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/* Top level of GCC compilers (cc1, cc1plus, etc.)

   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,

   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,

   2011 Free Software Foundation, Inc.

This file is part of GCC.

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

the terms of the GNU General Public License as published by the Free

Software Foundation; either version 3, or (at your option) any later

version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

You should have received a copy of the GNU General Public License

along with GCC; see the file COPYING3.  If not see

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

/* This is the top level of cc1/c++.

   It parses command args, opens files, invokes the various passes

   in the proper order, and counts the time used by each.

   Error messages and low-level interface to malloc also handled here.  */

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "tm.h"

#include "line-map.h"

#include "input.h"

#include "tree.h"

#include "realmpfr.h"   /* For GMP/MPFR/MPC versions, in print_version.  */

#include "version.h"

#include "rtl.h"

#include "tm_p.h"

#include "flags.h"

#include "insn-attr.h"

#include "insn-config.h"

#include "insn-flags.h"

#include "hard-reg-set.h"

#include "recog.h"

#include "output.h"

#include "except.h"

#include "function.h"

#include "toplev.h"

#include "expr.h"

#include "basic-block.h"

#include "intl.h"

#include "ggc.h"

#include "graph.h"

#include "regs.h"

#include "timevar.h"

#include "diagnostic.h"

#include "tree-diagnostic.h"

#include "tree-pretty-print.h"

#include "params.h"

#include "reload.h"

#include "ira.h"

#include "dwarf2asm.h"

#include "integrate.h"

#include "debug.h"

#include "target.h"

#include "common/common-target.h"

#include "langhooks.h"

#include "cfglayout.h"

#include "cfgloop.h"

#include "hosthooks.h"

#include "cgraph.h"

#include "opts.h"

#include "opts-diagnostic.h"

#include "coverage.h"

#include "value-prof.h"

#include "alloc-pool.h"

#include "tree-mudflap.h"

#include "tree-pass.h"

#include "gimple.h"

#include "tree-ssa-alias.h"

#include "plugin.h"

#if defined (DWARF2_UNWIND_INFO) || defined (DWARF2_DEBUGGING_INFO)

#include "dwarf2out.h"

#endif

#if defined(DBX_DEBUGGING_INFO) || defined(XCOFF_DEBUGGING_INFO)

#include "dbxout.h"

#endif

#ifdef SDB_DEBUGGING_INFO

#include "sdbout.h"

#endif

#ifdef XCOFF_DEBUGGING_INFO

#include "xcoffout.h"           /* Needed for external data

                                   declarations for e.g. AIX 4.x.  */

#endif

static void general_init (const char *);

static void do_compile (void);

static void process_options (void);

static void backend_init (void);

static int lang_dependent_init (const char *);

static void init_asm_output (const char *);

static void finalize (bool);

static void crash_signal (int) ATTRIBUTE_NORETURN;

static void compile_file (void);

/* True if we don't need a backend (e.g. preprocessing only).  */

static bool no_backend;

/* Length of line when printing switch values.  */

#define MAX_LINE 75

/* Decoded options, and number of such options.  */

struct cl_decoded_option *save_decoded_options;

unsigned int save_decoded_options_count;

/* Used to enable -fvar-tracking, -fweb and -frename-registers according

   to optimize in process_options ().  */

#define AUTODETECT_VALUE 2

/* Debug hooks - dependent upon command line options.  */

const struct gcc_debug_hooks *debug_hooks;

/* The FUNCTION_DECL for the function currently being compiled,

   or 0 if between functions.  */

tree current_function_decl;

/* Set to the FUNC_BEGIN label of the current function, or NULL

   if none.  */

const char * current_function_func_begin_label;

/* A random sequence of characters, unless overridden by user.  */

static const char *flag_random_seed;

/* A local time stamp derived from the time of compilation. It will be

   zero if the system cannot provide a time.  It will be -1u, if the

   user has specified a particular random seed.  */

unsigned local_tick;

/* Random number for this compilation */

HOST_WIDE_INT random_seed;

/* -f flags.  */

/* Nonzero means make permerror produce warnings instead of errors.  */

int flag_permissive = 0;

/* When non-NULL, indicates that whenever space is allocated on the

   stack, the resulting stack pointer must not pass this

   address---that is, for stacks that grow downward, the stack pointer

   must always be greater than or equal to this address; for stacks

   that grow upward, the stack pointer must be less than this address.

