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/****************************************************************************

 *                                                                          *

 *                         GNAT COMPILER COMPONENTS                         *

 *                                                                          *

 *                                 M I S C                                  *

 *                                                                          *

 *                           C Implementation File                          *

 *                                                                          *

 *          Copyright (C) 1992-2012, Free Software Foundation, Inc.         *

 *                                                                          *

 * GNAT is free software;  you can  redistribute it  and/or modify it under *

 * terms of the  GNU General Public License as published  by the Free Soft- *

 * ware  Foundation;  either version 3,  or (at your option) any later ver- *

 * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *

 * OUT 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  distributed  with GNAT;  see file  COPYING3.  If not see *

 * <http://www.gnu.org/licenses/>.                                          *

 *                                                                          *

 * GNAT was originally developed  by the GNAT team at  New York University. *

 * Extensive contributions were provided by Ada Core Technologies Inc.      *

 *                                                                          *

 ****************************************************************************/

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "tm.h"

#include "tree.h"

#include "diagnostic.h"

#include "target.h"

#include "ggc.h"

#include "flags.h"

#include "debug.h"

#include "toplev.h"

#include "langhooks.h"

#include "langhooks-def.h"

#include "opts.h"

#include "options.h"

#include "plugin.h"

#include "real.h"

#include "function.h"   /* For pass_by_reference.  */

#include "ada.h"

#include "adadecode.h"

#include "types.h"

#include "atree.h"

#include "elists.h"

#include "namet.h"

#include "nlists.h"

#include "stringt.h"

#include "uintp.h"

#include "fe.h"

#include "sinfo.h"

#include "einfo.h"

#include "ada-tree.h"

#include "gigi.h"

/* This symbol needs to be defined for the front-end.  */

void *callgraph_info_file = NULL;

/* Command-line argc and argv.  These variables are global since they are

   imported in back_end.adb.  */

unsigned int save_argc;

const char **save_argv;

/* GNAT argc and argv.  */

extern int gnat_argc;

extern char **gnat_argv;

#ifdef __cplusplus

extern "C" {

#endif

/* Declare functions we use as part of startup.  */

extern void __gnat_initialize (void *);

extern void __gnat_install_SEH_handler (void *);

extern void adainit (void);

extern void _ada_gnat1drv (void);

#ifdef __cplusplus

}

#endif

/* The parser for the language.  For us, we process the GNAT tree.  */

static void

gnat_parse_file (void)

{

  int seh[2];

  /* Call the target specific initializations.  */

  __gnat_initialize (NULL);

  /* ??? Call the SEH initialization routine.  This is to workaround

  a bootstrap path problem.  The call below should be removed at some

  point and the SEH pointer passed to __gnat_initialize() above.  */

  __gnat_install_SEH_handler((void *)seh);

  /* Call the front-end elaboration procedures.  */

  adainit ();

  /* Call the front end.  */

  _ada_gnat1drv ();

}

/* Decode all the language specific options that cannot be decoded by GCC.

   The option decoding phase of GCC calls this routine on the flags that

   are marked as Ada-specific.  Return true on success or false on failure.  */

static bool

gnat_handle_option (size_t scode, const char *arg ATTRIBUTE_UNUSED, int value,

                    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;

  switch (code)

    {

    case OPT_Wall:

      warn_unused = value;

      warn_uninitialized = value;

      warn_maybe_uninitialized = value;

      break;

    case OPT_gant:

      warning (0, "%<-gnat%> misspelled as %<-gant%>");

      /* ... fall through ... */

    case OPT_gnat:

    case OPT_gnatO:

    case OPT_fRTS_:

    case OPT_I:

    case OPT_nostdinc:

    case OPT_nostdlib:

      /* These are handled by the front-end.  */

      break;

    default:

      gcc_unreachable ();

    }

  return true;

}

/* Return language mask for option processing.  */

static unsigned int

gnat_option_lang_mask (void)

{

  return CL_Ada;

}

/* Initialize options structure OPTS.  */

static void

gnat_init_options_struct (struct gcc_options *opts)

{

  /* Uninitialized really means uninitialized in Ada.  */

  opts->x_flag_zero_initialized_in_bss = 0;

}

/* Initialize for option processing.  */

static void

gnat_init_options (unsigned int decoded_options_count,

                   struct cl_decoded_option *decoded_options)

{

  /* Reconstruct an argv array for use of back_end.adb.

