coregrind/vg_main.c

/*--------------------------------------------------------------------*/
/*--- C startup stuff, reached from vg_startup.S.                  ---*/
/*---                                                    vg_main.c ---*/
/*--------------------------------------------------------------------*/

/*
   This file is part of Valgrind, an extensible x86 protected-mode
   emulator for monitoring program execution on x86-Unixes.

   Copyright (C) 2000-2003 Julian Seward 
      jseward@acm.org

   This program 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 of the
   License, or (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#include "vg_include.h"

/* ---------------------------------------------------------------------
   Compute offsets into baseBlock.  See comments in vg_include.h.
   ------------------------------------------------------------------ */

/* The variables storing offsets. */

#define INVALID_OFFSET (-1)

Int VGOFF_(m_eax) = INVALID_OFFSET;
Int VGOFF_(m_ecx) = INVALID_OFFSET;
Int VGOFF_(m_edx) = INVALID_OFFSET;
Int VGOFF_(m_ebx) = INVALID_OFFSET;
Int VGOFF_(m_esp) = INVALID_OFFSET;
Int VGOFF_(m_ebp) = INVALID_OFFSET;
Int VGOFF_(m_esi) = INVALID_OFFSET;
Int VGOFF_(m_edi) = INVALID_OFFSET;
Int VGOFF_(m_eflags) = INVALID_OFFSET;
Int VGOFF_(m_dflag)  = INVALID_OFFSET;
Int VGOFF_(m_ssestate) = INVALID_OFFSET;
Int VGOFF_(ldt)   = INVALID_OFFSET;
Int VGOFF_(m_cs)  = INVALID_OFFSET;
Int VGOFF_(m_ss)  = INVALID_OFFSET;
Int VGOFF_(m_ds)  = INVALID_OFFSET;
Int VGOFF_(m_es)  = INVALID_OFFSET;
Int VGOFF_(m_fs)  = INVALID_OFFSET;
Int VGOFF_(m_gs)  = INVALID_OFFSET;
Int VGOFF_(m_eip) = INVALID_OFFSET;
Int VGOFF_(spillslots) = INVALID_OFFSET;
Int VGOFF_(sh_eax) = INVALID_OFFSET;
Int VGOFF_(sh_ecx) = INVALID_OFFSET;
Int VGOFF_(sh_edx) = INVALID_OFFSET;
Int VGOFF_(sh_ebx) = INVALID_OFFSET;
Int VGOFF_(sh_esp) = INVALID_OFFSET;
Int VGOFF_(sh_ebp) = INVALID_OFFSET;
Int VGOFF_(sh_esi) = INVALID_OFFSET;
Int VGOFF_(sh_edi) = INVALID_OFFSET;
Int VGOFF_(sh_eflags) = INVALID_OFFSET;

Int VGOFF_(helper_idiv_64_32) = INVALID_OFFSET;
Int VGOFF_(helper_div_64_32) = INVALID_OFFSET;
Int VGOFF_(helper_idiv_32_16) = INVALID_OFFSET;
Int VGOFF_(helper_div_32_16) = INVALID_OFFSET;
Int VGOFF_(helper_idiv_16_8) = INVALID_OFFSET;
Int VGOFF_(helper_div_16_8) = INVALID_OFFSET;
Int VGOFF_(helper_imul_32_64) = INVALID_OFFSET;
Int VGOFF_(helper_mul_32_64) = INVALID_OFFSET;
Int VGOFF_(helper_imul_16_32) = INVALID_OFFSET;
Int VGOFF_(helper_mul_16_32) = INVALID_OFFSET;
Int VGOFF_(helper_imul_8_16) = INVALID_OFFSET;
Int VGOFF_(helper_mul_8_16) = INVALID_OFFSET;
Int VGOFF_(helper_CLD) = INVALID_OFFSET;
Int VGOFF_(helper_STD) = INVALID_OFFSET;
Int VGOFF_(helper_get_dirflag) = INVALID_OFFSET;
Int VGOFF_(helper_CLC) = INVALID_OFFSET;
Int VGOFF_(helper_STC) = INVALID_OFFSET;
Int VGOFF_(helper_shldl) = INVALID_OFFSET;
Int VGOFF_(helper_shldw) = INVALID_OFFSET;
Int VGOFF_(helper_shrdl) = INVALID_OFFSET;
Int VGOFF_(helper_shrdw) = INVALID_OFFSET;
Int VGOFF_(helper_RDTSC) = INVALID_OFFSET;
Int VGOFF_(helper_CPUID) = INVALID_OFFSET;
Int VGOFF_(helper_BSWAP) = INVALID_OFFSET;
Int VGOFF_(helper_bsf) = INVALID_OFFSET;
Int VGOFF_(helper_bsr) = INVALID_OFFSET;
Int VGOFF_(helper_fstsw_AX) = INVALID_OFFSET;
Int VGOFF_(helper_SAHF) = INVALID_OFFSET;
Int VGOFF_(helper_DAS) = INVALID_OFFSET;
Int VGOFF_(helper_DAA) = INVALID_OFFSET;
Int VGOFF_(helper_undefined_instruction) = INVALID_OFFSET;

/* MAX_NONCOMPACT_HELPERS can be increased easily.  If MAX_COMPACT_HELPERS is
 * increased too much, they won't really be compact any more... */
#define  MAX_COMPACT_HELPERS     8
#define  MAX_NONCOMPACT_HELPERS  50 

UInt VG_(n_compact_helpers)    = 0;
UInt VG_(n_noncompact_helpers) = 0;

Addr VG_(compact_helper_addrs)  [MAX_COMPACT_HELPERS];
Int  VG_(compact_helper_offsets)[MAX_COMPACT_HELPERS];
Addr VG_(noncompact_helper_addrs)  [MAX_NONCOMPACT_HELPERS];
Int  VG_(noncompact_helper_offsets)[MAX_NONCOMPACT_HELPERS];

/* This is the actual defn of baseblock. */
UInt VG_(baseBlock)[VG_BASEBLOCK_WORDS];


/* Words. */
static Int baB_off = 0;

/* Returns the offset, in words. */
static Int alloc_BaB ( Int words )
{
   Int off = baB_off;
   baB_off += words;
   if (baB_off >= VG_BASEBLOCK_WORDS)
      VG_(core_panic)( "alloc_BaB: baseBlock is too small");

   return off;   
}

/* Align offset, in *bytes* */
static void align_BaB ( UInt align )
{
   vg_assert(2 == align || 4 == align || 8 == align || 16 == align);
   baB_off +=  (align-1);
   baB_off &= ~(align-1);
}

/* Allocate 1 word in baseBlock and set it to the given value. */
static Int alloc_BaB_1_set ( Addr a )
{
   Int off = alloc_BaB(1);
   VG_(baseBlock)[off] = (UInt)a;
   return off;
}

/* Registers a function in compact_helper_addrs;  compact_helper_offsets is
   filled in later. */
void VG_(register_compact_helper)(Addr a)
{
   if (MAX_COMPACT_HELPERS <= VG_(n_compact_helpers)) {
      VG_(printf)("Can only register %d compact helpers\n", 
                  MAX_COMPACT_HELPERS);
      VG_(core_panic)("Too many compact helpers registered");
   }
   VG_(compact_helper_addrs)[VG_(n_compact_helpers)] = a;
   VG_(n_compact_helpers)++;
}

/* Registers a function in noncompact_helper_addrs;  noncompact_helper_offsets
 * is filled in later.
 */
void VG_(register_noncompact_helper)(Addr a)
{
   if (MAX_NONCOMPACT_HELPERS <= VG_(n_noncompact_helpers)) {
      VG_(printf)("Can only register %d non-compact helpers\n", 
                  MAX_NONCOMPACT_HELPERS);
      VG_(printf)("Try increasing MAX_NON_COMPACT_HELPERS\n");
      VG_(core_panic)("Too many non-compact helpers registered");
   }
   VG_(noncompact_helper_addrs)[VG_(n_noncompact_helpers)] = a;
   VG_(n_noncompact_helpers)++;
}

/* Allocate offsets in baseBlock for the skin helpers */
static void assign_helpers_in_baseBlock(UInt n, Int offsets[], Addr addrs[])
{
   Int i;
   for (i = 0; i < n; i++) offsets[i] = alloc_BaB_1_set( addrs[i] );
}

Bool VG_(need_to_handle_esp_assignment)(void)
{
   return ( VG_(track_events).new_mem_stack_4  ||
            VG_(track_events).die_mem_stack_4  ||
            VG_(track_events).new_mem_stack_8  ||
            VG_(track_events).die_mem_stack_8  ||
            VG_(track_events).new_mem_stack_12 ||
            VG_(track_events).die_mem_stack_12 ||
            VG_(track_events).new_mem_stack_16 ||
            VG_(track_events).die_mem_stack_16 ||
            VG_(track_events).new_mem_stack_32 ||
            VG_(track_events).die_mem_stack_32 ||
            VG_(track_events).new_mem_stack    ||
            VG_(track_events).die_mem_stack
          );
}

/* Here we assign actual offsets.  It's important to get the most
   popular referents within 128 bytes of the start, so we can take
   advantage of short addressing modes relative to %ebp.  Popularity
   of offsets was measured on 22 Feb 02 running a KDE application, and
   the slots rearranged accordingly, with a 1.5% reduction in total
   size of translations. */
static void vg_init_baseBlock ( void )
{
   /* Those with offsets under 128 are carefully chosen. */

