+{
+  return type_for_size (TYPE_PRECISION (type), 1);
+}
+
+/*  Return the signed version of a TYPE_NODE, a scalar type.  */
+static tree
+signed_type (tree type)
+{
+  return type_for_size (TYPE_PRECISION (type), 0);
+}
+
+/*  Return a type the same as TYPE except unsigned or signed according to
+    UNSIGNEDP.  */
+static tree
+signed_or_unsigned_type (int unsignedp, tree type)
+{
+  if (!INTEGRAL_TYPE_P (type)
+      || TYPE_UNSIGNED (type) == unsignedp)
+    return type;
+  else
+    return type_for_size (TYPE_PRECISION (type), unsignedp);
+}
+
+#undef LANG_HOOKS_NAME
+#define LANG_HOOKS_NAME "vhdl"
+#undef LANG_HOOKS_IDENTIFIER_SIZE
+#define LANG_HOOKS_IDENTIFIER_SIZE sizeof (struct tree_identifier)
+#undef LANG_HOOKS_INIT
+#define LANG_HOOKS_INIT ortho_init
+#undef LANG_HOOKS_FINISH
+#define LANG_HOOKS_FINISH ortho_finish
+#undef LANG_HOOKS_INIT_OPTIONS
+#define LANG_HOOKS_INIT_OPTIONS ortho_init_options
+#undef LANG_HOOKS_HANDLE_OPTION
+#define LANG_HOOKS_HANDLE_OPTION ortho_handle_option
+#undef LANG_HOOKS_POST_OPTIONS
+#define LANG_HOOKS_POST_OPTIONS ortho_post_options
+#undef LANG_HOOKS_HONOR_READONLY
+#define LANG_HOOKS_HONOR_READONLY true
+#undef LANG_HOOKS_TRUTHVALUE_CONVERSION
+#define LANG_HOOKS_TRUTHVALUE_CONVERSION ortho_truthvalue_conversion
+#undef LANG_HOOKS_MARK_ADDRESSABLE
+#define LANG_HOOKS_MARK_ADDRESSABLE ortho_mark_addressable
+#undef LANG_HOOKS_CALLGRAPH_EXPAND_FUNCTION
+#define LANG_HOOKS_CALLGRAPH_EXPAND_FUNCTION ortho_expand_function
+
+#undef LANG_HOOKS_TYPE_FOR_MODE
+#define LANG_HOOKS_TYPE_FOR_MODE type_for_mode
+#undef LANG_HOOKS_TYPE_FOR_SIZE
+#define LANG_HOOKS_TYPE_FOR_SIZE type_for_size
+#undef LANG_HOOKS_SIGNED_TYPE
+#define LANG_HOOKS_SIGNED_TYPE signed_type
+#undef LANG_HOOKS_UNSIGNED_TYPE
+#define LANG_HOOKS_UNSIGNED_TYPE unsigned_type
+#undef LANG_HOOKS_SIGNED_OR_UNSIGNED_TYPE
+#define LANG_HOOKS_SIGNED_OR_UNSIGNED_TYPE signed_or_unsigned_type
+#undef LANG_HOOKS_PARSE_FILE
+#define LANG_HOOKS_PARSE_FILE ortho_parse_file
+
+#define pushlevel lhd_do_nothing_i
+#define poplevel lhd_do_nothing_iii_return_null_tree
+#define set_block lhd_do_nothing_t
+#undef LANG_HOOKS_GETDECLS
+#define LANG_HOOKS_GETDECLS lhd_return_null_tree_v
+
+const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
+
+/* Tree code classes.  */
+
+#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
+
+const enum tree_code_class tree_code_type[] = {
+#include "tree.def"
+  'x'
+};
+#undef DEFTREECODE
+
+/* Table indexed by tree code giving number of expression
+   operands beyond the fixed part of the node structure.
+   Not used for types or decls.  */
+
+#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
+
+const unsigned char tree_code_length[] = {
+#include "tree.def"
+  0
+};
+#undef DEFTREECODE
+
+#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) NAME,
+const char * const tree_code_name[] = {
+#include "tree.def"
+  "@@dummy"
+};
+#undef DEFTREECODE
+
+union lang_tree_node 
+  GTY((desc ("0"),
+       chain_next ("(union lang_tree_node *)TREE_CHAIN (&%h.generic)")))
+{
+  union tree_node GTY ((tag ("0"), 
+			desc ("tree_node_structure (&%h)"))) 
+    generic;
+};
+
+struct lang_decl GTY(())
+{
+};
+
+struct lang_type GTY (())
+{
+};
+
+struct language_function GTY (())
+{
+};
+
+struct chain_constr_type
+{
+  tree first;
+  tree last;
+};
+
+static void
+chain_init (struct chain_constr_type *constr)
+{
+  constr->first = NULL_TREE;
+  constr->last = NULL_TREE;
+}
+
+static void
+chain_append (struct chain_constr_type *constr, tree el)
+{
+  if (constr->first == NULL_TREE)
+    {
+      if (constr->last != NULL_TREE)
+	abort ();
+      constr->first = el;
+    }
+  else
+    TREE_CHAIN (constr->last) = el;
+  constr->last = el;
+}
+
+struct list_constr_type
+{
+  tree first;
+  tree last;
+};
+
+static void
+list_init (struct list_constr_type *constr)
+{
+  constr->first = NULL_TREE;
+  constr->last = NULL_TREE;
+}
+
+static void
+ortho_list_append (struct list_constr_type *constr, tree el)
+{
+  tree res;
+
+  res = tree_cons (NULL_TREE, el, NULL_TREE);
+  if (constr->first == NULL_TREE)
+    constr->first = res;
+  else
+    TREE_CHAIN (constr->last) = res;
+  constr->last = res;
+}
+
+enum ON_op_kind {
+  /*  Not an operation; invalid.  */
+  ON_Nil,
+
+  /*  Dyadic operations.  */
+  ON_Add_Ov,
+  ON_Sub_Ov,
+  ON_Mul_Ov,
+  ON_Div_Ov,
+  ON_Rem_Ov,
+  ON_Mod_Ov,
+
+  /*  Binary operations.  */
+  ON_And,
+  ON_Or, 
+  ON_Xor,
+  ON_And_Then,
+  ON_Or_Else,
+
+  /*  Monadic operations.  */
+  ON_Not,
+  ON_Neg_Ov,
+  ON_Abs_Ov,
+
+  /*  Comparaisons  */
+  ON_Eq,
+  ON_Neq,
+  ON_Le,
+  ON_Lt,
+  ON_Ge,
+  ON_Gt,
+
+  ON_LAST
+};
+
+
+static enum tree_code ON_op_to_TREE_CODE[ON_LAST] = {
+  ERROR_MARK,
+
+  PLUS_EXPR,
+  MINUS_EXPR,
+  MULT_EXPR,
+  ERROR_MARK,
+  TRUNC_MOD_EXPR,
+  FLOOR_MOD_EXPR,
+
+  TRUTH_AND_EXPR,
+  TRUTH_OR_EXPR,
+  TRUTH_XOR_EXPR,
+  TRUTH_ANDIF_EXPR,
+  TRUTH_ORIF_EXPR,
+
+  TRUTH_NOT_EXPR,
+  NEGATE_EXPR,
+  ABS_EXPR,
+
+  EQ_EXPR,
+  NE_EXPR,
+  LE_EXPR,
+  LT_EXPR,
+  GE_EXPR,
+  GT_EXPR,
+};
+
+tree
+new_dyadic_op (enum ON_op_kind kind, tree left, tree right)
+{
+  tree left_type;
+  enum tree_code code;
+
+  left_type = TREE_TYPE (left);
+  if (left_type != TREE_TYPE (right))
+    abort ();
+
+  switch (kind)
+    {
+    case ON_Div_Ov:
+      if (TREE_CODE (left_type) == REAL_TYPE)
+	code = RDIV_EXPR;
+      else
+	code = TRUNC_DIV_EXPR;
+      break;
+    default:
+      code = ON_op_to_TREE_CODE[kind];
+      break;
+    }
+  return build2 (code, left_type, left, right);
+}
+
+tree
+new_monadic_op (enum ON_op_kind kind, tree operand)
+{
+  return build1 (ON_op_to_TREE_CODE[kind], TREE_TYPE (operand), operand);
+}
+
+tree
+new_compare_op (enum ON_op_kind kind, tree left, tree right, tree ntype)
+{
+  if (TREE_CODE (ntype) != BOOLEAN_TYPE)
+    abort ();
+  if (TREE_TYPE (left) != TREE_TYPE (right))
+    abort ();
+  return build2 (ON_op_to_TREE_CODE[kind], ntype, left, right);
+}
+
+tree
+new_convert_ov (tree val, tree rtype)
+{
+  tree val_type;
+  enum tree_code val_code;
+  enum tree_code rtype_code;
+  enum tree_code code;
+
+  val_type = TREE_TYPE (val);
+  if (val_type == rtype)
+    return val;
+
+  /*  FIXME: check conversions.  */
+  val_code = TREE_CODE (val_type);
+  rtype_code = TREE_CODE (rtype);
+  if (val_code == POINTER_TYPE && rtype_code == POINTER_TYPE)
+    code = NOP_EXPR;
+  else if (val_code == INTEGER_TYPE && rtype_code == INTEGER_TYPE)
+    code = CONVERT_EXPR;
+  else if (val_code == REAL_TYPE && rtype_code == INTEGER_TYPE)
+    {
+      /*  REAL to INTEGER
+          Gcc only handles FIX_TRUNC_EXPR, but we need rounding.  */
+      tree m_p5;
+      tree p5;
+      tree zero;
+      tree saved;
+      tree comp;
+      tree adj;
+      tree res;
+
+      m_p5 = build_real (val_type, fp_const_m_p5);
+      p5 = build_real (val_type, fp_const_p5);
+      zero = build_real (val_type, fp_const_zero);
+      saved = save_expr (val);
+      comp = build2 (GE_EXPR, integer_type_node, saved, zero);
+      /*  FIXME: instead of res = res + (comp ? .5 : -.5)
+	  do: res = res (comp ? + : -) .5  */
+      adj = build3 (COND_EXPR, val_type, comp, p5, m_p5);
+      res = build2 (PLUS_EXPR, val_type, saved, adj);
+      res = build1 (FIX_TRUNC_EXPR, rtype, res);
+      return res;
+    }
+  else if (val_code == INTEGER_TYPE && rtype_code == ENUMERAL_TYPE)
+    code = CONVERT_EXPR;
+  else if (val_code == ENUMERAL_TYPE && rtype_code == INTEGER_TYPE)
+    code = CONVERT_EXPR;
+  else if (val_code == INTEGER_TYPE && rtype_code == REAL_TYPE)
+    code = FLOAT_EXPR;
+  else if (val_code == BOOLEAN_TYPE && rtype_code == BOOLEAN_TYPE)
+    code = NOP_EXPR;
+  else if (val_code == BOOLEAN_TYPE && rtype_code == INTEGER_TYPE)
+    code = CONVERT_EXPR;
+  else if (val_code == INTEGER_TYPE && rtype_code == BOOLEAN_TYPE)
+    code = NOP_EXPR;
+  else if (val_code == REAL_TYPE && rtype_code == REAL_TYPE)