     ??? back_end.adb should not rely on this; instead, it should work with

     decoded options without such reparsing, to ensure consistency in how

     options are decoded.  */

  unsigned int i;

  save_argv = XNEWVEC (const char *, 2 * decoded_options_count + 1);

  save_argc = 0;

  for (i = 0; i < decoded_options_count; i++)

    {

      size_t num_elements = decoded_options[i].canonical_option_num_elements;

      if (decoded_options[i].errors

          || decoded_options[i].opt_index == OPT_SPECIAL_unknown

          || num_elements == 0)

        continue;

      /* Deal with -I- specially since it must be a single switch.  */

      if (decoded_options[i].opt_index == OPT_I

          && num_elements == 2

          && decoded_options[i].canonical_option[1][0] == '-'

          && decoded_options[i].canonical_option[1][1] == '\0')

        save_argv[save_argc++] = "-I-";

      else

        {

          gcc_assert (num_elements >= 1 && num_elements <= 2);

          save_argv[save_argc++] = decoded_options[i].canonical_option[0];

          if (num_elements >= 2)

            save_argv[save_argc++] = decoded_options[i].canonical_option[1];

        }

    }

  save_argv[save_argc] = NULL;

  gnat_argv = (char **) xmalloc (sizeof (save_argv[0]));

  gnat_argv[0] = xstrdup (save_argv[0]);     /* name of the command */

  gnat_argc = 1;

}

/* Ada code requires variables for these settings rather than elements

   of the global_options structure.  */

#undef optimize

#undef optimize_size

#undef flag_compare_debug

#undef flag_stack_check

int optimize;

int optimize_size;

int flag_compare_debug;

enum stack_check_type flag_stack_check = NO_STACK_CHECK;

/* Post-switch processing.  */

static bool

gnat_post_options (const char **pfilename ATTRIBUTE_UNUSED)

{

  /* Excess precision other than "fast" requires front-end support.  */

  if (flag_excess_precision_cmdline == EXCESS_PRECISION_STANDARD

      && TARGET_FLT_EVAL_METHOD_NON_DEFAULT)

    sorry ("-fexcess-precision=standard for Ada");

  flag_excess_precision_cmdline = EXCESS_PRECISION_FAST;

  /* ??? The warning machinery is outsmarted by Ada.  */

  warn_unused_parameter = 0;

  /* No psABI change warnings for Ada.  */

  warn_psabi = 0;

  optimize = global_options.x_optimize;

  optimize_size = global_options.x_optimize_size;

  flag_compare_debug = global_options.x_flag_compare_debug;

  flag_stack_check = global_options.x_flag_stack_check;

  return false;

}

/* Here is the function to handle the compiler error processing in GCC.  */

static void

internal_error_function (diagnostic_context *context,

                         const char *msgid, va_list *ap)

{

  text_info tinfo;

  char *buffer, *p, *loc;

  String_Template temp, temp_loc;

  Fat_Pointer fp, fp_loc;

  expanded_location s;

  /* Warn if plugins present.  */

  warn_if_plugins ();

  /* Reset the pretty-printer.  */

  pp_clear_output_area (context->printer);

  /* Format the message into the pretty-printer.  */

  tinfo.format_spec = msgid;

  tinfo.args_ptr = ap;

  tinfo.err_no = errno;

  pp_format_verbatim (context->printer, &tinfo);

  /* Extract a (writable) pointer to the formatted text.  */

  buffer = xstrdup (pp_formatted_text (context->printer));

  /* Go up to the first newline.  */

  for (p = buffer; *p; p++)

    if (*p == '\n')

      {

        *p = '\0';

        break;

      }

  temp.Low_Bound = 1;

  temp.High_Bound = p - buffer;

  fp.Bounds = &temp;

  fp.Array = buffer;

  s = expand_location (input_location);

  if (context->show_column && s.column != 0)

    asprintf (&loc, "%s:%d:%d", s.file, s.line, s.column);

  else

    asprintf (&loc, "%s:%d", s.file, s.line);

  temp_loc.Low_Bound = 1;

  temp_loc.High_Bound = strlen (loc);

  fp_loc.Bounds = &temp_loc;

  fp_loc.Array = loc;

  Current_Error_Node = error_gnat_node;

  Compiler_Abort (fp, -1, fp_loc);

}

/* Perform all the initialization steps that are language-specific.  */

static bool

gnat_init (void)

{

  /* Do little here, most of the standard declarations are set up after the

     front-end has been run.  Use the same `char' as C, this doesn't really

     matter since we'll use the explicit `unsigned char' for Character.  */

  build_common_tree_nodes (flag_signed_char, false);

  /* In Ada, we use an unsigned 8-bit type for the default boolean type.  */

  boolean_type_node = make_unsigned_type (8);

  TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);

  SET_TYPE_RM_MAX_VALUE (boolean_type_node,

                         build_int_cst (boolean_type_node, 1));

  SET_TYPE_RM_SIZE (boolean_type_node, bitsize_int (1));

  boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);

  boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);

  sbitsize_one_node = sbitsize_int (1);

  sbitsize_unit_node = sbitsize_int (BITS_PER_UNIT);

  ptr_void_type_node = build_pointer_type (void_type_node);

  /* Show that REFERENCE_TYPEs are internal and should be Pmode.  */

  internal_reference_types ();

  /* Register our internal error function.  */

  global_dc->internal_error = &internal_error_function;

  return true;

}

/* If we are using the GCC mechanism to process exception handling, we

   have to register the personality routine for Ada and to initialize

   various language dependent hooks.  */

void

gnat_init_gcc_eh (void)

{

  /* We shouldn't do anything if the No_Exceptions_Handler pragma is set,

     though. This could for instance lead to the emission of tables with

     references to symbols (such as the Ada eh personality routine) within

     libraries we won't link against.  */

  if (No_Exception_Handlers_Set ())

    return;

  /* Tell GCC we are handling cleanup actions through exception propagation.

     This opens possibilities that we don't take advantage of yet, but is

     nonetheless necessary to ensure that fixup code gets assigned to the

     right exception regions.  */

  using_eh_for_cleanups ();

  /* Turn on -fexceptions and -fnon-call-exceptions.  The first one triggers

     the generation of the necessary exception tables.  The second one is

     useful for two reasons: 1/ we map some asynchronous signals like SEGV to

     exceptions, so we need to ensure that the insns which can lead to such

     signals are correctly attached to the exception region they pertain to,

     2/ Some calls to pure subprograms are handled as libcall blocks and then

     marked as "cannot trap" if the flag is not set (see emit_libcall_block).

     We should not let this be since it is possible for such calls to actually

     raise in Ada.  */

  flag_exceptions = 1;

  flag_non_call_exceptions = 1;

  init_eh ();

}

/* Print language-specific items in declaration NODE.  */

static void

gnat_print_decl (FILE *file, tree node, int indent)

{

  switch (TREE_CODE (node))

    {

    case CONST_DECL:

      print_node (file, "corresponding var",

                  DECL_CONST_CORRESPONDING_VAR (node), indent + 4);

      break;

    case FIELD_DECL:

      print_node (file, "original field", DECL_ORIGINAL_FIELD (node),

                  indent + 4);

      break;

    case VAR_DECL:

      if (DECL_LOOP_PARM_P (node))

        print_node (file, "induction var", DECL_INDUCTION_VAR (node),

                    indent + 4);

      else

        print_node (file, "renamed object", DECL_RENAMED_OBJECT (node),

                    indent + 4);

      break;

    default:

      break;

    }

}

/* Print language-specific items in type NODE.  */

static void

gnat_print_type (FILE *file, tree node, int indent)

{

  switch (TREE_CODE (node))

    {

    case FUNCTION_TYPE:

      print_node (file, "ci/co list", TYPE_CI_CO_LIST (node), indent + 4);

      break;

    case INTEGER_TYPE:

      if (TYPE_MODULAR_P (node))

        print_node_brief (file, "modulus", TYPE_MODULUS (node), indent + 4);

      else if (TYPE_HAS_ACTUAL_BOUNDS_P (node))

        print_node (file, "actual bounds", TYPE_ACTUAL_BOUNDS (node),

                    indent + 4);

      else if (TYPE_VAX_FLOATING_POINT_P (node))

        ;

      else

        print_node (file, "index type", TYPE_INDEX_TYPE (node), indent + 4);

      /* ... fall through ... */

    case ENUMERAL_TYPE:

    case BOOLEAN_TYPE:

      print_node_brief (file, "RM size", TYPE_RM_SIZE (node), indent + 4);

      /* ... fall through ... */

    case REAL_TYPE:

      print_node_brief (file, "RM min", TYPE_RM_MIN_VALUE (node), indent + 4);

      print_node_brief (file, "RM max", TYPE_RM_MAX_VALUE (node), indent + 4);

      break;

    case ARRAY_TYPE:

      print_node (file,"actual bounds", TYPE_ACTUAL_BOUNDS (node), indent + 4);

      break;

    case VECTOR_TYPE:

      print_node (file,"representative array",

                  TYPE_REPRESENTATIVE_ARRAY (node), indent + 4);

      break;

    case RECORD_TYPE:

      if (TYPE_FAT_POINTER_P (node) || TYPE_CONTAINS_TEMPLATE_P (node))

        print_node (file, "unconstrained array",

                    TYPE_UNCONSTRAINED_ARRAY (node), indent + 4);

      else

        print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);

      break;

    case UNION_TYPE:

    case QUAL_UNION_TYPE:

      print_node (file, "Ada size", TYPE_ADA_SIZE (node), indent + 4);

      break;

    default:

      break;