   /* WORD offsets in this column */
   /* 0   */ VGOFF_(m_eax)     = alloc_BaB(1);
   /* 1   */ VGOFF_(m_ecx)     = alloc_BaB(1);
   /* 2   */ VGOFF_(m_edx)     = alloc_BaB(1);
   /* 3   */ VGOFF_(m_ebx)     = alloc_BaB(1);
   /* 4   */ VGOFF_(m_esp)     = alloc_BaB(1);
   /* 5   */ VGOFF_(m_ebp)     = alloc_BaB(1);
   /* 6   */ VGOFF_(m_esi)     = alloc_BaB(1);
   /* 7   */ VGOFF_(m_edi)     = alloc_BaB(1);
   /* 8   */ VGOFF_(m_eflags)  = alloc_BaB(1);

   if (VG_(needs).shadow_regs) {
      /* 9   */ VGOFF_(sh_eax)    = alloc_BaB(1);
      /* 10  */ VGOFF_(sh_ecx)    = alloc_BaB(1);
      /* 11  */ VGOFF_(sh_edx)    = alloc_BaB(1);
      /* 12  */ VGOFF_(sh_ebx)    = alloc_BaB(1);
      /* 13  */ VGOFF_(sh_esp)    = alloc_BaB(1);
      /* 14  */ VGOFF_(sh_ebp)    = alloc_BaB(1);
      /* 15  */ VGOFF_(sh_esi)    = alloc_BaB(1);
      /* 16  */ VGOFF_(sh_edi)    = alloc_BaB(1);
      /* 17  */ VGOFF_(sh_eflags) = alloc_BaB(1);
   }

   /* 9,10,11 or 18,19,20... depends on number whether shadow regs are used
    * and on compact helpers registered */ 

   /* Make these most-frequently-called specialised ones compact, if they
      are used. */
   if (VG_(track_events).new_mem_stack_4)
      VG_(register_compact_helper)( (Addr) VG_(track_events).new_mem_stack_4);

   if (VG_(track_events).die_mem_stack_4)
      VG_(register_compact_helper)( (Addr) VG_(track_events).die_mem_stack_4);

   /* (9 or 18) + n_compact_helpers  */
   /* Allocate slots for compact helpers */
   assign_helpers_in_baseBlock(VG_(n_compact_helpers), 
                               VG_(compact_helper_offsets), 
                               VG_(compact_helper_addrs));

   /* (9/10 or 18/19) + n_compact_helpers */
   VGOFF_(m_eip) = alloc_BaB(1);

   /* There are currently 24 spill slots */
   /* (11+/20+ .. 32+/43+) + n_compact_helpers.  This can overlap the magic
    * boundary at >= 32 words, but most spills are to low numbered spill
    * slots, so the ones above the boundary don't see much action. */
   VGOFF_(spillslots) = alloc_BaB(VG_MAX_SPILLSLOTS);

   /* I gave up counting at this point.  Since they're above the
      short-amode-boundary, there's no point. */

   VGOFF_(m_dflag) = alloc_BaB(1);

   /* The FPU/SSE state.  This _must_ be 16-byte aligned. */
   align_BaB(16);
   VGOFF_(m_ssestate) = alloc_BaB(VG_SIZE_OF_SSESTATE_W);
   vg_assert( 
      (  ((UInt)(& VG_(baseBlock)[VGOFF_(m_ssestate)]))
         % 16  )
      == 0
   );

   /* This thread's LDT pointer, and segment registers. */
   VGOFF_(ldt)   = alloc_BaB(1);
   VGOFF_(m_cs)  = alloc_BaB(1);
   VGOFF_(m_ss)  = alloc_BaB(1);
   VGOFF_(m_ds)  = alloc_BaB(1);
   VGOFF_(m_es)  = alloc_BaB(1);
   VGOFF_(m_fs)  = alloc_BaB(1);
   VGOFF_(m_gs)  = alloc_BaB(1);

   VG_(register_noncompact_helper)( (Addr) & VG_(do_useseg) );

#define REG(kind, size) \
   if (VG_(track_events).kind##_mem_stack##size) \
      VG_(register_noncompact_helper)(           \
          (Addr) VG_(track_events).kind##_mem_stack##size );

   REG(new, _8);
   REG(new, _12);
   REG(new, _16);
   REG(new, _32);
   REG(new, );
   REG(die, _8);
   REG(die, _12);
   REG(die, _16);
   REG(die, _32);
   REG(die, );
#undef REG

   if (VG_(need_to_handle_esp_assignment)())
      VG_(register_noncompact_helper)((Addr) VG_(unknown_esp_update));

   /* Helper functions. */
   VGOFF_(helper_idiv_64_32)
      = alloc_BaB_1_set( (Addr) & VG_(helper_idiv_64_32) );
   VGOFF_(helper_div_64_32)
      = alloc_BaB_1_set( (Addr) & VG_(helper_div_64_32) );
   VGOFF_(helper_idiv_32_16)
      = alloc_BaB_1_set( (Addr) & VG_(helper_idiv_32_16) );
   VGOFF_(helper_div_32_16)
      = alloc_BaB_1_set( (Addr) & VG_(helper_div_32_16) );
   VGOFF_(helper_idiv_16_8)
      = alloc_BaB_1_set( (Addr) & VG_(helper_idiv_16_8) );
   VGOFF_(helper_div_16_8)
      = alloc_BaB_1_set( (Addr) & VG_(helper_div_16_8) );

   VGOFF_(helper_imul_32_64)
      = alloc_BaB_1_set( (Addr) & VG_(helper_imul_32_64) );
   VGOFF_(helper_mul_32_64)
      = alloc_BaB_1_set( (Addr) & VG_(helper_mul_32_64) );
   VGOFF_(helper_imul_16_32)
      = alloc_BaB_1_set( (Addr) & VG_(helper_imul_16_32) );
   VGOFF_(helper_mul_16_32)
      = alloc_BaB_1_set( (Addr) & VG_(helper_mul_16_32) );
   VGOFF_(helper_imul_8_16)
      = alloc_BaB_1_set( (Addr) & VG_(helper_imul_8_16) );
   VGOFF_(helper_mul_8_16)
      = alloc_BaB_1_set( (Addr) & VG_(helper_mul_8_16) );

   VGOFF_(helper_CLD)
      = alloc_BaB_1_set( (Addr) & VG_(helper_CLD) );
   VGOFF_(helper_STD)
      = alloc_BaB_1_set( (Addr) & VG_(helper_STD) );
   VGOFF_(helper_get_dirflag)
      = alloc_BaB_1_set( (Addr) & VG_(helper_get_dirflag) );

   VGOFF_(helper_CLC)
      = alloc_BaB_1_set( (Addr) & VG_(helper_CLC) );
   VGOFF_(helper_STC)
      = alloc_BaB_1_set( (Addr) & VG_(helper_STC) );

   VGOFF_(helper_shldl)
      = alloc_BaB_1_set( (Addr) & VG_(helper_shldl) );
   VGOFF_(helper_shldw)
      = alloc_BaB_1_set( (Addr) & VG_(helper_shldw) );
   VGOFF_(helper_shrdl)
      = alloc_BaB_1_set( (Addr) & VG_(helper_shrdl) );
   VGOFF_(helper_shrdw)
      = alloc_BaB_1_set( (Addr) & VG_(helper_shrdw) );

   VGOFF_(helper_RDTSC)
      = alloc_BaB_1_set( (Addr) & VG_(helper_RDTSC) );
   VGOFF_(helper_CPUID)
      = alloc_BaB_1_set( (Addr) & VG_(helper_CPUID) );

   VGOFF_(helper_bsf)
      = alloc_BaB_1_set( (Addr) & VG_(helper_bsf) );
   VGOFF_(helper_bsr)
      = alloc_BaB_1_set( (Addr) & VG_(helper_bsr) );

   VGOFF_(helper_fstsw_AX)
      = alloc_BaB_1_set( (Addr) & VG_(helper_fstsw_AX) );
   VGOFF_(helper_SAHF)
      = alloc_BaB_1_set( (Addr) & VG_(helper_SAHF) );
   VGOFF_(helper_DAS)
      = alloc_BaB_1_set( (Addr) & VG_(helper_DAS) );
   VGOFF_(helper_DAA)
      = alloc_BaB_1_set( (Addr) & VG_(helper_DAA) );

   VGOFF_(helper_undefined_instruction)
      = alloc_BaB_1_set( (Addr) & VG_(helper_undefined_instruction) );

   /* Allocate slots for noncompact helpers */
   assign_helpers_in_baseBlock(VG_(n_noncompact_helpers), 
                               VG_(noncompact_helper_offsets), 
                               VG_(noncompact_helper_addrs));


   /* Initialise slots that require it */
   VG_(copy_m_state_static_to_baseBlock)();

   /* Pretend the root thread has a completely empty LDT to start with. */
   VG_(baseBlock)[VGOFF_(ldt)] = (UInt)NULL;

   /* Initialise shadow regs */
   if (VG_(needs).shadow_regs) {
      UInt eflags;
   
      SK_(written_shadow_regs_values) ( & VG_(written_shadow_reg), & eflags );
      VG_(baseBlock)[VGOFF_(sh_esp)]    = 
      VG_(baseBlock)[VGOFF_(sh_ebp)]    =
      VG_(baseBlock)[VGOFF_(sh_eax)]    =
      VG_(baseBlock)[VGOFF_(sh_ecx)]    =
      VG_(baseBlock)[VGOFF_(sh_edx)]    =
      VG_(baseBlock)[VGOFF_(sh_ebx)]    =
      VG_(baseBlock)[VGOFF_(sh_esi)]    =
      VG_(baseBlock)[VGOFF_(sh_edi)]    = VG_(written_shadow_reg);
      VG_(baseBlock)[VGOFF_(sh_eflags)] = eflags;

   } else {
      VG_(written_shadow_reg) = VG_UNUSED_SHADOW_REG_VALUE;
   }
}


/* ---------------------------------------------------------------------
   Global entities which are not referenced from generated code.
   ------------------------------------------------------------------ */

/* The stack on which Valgrind runs.  We can't use the same stack as
   the simulatee -- that's an important design decision.  */
UInt VG_(stack)[VG_STACK_SIZE_W];