   At present, the rtx may be either a REG or a SYMBOL_REF, although

   the support provided depends on the backend.  */

rtx stack_limit_rtx;

/* True if the user has tagged the function with the 'section'

   attribute.  */

bool user_defined_section_attribute = false;

struct target_flag_state default_target_flag_state;

#if SWITCHABLE_TARGET

struct target_flag_state *this_target_flag_state = &default_target_flag_state;

#else

#define this_target_flag_state (&default_target_flag_state)

#endif

/* The user symbol prefix after having resolved same.  */

const char *user_label_prefix;

/* Output files for assembler code (real compiler output)

   and debugging dumps.  */

FILE *asm_out_file;

FILE *aux_info_file;

FILE *stack_usage_file = NULL;

FILE *dump_file = NULL;

const char *dump_file_name;

/* The current working directory of a translation.  It's generally the

   directory from which compilation was initiated, but a preprocessed

   file may specify the original directory in which it was

   created.  */

static const char *src_pwd;

/* Initialize src_pwd with the given string, and return true.  If it

   was already initialized, return false.  As a special case, it may

   be called with a NULL argument to test whether src_pwd has NOT been

   initialized yet.  */

bool

set_src_pwd (const char *pwd)

{

  if (src_pwd)

    {

      if (strcmp (src_pwd, pwd) == 0)

        return true;

      else

        return false;

    }

  src_pwd = xstrdup (pwd);

  return true;

}

/* Return the directory from which the translation unit was initiated,

   in case set_src_pwd() was not called before to assign it a

   different value.  */

const char *

get_src_pwd (void)

{

  if (! src_pwd)

    {

      src_pwd = getpwd ();

      if (!src_pwd)

        src_pwd = ".";

    }

   return src_pwd;

}

/* Called when the start of a function definition is parsed,

   this function prints on stderr the name of the function.  */

void

announce_function (tree decl)

{

  if (!quiet_flag)

    {

      if (rtl_dump_and_exit)

        fprintf (stderr, "%s ",

                 identifier_to_locale (IDENTIFIER_POINTER (DECL_NAME (decl))));

      else

        fprintf (stderr, " %s",

                 identifier_to_locale (lang_hooks.decl_printable_name (decl, 2)));

      fflush (stderr);

      pp_needs_newline (global_dc->printer) = true;

      diagnostic_set_last_function (global_dc, (diagnostic_info *) NULL);

    }

}

/* Initialize local_tick with a random number or -1 if

   flag_random_seed is set.  */

static void

init_local_tick (void)

{

  if (!flag_random_seed)

    {

      /* Try urandom first. Time of day is too likely to collide.

         In case of any error we just use the local tick. */

      int fd = open ("/dev/urandom", O_RDONLY);

      if (fd >= 0)

        {

          read (fd, &random_seed, sizeof (random_seed));

          close (fd);

        }

      /* Now get the tick anyways  */

#ifdef HAVE_GETTIMEOFDAY

      {

        struct timeval tv;

        gettimeofday (&tv, NULL);

        local_tick = tv.tv_sec * 1000 + tv.tv_usec / 1000;

      }

#else

      {

        time_t now = time (NULL);

        if (now != (time_t)-1)

          local_tick = (unsigned) now;

      }

#endif

    }

  else

    local_tick = -1;

}

/* Set up a default flag_random_seed and local_tick, unless the user

   already specified one.  Must be called after init_local_tick.  */

static void

init_random_seed (void)

{

  if (flag_random_seed)

    {

      char *endp;