    }

}

/* Return the name to be printed for DECL.  */

static const char *

gnat_printable_name (tree decl, int verbosity)

{

  const char *coded_name = IDENTIFIER_POINTER (DECL_NAME (decl));

  char *ada_name = (char *) ggc_alloc_atomic (strlen (coded_name) * 2 + 60);

  __gnat_decode (coded_name, ada_name, 0);

  if (verbosity == 2 && !DECL_IS_BUILTIN (decl))

    {

      Set_Identifier_Casing (ada_name, DECL_SOURCE_FILE (decl));

      return ggc_strdup (Name_Buffer);

    }

  return ada_name;

}

/* Return the name to be used in DWARF debug info for DECL.  */

static const char *

gnat_dwarf_name (tree decl, int verbosity ATTRIBUTE_UNUSED)

{

  gcc_assert (DECL_P (decl));

  return (const char *) IDENTIFIER_POINTER (DECL_NAME (decl));

}

/* Return the descriptive type associated with TYPE, if any.  */

static tree

gnat_descriptive_type (const_tree type)

{

  if (TYPE_STUB_DECL (type))

    return DECL_PARALLEL_TYPE (TYPE_STUB_DECL (type));

  else

    return NULL_TREE;

}

/* Return true if types T1 and T2 are identical for type hashing purposes.

   Called only after doing all language independent checks.  At present,

   this function is only called when both types are FUNCTION_TYPE.  */

static bool

gnat_type_hash_eq (const_tree t1, const_tree t2)

{

  gcc_assert (TREE_CODE (t1) == FUNCTION_TYPE);

  return fntype_same_flags_p (t1, TYPE_CI_CO_LIST (t2),

                              TYPE_RETURN_UNCONSTRAINED_P (t2),

                              TYPE_RETURN_BY_DIRECT_REF_P (t2),

                              TREE_ADDRESSABLE (t2));

}

/* Do nothing (return the tree node passed).  */

static tree

gnat_return_tree (tree t)

{

  return t;

}

/* Get the alias set corresponding to a type or expression.  */

static alias_set_type

gnat_get_alias_set (tree type)

{

  /* If this is a padding type, use the type of the first field.  */

  if (TYPE_IS_PADDING_P (type))

    return get_alias_set (TREE_TYPE (TYPE_FIELDS (type)));

  /* If the type is an unconstrained array, use the type of the

     self-referential array we make.  */

  else if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE)

    return

      get_alias_set (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))));

  /* If the type can alias any other types, return the alias set 0.  */

  else if (TYPE_P (type)

           && TYPE_UNIVERSAL_ALIASING_P (TYPE_MAIN_VARIANT (type)))

    return 0;

  return -1;

}

/* GNU_TYPE is a type.  Return its maximum size in bytes, if known,

   as a constant when possible.  */

static tree

gnat_type_max_size (const_tree gnu_type)

{

  /* First see what we can get from TYPE_SIZE_UNIT, which might not

     be constant even for simple expressions if it has already been

     elaborated and possibly replaced by a VAR_DECL.  */

  tree max_unitsize = max_size (TYPE_SIZE_UNIT (gnu_type), true);

  /* If we don't have a constant, see what we can get from TYPE_ADA_SIZE,

     which should stay untouched.  */

  if (!host_integerp (max_unitsize, 1)

      && RECORD_OR_UNION_TYPE_P (gnu_type)

      && !TYPE_FAT_POINTER_P (gnu_type)

      && TYPE_ADA_SIZE (gnu_type))

    {

      tree max_adasize = max_size (TYPE_ADA_SIZE (gnu_type), true);

      /* If we have succeeded in finding a constant, round it up to the

         type's alignment and return the result in units.  */

      if (host_integerp (max_adasize, 1))

        max_unitsize

          = size_binop (CEIL_DIV_EXPR,

                        round_up (max_adasize, TYPE_ALIGN (gnu_type)),

                        bitsize_unit_node);

    }

  return max_unitsize;

}

/* GNU_TYPE is a subtype of an integral type.  Set LOWVAL to the low bound

   and HIGHVAL to the high bound, respectively.  */

static void

gnat_get_subrange_bounds (const_tree gnu_type, tree *lowval, tree *highval)