/* Ditto our signal delivery stack. */
UInt VG_(sigstack)[VG_SIGSTACK_SIZE_W];

/* Saving stuff across system calls. */
__attribute__ ((aligned (16)))
UInt VG_(real_sse_state_saved_over_syscall)[VG_SIZE_OF_SSESTATE_W];
Addr VG_(esp_saved_over_syscall);

/* Counts downwards in vg_run_innerloop. */
UInt VG_(dispatch_ctr);


/* 64-bit counter for the number of basic blocks done. */
ULong VG_(bbs_done);
/* 64-bit counter for the number of bbs to go before a debug exit. */
ULong VG_(bbs_to_go);

/* This is the ThreadId of the last thread the scheduler ran. */
ThreadId VG_(last_run_tid) = 0;

/* This is the argument to __NR_exit() supplied by the first thread to
   call that syscall.  We eventually pass that to __NR_exit() for
   real. */
Int VG_(exitcode) = 0;

/* Tell the logging mechanism whether we are logging to a file
   descriptor or a socket descriptor. */
Bool VG_(logging_to_filedes) = True;

/* Is this a SSE/SSE2-capable CPU?  If so, we had better save/restore
   the SSE state all over the place.  This is set up very early, in
   vg_startup.S.  We have to determine it early since we can't even
   correctly snapshot the startup machine state without it. */
/* Initially True.  Safer to err on the side of SSEness and get SIGILL
   than to not notice for some reason that we have SSE and get wierd
   errors later on. */
Bool VG_(have_ssestate) = True;


/* ---------------------------------------------------------------------
   Counters, for informational purposes only.
   ------------------------------------------------------------------ */

/* Number of lookups which miss the fast tt helper. */
UInt VG_(tt_fast_misses) = 0;


/* Counts for TT/TC informational messages. */

/* Number and total o/t size of translations overall. */
UInt VG_(overall_in_count) = 0;
UInt VG_(overall_in_osize) = 0;
UInt VG_(overall_in_tsize) = 0;
/* Number and total o/t size of discards overall. */
UInt VG_(overall_out_count) = 0;
UInt VG_(overall_out_osize) = 0;
UInt VG_(overall_out_tsize) = 0;
/* The number of discards of TT/TC. */
UInt VG_(number_of_tc_discards) = 0;
/* Counts of chain and unchain operations done. */
UInt VG_(bb_enchain_count) = 0;
UInt VG_(bb_dechain_count) = 0;
/* Number of unchained jumps performed. */
UInt VG_(unchained_jumps_done) = 0;


/* Counts pertaining to the register allocator. */

/* total number of uinstrs input to reg-alloc */
UInt VG_(uinstrs_prealloc) = 0;

/* total number of uinstrs added due to spill code */
UInt VG_(uinstrs_spill) = 0;

/* number of bbs requiring spill code */
UInt VG_(translations_needing_spill) = 0;

/* total of register ranks over all translations */
UInt VG_(total_reg_rank) = 0;


/* Counts pertaining to internal sanity checking. */
UInt VG_(sanity_fast_count) = 0;
UInt VG_(sanity_slow_count) = 0;

/* Counts pertaining to the scheduler. */
UInt VG_(num_scheduling_events_MINOR) = 0;
UInt VG_(num_scheduling_events_MAJOR) = 0;


/* ---------------------------------------------------------------------
   Values derived from command-line options.
   ------------------------------------------------------------------ */

/* Define, and set defaults. */
Bool   VG_(clo_error_limit)    = True;
Bool   VG_(clo_GDB_attach)     = False;
Bool   VG_(clo_gen_suppressions) = False;
Int    VG_(sanity_level)       = 1;
Int    VG_(clo_verbosity)      = 1;
Bool   VG_(clo_demangle)       = True;
Bool   VG_(clo_trace_children) = False;

/* See big comment in vg_include.h for meaning of these three. */
VgLogTo VG_(clo_log_to)        = VgLogTo_Fd;
Int     VG_(clo_logfile_fd)    = 2;
Char*   VG_(clo_logfile_name)  = NULL;

Int    VG_(clo_n_suppressions) = 0;
Char*  VG_(clo_suppressions)[VG_CLO_MAX_SFILES];
Bool   VG_(clo_profile)        = False;
Bool   VG_(clo_single_step)    = False;
Bool   VG_(clo_optimise)       = True;
UChar  VG_(clo_trace_codegen)  = 0; // 00000000b
Bool   VG_(clo_trace_syscalls) = False;
Bool   VG_(clo_trace_signals)  = False;
Bool   VG_(clo_trace_symtab)   = False;
Bool   VG_(clo_trace_sched)    = False;
Int    VG_(clo_trace_pthread_level) = 0;
ULong  VG_(clo_stop_after)     = 1000000000000000LL;
Int    VG_(clo_dump_error)     = 0;
Int    VG_(clo_backtrace_size) = 4;
Char*  VG_(clo_weird_hacks)    = NULL;
Bool   VG_(clo_run_libc_freeres) = True;
Bool   VG_(clo_chain_bb)       = True;

/* This Bool is needed by wrappers in vg_clientmalloc.c to decide how
   to behave.  Initially we say False. */
Bool VG_(running_on_simd_CPU) = False;

/* Holds client's %esp at the point we gained control. */
Addr VG_(esp_at_startup);

/* Indicates presence, and holds address of client's sysinfo page, a
   feature of some modern kernels used to provide vsyscalls, etc. */
Bool VG_(sysinfo_page_exists) = False;
Addr VG_(sysinfo_page_addr) = 0;

/* As deduced from VG_(esp_at_startup), the client's argc, argv[] and
   envp[] as extracted from the client's stack at startup-time. */
Int    VG_(client_argc);
Char** VG_(client_argv);
Char** VG_(client_envp);

/* A place into which to copy the value of env var VG_ARGS, so we
   don't have to modify the original. */
static Char vg_cmdline_copy[M_VG_CMDLINE_STRLEN];

/* ---------------------------------------------------------------------
   Processing of command-line options.
   ------------------------------------------------------------------ */

void VG_(bad_option) ( Char* opt )
{
   VG_(shutdown_logging)();
   VG_(clo_log_to)     = VgLogTo_Fd;
   VG_(clo_logfile_fd) = 2; /* stderr */
   VG_(printf)("valgrind.so: Bad option `%s'; aborting.\n", opt);
   VG_(exit)(1);
}

static void config_error ( Char* msg )
{
   VG_(shutdown_logging)();
   VG_(clo_log_to)     = VgLogTo_Fd;
   VG_(clo_logfile_fd) = 2; /* stderr */
   VG_(printf)(
      "valgrind.so: Startup or configuration error:\n   %s\n", msg);
   VG_(printf)(
      "valgrind.so: Unable to start up properly.  Giving up.\n");
   VG_(exit)(1);
}

static void args_grok_error ( Char* msg )
{
   VG_(shutdown_logging)();
   VG_(clo_log_to)     = VgLogTo_Fd;
   VG_(clo_logfile_fd) = 2; /* stderr */
   VG_(printf)("valgrind.so: When searching for "
               "client's argc/argc/envp:\n\t%s\n", msg);
   config_error("couldn't find client's argc/argc/envp");
}   

static void usage ( void )
{
   Char* usage1 = 
"usage: valgrind [options] prog-and-args\n"
"\n"
"  core user options, with defaults in [ ], are:\n"
"    --help                    show this message\n"
"    --version                 show version\n"
"    --skin=<name>             main task (skin to use) [Valgrind]\n"
"    -q --quiet                run silently; only print error msgs\n"
"    -v --verbose              be more verbose, incl counts of errors\n"
"    --gdb-attach=no|yes       start GDB when errors detected? [no]\n"
"    --gen-suppressions=no|yes print suppressions for errors detected [no]\n"
"    --demangle=no|yes         automatically demangle C++ names? [yes]\n"
"    --num-callers=<number>    show <num> callers in stack traces [4]\n"
"    --error-limit=no|yes      stop showing new errors if too many? [yes]\n"
"    --trace-children=no|yes   Valgrind-ise child processes? [no]\n"
"    --run-libc-freeres=no|yes Free up glibc memory at exit? [yes]\n"
"    --logfile-fd=<number>     file descriptor for messages [2=stderr]\n"
"    --logfile=<file>          log messages to <file>.pid<pid>\n"
"    --logsocket=ipaddr:port   log messages to socket ipaddr:port\n"
"    --suppressions=<filename> suppress errors described in\n"
"                              suppressions file <filename>\n"
"    --weird-hacks=hack1,hack2,...  [no hacks selected]\n"
"         recognised hacks are: ioctl-VTIME truncate-writes lax-ioctls\n"
"\n"
"  %s skin user options:\n";


   Char* usage2 = 
"\n"
"  core options for debugging Valgrind itself are:\n"
"    --sanity-level=<number>   level of sanity checking to do [1]\n"
"    --single-step=no|yes      translate each instr separately? [no]\n"
"    --optimise=no|yes         improve intermediate code? [yes]\n"
"    --profile=no|yes          profile? (skin must be built for it) [no]\n"
"    --chain-bb=no|yes         do basic-block chaining? [yes]\n"
"    --trace-codegen=<XXXXX>   show generated code? (X = 0|1) [00000]\n"
"    --trace-syscalls=no|yes   show all system calls? [no]\n"
"    --trace-signals=no|yes    show signal handling details? [no]\n"
"    --trace-symtab=no|yes     show symbol table details? [no]\n"
"    --trace-sched=no|yes      show thread scheduler details? [no]\n"
"    --trace-pthread=none|some|all  show pthread event details? [none]\n"
"    --stop-after=<number>     switch to real CPU after executing\n"
"                              <number> basic blocks [infinity]\n"
"    --dump-error=<number>     show translation for basic block\n"
"                              associated with <number>'th\n"
"                              error context [0=don't show any]\n"
"\n"
"  %s skin debugging options:\n";