+    code = NOP_EXPR;
+  else
+    abort ();
+
+  return build1 (code, rtype, val);
+}
+
+tree
+new_alloca (tree rtype, tree size)
+{
+  tree res;
+  tree args;
+
+  /* Must save stack.  */
+  cur_binding_level->save_stack = 1;
+
+  args = tree_cons (NULL_TREE, fold_convert (size_type_node, size), NULL_TREE);
+  res = build3 (CALL_EXPR, ptr_type_node, stack_alloc_function_ptr,
+		 args, NULL_TREE);
+  return fold_convert (rtype, res);
+}
+
+tree
+new_signed_literal (tree ltype, long long value)
+{
+  tree res;
+
+  res = build_int_cst_wide (ltype,
+			    value, value >> (8 * sizeof (HOST_WIDE_INT)));
+  return res;
+}
+
+tree
+new_unsigned_literal (tree ltype, unsigned long long value)
+{
+  tree res;
+
+  res = build_int_cst_wide (ltype,
+			    value, value >> (8 * sizeof (HOST_WIDE_INT)));
+  return res;
+}
+
+tree
+new_null_access (tree ltype)
+{
+  tree res;
+
+  res = build_int_cst_wide (ltype, 0, 0);
+  return res;
+}
+
+tree
+new_float_literal (tree ltype, double value)
+{
+  signed long long s;
+  double frac;
+  int ex;
+  REAL_VALUE_TYPE r_sign;
+  REAL_VALUE_TYPE r_exp;
+  REAL_VALUE_TYPE r;
+  tree res;
+
+  frac = frexp (value, &ex);
+  
+  s = ldexp (frac, 60);
+  REAL_VALUE_FROM_INT (r_sign,
+		       (HOST_WIDE_INT) s,
+		       (HOST_WIDE_INT) (s >> (8 * sizeof (HOST_WIDE_INT))),
+		       DFmode);
+  real_2expN (&r_exp, ex - 60);
+  real_arithmetic (&r, MULT_EXPR, &r_sign, &r_exp);
+  res = build_real (ltype, r);
+  return res;
+}
+
+struct o_element_list
+{
+  tree res;
+  struct chain_constr_type chain;
+};
+
+void
+new_uncomplete_record_type (tree *res)
+{
+  *res = make_node (RECORD_TYPE);
+}
+
+void
+start_record_type (struct o_element_list *elements)
+{
+  elements->res = make_node (RECORD_TYPE);
+  chain_init (&elements->chain);
+}
+
+void
+start_uncomplete_record_type (tree res, struct o_element_list *elements)
+{
+  elements->res = res;
+  chain_init (&elements->chain);
+}
+
+static void
+new_record_union_field (struct o_element_list *list,
+			tree *el,
+			tree ident,
+			tree etype)
+{
+  tree res;
+
+  res = build_decl (FIELD_DECL, ident, etype);
+  DECL_CONTEXT (res) = list->res;
+  chain_append (&list->chain, res);
+  *el = res;
+}
+
+void
+new_record_field (struct o_element_list *list,
+		  tree *el,
+		  tree ident,
+		  tree etype)
+{
+  return new_record_union_field (list, el, ident, etype);
+}
+
+void
+finish_record_type (struct o_element_list *elements, tree *res)
+{
+  TYPE_FIELDS (elements->res) = elements->chain.first;
+  layout_type (elements->res);
+  *res = elements->res;
+
+  if (TYPE_NAME (elements->res) != NULL_TREE)
+    {
+      /*  The type was completed.  */
+      rest_of_type_compilation (elements->res, 1);
+    }
+}
+
+
+void
+start_union_type (struct o_element_list *elements)
+{
+  elements->res =  make_node (UNION_TYPE);
+  chain_init (&elements->chain);
+}
+
+void
+new_union_field (struct o_element_list *elements,
+		 tree *el,
+		 tree ident,
+		 tree etype)
+{
+  return new_record_union_field (elements, el, ident, etype);
+}
+
+void
+finish_union_type (struct o_element_list *elements, tree *res)
+{
+  TYPE_FIELDS (elements->res) = elements->chain.first;
+  layout_type (elements->res);
+  *res = elements->res;
+}
+
+tree
+new_unsigned_type (int size)
+{
+  return make_unsigned_type (size);
+}
+
+tree
+new_signed_type (int size)
+{
+  return make_signed_type (size);
+}
+
+tree
+new_float_type (void)
+{
+  tree res;
+
+  res = make_node (REAL_TYPE);
+  TYPE_PRECISION (res) = DOUBLE_TYPE_SIZE;
+  layout_type (res);
+  return res;
+}
+
+tree
+new_access_type (tree dtype)
+{
+  tree res;
+
+  if (dtype == NULL_TREE)
+    {
+      res = make_node (POINTER_TYPE);
+      TREE_TYPE (res) = NULL_TREE;
+      /* Seems necessary.  */
+      TYPE_MODE (res) = Pmode;
+      layout_type (res);
+      return res;
+    }
+  else
+    return build_pointer_type (dtype);
+}
+
+void
+finish_access_type (tree atype, tree dtype)
+{
+  if (TREE_CODE (atype) != POINTER_TYPE
+      || TREE_TYPE (atype) != NULL_TREE)
+    abort ();
+
+  TREE_TYPE (atype) = dtype;
+}
+
+tree
+new_array_type (tree el_type, tree index_type)
+{
+  return build_array_type (el_type, index_type);
+}
+
+
+tree
+new_constrained_array_type (tree atype, tree length)
+{
+  tree range_type;
+  tree index_type;
+  tree len;
+  tree one;
+
+  index_type = TYPE_DOMAIN (atype);
+  if (integer_zerop (length))
+    {
+      /*  Handle null array, by creating a one-length array...  */
+      len = size_zero_node;
+    }
+  else
+    {
+      one = build_int_cstu (index_type, 1);
+      len = build2 (MINUS_EXPR, index_type, length, one);
+      len = fold (len);
+    }
+
+  range_type = build_range_type (index_type, size_zero_node, len);
+  return build_array_type (TREE_TYPE (atype), range_type);
+}
+
+void
+new_boolean_type (tree *res,
+		  tree false_id, tree *false_e,
+		  tree true_id, tree *true_e)
+{
+  *res = make_node (BOOLEAN_TYPE);
+  TYPE_PRECISION (*res) = 1;
+  fixup_unsigned_type (*res);
+  *false_e = TYPE_MIN_VALUE (*res);
+  *true_e = TYPE_MAX_VALUE (*res);
+}
+
+struct o_enum_list
+{
+  tree res;
+  struct chain_constr_type chain;
+  int num;
+  int size;
+};
+
+void
+start_enum_type (struct o_enum_list *list, int size)
+{
+  list->res = make_node (ENUMERAL_TYPE);
+  chain_init (&list->chain);
+  list->num = 0;
+  list->size = size;
+}
+
+void
+new_enum_literal (struct o_enum_list *list, tree ident, tree *res)
+{
+  *res = build_int_cstu (list->res, list->num);
+  chain_append (&list->chain, tree_cons (ident, *res, NULL_TREE));
+  list->num++;
+}
+
+void
+finish_enum_type (struct o_enum_list *list, tree *res)
+{
+  *res = list->res;
+  TYPE_VALUES (*res) = list->chain.first;
+  TYPE_MIN_VALUE (*res) = TREE_VALUE (list->chain.first);
+  TYPE_MAX_VALUE (*res) = TREE_VALUE (list->chain.last);
+  TYPE_UNSIGNED (*res) = 1;
+  TYPE_PRECISION (*res) = list->size;
+  layout_type (*res);
+}
+
+struct o_record_aggr_list
+{
+  tree atype;
+  struct chain_constr_type chain;
+};
+
+void
+start_record_aggr (struct o_record_aggr_list *list, tree atype)
+{
+  list->atype = atype;
+  chain_init (&list->chain);
+}
+
+void
+new_record_aggr_el (struct o_record_aggr_list *list, tree value)
+{
+  chain_append (&list->chain, build_tree_list (NULL_TREE, value));
+}
+
+void
+finish_record_aggr (struct o_record_aggr_list *list, tree *res)
+{
+  *res = build_constructor (list->atype, list->chain.first);
+}
+ 
+
+struct o_array_aggr_list
+{
+  tree atype;
+  struct chain_constr_type chain;
+};
+
+void
+start_array_aggr (struct o_array_aggr_list *list, tree atype)
+{
+  list->atype = atype;
+  chain_init (&list->chain);
+}
+
+void
+new_array_aggr_el (struct o_array_aggr_list *list, tree value)
+{
+  chain_append (&list->chain, build_tree_list (NULL_TREE, value));
+}
+ 
+void
+finish_array_aggr (struct o_array_aggr_list *list, tree *res)
+{
+  *res = build_constructor (list->atype, list->chain.first);
+}
+
+
+tree
+new_union_aggr (tree atype, tree field, tree value)
+{
+  tree el;
+  tree res;
+
+  el = build_tree_list (field, value);
+  res = build_constructor (atype, el);
+  TREE_CONSTANT (res) = 1;
+  return res;
+}
+
+tree
+new_indexed_element (tree arr, tree index)
+{
+  ortho_mark_addressable (arr);
+  return build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (arr)),
+		 arr, index, NULL_TREE, NULL_TREE);
+}
+
+tree
+new_slice (tree arr, tree res_type, tree index)
+{
+  tree res;
+  tree el_ptr_type;
+  tree el_type;
+  tree res_ptr_type;
+
+  /*  *((RES_TYPE *)(&ARR[INDEX]))
+      convert ARR to a pointer, add index, and reconvert to array ?  */
+  if (TREE_CODE (res_type) != ARRAY_TYPE)
+    abort ();
+
+  ortho_mark_addressable (arr);
+  el_type = TREE_TYPE (TREE_TYPE (arr));
+  el_ptr_type = build_pointer_type (el_type);
+
+  res = build4 (ARRAY_REF, el_type, arr, index, NULL_TREE, NULL_TREE);
+  res = build1 (ADDR_EXPR, el_ptr_type, res);