{

  *lowval = TYPE_MIN_VALUE (gnu_type);

  *highval = TYPE_MAX_VALUE (gnu_type);

}

/* GNU_TYPE is the type of a subprogram parameter.  Determine if it should be

   passed by reference by default.  */

bool

default_pass_by_ref (tree gnu_type)

{

  /* We pass aggregates by reference if they are sufficiently large.  The

     choice of constant here is somewhat arbitrary.  We also pass by

     reference if the target machine would either pass or return by

     reference.  Strictly speaking, we need only check the return if this

     is an In Out parameter, but it's probably best to err on the side of

     passing more things by reference.  */

  if (pass_by_reference (NULL, TYPE_MODE (gnu_type), gnu_type, true))

    return true;

  if (targetm.calls.return_in_memory (gnu_type, NULL_TREE))

    return true;

  if (AGGREGATE_TYPE_P (gnu_type)

      && (!host_integerp (TYPE_SIZE (gnu_type), 1)

          || 0 < compare_tree_int (TYPE_SIZE (gnu_type),

                                   8 * TYPE_ALIGN (gnu_type))))

    return true;

  return false;

}

/* GNU_TYPE is the type of a subprogram parameter.  Determine if it must be

   passed by reference.  */

bool

must_pass_by_ref (tree gnu_type)

{

  /* We pass only unconstrained objects, those required by the language

     to be passed by reference, and objects of variable size.  The latter

     is more efficient, avoids problems with variable size temporaries,

     and does not produce compatibility problems with C, since C does

     not have such objects.  */

  return (TREE_CODE (gnu_type) == UNCONSTRAINED_ARRAY_TYPE

          || TYPE_IS_BY_REFERENCE_P (gnu_type)

          || (TYPE_SIZE (gnu_type)

              && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));

}

/* This function is called by the front-end to enumerate all the supported

   modes for the machine, as well as some predefined C types.  F is a function

   which is called back with the parameters as listed below, first a string,

   then six ints.  The name is any arbitrary null-terminated string and has

   no particular significance, except for the case of predefined C types, where

   it should be the name of the C type.  For integer types, only signed types

   should be listed, unsigned versions are assumed.  The order of types should

   be in order of preference, with the smallest/cheapest types first.

   In particular, C predefined types should be listed before other types,

   binary floating point types before decimal ones, and narrower/cheaper

   type versions before more expensive ones.  In type selection the first

   matching variant will be used.

   NAME         pointer to first char of type name

   DIGS         number of decimal digits for floating-point modes, else 0

   COMPLEX_P    nonzero is this represents a complex mode

   COUNT        count of number of items, nonzero for vector mode

   FLOAT_REP    Float_Rep_Kind for FP, otherwise undefined

   SIZE         number of bits used to store data

   ALIGN        number of bits to which mode is aligned.  */

void

enumerate_modes (void (*f) (const char *, int, int, int, int, int, int))

{

  const tree c_types[]

    = { float_type_node, double_type_node, long_double_type_node };

  const char *const c_names[]

    = { "float", "double", "long double" };

  int iloop;

  for (iloop = 0; iloop < NUM_MACHINE_MODES; iloop++)

    {

      enum machine_mode i = (enum machine_mode) iloop;

      enum machine_mode inner_mode = i;

      bool float_p = false;

      bool complex_p = false;

      bool vector_p = false;

      bool skip_p = false;

      int digs = 0;

      unsigned int nameloop;

      Float_Rep_Kind float_rep = IEEE_Binary; /* Until proven otherwise */

      switch (GET_MODE_CLASS (i))

        {

        case MODE_INT:

          break;

        case MODE_FLOAT:

          float_p = true;

          break;

        case MODE_COMPLEX_INT:

          complex_p = true;

          inner_mode = GET_MODE_INNER (i);

          break;

        case MODE_COMPLEX_FLOAT:

          float_p = true;

          complex_p = true;

          inner_mode = GET_MODE_INNER (i);

          break;

        case MODE_VECTOR_INT:

          vector_p = true;

          inner_mode = GET_MODE_INNER (i);

          break;

        case MODE_VECTOR_FLOAT:

          float_p = true;

          vector_p = true;

          inner_mode = GET_MODE_INNER (i);

          break;

        default:

          skip_p = true;

        }

      if (float_p)

        {

          const struct real_format *fmt = REAL_MODE_FORMAT (inner_mode);

          /* ??? Cope with the ghost XFmode of the ARM port.  */

          if (!fmt)

            continue;

          if (fmt->b == 2)