   Char* usage3 =
"\n"
"  Extra options are read from env variable $VALGRIND_OPTS\n"
"\n"
"  Valgrind is Copyright (C) 2000-2003 Julian Seward\n"
"  and licensed under the GNU General Public License, version 2.\n"
"  Bug reports, feedback, admiration, abuse, etc, to: %s.\n"
"\n"
"  Skins are copyright and licensed by their authors.  See each\n"
"  skin's start-up message for more information.\n"
"\n";

   VG_(printf)(usage1, VG_(details).name);
   /* Don't print skin string directly for security, ha! */
   if (VG_(needs).command_line_options)
      SK_(print_usage)();
   else
      VG_(printf)("    (none)\n");
   VG_(printf)(usage2, VG_(details).name);
   if (VG_(needs).command_line_options)
      SK_(print_debug_usage)();
   else
      VG_(printf)("    (none)\n");
   VG_(printf)(usage3, VG_EMAIL_ADDR);

   VG_(shutdown_logging)();
   VG_(clo_log_to)     = VgLogTo_Fd;
   VG_(clo_logfile_fd) = 2; /* stderr */
   VG_(exit)(1);
}


/* Callback for looking for the stack segment. */
Addr VG_(foundstack_start) = (Addr)NULL;
UInt VG_(foundstack_size)  = 0;

static void vg_findstack_callback ( Addr start, UInt size, 
                                    Char r, Char w, Char x, 
                                    UInt foffset, UChar* filename )
{
   Addr lastword;
   if (size == 0) return;
   if (r != 'r' || w != 'w' 
       /* || x != 'x'  --not necessarily so on x86-64*/
      ) return;
   lastword = start + size - 4;
   if (start <= VG_(esp_at_startup) 
       && VG_(esp_at_startup) <= lastword) {
      VG_(foundstack_start) = start;
      VG_(foundstack_size) = size;
      vg_assert(VG_(foundstack_size) > 0);
   }
}



static void process_cmd_line_options ( void )
{
   Char* argv[M_VG_CMDLINE_OPTS];
   UInt  argc;
   Char* p;
   Char* str;
   Int   i, eventually_logfile_fd, ctr;

#  define ISSPACE(cc)      ((cc) == ' ' || (cc) == '\t' || (cc) == '\n')

   eventually_logfile_fd = VG_(clo_logfile_fd);

   /* Once logging is started, we can safely send messages pertaining
      to failures in initialisation. */
   VG_(startup_logging)();

   /* Check for sane path in ./configure --prefix=... */
   if (VG_(strlen)(VG_LIBDIR) < 1 
       || VG_LIBDIR[0] != '/') 
     config_error("Please use absolute paths in "
                  "./configure --prefix=... or --libdir=...");

   /* (Suggested by Fabrice Bellard ... )
      We look for the Linux ELF table and go down until we find the
      envc & envp. It is not fool-proof, but these structures should
      change less often than the libc ones. */
   {
       UInt* sp;

       /* Look for the stack segment by parsing /proc/self/maps and
	  looking for a section bracketing VG_(esp_at_startup) which
	  has rwx permissions and no associated file.  Note that this uses
          the /proc/self/maps contents read at the start of VG_(main)(),
          and doesn't re-read /proc/self/maps. */

       VG_(read_procselfmaps)( vg_findstack_callback, /*read_from_file*/False );

       /* Now foundstack_start and foundstack_size should delimit the stack. */
       if (VG_(foundstack_size) == 0) {
          args_grok_error("Cannot determine stack segment "
                          "from /proc/self/maps");
       }

       if (0)
          VG_(printf)("stack segment is %p .. %p\n", 
                      VG_(foundstack_start), 
                      VG_(foundstack_start) + VG_(foundstack_size) - 4 );

       sp = (UInt*)(VG_(foundstack_start) + VG_(foundstack_size) );
       if ((((UInt)(sp)) % VKI_BYTES_PER_PAGE) != 0) {
          args_grok_error("Stack segment is not page aligned?!");
       }

       /* we locate: NEW_AUX_ENT(1, AT_PAGESZ, ELF_EXEC_PAGESIZE) in
          the elf interpreter table */

       sp -= 2;
       while (sp[0] != VKI_AT_PAGESZ || sp[1] != 4096) {
           /* VG_(printf)("trying %p\n", sp); */
           sp--;
       }

       if (sp[2] == VKI_AT_BASE 
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_PHNUM
           && sp[-4] == VKI_AT_PHENT
           && sp[-6] == VKI_AT_PHDR
           && sp[-6-1] == 0) {
          if (0)
             VG_(printf)("Looks like you've got a 2.2.X kernel here.\n");
          sp -= 6;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-2-1] == 0) {
          if (0)
             VG_(printf)("Looks like you've got a 2.4.X kernel here.\n");
          sp -= 2;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-4] == VKI_AT_SYSINFO
           && sp[-4-1] == 0) {
          if (0)
             VG_(printf)("Looks like you've got a 2.4.X kernel with "
                         "a sysinfo page at %x here.\n", sp[-3]);
	  VG_(sysinfo_page_exists) = True;
	  VG_(sysinfo_page_addr) = sp[-3];
          sp -= 4;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-4] == VKI_AT_USER_AUX_SEGMENT
           && sp[-4-1] == 0) {
          if (0)
             VG_(printf)("Looks like you've got a R-H Limbo 2.4.X "
                         "kernel here.\n");
          sp -= 4;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-2-20-1] == 0) {
          if (0)
             VG_(printf)("Looks like you've got a early 2.4.X kernel here.\n");
          sp -= 22;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-4-1] == 0) {
          if (0)
             VG_(printf)("Looks like a 2.5.43-2.5.67 kernel here.\n");
          sp -= 4;
       } else
       if (sp[2] == VKI_AT_CLKTCK
           && sp[0] == VKI_AT_PAGESZ
           && sp[-2] == VKI_AT_HWCAP
           && sp[-6] == VKI_AT_SYSINFO
           && sp[-6-1] == 0) {
          if (0)
             VG_(printf)("Looks like a >= 2.5.68 kernel with "
                         "a sysinfo page at %x here.\n", sp[-5]);
	  VG_(sysinfo_page_exists) = True;
	  VG_(sysinfo_page_addr) = sp[-5];
          sp -= 6;
       } else
         args_grok_error(
            "ELF frame does not look like 2.2.X or 2.4.X.\n   "
            "See kernel sources linux/fs/binfmt_elf.c to make sense of this."
         );

       sp--;
       if (*sp != 0)
	 args_grok_error("can't find NULL at end of env[]");

       /* sp now points to NULL at the end of env[] */
       ctr = 0;
       while (True) {
           sp --;
           if (*sp == 0) break;
           if (++ctr >= 1000)
              args_grok_error(
                 "suspiciously many (1000) env[] entries; giving up");
           
       }
       /* sp now points to NULL at the end of argv[] */
       VG_(client_envp) = (Char**)(sp+1);

       ctr = 0;
       VG_(client_argc) = 0;
       while (True) {
          sp--;
          if (*sp == VG_(client_argc))
             break;
          VG_(client_argc)++;
           if (++ctr >= 1000)
              args_grok_error(
                 "suspiciously many (1000) argv[] entries; giving up");
       }

       VG_(client_argv) = (Char**)(sp+1);
   }

   /* Now that VG_(client_envp) has been set, we can extract the args
      for Valgrind itself.  Copy into global var so that we don't have to
      write zeroes to the getenv'd value itself. */
   str = VG_(getenv)("VG_ARGS");
   argc = 0;

   if (!str) {
      config_error("Can't read options from env var VG_ARGS.");
   }

   if (VG_(strlen)(str) >= M_VG_CMDLINE_STRLEN-1) {
      config_error("Command line length exceeds M_CMDLINE_STRLEN.");
   }
   VG_(strcpy)(vg_cmdline_copy, str);
   str = NULL;

   p = &vg_cmdline_copy[0];
   while (True) {
      while (ISSPACE(*p)) { *p = 0; p++; }
      if (*p == 0) break;
      if (argc < M_VG_CMDLINE_OPTS-1) { 
         argv[argc] = p; argc++; 
      } else {
         config_error(
            "Found more than M_CMDLINE_OPTS command-line opts.");
      }
      while (*p != 0 && !ISSPACE(*p)) p++;
   }

   for (i = 0; i < argc; i++) {

      if      (VG_CLO_STREQ(argv[i], "-v") ||
               VG_CLO_STREQ(argv[i], "--verbose"))
         VG_(clo_verbosity)++;
      else if (VG_CLO_STREQ(argv[i], "-q") ||
               VG_CLO_STREQ(argv[i], "--quiet"))
         VG_(clo_verbosity)--;

      else if (VG_CLO_STREQ(argv[i], "--error-limit=yes"))
         VG_(clo_error_limit) = True;
      else if (VG_CLO_STREQ(argv[i], "--error-limit=no"))
         VG_(clo_error_limit) = False;

      else if (VG_CLO_STREQ(argv[i], "--gdb-attach=yes"))
         VG_(clo_GDB_attach) = True;
      else if (VG_CLO_STREQ(argv[i], "--gdb-attach=no"))
         VG_(clo_GDB_attach) = False;

      else if (VG_CLO_STREQ(argv[i], "--gen-suppressions=yes"))
         VG_(clo_gen_suppressions) = True;
      else if (VG_CLO_STREQ(argv[i], "--gen-suppressions=no"))
         VG_(clo_gen_suppressions) = False;

      else if (VG_CLO_STREQ(argv[i], "--demangle=yes"))
         VG_(clo_demangle) = True;
      else if (VG_CLO_STREQ(argv[i], "--demangle=no"))
         VG_(clo_demangle) = False;

      else if (VG_CLO_STREQ(argv[i], "--trace-children=yes"))
         VG_(clo_trace_children) = True;
      else if (VG_CLO_STREQ(argv[i], "--trace-children=no"))
         VG_(clo_trace_children) = False;