      /* When the driver passed in a hex number don't crc it again */

      random_seed = strtoul (flag_random_seed, &endp, 0);

      if (!(endp > flag_random_seed && *endp == 0))

        random_seed = crc32_string (0, flag_random_seed);

    }

  else if (!random_seed)

    random_seed = local_tick ^ getpid ();  /* Old racey fallback method */

}

/* Obtain the random_seed.  Unless NOINIT, initialize it if

   it's not provided in the command line.  */

HOST_WIDE_INT

get_random_seed (bool noinit)

{

  if (!flag_random_seed && !noinit)

    init_random_seed ();

  return random_seed;

}

/* Modify the random_seed string to VAL.  Return its previous

   value.  */

const char *

set_random_seed (const char *val)

{

  const char *old = flag_random_seed;

  flag_random_seed = val;

  return old;

}

/* Handler for fatal signals, such as SIGSEGV.  These are transformed

   into ICE messages, which is much more user friendly.  In case the

   error printer crashes, reset the signal to prevent infinite recursion.  */

static void

crash_signal (int signo)

{

  signal (signo, SIG_DFL);

  /* If we crashed while processing an ASM statement, then be a little more

     graceful.  It's most likely the user's fault.  */

  if (this_is_asm_operands)

    {

      output_operand_lossage ("unrecoverable error");

      exit (FATAL_EXIT_CODE);

    }

  internal_error ("%s", strsignal (signo));

}

/* A subroutine of wrapup_global_declarations.  We've come to the end of

   the compilation unit.  All deferred variables should be undeferred,

   and all incomplete decls should be finalized.  */

void

wrapup_global_declaration_1 (tree decl)

{

  /* We're not deferring this any longer.  Assignment is conditional to

     avoid needlessly dirtying PCH pages.  */

  if (CODE_CONTAINS_STRUCT (TREE_CODE (decl), TS_DECL_WITH_VIS)

      && DECL_DEFER_OUTPUT (decl) != 0)

    DECL_DEFER_OUTPUT (decl) = 0;

  if (TREE_CODE (decl) == VAR_DECL && DECL_SIZE (decl) == 0)

    lang_hooks.finish_incomplete_decl (decl);

}

/* A subroutine of wrapup_global_declarations.  Decide whether or not DECL

   needs to be output.  Return true if it is output.  */

bool

wrapup_global_declaration_2 (tree decl)

{

  if (TREE_ASM_WRITTEN (decl) || DECL_EXTERNAL (decl))

    return false;

  /* Don't write out static consts, unless we still need them.

     We also keep static consts if not optimizing (for debugging),

     unless the user specified -fno-keep-static-consts.

     ??? They might be better written into the debug information.

     This is possible when using DWARF.

     A language processor that wants static constants to be always

     written out (even if it is not used) is responsible for

     calling rest_of_decl_compilation itself.  E.g. the C front-end

     calls rest_of_decl_compilation from finish_decl.

     One motivation for this is that is conventional in some

     environments to write things like:

     static const char rcsid[] = "... version string ...";

     intending to force the string to be in the executable.

     A language processor that would prefer to have unneeded

     static constants "optimized away" would just defer writing

     them out until here.  E.g. C++ does this, because static

     constants are often defined in header files.

     ??? A tempting alternative (for both C and C++) would be

     to force a constant to be written if and only if it is

     defined in a main file, as opposed to an include file.  */

  if (TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))

    {

      struct varpool_node *node;

      bool needed = true;

      node = varpool_get_node (decl);

      if (!node && flag_ltrans)

        needed = false;

      else if (node && node->finalized)

        needed = false;

      else if (node && node->alias)

        needed = false;

      else if (!cgraph_global_info_ready

               && (TREE_USED (decl)

                   || TREE_USED (DECL_ASSEMBLER_NAME (decl))))

        /* needed */;

      else if (node && node->needed)

        /* needed */;

      else if (DECL_COMDAT (decl))

        needed = false;

      else if (TREE_READONLY (decl) && !TREE_PUBLIC (decl)

               && (optimize || !flag_keep_static_consts

                   || DECL_ARTIFICIAL (decl)))

        needed = false;

      if (needed)

        {

          rest_of_decl_compilation (decl, 1, 1);

          return true;

        }

    }

  return false;

}

/* Do any final processing required for the declarations in VEC, of

   which there are LEN.  We write out inline functions and variables

   that have been deferred until this point, but which are required.