+  res_ptr_type = build_pointer_type (res_type);
+  res = build1 (NOP_EXPR, res_ptr_type, res);
+  res = build1 (INDIRECT_REF, res_type, res);
+  return res;
+}
+
+tree
+new_selected_element (tree rec, tree el)
+{
+  tree res;
+
+  if (TREE_CODE (TREE_TYPE (rec)) != RECORD_TYPE)
+    abort ();
+
+  res = build3 (COMPONENT_REF, TREE_TYPE (el), rec, el, NULL_TREE);
+  return res;
+}
+
+tree
+new_access_element (tree acc)
+{
+  tree acc_type;
+
+  acc_type = TREE_TYPE (acc);
+  if (TREE_CODE (acc_type) != POINTER_TYPE)
+    abort ();
+
+  return build1 (INDIRECT_REF, TREE_TYPE (acc_type), acc);
+}
+
+tree
+new_offsetof (tree field, tree rtype)
+{
+  tree off;
+  tree bit_off;
+  HOST_WIDE_INT pos;
+  tree res;
+
+  off = DECL_FIELD_OFFSET (field);
+  if (!host_integerp (off, 1))
+    {
+      /*  The offset must be a constant.  */
+      abort ();
+    }
+
+  bit_off = DECL_FIELD_BIT_OFFSET (field);
+  if (!host_integerp (bit_off, 1))
+    {
+      /*  The offset must be a constant.  */
+      abort ();
+    }
+
+  pos = TREE_INT_CST_LOW (off)
+        + (TREE_INT_CST_LOW (bit_off) / BITS_PER_UNIT);
+  res = build_int_cstu (rtype, pos);
+  return res;
+}
+
+tree
+new_sizeof (tree atype, tree rtype)
+{
+ tree size;
+
+ size = TYPE_SIZE_UNIT (atype);
+
+ return fold (build1 (NOP_EXPR, rtype, size));
+}
+
+#if 0
+static tree
+ortho_build_addr (tree operand, tree atype)
+{
+  tree base = exp;
+
+  while (handled_component_p (base))
+    base = TREE_OPERAND (base, 0);
+
+  if (DECL_P (base))
+    TREE_ADDRESSABLE (base) = 1;
+
+  return build1 (ADDR_EXPR, atype, exp);
+}
+#endif
+
+tree
+new_unchecked_address (tree lvalue, tree atype)
+{
+  tree res;
+
+  if (TREE_CODE (lvalue) == INDIRECT_REF)
+    {
+      res = TREE_OPERAND (lvalue, 0);
+    }
+  else
+    {
+      ortho_mark_addressable (lvalue);
+
+      if (TREE_TYPE (lvalue) != TREE_TYPE (atype))
+	{
+	  tree ptr;
+	  ptr = build_pointer_type (TREE_TYPE (lvalue));
+	  res = build1 (ADDR_EXPR, ptr, lvalue);
+	}
+      else
+	res = build1 (ADDR_EXPR, atype, lvalue);
+    }
+
+  if (TREE_TYPE (res) != atype)
+    res = fold (build1 (NOP_EXPR, atype, res));
+
+  return res;
+
+#if 0
+  /* res = build_addr (lvalue, atype); */
+  if (TREE_TYPE (res) != atype)
+    {
+      if (TREE_CODE (TREE_TYPE (res)) != POINTER_TYPE)
+	abort ();
+      res = build1 (NOP_EXPR, atype, res);
+    }
+  return res;
+#endif
+}
+
+tree
+new_address (tree lvalue, tree atype)
+{
+  return new_unchecked_address (lvalue, atype);
+}
+
+tree
+new_global_address (tree lvalue, tree atype)
+{
+  return new_unchecked_address (lvalue, atype);
+}
+
+tree
+new_global_unchecked_address (tree lvalue, tree atype)
+{
+  return new_unchecked_address (lvalue, atype);
+}
+
+/*  Return a pointer to function FUNC. */
+static tree
+build_function_ptr (tree func)
+{
+  return build1 (ADDR_EXPR,
+		 build_pointer_type (TREE_TYPE (func)), func);
+}
+
+tree
+new_subprogram_address (tree subprg, tree atype)
+{
+  return fold (build1 (NOP_EXPR, atype, build_function_ptr (subprg)));
+}
+
+tree
+new_value (tree lvalue)
+{
+  return lvalue;
+}
+
+void
+new_debug_line_decl (int line)
+{
+  input_location.line = line;
+}
+
+void
+new_type_decl (tree ident, tree atype)
+{
+  tree decl;
+
+  TYPE_NAME (atype) = ident;
+  decl = build_decl (TYPE_DECL, ident, atype);
+  TYPE_STUB_DECL (atype) = decl;
+  push_decl (decl);
+  /*
+      if Get_TYPE_SIZE (Ttype) /= NULL_TREE then
+         --  Do not generate debug info for uncompleted types.
+         Rest_Of_Type_Compilation (Ttype, C_True);
+      end if;
+  */
+}
+
+enum o_storage { o_storage_external,
+		 o_storage_public,
+		 o_storage_private,
+		 o_storage_local };
+
+static void
+set_storage (tree Node, enum o_storage storage)
+{
+  switch (storage)
+    {
+    case o_storage_external:
+      DECL_EXTERNAL (Node) = 1;
+      TREE_PUBLIC (Node) = 1;
+      TREE_STATIC (Node) = 0;
+      break;
+    case o_storage_public:
+      DECL_EXTERNAL (Node) = 0;
+      TREE_PUBLIC (Node) = 1;
+      TREE_STATIC (Node) = 1;
+      break;
+    case o_storage_private:
+      DECL_EXTERNAL (Node) = 0;
+      TREE_PUBLIC (Node) = 0;
+      TREE_STATIC (Node) = 1;
+      break;
+    case o_storage_local:
+      DECL_EXTERNAL (Node) = 0;
+      TREE_PUBLIC (Node) = 0;
+      TREE_STATIC (Node) = 0;
+      break;
+    }
+}
+
+void
+new_const_decl (tree *res, tree ident, enum o_storage storage, tree atype)
+{
+  tree cst;
+
+  cst = build_decl (VAR_DECL, ident, atype);
+  set_storage (cst, storage);
+  TREE_READONLY (cst) = 1;
+  push_decl (cst);
+  switch (storage)
+    {
+    case o_storage_local:
+      abort ();
+    case o_storage_external:
+      /*  We are at top level if Current_Function_Decl is null.  */
+      rest_of_decl_compilation
+	(cst, current_function_decl == NULL_TREE, 0);
+      break;
+    case o_storage_public:
+    case o_storage_private:
+      break;
+    }
+  *res = cst;
+}
+
+void
+start_const_value (tree *cst)
+{
+}
+
+void
+finish_const_value (tree *cst, tree val)
+{
+  DECL_INITIAL (*cst) = val;
+  TREE_CONSTANT (val) = 1;
+  rest_of_decl_compilation
+        (*cst, current_function_decl == NULL_TREE, 0);
+}
+
+void
+new_var_decl (tree *res, tree ident, enum o_storage storage, tree atype)
+{
+  tree var;
+
+  var = build_decl (VAR_DECL, ident, atype);
+  if (current_function_decl != NULL_TREE)
+    {    
+      /*  Local variable. */
+      TREE_STATIC (var) = 0;
+      DECL_EXTERNAL (var) = 0;
+      TREE_PUBLIC (var) = 0;
+    }
+  else
+    set_storage (var, storage);
+
+  push_decl (var);
+
+  if (current_function_decl == NULL_TREE)
+    rest_of_decl_compilation (var, 1, 0);
+
+  *res = var;
+}
+
+struct o_inter_list
+{
+  tree ident;
+  enum o_storage storage;
+
+  /*  Return type.  */
+  tree rtype;
+
+  /*  List of parameter types.  */
+  struct list_constr_type param_list;
+
+  /*  Chain of parameters declarations.  */
+  struct chain_constr_type param_chain;
+};
+
+void
+start_function_decl (struct o_inter_list *interfaces,
+		     tree ident,
+		     enum o_storage storage,
+		     tree rtype)
+{
+  interfaces->ident = ident;
+  interfaces->storage = storage;
+  interfaces->rtype = rtype;
+  chain_init (&interfaces->param_chain);
+  list_init (&interfaces->param_list);
+}
+
+void
+start_procedure_decl (struct o_inter_list *interfaces,
+		      tree ident,
+		      enum o_storage storage)
+{
+  start_function_decl (interfaces, ident, storage, void_type_node);
+}
+
+void
+new_interface_decl (struct o_inter_list *interfaces,
+		    tree *res,
+		    tree ident,
+		    tree atype)
+{
+  tree r;
+
+  r = build_decl (PARM_DECL, ident, atype);
+  /* DECL_CONTEXT (Res, Xxx); */
+
+  /*  Do type conversion: convert boolean and enums to int  */
+  switch (TREE_CODE (atype))
+    {
+    case ENUMERAL_TYPE:
+    case BOOLEAN_TYPE:
+      DECL_ARG_TYPE (r) = integer_type_node;
+    default:
+      DECL_ARG_TYPE (r) = atype;
+    }
+
+  chain_append (&interfaces->param_chain, r);
+  ortho_list_append (&interfaces->param_list, atype);
+  *res = r;
+}
+
+/*  Current function nest level, or the number of parents.  */
+/* static int function_nest_level; */
+
+
+void
+finish_subprogram_decl (struct o_inter_list *interfaces, tree *res)
+{
+  tree decl;
+  tree result;
+  tree parm;
+  int is_global;
+
+  decl = build_decl (FUNCTION_DECL, interfaces->ident,
+		     build_function_type (interfaces->rtype,
+					  interfaces->param_list.first));
+  is_global = current_function_decl == NULL_TREE
+    || interfaces->storage == o_storage_external;
+  if (is_global)
+    set_storage (decl, interfaces->storage);
+  else
+    {
+      /*  A nested subprogram.  */
+      DECL_EXTERNAL (decl) = 0;
+      TREE_PUBLIC (decl) = 0;
+    }
+  /*  The function exist in static storage. */
+  TREE_STATIC (decl) = 1;
+  DECL_INITIAL (decl) = error_mark_node;
+  TREE_ADDRESSABLE (decl) = 1;
+
+  /*  Declare the result.