      else if (VG_CLO_STREQ(argv[i], "--run-libc-freeres=yes"))
         VG_(clo_run_libc_freeres) = True;
      else if (VG_CLO_STREQ(argv[i], "--run-libc-freeres=no"))
         VG_(clo_run_libc_freeres) = False;

      else if (VG_CLO_STREQN(15, argv[i], "--sanity-level="))
         VG_(sanity_level) = (Int)VG_(atoll)(&argv[i][15]);

      else if (VG_CLO_STREQN(13, argv[i], "--logfile-fd=")) {
         VG_(clo_log_to)       = VgLogTo_Fd;
         VG_(clo_logfile_name) = NULL;
         eventually_logfile_fd = (Int)VG_(atoll)(&argv[i][13]);
      }

      else if (VG_CLO_STREQN(10, argv[i], "--logfile=")) {
         VG_(clo_log_to)       = VgLogTo_File;
         VG_(clo_logfile_name) = &argv[i][10];
      }

      else if (VG_CLO_STREQN(12, argv[i], "--logsocket=")) {
         VG_(clo_log_to)       = VgLogTo_Socket;
         VG_(clo_logfile_name) = &argv[i][12];
      }

      else if (VG_CLO_STREQN(15, argv[i], "--suppressions=")) {
         if (VG_(clo_n_suppressions) >= VG_CLO_MAX_SFILES) {
            VG_(message)(Vg_UserMsg, "Too many suppression files specified.");
            VG_(message)(Vg_UserMsg, 
                         "Increase VG_CLO_MAX_SFILES and recompile.");
            VG_(bad_option)(argv[i]);
         }
         VG_(clo_suppressions)[VG_(clo_n_suppressions)] = &argv[i][15];
         VG_(clo_n_suppressions)++;
      }
      else if (VG_CLO_STREQ(argv[i], "--profile=yes"))
         VG_(clo_profile) = True;
      else if (VG_CLO_STREQ(argv[i], "--profile=no"))
         VG_(clo_profile) = False;

      else if (VG_CLO_STREQ(argv[i], "--chain-bb=yes"))
	 VG_(clo_chain_bb) = True;
      else if (VG_CLO_STREQ(argv[i], "--chain-bb=no"))
	 VG_(clo_chain_bb) = False;

      else if (VG_CLO_STREQ(argv[i], "--single-step=yes"))
         VG_(clo_single_step) = True;
      else if (VG_CLO_STREQ(argv[i], "--single-step=no"))
         VG_(clo_single_step) = False;

      else if (VG_CLO_STREQ(argv[i], "--optimise=yes"))
         VG_(clo_optimise) = True;
      else if (VG_CLO_STREQ(argv[i], "--optimise=no"))
         VG_(clo_optimise) = False;

      /* "vwxyz" --> 000zyxwv (binary) */
      else if (VG_CLO_STREQN(16, argv[i], "--trace-codegen=")) {
         Int j;
         char* opt = & argv[i][16];
   
         if (5 != VG_(strlen)(opt)) {
            VG_(message)(Vg_UserMsg, 
                         "--trace-codegen argument must have 5 digits");
            VG_(bad_option)(argv[i]);
         }
         for (j = 0; j < 5; j++) {
            if      ('0' == opt[j]) { /* do nothing */ }
            else if ('1' == opt[j]) VG_(clo_trace_codegen) |= (1 << j);
            else {
               VG_(message)(Vg_UserMsg, "--trace-codegen argument can only "
                                        "contain 0s and 1s");
               VG_(bad_option)(argv[i]);
            }
         }
      }

      else if (VG_CLO_STREQ(argv[i], "--trace-syscalls=yes"))
         VG_(clo_trace_syscalls) = True;
      else if (VG_CLO_STREQ(argv[i], "--trace-syscalls=no"))
         VG_(clo_trace_syscalls) = False;

      else if (VG_CLO_STREQ(argv[i], "--trace-signals=yes"))
         VG_(clo_trace_signals) = True;
      else if (VG_CLO_STREQ(argv[i], "--trace-signals=no"))
         VG_(clo_trace_signals) = False;

      else if (VG_CLO_STREQ(argv[i], "--trace-symtab=yes"))
         VG_(clo_trace_symtab) = True;
      else if (VG_CLO_STREQ(argv[i], "--trace-symtab=no"))
         VG_(clo_trace_symtab) = False;

      else if (VG_CLO_STREQ(argv[i], "--trace-sched=yes"))
         VG_(clo_trace_sched) = True;
      else if (VG_CLO_STREQ(argv[i], "--trace-sched=no"))
         VG_(clo_trace_sched) = False;

      else if (VG_CLO_STREQ(argv[i], "--trace-pthread=none"))
         VG_(clo_trace_pthread_level) = 0;
      else if (VG_CLO_STREQ(argv[i], "--trace-pthread=some"))
         VG_(clo_trace_pthread_level) = 1;
      else if (VG_CLO_STREQ(argv[i], "--trace-pthread=all"))
         VG_(clo_trace_pthread_level) = 2;

      else if (VG_CLO_STREQN(14, argv[i], "--weird-hacks="))
         VG_(clo_weird_hacks) = &argv[i][14];

      else if (VG_CLO_STREQN(13, argv[i], "--stop-after="))
         VG_(clo_stop_after) = VG_(atoll)(&argv[i][13]);

      else if (VG_CLO_STREQN(13, argv[i], "--dump-error="))
         VG_(clo_dump_error) = (Int)VG_(atoll)(&argv[i][13]);

      else if (VG_CLO_STREQN(14, argv[i], "--num-callers=")) {
         /* Make sure it's sane. */
	 VG_(clo_backtrace_size) = (Int)VG_(atoll)(&argv[i][14]);
         if (VG_(clo_backtrace_size) < 2)
            VG_(clo_backtrace_size) = 2;
         if (VG_(clo_backtrace_size) >= VG_DEEPEST_BACKTRACE)
            VG_(clo_backtrace_size) = VG_DEEPEST_BACKTRACE;
      }

      else if (VG_(needs).command_line_options) {
         Bool ok = SK_(process_cmd_line_option)(argv[i]);
         if (!ok)
            usage();
      }
      else
         usage();
   }

#  undef ISSPACE

   if (VG_(clo_verbosity) < 0)
      VG_(clo_verbosity) = 0;

   if (VG_(clo_GDB_attach) && VG_(clo_trace_children)) {
      VG_(message)(Vg_UserMsg, "");
      VG_(message)(Vg_UserMsg, 
         "--gdb-attach=yes conflicts with --trace-children=yes");
      VG_(message)(Vg_UserMsg, 
         "Please choose one or the other, but not both.");
      VG_(bad_option)("--gdb-attach=yes and --trace-children=yes");
   }

   /* Set up logging now.  After this is done, VG_(clo_logfile_fd)
      should be connected to whatever sink has been selected, and we
      indiscriminately chuck stuff into it without worrying what the
      nature of it is.  Oh the wonder of Unix streams. */

   /* So far we should be still attached to stderr, so we can show on
      the terminal any problems to do with processing command line
      opts. */
   vg_assert(VG_(clo_logfile_fd) == 2 /* stderr */);
   vg_assert(VG_(logging_to_filedes) == True);

   switch (VG_(clo_log_to)) {

      case VgLogTo_Fd: 
         vg_assert(VG_(clo_logfile_name) == NULL);
         VG_(clo_logfile_fd) = eventually_logfile_fd;
         break;

      case VgLogTo_File: {
         Char logfilename[1000];
         vg_assert(VG_(clo_logfile_name) != NULL);
         vg_assert(VG_(strlen)(VG_(clo_logfile_name)) <= 900); /* paranoia */
         VG_(sprintf)(logfilename, "%s.pid%d",
                      VG_(clo_logfile_name), VG_(getpid)() );
         eventually_logfile_fd 
            = VG_(open)(logfilename, VKI_O_CREAT|VKI_O_WRONLY, 
                                     VKI_S_IRUSR|VKI_S_IWUSR);
         if (eventually_logfile_fd != -1) {
            VG_(clo_logfile_fd) = eventually_logfile_fd;
         } else {
            VG_(message)(Vg_UserMsg, 
               "Can't create/open log file `%s.pid%d'; giving up!", 
               VG_(clo_logfile_name), VG_(getpid)());
            VG_(bad_option)(
               "--logfile=<file> didn't work out for some reason.");
         }
         break;
      }

      case VgLogTo_Socket: {
         vg_assert(VG_(clo_logfile_name) != NULL);
         vg_assert(VG_(strlen)(VG_(clo_logfile_name)) <= 900); /* paranoia */
         eventually_logfile_fd 
            = VG_(connect_via_socket)( VG_(clo_logfile_name) );
         if (eventually_logfile_fd == -1) {
            VG_(message)(Vg_UserMsg, 
               "Invalid --logsocket=ipaddr or --logsocket=ipaddr:port spec"); 
            VG_(message)(Vg_UserMsg, 
               "of `%s'; giving up!", VG_(clo_logfile_name) );
            VG_(bad_option)(
               "--logsocket=");
	 }
         if (eventually_logfile_fd == -2) {
            VG_(message)(Vg_UserMsg, 
               "valgrind: failed to connect to logging server `%s'.",
               VG_(clo_logfile_name) ); 
            VG_(message)(Vg_UserMsg, 
                "Log messages will sent to stderr instead." );
            VG_(message)(Vg_UserMsg, 
                "" );
            /* We don't change anything here. */
	 } else {
            vg_assert(eventually_logfile_fd > 0);
            VG_(clo_logfile_fd) = eventually_logfile_fd;
            VG_(logging_to_filedes) = False;
         }
         break;
      }