   Returns nonzero if anything was put out.  */

bool

wrapup_global_declarations (tree *vec, int len)

{

  bool reconsider, output_something = false;

  int i;

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

    wrapup_global_declaration_1 (vec[i]);

  /* Now emit any global variables or functions that we have been

     putting off.  We need to loop in case one of the things emitted

     here references another one which comes earlier in the list.  */

  do

    {

      reconsider = false;

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

        reconsider |= wrapup_global_declaration_2 (vec[i]);

      if (reconsider)

        output_something = true;

    }

  while (reconsider);

  return output_something;

}

/* A subroutine of check_global_declarations.  Issue appropriate warnings

   for the global declaration DECL.  */

void

check_global_declaration_1 (tree decl)

{

  /* Warn about any function declared static but not defined.  We don't

     warn about variables, because many programs have static variables

     that exist only to get some text into the object file.  */

  if (TREE_CODE (decl) == FUNCTION_DECL

      && DECL_INITIAL (decl) == 0

      && DECL_EXTERNAL (decl)

      && ! DECL_ARTIFICIAL (decl)

      && ! TREE_NO_WARNING (decl)

      && ! TREE_PUBLIC (decl)

      && (warn_unused_function

          || TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))))

    {

      if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))

        pedwarn (input_location, 0, "%q+F used but never defined", decl);

      else

        warning (OPT_Wunused_function, "%q+F declared %<static%> but never defined", decl);

      /* This symbol is effectively an "extern" declaration now.  */

      TREE_PUBLIC (decl) = 1;

      assemble_external (decl);

    }

  /* Warn about static fns or vars defined but not used.  */

  if (((warn_unused_function && TREE_CODE (decl) == FUNCTION_DECL)

       /* We don't warn about "static const" variables because the

          "rcs_id" idiom uses that construction.  */

       || (warn_unused_variable

           && TREE_CODE (decl) == VAR_DECL && ! TREE_READONLY (decl)))

      && ! DECL_IN_SYSTEM_HEADER (decl)

      && ! TREE_USED (decl)

      /* The TREE_USED bit for file-scope decls is kept in the identifier,

         to handle multiple external decls in different scopes.  */

      && ! (DECL_NAME (decl) && TREE_USED (DECL_NAME (decl)))

      && ! DECL_EXTERNAL (decl)

      && ! TREE_PUBLIC (decl)

      /* A volatile variable might be used in some non-obvious way.  */

      && ! TREE_THIS_VOLATILE (decl)

      /* Global register variables must be declared to reserve them.  */

      && ! (TREE_CODE (decl) == VAR_DECL && DECL_REGISTER (decl))

      /* Otherwise, ask the language.  */

      && lang_hooks.decls.warn_unused_global (decl))

    warning ((TREE_CODE (decl) == FUNCTION_DECL)

             ? OPT_Wunused_function

             : OPT_Wunused_variable,

             "%q+D defined but not used", decl);

}

/* Issue appropriate warnings for the global declarations in VEC (of

   which there are LEN).  */

void

check_global_declarations (tree *vec, int len)

{

  int i;

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

    check_global_declaration_1 (vec[i]);

}

/* Emit debugging information for all global declarations in VEC.  */

void

emit_debug_global_declarations (tree *vec, int len)

{

  int i;

  /* Avoid confusing the debug information machinery when there are errors.  */

  if (seen_error ())

    return;

  timevar_push (TV_SYMOUT);

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

    debug_hooks->global_decl (vec[i]);

  timevar_pop (TV_SYMOUT);