+      FIXME: should be moved in start_function_body. */
+  result = build_decl (RESULT_DECL, NULL_TREE, interfaces->rtype);
+  DECL_RESULT (decl) = result;
+  DECL_CONTEXT (result) = decl;
+
+  DECL_ARGUMENTS (decl) = interfaces->param_chain.first;
+  /* Set DECL_CONTEXT of parameters.  */
+  for (parm = interfaces->param_chain.first;
+       parm != NULL_TREE;
+       parm = TREE_CHAIN (parm))
+    DECL_CONTEXT (parm) = decl;
+
+  push_decl (decl);
+
+  /* External functions are never nested.
+     Remove their context, which is set by push_decl.  */
+  if (interfaces->storage == o_storage_external)
+    DECL_CONTEXT (decl) = NULL_TREE;
+
+  if (is_global)
+    rest_of_decl_compilation (decl, 1, 0);
+
+  *res = decl;
+}
+
+void
+start_subprogram_body (tree func)
+{
+  if (current_function_decl != DECL_CONTEXT (func))
+    abort ();
+  current_function_decl = func;
+
+  /* The function is not anymore external.  */
+  DECL_EXTERNAL (func) = 0;
+
+  push_stmts (alloc_stmt_list ());
+  push_binding ();
+}
+
+void
+finish_subprogram_body (void)
+{
+  tree bind;
+  tree func;
+  tree parent;
+
+  bind = pop_binding ();
+  pop_stmts ();
+
+  func = current_function_decl;
+  DECL_INITIAL (func) = BIND_EXPR_BLOCK (bind);
+  DECL_SAVED_TREE (func) = bind;
+
+  /* Initialize the RTL code for the function.  */
+  allocate_struct_function (func);
+
+  /* Store the end of the function.  */
+  cfun->function_end_locus = input_location;
+  
+  /* This function is being processed in whole-function mode.  */
+  /* cfun->x_whole_function_mode_p = 1; */
+
+  gimplify_function_tree (func);
+
+  parent = DECL_CONTEXT (func);
+
+  if (parent != NULL)
+    cgraph_node (func);
+  else
+    cgraph_finalize_function (func, false);
+
+  current_function_decl = parent;
+  cfun = NULL;
+}
+
+
+void
+new_debug_line_stmt (int line)
+{
+  input_location.line = line;
+}
+
+void
+start_declare_stmt (void)
+{
+  push_stmts (alloc_stmt_list ());
+  push_binding ();
+}
+
+void
+finish_declare_stmt (void)
+{
+  tree bind;
+
+  bind = pop_binding ();
+  pop_stmts ();
+  append_stmt (bind);
+}
+
+
+struct o_assoc_list
+{
+  tree subprg;
+  struct list_constr_type list;
+};
+
+void
+start_association (struct o_assoc_list *assocs, tree subprg)
+{
+  assocs->subprg = subprg;
+  list_init (&assocs->list);
+}
+
+void
+new_association (struct o_assoc_list *assocs, tree val)
+{
+  ortho_list_append (&assocs->list, val);
+}
+
+tree
+new_function_call (struct o_assoc_list *assocs)
+{
+  return build3 (CALL_EXPR,
+		 TREE_TYPE (TREE_TYPE (assocs->subprg)),
+		 build_function_ptr (assocs->subprg),
+		 assocs->list.first, NULL_TREE);
+}
+
+void
+new_procedure_call (struct o_assoc_list *assocs)
+{
+  tree res;
+
+  res = build3 (CALL_EXPR,
+		TREE_TYPE (TREE_TYPE (assocs->subprg)),
+		build_function_ptr (assocs->subprg),
+		assocs->list.first, NULL_TREE);
+  TREE_SIDE_EFFECTS (res) = 1;
+  append_stmt (res);
+}
+
+void
+new_assign_stmt (tree target, tree value)
+{
+  tree n;
+
+  n = build2 (MODIFY_EXPR, TREE_TYPE (target), target, value);
+  TREE_SIDE_EFFECTS (n) = 1;
+  append_stmt (n);
+}
+
+void
+new_func_return_stmt (tree value)
+{
+  tree assign;
+  tree stmt;
+  tree res;
+
+  res = DECL_RESULT (current_function_decl);
+  assign = build2 (MODIFY_EXPR, TREE_TYPE (value), res, value);
+  TREE_SIDE_EFFECTS (assign) = 1;
+  stmt = build1 (RETURN_EXPR, TREE_TYPE (value), assign);
+  append_stmt (stmt);
+}
+
+void
+new_proc_return_stmt (void)
+{
+  tree stmt;
+
+  stmt = build1 (RETURN_EXPR, void_type_node, NULL_TREE);
+  TREE_SIDE_EFFECTS (stmt) = 1;
+  append_stmt (stmt);
+}
+
+
+struct o_if_block
+{
+  tree stmt;
+};
+
+void
+start_if_stmt (struct o_if_block *block, tree cond)
+{
+  tree stmt;
+  tree stmts;
+
+  stmts = alloc_stmt_list ();
+  stmt = build3 (COND_EXPR, void_type_node, cond, stmts, NULL_TREE);
+  block->stmt = stmt;
+  append_stmt (stmt);
+  push_stmts (stmts);
+}
+
+void
+new_elsif_stmt (struct o_if_block *block, tree cond)
+{
+  tree stmts;
+  tree stmt;
+
+  pop_stmts ();
+  stmts = alloc_stmt_list ();
+  stmt = build3 (COND_EXPR, void_type_node, cond, stmts, NULL_TREE);
+  COND_EXPR_ELSE (block->stmt) = stmt;
+  block->stmt = stmt;
+  push_stmts (stmts);
+}
+
+void
+new_else_stmt (struct o_if_block *block)
+{
+  tree stmts;
+
+  pop_stmts ();
+  stmts = alloc_stmt_list ();
+  COND_EXPR_ELSE (block->stmt) = stmts;
+  push_stmts (stmts);
+}
+
+void
+finish_if_stmt (struct o_if_block *block)
+{
+  pop_stmts ();
+}
+
+
+struct o_loop_block
+{
+  tree beg_label;
+  tree end_label;
+};
+
+struct o_snode
+{
+  tree beg_label;
+  tree end_label;
+};
+
+/* Create an artificial label.  */
+static tree
+build_label (void)
+{
+  tree res;
+
+  res = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
+  DECL_CONTEXT (res) = current_function_decl;
+  DECL_ARTIFICIAL (res) = 1;
+  return res;
+}
+
+void
+start_loop_stmt (struct o_snode *label)
+{
+  tree stmt;
+
+  label->beg_label = build_label ();
+
+  stmt = build1 (LABEL_EXPR, void_type_node, label->beg_label);
+  append_stmt (stmt);
+
+  label->end_label = build_label ();
+}
+
+void
+finish_loop_stmt (struct o_snode *label)
+{
+  tree stmt;
+
+  stmt = build1 (GOTO_EXPR, void_type_node, label->beg_label);
+  TREE_USED (label->beg_label) = 1;
+  append_stmt (stmt);
+  /*  Emit the end label only if there is a goto to it.