   }

   /* Ok, the logging sink is running now.  Print a suitable preamble.
      If logging to file or a socket, write details of parent PID and
      command line args, to help people trying to interpret the
      results of a run which encompasses multiple processes. */

   if (VG_(clo_verbosity > 0)) {
      /* Skin details */
      VG_(message)(Vg_UserMsg, "%s%s%s, %s for x86-linux.",
                   VG_(details).name, 
                   NULL == VG_(details).version ?        "" : "-",
                   NULL == VG_(details).version 
                      ? (Char*)"" : VG_(details).version,
                   VG_(details).description);
      VG_(message)(Vg_UserMsg, "%s", VG_(details).copyright_author);

      /* Core details */
      VG_(message)(Vg_UserMsg,
         "Using valgrind-%s, a program supervision framework for x86-linux.",
         VERSION);
      VG_(message)(Vg_UserMsg, 
         "Copyright (C) 2000-2003, and GNU GPL'd, by Julian Seward.");
   }

   if (VG_(clo_log_to) != VgLogTo_Fd) {
      VG_(message)(Vg_UserMsg, "");
      VG_(message)(Vg_UserMsg, 
         "My PID = %d, parent PID = %d.  Prog and args are:",
         VG_(getpid)(), VG_(getppid)() );
      for (i = 0; i < VG_(client_argc); i++) 
         VG_(message)(Vg_UserMsg, "   %s", VG_(client_argv)[i]);
   }

   if (VG_(clo_verbosity) > 1) {
      if (VG_(clo_log_to) != VgLogTo_Fd)
         VG_(message)(Vg_UserMsg, "");
      VG_(message)(Vg_UserMsg, "Startup, with flags:");
      for (i = 0; i < argc; i++) {
         VG_(message)(Vg_UserMsg, "   %s", argv[i]);
      }
   }

   if (VG_(clo_n_suppressions) == 0 && 
       (VG_(needs).core_errors || VG_(needs).skin_errors)) {
      config_error("No error-suppression files were specified.");
   }

}

/* ---------------------------------------------------------------------
   Copying to/from m_state_static.
   ------------------------------------------------------------------ */

/* See comment about this in vg_include.h.  Change only with
   great care.
*/
__attribute__ ((aligned (16)))
UInt VG_(m_state_static) [6 /* segment regs, Intel order */
                          + 8 /* int regs, in Intel order */ 
                          + 1 /* %eflags */ 
                          + 1 /* %eip */
                          + VG_SIZE_OF_SSESTATE_W /* FPU state */
                         ];

UInt VG_(insertDflag)(UInt eflags, Int d)
{
   vg_assert(d == 1 || d == -1);
   eflags &= ~EFlagD;

   if (d < 0)
      eflags |= EFlagD;

   return eflags;
}

Int VG_(extractDflag)(UInt eflags)
{
   Int ret;

   if (eflags & EFlagD)
      ret = -1;
   else
      ret = 1;

   return ret;
}

void VG_(copy_baseBlock_to_m_state_static) ( void )
{
   Int i;
   VG_(m_state_static)[ 0/4] = VG_(baseBlock)[VGOFF_(m_cs)];
   VG_(m_state_static)[ 4/4] = VG_(baseBlock)[VGOFF_(m_ss)];
   VG_(m_state_static)[ 8/4] = VG_(baseBlock)[VGOFF_(m_ds)];
   VG_(m_state_static)[12/4] = VG_(baseBlock)[VGOFF_(m_es)];
   VG_(m_state_static)[16/4] = VG_(baseBlock)[VGOFF_(m_fs)];
   VG_(m_state_static)[20/4] = VG_(baseBlock)[VGOFF_(m_gs)];

   VG_(m_state_static)[24/4] = VG_(baseBlock)[VGOFF_(m_eax)];
   VG_(m_state_static)[28/4] = VG_(baseBlock)[VGOFF_(m_ecx)];
   VG_(m_state_static)[32/4] = VG_(baseBlock)[VGOFF_(m_edx)];
   VG_(m_state_static)[36/4] = VG_(baseBlock)[VGOFF_(m_ebx)];
   VG_(m_state_static)[40/4] = VG_(baseBlock)[VGOFF_(m_esp)];
   VG_(m_state_static)[44/4] = VG_(baseBlock)[VGOFF_(m_ebp)];
   VG_(m_state_static)[48/4] = VG_(baseBlock)[VGOFF_(m_esi)];
   VG_(m_state_static)[52/4] = VG_(baseBlock)[VGOFF_(m_edi)];

   VG_(m_state_static)[56/4] 
      = VG_(insertDflag)(VG_(baseBlock)[VGOFF_(m_eflags)],
                         VG_(baseBlock)[VGOFF_(m_dflag)]);
   VG_(m_state_static)[60/4] = VG_(baseBlock)[VGOFF_(m_eip)];

   for (i = 0; i < VG_SIZE_OF_SSESTATE_W; i++)
      VG_(m_state_static)[64/4 + i] 
         = VG_(baseBlock)[VGOFF_(m_ssestate) + i];
}


void VG_(copy_m_state_static_to_baseBlock) ( void )
{
   Int i;
   VG_(baseBlock)[VGOFF_(m_cs)] = VG_(m_state_static)[ 0/4];
   VG_(baseBlock)[VGOFF_(m_ss)] = VG_(m_state_static)[ 4/4];
   VG_(baseBlock)[VGOFF_(m_ds)] = VG_(m_state_static)[ 8/4];
   VG_(baseBlock)[VGOFF_(m_es)] = VG_(m_state_static)[12/4];
   VG_(baseBlock)[VGOFF_(m_fs)] = VG_(m_state_static)[16/4];
   VG_(baseBlock)[VGOFF_(m_gs)] = VG_(m_state_static)[20/4];

   VG_(baseBlock)[VGOFF_(m_eax)] = VG_(m_state_static)[24/4];
   VG_(baseBlock)[VGOFF_(m_ecx)] = VG_(m_state_static)[28/4];
   VG_(baseBlock)[VGOFF_(m_edx)] = VG_(m_state_static)[32/4];
   VG_(baseBlock)[VGOFF_(m_ebx)] = VG_(m_state_static)[36/4];
   VG_(baseBlock)[VGOFF_(m_esp)] = VG_(m_state_static)[40/4];
   VG_(baseBlock)[VGOFF_(m_ebp)] = VG_(m_state_static)[44/4];
   VG_(baseBlock)[VGOFF_(m_esi)] = VG_(m_state_static)[48/4];
   VG_(baseBlock)[VGOFF_(m_edi)] = VG_(m_state_static)[52/4];

   VG_(baseBlock)[VGOFF_(m_eflags)] 
      = VG_(m_state_static)[56/4] & ~EFlagD;
   VG_(baseBlock)[VGOFF_(m_dflag)] 
      = VG_(extractDflag)(VG_(m_state_static)[56/4]);

   VG_(baseBlock)[VGOFF_(m_eip)] = VG_(m_state_static)[60/4];

   for (i = 0; i < VG_SIZE_OF_SSESTATE_W; i++)
      VG_(baseBlock)[VGOFF_(m_ssestate) + i]
         = VG_(m_state_static)[64/4 + i];
}

Addr VG_(get_stack_pointer) ( void )
{
   return VG_(baseBlock)[VGOFF_(m_esp)];
}

/* Some random tests needed for leak checking */

Bool VG_(within_stack)(Addr a)
{
   if (a >= ((Addr)(&VG_(stack)))
       && a <= ((Addr)(&VG_(stack))) + sizeof(VG_(stack)))
      return True;
   else
      return False;
}

Bool VG_(within_m_state_static)(Addr a)
{
   if (a >= ((Addr)(&VG_(m_state_static)))
       && a <= ((Addr)(&VG_(m_state_static))) + sizeof(VG_(m_state_static)))
      return True;
   else
      return False;
}

/* ---------------------------------------------------------------------
   Show accumulated counts.
   ------------------------------------------------------------------ */

static __inline__ Int safe_idiv(Int a, Int b)
{
   return (b == 0 ? 0 : a / b);
}

static void vg_show_counts ( void )
{
   VG_(message)(Vg_DebugMsg,
		"    TT/TC: %d tc sectors discarded.",
                VG_(number_of_tc_discards) );
   VG_(message)(Vg_DebugMsg,
                "           %d chainings, %d unchainings.",
                VG_(bb_enchain_count), VG_(bb_dechain_count) );
   VG_(message)(Vg_DebugMsg,
                "translate: new     %d (%d -> %d; ratio %d:10)",
                VG_(overall_in_count),
                VG_(overall_in_osize),
                VG_(overall_in_tsize),
                safe_idiv(10*VG_(overall_in_tsize), VG_(overall_in_osize)));
   VG_(message)(Vg_DebugMsg,
                "           discard %d (%d -> %d; ratio %d:10).",
                VG_(overall_out_count),
                VG_(overall_out_osize),
                VG_(overall_out_tsize),
                safe_idiv(10*VG_(overall_out_tsize), VG_(overall_out_osize)));
   VG_(message)(Vg_DebugMsg,
      " dispatch: %llu jumps (bb entries), of which %u (%lu%%) were unchained.",
      VG_(bbs_done), 
      VG_(unchained_jumps_done),
      ((ULong)(100) * (ULong)(VG_(unchained_jumps_done)))
         / ( VG_(bbs_done)==0 ? 1 : VG_(bbs_done) )
   );

   VG_(message)(Vg_DebugMsg,
      "           %d/%d major/minor sched events.  %d tt_fast misses.", 
                     VG_(num_scheduling_events_MAJOR), 
                     VG_(num_scheduling_events_MINOR), 
                     VG_(tt_fast_misses));