}

/* Compile an entire translation unit.  Write a file of assembly

   output and various debugging dumps.  */

static void

compile_file (void)

{

  timevar_start (TV_PHASE_PARSING);

  timevar_push (TV_PARSE_GLOBAL);

  /* Call the parser, which parses the entire file (calling

     rest_of_compilation for each function).  */

  lang_hooks.parse_file ();

  timevar_pop (TV_PARSE_GLOBAL);

  timevar_stop (TV_PHASE_PARSING);

  /* Compilation is now finished except for writing

     what's left of the symbol table output.  */

  if (flag_syntax_only || flag_wpa)

    return;

  timevar_start (TV_PHASE_GENERATE);

  ggc_protect_identifiers = false;

  /* This must also call cgraph_finalize_compilation_unit.  */

  lang_hooks.decls.final_write_globals ();

  if (seen_error ())

    {

      timevar_stop (TV_PHASE_GENERATE);

      return;

    }

  /* Compilation unit is finalized.  When producing non-fat LTO object, we are

     basically finished.  */

  if (in_lto_p || !flag_lto || flag_fat_lto_objects)

    {

      varpool_assemble_pending_decls ();

      finish_aliases_2 ();

      /* Likewise for mudflap static object registrations.  */

      if (flag_mudflap)

        mudflap_finish_file ();

      output_shared_constant_pool ();

      output_object_blocks ();

  finish_tm_clone_pairs ();

      /* Write out any pending weak symbol declarations.  */

      weak_finish ();

      /* This must be at the end before unwind and debug info.

         Some target ports emit PIC setup thunks here.  */

      targetm.asm_out.code_end ();

      /* Do dbx symbols.  */

      timevar_push (TV_SYMOUT);

    #if defined DWARF2_DEBUGGING_INFO || defined DWARF2_UNWIND_INFO

      if (dwarf2out_do_frame ())

        dwarf2out_frame_finish ();

    #endif

      (*debug_hooks->finish) (main_input_filename);

      timevar_pop (TV_SYMOUT);

      /* Output some stuff at end of file if nec.  */

      dw2_output_indirect_constants ();

      /* Flush any pending external directives.  */

      process_pending_assemble_externals ();

   }

  /* Emit LTO marker if LTO info has been previously emitted.  This is

     used by collect2 to determine whether an object file contains IL.

     We used to emit an undefined reference here, but this produces

     link errors if an object file with IL is stored into a shared

     library without invoking lto1.  */

  if (flag_generate_lto)

    {

#if defined ASM_OUTPUT_ALIGNED_DECL_COMMON

      ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, NULL_TREE,

                                      "__gnu_lto_v1",

                                      (unsigned HOST_WIDE_INT) 1, 8);

#elif defined ASM_OUTPUT_ALIGNED_COMMON

      ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, "__gnu_lto_v1",

                                 (unsigned HOST_WIDE_INT) 1, 8);

#else

      ASM_OUTPUT_COMMON (asm_out_file, "__gnu_lto_v1",

                         (unsigned HOST_WIDE_INT) 1,

                         (unsigned HOST_WIDE_INT) 1);

#endif

      /* Let linker plugin know that this is a slim object and must be LTOed

         even when user did not ask for it.  */

      if (!flag_fat_lto_objects)

        {

#if defined ASM_OUTPUT_ALIGNED_DECL_COMMON

          ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, NULL_TREE,

                                          "__gnu_lto_slim",

                                          (unsigned HOST_WIDE_INT) 1, 8);

#elif defined ASM_OUTPUT_ALIGNED_COMMON

          ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, "__gnu_lto_slim",

                                     (unsigned HOST_WIDE_INT) 1, 8);

#else

          ASM_OUTPUT_COMMON (asm_out_file, "__gnu_lto_slim",

                             (unsigned HOST_WIDE_INT) 1,

                             (unsigned HOST_WIDE_INT) 1);