+      (Return may be used to exit from the loop).  */
+  if (TREE_USED (label->end_label))
+    {
+      stmt = build1 (LABEL_EXPR, void_type_node, label->end_label);
+      append_stmt (stmt);
+    }
+}
+
+void
+new_exit_stmt (struct o_snode *l)
+{
+  tree stmt;
+
+  stmt = build1 (GOTO_EXPR, void_type_node, l->end_label);
+  append_stmt (stmt);
+  TREE_USED (l->end_label) = 1;
+}
+
+void
+new_next_stmt (struct o_snode *l)
+{
+  tree stmt;
+
+  stmt = build1 (GOTO_EXPR, void_type_node, l->beg_label);
+  TREE_USED (l->beg_label) = 1;
+  append_stmt (stmt);
+}
+
+struct o_case_block
+{
+  tree end_label;
+  int add_break;
+};
+
+void
+start_case_stmt (struct o_case_block *block, tree value)
+{
+  tree stmt;
+  tree stmts;
+
+  block->end_label = build_label ();
+  block->add_break = 0;
+  stmts = alloc_stmt_list ();
+  stmt = build3 (SWITCH_EXPR, void_type_node, value, stmts, NULL_TREE);
+  append_stmt (stmt);
+  push_stmts (stmts);
+}
+
+void
+start_choice (struct o_case_block *block)
+{
+  tree stmt;
+
+  if (block->add_break)
+    {
+      stmt = build1 (GOTO_EXPR, void_type_node, block->end_label);
+      append_stmt (stmt);
+
+      block->add_break = 0;
+    }
+}
+
+void
+new_expr_choice (struct o_case_block *block, tree expr)
+{
+  tree stmt;
+  
+  stmt = build3 (CASE_LABEL_EXPR, void_type_node,
+		 expr, NULL_TREE, create_artificial_label ());
+  append_stmt (stmt);
+}
+
+void
+new_range_choice (struct o_case_block *block, tree low, tree high)
+{
+  tree stmt;
+
+  stmt = build3 (CASE_LABEL_EXPR, void_type_node,
+		 low, high, create_artificial_label ());
+  append_stmt (stmt);
+}
+
+void
+new_default_choice (struct o_case_block *block)
+{
+  tree stmt;
+
+  stmt = build3 (CASE_LABEL_EXPR, void_type_node,
+		 NULL_TREE, NULL_TREE, create_artificial_label ());
+  append_stmt (stmt);
+}
+
+void
+finish_choice (struct o_case_block *block)
+{
+  block->add_break = 1;
+}
+
+void
+finish_case_stmt (struct o_case_block *block)
+{
+  tree stmt;
+
+  pop_stmts ();
+  stmt = build1 (LABEL_EXPR, void_type_node, block->end_label);
+  append_stmt (stmt);
+}
+
+bool
+compare_identifier_string (tree id, const char *str, size_t len)
+{
+  if (IDENTIFIER_LENGTH (id) != len)
+    return false;
+  if (!memcmp (IDENTIFIER_POINTER (id), str, len))
+    return true;
+  else
+    return false;
+}
+
+void
+get_identifier_string (tree id, const char **str, int *len)
+{
+  *len = IDENTIFIER_LENGTH (id);
+  *str = IDENTIFIER_POINTER (id);
+}
+
+#include "debug.h"
+#include "gt-vhdl-ortho-lang.h"
+#include "gtype-vhdl.h"
diff --git a/ortho/gcc/ortho_gcc-main.adb b/ortho/gcc/ortho_gcc-main.adb
new file mode 100644
index 000000000..5a71aacb4
--- /dev/null
+++ b/ortho/gcc/ortho_gcc-main.adb
@@ -0,0 +1,26 @@
+with System;
+with Ortho_Gcc_Front;
+with Ada.Command_Line; use Ada.Command_Line;
+
+procedure Ortho_Gcc.Main
+is
+   gnat_argc : Integer;
+   gnat_argv : System.Address;
+   gnat_envp : System.Address;
+
+   pragma Import (C, gnat_argc);
+   pragma Import (C, gnat_argv);
+   pragma Import (C, gnat_envp);
+
+   function Toplev_Main (Argc : Integer; Argv : System.Address)
+                        return Integer;
+   pragma Import (C, Toplev_Main);
+
+   Status : Exit_Status;
+begin
+   Ortho_Gcc_Front.Init;
+
+   --  Note: GCC set signal handlers...
+   Status := Exit_Status (Toplev_Main (gnat_argc, gnat_argv));
+   Set_Exit_Status (Status);
+end Ortho_Gcc.Main;
diff --git a/ortho/gcc/ortho_gcc-main.ads b/ortho/gcc/ortho_gcc-main.ads
new file mode 100644
index 000000000..4bd73a1b6
--- /dev/null
+++ b/ortho/gcc/ortho_gcc-main.ads
@@ -0,0 +1 @@
+procedure Ortho_Gcc.Main;
diff --git a/ortho/gcc/ortho_gcc.adb b/ortho/gcc/ortho_gcc.adb
new file mode 100644
index 000000000..c5234fc9c
--- /dev/null
+++ b/ortho/gcc/ortho_gcc.adb
@@ -0,0 +1,110 @@
+with Ada.Unchecked_Deallocation;
+with Ortho_Gcc_Front; use Ortho_Gcc_Front;
+
+package body Ortho_Gcc is
+
+   function New_Lit (Lit : O_Cnode) return O_Enode is
+   begin
+      return O_Enode (Lit);
+   end New_Lit;
+
+   function New_Obj (Decl : O_Dnode) return O_Lnode is
+   begin
+      return O_Lnode (Decl);
+   end New_Obj;
+
+   function New_Obj_Value (Obj : O_Dnode) return O_Enode is
+   begin
+      return O_Enode (Obj);
+   end New_Obj_Value;
+
+   procedure Init
+   is
+   begin
+      null;
+   end Init;
+
+   procedure New_Debug_Filename_Decl (Filename : String) is
+   begin
+      null;
+   end New_Debug_Filename_Decl;
+
+   procedure New_Debug_Comment_Decl (Comment : String)
+   is
+      pragma Unreferenced (Comment);
+   begin
+      null;
+   end New_Debug_Comment_Decl;
+
+   procedure New_Debug_Comment_Stmt (Comment : String)
+   is
+      pragma Unreferenced (Comment);
+   begin
+      null;
+   end New_Debug_Comment_Stmt;
+
+   --  Representation of a C String: this is an access to a bounded string.
+   --  Therefore, with GNAT, such an access is a thin pointer.
+   subtype Fat_C_String is String (Positive);
+   type C_String is access all Fat_C_String;
+   pragma Convention (C, C_String);
+
+   C_String_Null : constant C_String := null;
+
+   --  Return the length of a C String (ie, the number of characters before
+   --  the Nul).
+   function C_String_Len (Str : C_String) return Natural;
+   pragma Import (C, C_String_Len, "strlen");
+
+   function Lang_Handle_Option (Opt : C_String; Arg : C_String)
+                               return Integer;
+   pragma Export (C, Lang_Handle_Option);
+
+   function Lang_Parse_File (Filename : C_String) return Integer;
+   pragma Export (C, Lang_Parse_File);
+
+   function Lang_Handle_Option (Opt : C_String; Arg : C_String)
+     return Integer
+   is
+      procedure Unchecked_Deallocation is new Ada.Unchecked_Deallocation
+        (Name => String_Acc, Object => String);
+
+      Res : Natural;
+      Ada_Opt : String_Acc;
+      Ada_Arg : String_Acc;
+      Len : Natural;
+   begin
+      Len := C_String_Len (Opt);
+      Ada_Opt := new String'(Opt (1 .. Len));
+      if Arg /= C_String_Null then
+         Len := C_String_Len (Arg);
+         Ada_Arg := new String'(Arg (1 .. Len));
+      else
+         Ada_Arg := null;
+      end if;
+      Res := Ortho_Gcc_Front.Decode_Option (Ada_Opt, Ada_Arg);
+      Unchecked_Deallocation (Ada_Opt);
+      Unchecked_Deallocation (Ada_Arg);
+      return Res;
+   end Lang_Handle_Option;
+
+   function Lang_Parse_File (Filename : C_String) return Integer
+   is
+      Len : Natural;
+      File : String_Acc;
+   begin
+      if Filename = C_String_Null then
+         File := null;
+      else
+         Len := C_String_Len (Filename);
+         File := new String'(Filename.all (1 .. Len));
+      end if;
+
+      if Ortho_Gcc_Front.Parse (File) then
+         return 1;
+      else
+         return 0;
+      end if;
+   end Lang_Parse_File;
+
+end Ortho_Gcc;
diff --git a/ortho/gcc/ortho_gcc.ads b/ortho/gcc/ortho_gcc.ads
new file mode 100644
index 000000000..a718f932a
--- /dev/null
+++ b/ortho/gcc/ortho_gcc.ads
@@ -0,0 +1,649 @@
+with System;
+with Interfaces; use Interfaces;
+with Ortho_Ident;
+use Ortho_Ident;
+
+--  Interface to create nodes.
+package Ortho_Gcc is
+   --- PUBLIC DECLARATIONS
+   --  PUBLIC PART is defined in ortho_nodes.common.ads
+   type O_Cnode is private;
+   type O_Enode is private;
+   type O_Lnode is private;
+   type O_Tnode is private;
+   type O_Fnode is private;
+   type O_Dnode is private;
+   type O_Snode is private;
+
+   --  Must be called during initialization, before use of any subprograms.
+   procedure Init;
+
+   O_Cnode_Null : constant O_Cnode;
+   O_Enode_Null : constant O_Enode;
+   O_Lnode_Null : constant O_Lnode;
+   O_Tnode_Null : constant O_Tnode;
+   O_Fnode_Null : constant O_Fnode;
+   O_Snode_Null : constant O_Snode;
+   O_Dnode_Null : constant O_Dnode;
+
+   ------------------------
+   --  Type definitions  --
+   ------------------------
+
+   type O_Element_List is limited private;
+
+   --  Build a record type.
+   procedure Start_Record_Type (Elements : out O_Element_List);
+   --  Add a field in the record; not constrained array are prohibited, since
+   --  its size is unlimited.