   VG_(message)(Vg_DebugMsg, 
                "reg-alloc: %d t-req-spill, "
                "%d+%d orig+spill uis, %d total-reg-r.",
                VG_(translations_needing_spill),
                VG_(uinstrs_prealloc),
                VG_(uinstrs_spill),
                VG_(total_reg_rank) );
   VG_(message)(Vg_DebugMsg, 
                "   sanity: %d cheap, %d expensive checks.",
                VG_(sanity_fast_count), 
                VG_(sanity_slow_count) );
   VG_(print_ccall_stats)();
}


/* ---------------------------------------------------------------------
   Main!
   ------------------------------------------------------------------ */

/* Where we jump to once Valgrind has got control, and the real
   machine's state has been copied to the m_state_static. */

void VG_(main) ( void )
{
   Int               i;
   VgSchedReturnCode src;
   ThreadState*      tst;

   if (0) {
      if (VG_(have_ssestate))
         VG_(printf)("Looks like a SSE-capable CPU\n");
      else
         VG_(printf)("Looks like a MMX-only CPU\n");
   }

   /* Check skin and core versions are compatible */
   if (VG_CORE_INTERFACE_MAJOR_VERSION != VG_(skin_interface_major_version)) {
      VG_(printf)("Error:\n"
                  "  Skin and core interface versions do not match.\n"
                  "  Interface version used by core is: %d.%d\n"
                  "  Interface version used by skin is: %d.%d\n"
                  "  The major version numbers must match.\n",
                  VG_CORE_INTERFACE_MAJOR_VERSION,
                  VG_CORE_INTERFACE_MINOR_VERSION,
                  VG_(skin_interface_major_version),
                  VG_(skin_interface_minor_version));
      VG_(printf)("  You need to at least recompile, and possibly update,\n");
      if (VG_CORE_INTERFACE_MAJOR_VERSION > VG_(skin_interface_major_version))
         VG_(printf)("  your skin to work with this version of Valgrind.\n");
      else
         VG_(printf)("  your version of Valgrind to work with this skin.\n");
      VG_(printf)("  Aborting, sorry.\n");
      VG_(exit)(1);
   }

   /* Set up our stack sanity-check words. */
   for (i = 0; i < 10; i++) {
      VG_(stack)[i] = (UInt)(&VG_(stack)[i])                   ^ 0xA4B3C2D1;
      VG_(stack)[VG_STACK_SIZE_W-1-i] 
                    = (UInt)(&VG_(stack)[VG_STACK_SIZE_W-i-1]) ^ 0xABCD4321;
   }

   /* Read /proc/self/maps into a buffer.  Must be before:
      - SK_(pre_clo_init)(): so that if it calls VG_(malloc)(), any mmap'd
        superblocks are not erroneously identified as being owned by the
        client, which would be bad.
      - init_memory(): that's where the buffer is parsed
      - init_tt_tc(): so the anonymous mmaps for the translation table and
        translation cache aren't identified as part of the client, which would
        waste > 20M of virtual address space, and be bad.
   */
   VG_(read_procselfmaps_contents)();

   /* Hook to delay things long enough so we can get the pid and
      attach GDB in another shell. */
   if (0) {
      Int p, q;
      VG_(printf)("pid=%d\n", VG_(getpid)());
      for (p = 0; p < 50000; p++)
         for (q = 0; q < 50000; q++) ;
   }

   /* Setup stuff that depends on the skin.  Must be before:
      - vg_init_baseBlock(): to register helpers
      - process_cmd_line_options(): to register skin name and description,
        and turn on/off 'command_line_options' need
      - init_memory() (to setup memory event trackers).
   */
   SK_(pre_clo_init)();
   VG_(sanity_check_needs)();

   /* Process Valgrind's command-line opts (from env var VG_ARGS). */
   process_cmd_line_options();

   /* Do post command-line processing initialisation.  Must be before:
      - vg_init_baseBlock(): to register any more helpers
   */
   SK_(post_clo_init)();

   /* Set up baseBlock offsets and copy the saved machine's state into it. */
   vg_init_baseBlock();

   /* Initialise the scheduler, and copy the client's state from
      baseBlock into VG_(threads)[1].  Must be before:
      - VG_(sigstartup_actions)()
   */
   VG_(scheduler_init)();

   /* Initialise the signal handling subsystem, temporarily parking
      the saved blocking-mask in saved_sigmask. */
   VG_(sigstartup_actions)();

   /* Perhaps we're profiling Valgrind? */
   if (VG_(clo_profile))
      VGP_(init_profiling)();

   /* Start calibration of our RDTSC-based clock. */
   VG_(start_rdtsc_calibration)();

   /* Parse /proc/self/maps to learn about startup segments. */
   VGP_PUSHCC(VgpInitMem);
   VG_(init_memory)();
   VGP_POPCC(VgpInitMem);

   /* Read the list of errors to suppress.  This should be found in
      the file specified by vg_clo_suppressions. */
   if (VG_(needs).core_errors || VG_(needs).skin_errors)
      VG_(load_suppressions)();

   /* End calibration of our RDTSC-based clock, leaving it as long as
      we can. */
   VG_(end_rdtsc_calibration)();

   /* Initialise translation table and translation cache. */
   VG_(init_tt_tc)();

   if (VG_(clo_verbosity) == 1) {
      VG_(message)(Vg_UserMsg, 
                   "For more details, rerun with: -v");
   }

   /* Now it is safe for malloc et al in vg_clientmalloc.c to act
      instrumented-ly. */
   if (VG_(clo_verbosity) > 0)
      VG_(message)(Vg_UserMsg, "");

   VG_(bbs_to_go) = VG_(clo_stop_after);

   /* Run! */
   VG_(running_on_simd_CPU) = True;
   VGP_PUSHCC(VgpSched);
   src = VG_(scheduler)();
   VGP_POPCC(VgpSched);
   VG_(running_on_simd_CPU) = False;

   if (VG_(clo_verbosity) > 0)
      VG_(message)(Vg_UserMsg, "");

   if (src == VgSrc_Deadlock) {
     VG_(message)(Vg_UserMsg, 
        "Warning: pthread scheduler exited due to deadlock");
   }

   if (VG_(needs).core_errors || VG_(needs).skin_errors)
      VG_(show_all_errors)();

   SK_(fini)( VG_(exitcode) );

   VG_(do_sanity_checks)( True /*include expensive checks*/ );

   if (VG_(clo_verbosity) > 1)
      vg_show_counts();

   if (VG_(clo_verbosity) > 3)
      VG_(print_UInstr_histogram)();

   if (0) {
      VG_(message)(Vg_DebugMsg, "");
      VG_(message)(Vg_DebugMsg, 
         "------ Valgrind's internal memory use stats follow ------" );
      VG_(mallocSanityCheckAll)();
      VG_(show_all_arena_stats)();
      VG_(message)(Vg_DebugMsg, 
         "------ Valgrind's ExeContext management stats follow ------" );
      VG_(show_ExeContext_stats)();
   }
 
   if (VG_(clo_profile))
      VGP_(done_profiling)();

   VG_(shutdown_logging)();

   /* Remove valgrind.so from a LD_PRELOAD=... string so child
      processes don't get traced into.  Also mess up $libdir/valgrind
      so that our libpthread.so disappears from view. */
   /* 26 Apr 03: doing this often causes trouble for no reason, and is
      pointless when we are just about to VgSrc_ExitSyscall.  So don't
      bother in that case. */
   if ((!VG_(clo_trace_children))
       && src != VgSrc_ExitSyscall) { 
      VG_(mash_LD_PRELOAD_and_LD_LIBRARY_PATH)(
         VG_(getenv)("LD_PRELOAD"),
         VG_(getenv)("LD_LIBRARY_PATH") 
      );
   }

   /* Decide how to exit.  This depends on what the scheduler
      returned. */
   switch (src) {
      case VgSrc_ExitSyscall: /* the normal way out */
         vg_assert(VG_(last_run_tid) > 0 
                   && VG_(last_run_tid) < VG_N_THREADS);
         tst = & VG_(threads)[VG_(last_run_tid)];
         vg_assert(tst->status == VgTs_Runnable);
         /* The thread's %EBX at the time it did __NR_exit() will hold
            the arg to __NR_exit(), so we just do __NR_exit() with
            that arg. */
         VG_(exit)( VG_(exitcode) );
         /* NOT ALIVE HERE! */
         VG_(core_panic)("entered the afterlife in vg_main() -- ExitSyscall");
         break; /* what the hell :) */

      case VgSrc_Deadlock:
         /* Just exit now.  No point in continuing. */
         VG_(exit)(0);
         VG_(core_panic)("entered the afterlife in vg_main() -- Deadlock");
         break;

      case VgSrc_BbsDone: 
         /* Tricky; we have to try and switch back to the real CPU.
            This is all very dodgy and won't work at all in the
            presence of threads, or if the client happened to be
            running a signal handler. */
         /* Prepare to restore state to the real CPU. */
         VG_(load_thread_state)(1 /* root thread */ );
         VG_(copy_baseBlock_to_m_state_static)();

         /* This pushes a return address on the simulator's stack,
            which is abandoned.  We call vg_sigshutdown_actions() at
            the end of vg_switch_to_real_CPU(), so as to ensure that
            the original stack and machine state is restored before
            the real signal mechanism is restored.  */
         VG_(switch_to_real_CPU)();

      default:
         VG_(core_panic)("vg_main(): unexpected scheduler return code");
   }
}


/* Debugging thing .. can be called from assembly with OYNK macro. */
void VG_(oynk) ( Int n )
{
   OINK(n);
}


/* Find "valgrind.so" in a LD_PRELOAD=... string, and convert it to
   "valgrinq.so", which doesn't do anything.  This is used to avoid
   tracing into child processes.  To make this work the build system
   also supplies a dummy file, "valgrinq.so". 

   Also replace "vgskin_<foo>.so" with whitespace, for the same reason;
   without it, child processes try to find valgrind.so symbols in the 
   skin .so.