#endif

        }

    }

  /* Attach a special .ident directive to the end of the file to identify

     the version of GCC which compiled this code.  The format of the .ident

     string is patterned after the ones produced by native SVR4 compilers.  */

#ifdef IDENT_ASM_OP

  if (!flag_no_ident)

    {

      const char *pkg_version = "(GNU) ";

      if (strcmp ("(GCC) ", pkgversion_string))

        pkg_version = pkgversion_string;

      fprintf (asm_out_file, "%s\"GCC: %s%s\"\n",

               IDENT_ASM_OP, pkg_version, version_string);

    }

#endif

  /* Invoke registered plugin callbacks.  */

  invoke_plugin_callbacks (PLUGIN_FINISH_UNIT, NULL);

  /* This must be at the end.  Some target ports emit end of file directives

     into the assembly file here, and hence we can not output anything to the

     assembly file after this point.  */

  targetm.asm_out.file_end ();

  timevar_stop (TV_PHASE_GENERATE);

}

/* Print version information to FILE.

   Each line begins with INDENT (for the case where FILE is the

   assembler output file).  */

void

print_version (FILE *file, const char *indent)

{

  static const char fmt1[] =

#ifdef __GNUC__

    N_("%s%s%s %sversion %s (%s)\n%s\tcompiled by GNU C version %s, ")

#else

    N_("%s%s%s %sversion %s (%s) compiled by CC, ")

#endif

    ;

  static const char fmt2[] =

    N_("GMP version %s, MPFR version %s, MPC version %s\n");

  static const char fmt3[] =

    N_("%s%swarning: %s header version %s differs from library version %s.\n");

  static const char fmt4[] =

    N_("%s%sGGC heuristics: --param ggc-min-expand=%d --param ggc-min-heapsize=%d\n");

#ifndef __VERSION__

#define __VERSION__ "[?]"

#endif

  fprintf (file,

           file == stderr ? _(fmt1) : fmt1,

           indent, *indent != 0 ? " " : "",

           lang_hooks.name, pkgversion_string, version_string, TARGET_NAME,

           indent, __VERSION__);

  /* We need to stringify the GMP macro values.  Ugh, gmp_version has

     two string formats, "i.j.k" and "i.j" when k is zero.  As of

     gmp-4.3.0, GMP always uses the 3 number format.  */

#define GCC_GMP_STRINGIFY_VERSION3(X) #X

#define GCC_GMP_STRINGIFY_VERSION2(X) GCC_GMP_STRINGIFY_VERSION3(X)

#define GCC_GMP_VERSION_NUM(X,Y,Z) (((X) << 16L) | ((Y) << 8) | (Z))

#define GCC_GMP_VERSION \

  GCC_GMP_VERSION_NUM(__GNU_MP_VERSION, __GNU_MP_VERSION_MINOR, __GNU_MP_VERSION_PATCHLEVEL)

#if GCC_GMP_VERSION < GCC_GMP_VERSION_NUM(4,3,0) && __GNU_MP_VERSION_PATCHLEVEL == 0

#define GCC_GMP_STRINGIFY_VERSION GCC_GMP_STRINGIFY_VERSION2(__GNU_MP_VERSION) "." \

  GCC_GMP_STRINGIFY_VERSION2(__GNU_MP_VERSION_MINOR)

#else

#define GCC_GMP_STRINGIFY_VERSION GCC_GMP_STRINGIFY_VERSION2(__GNU_MP_VERSION) "." \

  GCC_GMP_STRINGIFY_VERSION2(__GNU_MP_VERSION_MINOR) "." \

  GCC_GMP_STRINGIFY_VERSION2(__GNU_MP_VERSION_PATCHLEVEL)

#endif

  fprintf (file,

           file == stderr ? _(fmt2) : fmt2,

           GCC_GMP_STRINGIFY_VERSION, MPFR_VERSION_STRING, MPC_VERSION_STRING);

  if (strcmp (GCC_GMP_STRINGIFY_VERSION, gmp_version))

    fprintf (file,