+   procedure New_Record_Field
+     (Elements : in out O_Element_List;
+      El : out O_Fnode;
+      Ident : O_Ident; Etype : O_Tnode);
+   --  Finish the record type.
+   procedure Finish_Record_Type
+     (Elements : in out O_Element_List; Res : out O_Tnode);
+
+   -- Build an uncomplete record type:
+   -- First call NEW_UNCOMPLETE_RECORD_TYPE, which returns a record type.
+   -- This type can be declared or used to define access types on it.
+   -- Then, complete (if necessary) the record type, by calling
+   -- START_UNCOMPLETE_RECORD_TYPE, NEW_RECORD_FIELD and FINISH_RECORD_TYPE.
+   procedure New_Uncomplete_Record_Type (Res : out O_Tnode);
+   procedure Start_Uncomplete_Record_Type (Res : O_Tnode;
+                                           Elements : out O_Element_List);
+
+   --  Build an union type.
+   procedure Start_Union_Type (Elements : out O_Element_List);
+   procedure New_Union_Field
+     (Elements : in out O_Element_List;
+      El : out O_Fnode;
+      Ident : O_Ident;
+      Etype : O_Tnode);
+   procedure Finish_Union_Type
+     (Elements : in out O_Element_List; Res : out O_Tnode);
+
+   --  Build an access type.
+   --  DTYPE may be O_tnode_null in order to build an incomplete access type.
+   --  It is completed with finish_access_type.
+   function New_Access_Type (Dtype : O_Tnode) return O_Tnode;
+   procedure Finish_Access_Type (Atype : O_Tnode; Dtype : O_Tnode);
+
+   --  Build an array type.
+   --  The array is not constrained and unidimensional.
+   function New_Array_Type (El_Type : O_Tnode; Index_Type : O_Tnode)
+     return O_Tnode;
+
+   --  Build a constrained array type.
+   function New_Constrained_Array_Type (Atype : O_Tnode; Length : O_Cnode)
+     return O_Tnode;
+
+   --  Build a scalar type; size may be 8, 16, 32 or 64.
+   function New_Unsigned_Type (Size : Natural) return O_Tnode;
+   function New_Signed_Type (Size : Natural) return O_Tnode;
+
+   --  Build a float type.
+   function New_Float_Type return O_Tnode;
+
+   --  Build a boolean type.
+   procedure New_Boolean_Type (Res : out O_Tnode;
+                               False_Id : O_Ident;
+                               False_E : out O_Cnode;
+                               True_Id : O_Ident;
+                               True_E : out O_Cnode);
+
+   --  Create an enumeration
+   type O_Enum_List is limited private;
+
+   --  Elements are declared in order, the first is ordered from 0.
+   procedure Start_Enum_Type (List : out O_Enum_List; Size : Natural);
+   procedure New_Enum_Literal (List : in out O_Enum_List;
+                               Ident : O_Ident; Res : out O_Cnode);
+   procedure Finish_Enum_Type (List : in out O_Enum_List; Res : out O_Tnode);
+
+   -------------------
+   --  Expressions  --
+   -------------------
+
+   type ON_Op_Kind is
+     (
+      --  Not an operation; invalid.
+      ON_Nil,
+
+      --  Dyadic operations.
+      ON_Add_Ov,                --  ON_Dyadic_Op_Kind
+      ON_Sub_Ov,                --  ON_Dyadic_Op_Kind
+      ON_Mul_Ov,                --  ON_Dyadic_Op_Kind
+      ON_Div_Ov,                --  ON_Dyadic_Op_Kind
+      ON_Rem_Ov,                --  ON_Dyadic_Op_Kind
+      ON_Mod_Ov,                --  ON_Dyadic_Op_Kind
+
+      --  Binary operations.
+      ON_And,                   --  ON_Dyadic_Op_Kind
+      ON_Or,                    --  ON_Dyadic_Op_Kind
+      ON_Xor,                   --  ON_Dyadic_Op_Kind
+      ON_And_Then,              --  ON_Dyadic_Op_Kind
+      ON_Or_Else,               --  ON_Dyadic_Op_Kind
+
+      --  Monadic operations.
+      ON_Not,                   --  ON_Monadic_Op_Kind
+      ON_Neg_Ov,                --  ON_Monadic_Op_Kind
+      ON_Abs_Ov,                --  ON_Monadic_Op_Kind
+
+      --  Comparaisons
+      ON_Eq,                    --  ON_Compare_Op_Kind
+      ON_Neq,                   --  ON_Compare_Op_Kind
+      ON_Le,                    --  ON_Compare_Op_Kind
+      ON_Lt,                    --  ON_Compare_Op_Kind
+      ON_Ge,                    --  ON_Compare_Op_Kind
+      ON_Gt                     --  ON_Compare_Op_Kind
+      );
+
+   pragma Convention (C, ON_Op_Kind);
+
+   subtype ON_Dyadic_Op_Kind is ON_Op_Kind range ON_Add_Ov .. ON_Or_Else;
+   subtype ON_Monadic_Op_Kind is ON_Op_Kind range ON_Not .. ON_Abs_Ov;
+   subtype ON_Compare_Op_Kind is ON_Op_Kind range ON_Eq .. ON_Gt;
+
+   type O_Storage is (O_Storage_External,
+                      O_Storage_Public,
+                      O_Storage_Private,
+                      O_Storage_Local);
+   pragma Convention (C, O_Storage);
+   --  Specifies the storage kind of a declaration.
+   --  O_STORAGE_EXTERNAL:
+   --    The declaration do not either reserve memory nor generate code, and
+   --    is imported either from an other file or from a later place in the
+   --    current file.
+   --  O_STORAGE_PUBLIC, O_STORAGE_PRIVATE:
+   --    The declaration reserves memory or generates code.
+   --    With O_STORAGE_PUBLIC, the declaration is exported outside of the
+   --    file while with O_STORAGE_PRIVATE, the declaration is local to the
+   --    file.
+
+   Type_Error : exception;
+   Syntax_Error : exception;
+
+   function New_Lit (Lit : O_Cnode) return O_Enode;
+   pragma Inline (New_Lit);
+
+   --  Create a dyadic operation.
+   --  Left and right nodes must have the same type.
+   --  Binary operation is allowed only on boolean types.
+   --  The result is of the type of the operands.
+   function New_Dyadic_Op (Kind : ON_Dyadic_Op_Kind; Left, Right : O_Enode)
+     return O_Enode;
+
+   --  Create a monadic operation.
+   --  Result is of the type of operand.
+   function New_Monadic_Op (Kind : ON_Monadic_Op_Kind; Operand : O_Enode)
+     return O_Enode;
+
+   --  Create a comparaison operator.
+   --  NTYPE is the type of the result and must be a boolean type.
+   function New_Compare_Op
+     (Kind : ON_Compare_Op_Kind; Left, Right : O_Enode; Ntype : O_Tnode)
+     return O_Enode;
+
+   --  Create a literal from an integer.
+   function New_Signed_Literal (Ltype : O_Tnode; Value : Integer_64)
+     return O_Cnode;
+   function New_Unsigned_Literal (Ltype : O_Tnode; Value : Unsigned_64)
+     return O_Cnode;
+
+   function New_Float_Literal (Ltype : O_Tnode; Value : IEEE_Float_64)
+     return O_Cnode;
+
+   --  Create a null access literal.
+   function New_Null_Access (Ltype : O_Tnode) return O_Cnode;
+
+   type O_Inter_List is limited private;
+   type O_Record_Aggr_List is limited private;
+   type O_Array_Aggr_List is limited private;
+   type O_Assoc_List is limited private;
+   type O_Loop_Block is limited private;
+   type O_If_Block is limited private;
+   type O_Case_Block is limited private;
+
+
+   --  Build a record/array aggregate.
+   --  The aggregate is constant, and therefore can be only used to initialize
+   --  constant declaration.
+   --  ATYPE must be either a record type or an array subtype.
+   --  Elements must be added in the order, and must be literals or aggregates.
+   procedure Start_Record_Aggr (List : out O_Record_Aggr_List;
+                                Atype : O_Tnode);
+   procedure New_Record_Aggr_El (List : in out O_Record_Aggr_List;
+                                 Value : O_Cnode);
+   procedure Finish_Record_Aggr (List : in out O_Record_Aggr_List;
+                                 Res : out O_Cnode);
+
+   procedure Start_Array_Aggr (List : out O_Array_Aggr_List; Atype : O_Tnode);
+   procedure New_Array_Aggr_El (List : in out O_Array_Aggr_List;
+                                Value : O_Cnode);
+   procedure Finish_Array_Aggr (List : in out O_Array_Aggr_List;
+                                Res : out O_Cnode);
+
+   --  Build an union aggregate.
+   function New_Union_Aggr (Atype : O_Tnode; Field : O_Fnode; Value : O_Cnode)
+                           return O_Cnode;
+
+   --  Returns the size in bytes of ATYPE.  The result is a literal of
+   --  unsigned type RTYPE
+   --  ATYPE cannot be an unconstrained array type.
+   function New_Sizeof (Atype : O_Tnode; Rtype : O_Tnode) return O_Cnode;
+
+   --  Returns the offset of FIELD in its record.  The result is a literal
+   --  of unsigned type RTYPE.
+   function New_Offsetof (Field : O_Fnode; Rtype : O_Tnode) return O_Cnode;
+
+   --  Get an element of an array.
+   --  INDEX must be of the type of the array index.
+   function New_Indexed_Element (Arr : O_Lnode; Index : O_Enode)
+     return O_Lnode;
+
+   --  Get a slice of an array; this is equivalent to a conversion between
+   --  an array or an array subtype and an array subtype.
+   --  RES_TYPE must be an array_sub_type whose base type is the same as the
+   --  base type of ARR.
+   --  INDEX must be of the type of the array index.