   Also look for $(libdir)/lib/valgrind in LD_LIBRARY_PATH and change
   it to $(libdir)/lib/valgrinq, so as to make our libpthread.so
   disappear.  
*/
void VG_(mash_LD_PRELOAD_and_LD_LIBRARY_PATH) ( Char* ld_preload_str,
                                                Char* ld_library_path_str )
{
   Char* vg_prel  = NULL;
   Char* sk_prel  = NULL;
   Char* pth_path = NULL;
   Char* p;
   Char* coredir_first;
   Char* coredir_last;
   Int   coredir_len;
   Int   i;
   Int   what;

#define MUTANCY(n)   { what = n; goto mutancy; }

   if (ld_preload_str == NULL || ld_library_path_str == NULL) MUTANCY(0);

   /* VG_(printf)("pre:\n%s\n%s\n", ld_preload_str, ld_library_path_str); */

   /* Setting up, finding things */

   /* LD_PRELOAD: Search for "valgrind.so" */
   vg_prel = VG_(strstr)(ld_preload_str, "valgrind.so");

   /* LD_PRELOAD: if "valgrind.so" not found, has been done before;
      "valgrindq.so" should be there instead.  Then stop. */
   if (NULL == vg_prel) {
      if (VG_(strstr)(ld_preload_str, "valgrinq.so") == NULL) MUTANCY(1);
      return;
   }

   /* LD_PRELOAD: coredir == directory containing "valgrind.so" */
   p = vg_prel;

   for (p = vg_prel;  *p != ':' && p > ld_preload_str;  p--) { }
   if (*p != ':') MUTANCY(2);  /* skin.so entry must precede it */
   coredir_first = p+1;
   coredir_last  = vg_prel - 1;
   coredir_len   = coredir_last - coredir_first + 1;
   
   /* LD_PRELOAD: find "vgskin_foo.so" */
   sk_prel = VG_(strstr)(ld_preload_str, "vgskin_");
   if (sk_prel == NULL) MUTANCY(4);

   /* LD_LIBRARY_PATH: find coredir */
   *coredir_last = '\0';      /* Temporarily zero-terminate coredir */
   pth_path = VG_(strstr)(ld_library_path_str, coredir_first);
   if (pth_path == NULL) MUTANCY(5);
   *coredir_last = '/';       /* Undo zero-termination */

   /* Changing things */

   /* LD_PRELOAD: "valgrind.so" --> "valgrinq.so" */
   if (vg_prel[7] != 'd') MUTANCY(6);
   vg_prel[7] = 'q';

   /* LD_PRELOAD: "/.../vgskin_foo.so" --> blank */
   /* Blank from "vgskin_" back to prev. LD_PRELOAD entry, or start */
   p = sk_prel;
   while (*p != ':' && p >= ld_preload_str) { 
      *p = ' ';
      p--;
   }
   /* Blank from "vgskin_" to next LD_PRELOAD entry (must be one, since
      the valgrind.so entry must follow) */
   p = sk_prel;
   while (*p != ':' && *p != '\0') { 
      *p = ' ';
      p++;
   }
   if (*p == '\0') MUTANCY(7);    /* valgrind.so has disappeared?! */
   *p = ' ';                        /* blank ending ':' */

   /* LD_LIBRARY_PATH: coredir --> blank */
   for (i = 0; i < coredir_len; i++)
      pth_path[i] = ' ';
      
   /* VG_(printf)("post:\n%s\n%s\n", ld_preload_str, ld_library_path_str); */

   return;


mutancy:
   VG_(printf)(
      "\nVG_(mash_LD_PRELOAD_and_LD_LIBRARY_PATH): internal error:\n"
      "   what                = %d\n"
      "   ld_preload_str      = `%s'\n"
      "   ld_library_path_str = `%s'\n"
      "   vg_prel             = `%s'\n"
      "   sk_prel             = `%s'\n"
      "   pth_path            = `%s'\n"
      "   VG_LIBDIR           = `%s'\n",
      what, ld_preload_str, ld_library_path_str, 
      vg_prel, sk_prel, pth_path, VG_LIBDIR 
   );
   VG_(printf)(
      "\n"
      "Note that this is often caused by mis-installation of valgrind.\n"
      "Correct installation procedure is:\n"
      "   ./configure --prefix=/install/dir\n"
      "   make install\n"
      "And then use /install/dir/bin/valgrind\n"
      "Moving the installation directory elsewhere after 'make install'\n"
      "will cause the above error.  Hand-editing the paths in the shell\n"
      "scripts is also likely to cause problems.\n"
      "\n"
   );
   VG_(core_panic)("VG_(mash_LD_PRELOAD_and_LD_LIBRARY_PATH) failed\n");
}


/* RUNS ON THE CLIENT'S STACK, but on the real CPU.  Start GDB and get
   it to attach to this process.  Called if the user requests this
   service after an error has been shown, so she can poke around and
   look at parameters, memory, etc.  You can't meaningfully get GDB to
   continue the program, though; to continue, quit GDB.  */
extern void VG_(start_GDB_whilst_on_client_stack) ( void )
{
   Int   res;
   UChar buf[100];

#define TO_STRING(x)    TO_STRING2(x)
#define TO_STRING2(x)   #x
   
   VG_(sprintf)(buf, "%s -nw /proc/%d/exe %d",
                TO_STRING(GDB_PATH), VG_(getpid)(), VG_(getpid)());
   VG_(message)(Vg_UserMsg, "starting GDB with cmd: %s", buf);
   res = VG_(system)(buf);
   if (res == 0) {      
      VG_(message)(Vg_UserMsg, "");
      VG_(message)(Vg_UserMsg, 
         "GDB has detached.  Valgrind regains control.  We continue.");
   } else {
      VG_(message)(Vg_UserMsg, "Apparently failed!");
      VG_(message)(Vg_UserMsg, "");
   }
#undef TO_STRING
#undef TO_STRING2
}


/* Print some helpful-ish text about unimplemented things, and give
   up. */
void VG_(unimplemented) ( Char* msg )
{
   VG_(message)(Vg_UserMsg, "");
   VG_(message)(Vg_UserMsg, 
      "Valgrind detected that your program requires");
   VG_(message)(Vg_UserMsg, 
      "the following unimplemented functionality:");
   VG_(message)(Vg_UserMsg, "   %s", msg);
   VG_(message)(Vg_UserMsg,
      "This may be because the functionality is hard to implement,");
   VG_(message)(Vg_UserMsg,
      "or because no reasonable program would behave this way,");
   VG_(message)(Vg_UserMsg,
      "or because nobody has yet needed it.  In any case, let me know");
   VG_(message)(Vg_UserMsg,
      "(jseward@acm.org) and/or try to work around the problem, if you can.");
   VG_(message)(Vg_UserMsg,
      "");
   VG_(message)(Vg_UserMsg,
      "Valgrind has to exit now.  Sorry.  Bye!");
   VG_(message)(Vg_UserMsg,
      "");
   VG_(pp_sched_status)();
   VG_(exit)(1);
}


/* ---------------------------------------------------------------------
   Sanity check machinery (permanently engaged).
   ------------------------------------------------------------------ */

/* A fast sanity check -- suitable for calling circa once per
   millisecond. */

void VG_(do_sanity_checks) ( Bool force_expensive )
{
   Int          i;

   VGP_PUSHCC(VgpCoreCheapSanity);

   if (VG_(sanity_level) < 1) return;

   /* --- First do all the tests that we can do quickly. ---*/

   VG_(sanity_fast_count)++;

   /* Check that we haven't overrun our private stack. */
   for (i = 0; i < 10; i++) {
      vg_assert(VG_(stack)[i]
                == ((UInt)(&VG_(stack)[i]) ^ 0xA4B3C2D1));
      vg_assert(VG_(stack)[VG_STACK_SIZE_W-1-i] 
                == ((UInt)(&VG_(stack)[VG_STACK_SIZE_W-i-1]) ^ 0xABCD4321));
   }

   /* Check stuff pertaining to the memory check system. */

   /* Check that nobody has spuriously claimed that the first or
      last 16 pages of memory have become accessible [...] */
   if (VG_(needs).sanity_checks) {
      VGP_PUSHCC(VgpSkinCheapSanity);
      vg_assert(SK_(cheap_sanity_check)());
      VGP_POPCC(VgpSkinCheapSanity);
   }

   /* --- Now some more expensive checks. ---*/

   /* Once every 25 times, check some more expensive stuff. */
   if ( force_expensive
     || VG_(sanity_level) > 1
     || (VG_(sanity_level) == 1 && (VG_(sanity_fast_count) % 25) == 0)) {

      VGP_PUSHCC(VgpCoreExpensiveSanity);
      VG_(sanity_slow_count)++;

#     if 0
      { void zzzmemscan(void); zzzmemscan(); }
#     endif

      if ((VG_(sanity_fast_count) % 250) == 0)
         VG_(sanity_check_tc_tt)();

      if (VG_(needs).sanity_checks) {
          VGP_PUSHCC(VgpSkinExpensiveSanity);
          vg_assert(SK_(expensive_sanity_check)());
          VGP_POPCC(VgpSkinExpensiveSanity);
      }
      /* 
      if ((VG_(sanity_fast_count) % 500) == 0) VG_(mallocSanityCheckAll)(); 
      */
      VGP_POPCC(VgpCoreExpensiveSanity);
   }

   if (VG_(sanity_level) > 1) {
      VGP_PUSHCC(VgpCoreExpensiveSanity);
      /* Check sanity of the low-level memory manager.  Note that bugs
         in the client's code can cause this to fail, so we don't do
         this check unless specially asked for.  And because it's
         potentially very expensive. */
      VG_(mallocSanityCheckAll)();
      VGP_POPCC(VgpCoreExpensiveSanity);
   }
   VGP_POPCC(VgpCoreCheapSanity);
}
/*--------------------------------------------------------------------*/
/*--- end                                                vg_main.c ---*/
/*--------------------------------------------------------------------*/