+   function New_Slice (Arr : O_Lnode; Res_Type : O_Tnode; Index : O_Enode)
+     return O_Lnode;
+
+   --  Get an element of a record.
+   --  Type of REC must be a record type.
+   function New_Selected_Element (Rec : O_Lnode; El : O_Fnode)
+     return O_Lnode;
+
+   --  Reference an access.
+   --  Type of ACC must be an access type.
+   function New_Access_Element (Acc : O_Enode) return O_Lnode;
+
+   --  Do a conversion.
+   --  Allowed conversions are:
+   --  FIXME: to write.
+   function New_Convert_Ov (Val : O_Enode; Rtype : O_Tnode) return O_Enode;
+
+   --  Get the address of LVALUE.
+   --  ATYPE must be a type access whose designated type is the type of LVALUE.
+   --  FIXME: what about arrays.
+   function New_Address (Lvalue : O_Lnode; Atype : O_Tnode) return O_Enode;
+   function New_Global_Address (Decl : O_Dnode; Atype : O_Tnode)
+                               return O_Cnode;
+
+   --  Same as New_Address but without any restriction.
+   function New_Unchecked_Address (Lvalue : O_Lnode; Atype : O_Tnode)
+     return O_Enode;
+   function New_Global_Unchecked_Address (Decl : O_Dnode; Atype : O_Tnode)
+                                         return O_Cnode;
+
+   --  Get the address of a subprogram.
+   function New_Subprogram_Address (Subprg : O_Dnode; Atype : O_Tnode)
+     return O_Cnode;
+
+   --  Get the value of an Lvalue.
+   function New_Value (Lvalue : O_Lnode) return O_Enode;
+   --  Get the value of an object.
+   function New_Obj_Value (Obj : O_Dnode) return O_Enode;
+   pragma Inline (New_Obj_Value);
+
+   --  Return a pointer of type RTPE to SIZE bytes allocated on the stack.
+   function New_Alloca (Rtype : O_Tnode; Size : O_Enode) return O_Enode;
+
+   --  Declare a type.
+   --  This simply gives a name to a type.
+   procedure New_Type_Decl (Ident : O_Ident; Atype : O_Tnode);
+
+   ---------------------
+   --  Declarations.  --
+   ---------------------
+
+   --  Filename.
+   procedure New_Debug_Filename_Decl (Filename : String);
+
+   --  Line number of the next declaration.
+   procedure New_Debug_Line_Decl (Line : Natural);
+
+   --  Add a comment in the declarative region.
+   procedure New_Debug_Comment_Decl (Comment : String);
+
+   --  Declare a constant.
+   --  This simply gives a name to a constant value or aggregate.
+   --  A constant cannot be modified and its storage cannot be local.
+   --  ATYPE must be constrained.
+   procedure New_Const_Decl
+     (Res : out O_Dnode;
+      Ident : O_Ident;
+      Storage : O_Storage;
+      Atype : O_Tnode);
+
+   --  Set the value of a non-external constant.
+   procedure Start_Const_Value (Const : in out O_Dnode);
+   procedure Finish_Const_Value (Const : in out O_Dnode; Val : O_Cnode);
+
+   --  Create a variable declaration.
+   --  A variable can be local only inside a function.
+   --  ATYPE must be constrained.
+   procedure New_Var_Decl
+     (Res : out O_Dnode;
+      Ident : O_Ident;
+      Storage : O_Storage;
+      Atype : O_Tnode);
+
+   function New_Obj (Decl : O_Dnode) return O_Lnode;
+   pragma Inline (New_Obj);
+
+   --  Start a subprogram declaration.
+   --  Note: nested subprograms are allowed, ie o_storage_local subprograms can
+   --   be declared inside a subprograms.  It is not allowed to declare
+   --   o_storage_external subprograms inside a subprograms.
+   --  Return type and interfaces cannot be a composite type.
+   procedure Start_Function_Decl
+     (Interfaces : out O_Inter_List;
+      Ident : O_Ident;
+      Storage : O_Storage;
+      Rtype : O_Tnode);
+   --  For a subprogram without return value.
+   procedure Start_Procedure_Decl
+     (Interfaces : out O_Inter_List;
+      Ident : O_Ident;
+      Storage : O_Storage);
+
+   --  Add an interface declaration to INTERFACES.
+   procedure New_Interface_Decl
+     (Interfaces : in out O_Inter_List;
+      Res : out O_Dnode;
+      Ident : O_Ident;
+      Atype : O_Tnode);
+   --  Finish the function declaration, get the node and a statement list.
+   procedure Finish_Subprogram_Decl
+     (Interfaces : in out O_Inter_List; Res : out O_Dnode);
+   --  Start a subprogram body.
+   --  Note: the declaration may have an external storage, in this case it
+   --  becomes public.
+   procedure Start_Subprogram_Body (Func : O_Dnode);
+   --  Finish a subprogram body.
+   procedure Finish_Subprogram_Body;
+
+
+   -------------------
+   --  Statements.  --
+   -------------------
+
+   --  Add a line number as a statement.
+   procedure New_Debug_Line_Stmt (Line : Natural);
+
+   --  Add a comment as a statement.
+   procedure New_Debug_Comment_Stmt (Comment : String);
+
+   --  Start a declarative region.
+   procedure Start_Declare_Stmt;
+   procedure Finish_Declare_Stmt;
+
+   --  Create a function call or a procedure call.
+   procedure Start_Association (Assocs : out O_Assoc_List; Subprg : O_Dnode);
+   procedure New_Association (Assocs : in out O_Assoc_List; Val : O_Enode);
+   function New_Function_Call (Assocs : O_Assoc_List) return O_Enode;
+   procedure New_Procedure_Call (Assocs : in out O_Assoc_List);
+
+   --  Assign VALUE to TARGET, type must be the same or compatible.
+   --  FIXME: what about slice assignment?
+   procedure New_Assign_Stmt (Target : O_Lnode; Value : O_Enode);
+
+   --  Exit from the subprogram and return VALUE.
+   procedure New_Return_Stmt (Value : O_Enode);
+   --  Exit from the subprogram, which doesn't return value.
+   procedure New_Return_Stmt;
+
+   --  Build an IF statement.
+   procedure Start_If_Stmt (Block : in out O_If_Block; Cond : O_Enode);
+   --  COND is NULL for the final else statement.
+   procedure New_Elsif_Stmt (Block : in out O_If_Block; Cond : O_Enode);
+   procedure New_Else_Stmt (Block : in out O_If_Block);
+   procedure Finish_If_Stmt (Block : in out O_If_Block);
+
+   --  Create a infinite loop statement.
+   procedure Start_Loop_Stmt (Label : out O_Snode);
+   procedure Finish_Loop_Stmt (Block : in out O_Snode);
+
+   --  Exit from a loop stmt or from a for stmt.
+   procedure New_Exit_Stmt (L : O_Snode);
+   --  Go to the start of a loop stmt or of a for stmt.
+   --  Loops/Fors between L and the current points are exited.
+   procedure New_Next_Stmt (L : O_Snode);
+
+   --  Case statement.
+   --  VALUE is the selector and must be a discrete type.
+   procedure Start_Case_Stmt (Block : in out O_Case_Block; Value : O_Enode);
+   procedure Start_Choice (Block : in out O_Case_Block);
+   procedure New_Expr_Choice (Block : in out O_Case_Block; Expr : O_Cnode);
+   procedure New_Range_Choice (Block : in out O_Case_Block;
+                               Low, High : O_Cnode);
+   procedure New_Default_Choice (Block : in out O_Case_Block);
+   procedure Finish_Choice (Block : in out O_Case_Block);
+   procedure Finish_Case_Stmt (Block : in out O_Case_Block);
+
+private
+   subtype Tree is System.Address;
+   NULL_TREE : constant Tree := System.Null_Address;
+   type O_Cnode is new Tree;
+   type O_Enode is new Tree;
+   type O_Lnode is new Tree;
+   type O_Tnode is new Tree;
+   type O_Fnode is new Tree;
+   type O_Dnode is new Tree;
+   type O_Snode is record
+      Beg_Label : Tree;
+      End_Label : Tree;
+   end record;
+   pragma Convention (C, O_Snode);
+
+   pragma Export (C, Init, "ortho_fe_init");
+
+   O_Cnode_Null : constant O_Cnode := O_Cnode (NULL_TREE);
+   O_Enode_Null : constant O_Enode := O_Enode (NULL_TREE);
+   O_Lnode_Null : constant O_Lnode := O_Lnode (NULL_TREE);
+   O_Tnode_Null : constant O_Tnode := O_Tnode (NULL_TREE);
+   O_Fnode_Null : constant O_Fnode := O_Fnode (NULL_TREE);
+   O_Snode_Null : constant O_Snode := (NULL_TREE, NULL_TREE);
+   O_Dnode_Null : constant O_Dnode := O_Dnode (NULL_TREE);
+
+   --  Efficiently append element EL to a chain.
+   --  FIRST is the first element of the chain (must NULL_TREE if the chain
+   --   is empty),
+   --  LAST is the last element of the chain (idem).
+   type Chain_Constr_Type is record
+      First : Tree;
+      Last : Tree;
+   end record;
+   pragma Convention (C, Chain_Constr_Type);
+   procedure Chain_Init (Constr : out Chain_Constr_Type);
+   pragma Import (C, Chain_Init);
+   procedure Chain_Append (Constr : in out Chain_Constr_Type; El : Tree);
+   pragma Import (C, Chain_Append);
+
+   --  Efficiently append element EL to a list.
+   type List_Constr_Type is record
+      First : Tree;
+      Last : Tree;
+   end record;
+   pragma Convention (C, List_Constr_Type);
+   procedure List_Init (Constr : out List_Constr_Type);
+   pragma Import (C, List_Init);
+   procedure List_Append (Constr : in out List_Constr_Type; El : Tree);
+   pragma Import (C, List_Append, "ortho_list_append");
+
+   type O_Loop_Block is record
+      Beg_Label : Tree;
+      End_Label : Tree;
+   end record;
+   pragma Convention (C, O_Loop_Block);
+
+   type O_Inter_List is record
+      Ident : O_Ident;
+      Storage : O_Storage;
+      --  Return type.
+      Rtype : O_Tnode;
+      --  List of parameter types.
+      Param_List : List_Constr_Type;
+      --  Chain of parameters declarations.
+      Param_Chain : Chain_Constr_Type;
+   end record;
+   pragma Convention (C, O_Inter_List);
+
+   type O_Element_List is record
+      Res : Tree;
+      Chain : Chain_Constr_Type;
+   end record;
+   pragma Convention (C, O_Element_List);
+
+   type O_Case_Block is record
+      End_Label : Tree;
+      Add_Break : Integer;
+   end record;
+   pragma Convention (C, O_Case_Block);
+
+   type O_If_Block is record
+      Stmt : Tree;
+   end record;
+   pragma Convention (C, O_If_Block);
+
+   type O_Aggr_List is record
+      Atype : Tree;
+      Chain : Chain_Constr_Type;
+   end record;
+
+   type O_Record_Aggr_List is new O_Aggr_List;
+   pragma Convention (C, O_Record_Aggr_List);
+   type O_Array_Aggr_List is new O_Aggr_List;
+   pragma Convention (C, O_Array_Aggr_List);
+
+   type O_Assoc_List is record
+      Subprg : Tree;
+      List : List_Constr_Type;
+   end record;
+   pragma Convention (C, O_Assoc_List);
+
+   type O_Enum_List is record
+      --  The enumeral_type node.
+      Res : Tree;
+      --  Chain of literals.
+      Chain : Chain_Constr_Type;
+      --  Numeral value (from 0 to nbr - 1) of the next literal to be declared.
+      Num : Natural;
+      --  Size of the enumeration type.
+      Size : Natural;
+   end record;
+   pragma Convention (C, O_Enum_List);
+
+   pragma Import (C, New_Dyadic_Op);
+   pragma Import (C, New_Monadic_Op);
+   pragma Import (C, New_Compare_Op);
+
+   pragma Import (C, New_Convert_Ov);
+   pragma Import (C, New_Alloca);
+
+   pragma Import (C, New_Signed_Literal);
+   pragma Import (C, New_Unsigned_Literal);
+   pragma Import (C, New_Float_Literal);
+   pragma Import (C, New_Null_Access);
+
+   pragma Import (C, Start_Record_Type);
+   pragma Import (C, New_Record_Field);
+   pragma Import (C, Finish_Record_Type);
+   pragma Import (C, New_Uncomplete_Record_Type);
+   pragma Import (C, Start_Uncomplete_Record_Type);
+
+   pragma Import (C, Start_Union_Type);
+   pragma Import (C, New_Union_Field);
+   pragma Import (C, Finish_Union_Type);
+
+   pragma Import (C, New_Unsigned_Type);
+   pragma Import (C, New_Signed_Type);
+   pragma Import (C, New_Float_Type);
+
+   pragma Import (C, New_Access_Type);
+   pragma Import (C, Finish_Access_Type);
+
+   pragma Import (C, New_Array_Type);
+   pragma Import (C, New_Constrained_Array_Type);
+
+   pragma Import (C, New_Boolean_Type);
+   pragma Import (C, Start_Enum_Type);
+   pragma Import (C, New_Enum_Literal);
+   pragma Import (C, Finish_Enum_Type);
+
+   pragma Import (C, Start_Record_Aggr);
+   pragma Import (C, New_Record_Aggr_El);
+   pragma Import (C, Finish_Record_Aggr);
+   pragma Import (C, Start_Array_Aggr);
+   pragma Import (C, New_Array_Aggr_El);
+   pragma Import (C, Finish_Array_Aggr);
+   pragma Import (C, New_Union_Aggr);
+
+   pragma Import (C, New_Indexed_Element);
+   pragma Import (C, New_Slice);
+   pragma Import (C, New_Selected_Element);
+   pragma Import (C, New_Access_Element);
+
+   pragma Import (C, New_Sizeof);
+   pragma Import (C, New_Offsetof);
+
+   pragma Import (C, New_Address);
+   pragma Import (C, New_Global_Address);
+   pragma Import (C, New_Unchecked_Address);
+   pragma Import (C, New_Global_Unchecked_Address);
+   pragma Import (C, New_Subprogram_Address);
+
+   pragma Import (C, New_Value);
+
+   pragma Import (C, New_Type_Decl);
+   pragma Import (C, New_Debug_Line_Decl);
+   pragma Import (C, New_Const_Decl);
+   pragma Import (C, New_Var_Decl);
+
+   pragma Import (C, Start_Const_Value);
+   pragma Import (C, Finish_Const_Value);
+
+   pragma Import (C, Start_Function_Decl);
+   pragma Import (C, Start_Procedure_Decl);
+   pragma Import (C, New_Interface_Decl);
+   pragma Import (C, Finish_Subprogram_Decl);
+
+   pragma Import (C, Start_Subprogram_Body);
+   pragma Import (C, Finish_Subprogram_Body);
+
+   pragma Import (C, New_Debug_Line_Stmt);
+   pragma Import (C, Start_Declare_Stmt);
+   pragma Import (C, Finish_Declare_Stmt);
+   pragma Import (C, Start_Association);
+   pragma Import (C, New_Association);
+   pragma Import (C, New_Function_Call);
+   pragma Import (C, New_Procedure_Call);
+
+   pragma Import (C, New_Assign_Stmt);
+
+   pragma Import (C, Start_If_Stmt);
+   pragma Import (C, New_Elsif_Stmt);
+   pragma Import (C, New_Else_Stmt);
+   pragma Import (C, Finish_If_Stmt);
+
+   pragma Import (C, New_Return_Stmt);
+   pragma Import_Procedure (New_Return_Stmt,
+                              "new_func_return_stmt", (O_Enode));
+   pragma Import_Procedure (New_Return_Stmt,
+                              "new_proc_return_stmt", null);
+
+   pragma Import (C, Start_Loop_Stmt);
+   pragma Import (C, Finish_Loop_Stmt);
+   pragma Import (C, New_Exit_Stmt);
+   pragma Import (C, New_Next_Stmt);
+
+   pragma Import (C, Start_Case_Stmt);
+   pragma Import (C, Start_Choice);
+   pragma Import (C, New_Expr_Choice);
+   pragma Import (C, New_Range_Choice);
+   pragma Import (C, New_Default_Choice);
+   pragma Import (C, Finish_Choice);
+   pragma Import (C, Finish_Case_Stmt);
+end Ortho_Gcc;
diff --git a/ortho/gcc/ortho_gcc_front.ads b/ortho/gcc/ortho_gcc_front.ads
new file mode 100644
index 000000000..553057b20
--- /dev/null
+++ b/ortho/gcc/ortho_gcc_front.ads
@@ -0,0 +1,2 @@
+with Ortho_Front;
+package Ortho_Gcc_Front renames Ortho_Front;
diff --git a/ortho/gcc/ortho_ident.adb b/ortho/gcc/ortho_ident.adb
new file mode 100644
index 000000000..c8acd58c5
--- /dev/null
+++ b/ortho/gcc/ortho_ident.adb
@@ -0,0 +1,36 @@
+package body Ortho_Ident is
+   function Get_Identifier_With_Length (Str : Address; Size : Integer)
+                                       return O_Ident;
+   pragma Import (C, Get_Identifier_With_Length);
+
+   function Compare_Identifier_String
+     (Id : O_Ident; Str : Address; Size : Integer)
+     return Boolean;
+   pragma Import (C, Compare_Identifier_String);
+
+   function Get_Identifier (Str : String) return O_Ident is
+   begin
+      return Get_Identifier_With_Length (Str'Address, Str'Length);
+   end Get_Identifier;
+
+   function Is_Equal (Id : O_Ident; Str : String) return Boolean is
+   begin
+      return Compare_Identifier_String (Id, Str'Address, Str'Length);
+   end Is_Equal;
+
+   function Get_String (Id : O_Ident) return String
+   is
+      procedure Get_Identifier_String
+        (Id : O_Ident; Str_Ptr : Address; Len_Ptr : Address);
+      pragma Import (C, Get_Identifier_String);
+
+      Len : Natural;
+      type Str_Acc is access String (Positive);
+      Str : Str_Acc;
+   begin
+      Get_Identifier_String (Id, Str'Address, Len'Address);
+      return Str (1 .. Len);
+   end Get_String;
+
+end Ortho_Ident;
+
diff --git a/ortho/gcc/ortho_ident.ads b/ortho/gcc/ortho_ident.ads
new file mode 100644
index 000000000..4675bc43c
--- /dev/null
+++ b/ortho/gcc/ortho_ident.ads
@@ -0,0 +1,12 @@
+with System; use System;
+
+package Ortho_Ident is
+   subtype O_Ident is Address;
+   function Get_Identifier (Str : String) return O_Ident;
+   function Get_String (Id : O_Ident) return String;
+   function Is_Equal (L, R : O_Ident) return Boolean renames System."=";
+   function Is_Equal (Id : O_Ident; Str : String) return Boolean;
+   O_Ident_Nul : constant O_Ident;
+private
+   O_Ident_Nul : constant O_Ident := Null_Address;
+end Ortho_Ident;
diff --git a/ortho/gcc/ortho_nodes.ads b/ortho/gcc/ortho_nodes.ads
new file mode 100644
index 000000000..7c6c4a076
--- /dev/null
+++ b/ortho/gcc/ortho_nodes.ads
@@ -0,0 +1,3 @@
+with Ortho_Gcc;
+
+package Ortho_Nodes renames Ortho_Gcc;