priv/main/vex_main.c

/*---------------------------------------------------------------*/
/*---                                                         ---*/
/*--- This file (main/vex_main.c) is                          ---*/
/*--- Copyright (c) 2004 OpenWorks LLP.  All rights reserved. ---*/
/*---                                                         ---*/
/*---------------------------------------------------------------*/

#include "libvex.h"
#include "libvex_guest_x86.h"

#include "main/vex_globals.h"
#include "main/vex_util.h"
#include "host-generic/h_generic_regs.h"
#include "host-x86/hdefs.h"
#include "guest-x86/gdefs.h"
#include "ir/iropt.h"


/* This file contains the top level interface to the library. */

/* --------- Initialise the library. --------- */

/* Exported to library client. */

void LibVEX_default_VexControl ( /*OUT*/ VexControl* vcon )
{
   vcon->iropt_verbosity            = 0;
   vcon->iropt_level                = 2;
   vcon->iropt_precise_memory_exns  = False;
   vcon->iropt_unroll_thresh        = 120;
   vcon->guest_max_insns            = 50;
   vcon->guest_chase_thresh         = 10;
}


/* Exported to library client. */

void LibVEX_Init (
   /* failure exit function */
   __attribute__ ((noreturn))
   void (*failure_exit) ( void ),
   /* logging output function */
   void (*log_bytes) ( Char*, Int nbytes ),
   /* debug paranoia level */
   Int debuglevel,
   /* initial verbosity level */
   Int verbosity,
   /* Are we supporting valgrind checking? */
   Bool valgrind_support,
   /* Control ... */
   /*READONLY*/VexControl* vcon
)
{
   /* First off, do enough minimal setup so that the following
      assertions can fail in a sane fashion, if need be. */
   vex_failure_exit = failure_exit;
   vex_log_bytes    = log_bytes;

   /* Now it's safe to check parameters for sanity. */
   vassert(!vex_initdone);
   vassert(failure_exit);
   vassert(log_bytes);
   vassert(debuglevel >= 0);
   vassert(verbosity >= 0);

   vassert(vcon->iropt_verbosity >= 0);
   vassert(vcon->iropt_level >= 0);
   vassert(vcon->iropt_level <= 2);
   vassert(vcon->iropt_unroll_thresh >= 0);
   vassert(vcon->iropt_unroll_thresh <= 400);
   vassert(vcon->guest_max_insns >= 1);
   vassert(vcon->guest_max_insns <= 100);
   vassert(vcon->guest_chase_thresh >= 0);
   vassert(vcon->guest_chase_thresh < vcon->guest_max_insns);

   /* All the guest state structs must have an 8-aligned size. */
   vassert(0 == sizeof(VexGuestX86State) % 8);

   /* Check that Vex has been built with sizes of basic types as
      stated in priv/libvex_basictypes.h.  Failure of any of these is
      a serious configuration error and should be corrected
      immediately.  If any of these assertions fail you can fully
      expect Vex not to work properly, if at all. */

   vassert(1 == sizeof(UChar));
   vassert(1 == sizeof(Char));
   vassert(2 == sizeof(UShort));
   vassert(2 == sizeof(Short));
   vassert(4 == sizeof(UInt));
   vassert(4 == sizeof(Int));
   vassert(8 == sizeof(ULong));
   vassert(8 == sizeof(Long));
   vassert(4 == sizeof(Float));
   vassert(8 == sizeof(Double));
   vassert(1 == sizeof(Bool));
   vassert(4 == sizeof(Addr32));
   vassert(8 == sizeof(Addr64));

   vassert(sizeof(void*) == 4 || sizeof(void*) == 8);
   vassert(sizeof(void*) == sizeof(int*));
   vassert(sizeof(void*) == sizeof(HWord));

   /* Really start up .. */
   vex_debuglevel         = debuglevel;
   vex_verbosity          = verbosity;
   vex_valgrind_support   = valgrind_support;
   vex_control            = *vcon;
   vex_initdone           = True;
   LibVEX_SetAllocMode ( AllocModeTEMPORARY );
}


/* --------- Make a translation. --------- */

/* Exported to library client. */

TranslateResult LibVEX_Translate (
   /* The instruction sets we are translating from and to. */
   InsnSet iset_guest,
   InsnSet iset_host,
   /* IN: the block to translate, and its guest address. */
   UChar* guest_bytes,
   Addr64 guest_bytes_addr,
   /* OUT: the number of bytes actually read */
   Int* guest_bytes_read,
   /* IN: a place to put the resulting code, and its size */
   UChar* host_bytes,
   Int    host_bytes_size,
   /* OUT: how much of the output area is used. */
   Int* host_bytes_used,
   /* IN: optionally, an instrumentation function. */
   IRBB* (*instrument) ( IRBB* ),
   /* IN: optionally, an access check function for guest code. */
   Bool (*byte_accessible) ( Addr64 ),
   /* IN: if > 0, use this verbosity for this bb */
   Int  bb_verbosity
)
{
   /* This the bundle of functions we need to do the back-end stuff
      (insn selection, reg-alloc, assembly) whilst being insulated
      from the target instruction set. */
   HReg* available_real_regs;
   Int   n_available_real_regs;
   Bool         (*isMove)      (HInstr*, HReg*, HReg*);
   void         (*getRegUsage) (HRegUsage*, HInstr*);
   void         (*mapRegs)     (HRegRemap*, HInstr*);
   HInstr*      (*genSpill)    ( HReg, Int );
   HInstr*      (*genReload)   ( HReg, Int );
   void         (*ppInstr)     ( HInstr* );
   void         (*ppReg)       ( HReg );
   HInstrArray* (*iselBB)      ( IRBB*, Addr64(*)(Char*) );
   IRBB*        (*bbToIR)      ( UChar*, Addr64, Int*, 
                                         Bool(*)(Addr64), Bool );
   Int          (*emit)        ( UChar*, Int, HInstr* );
   Addr64       (*findHelper)  ( Char* );
   IRExpr*      (*specHelper)  ( Char*, IRExpr** );
   Bool         (*preciseMemExnsFn) ( Int, Int );

   Bool         host_is_bigendian = False;
   IRBB*        irbb;
   HInstrArray* vcode;
   HInstrArray* rcode;
   Int          i, j, k, out_used, saved_verbosity, guest_sizeB;
   UChar        insn_bytes[32];

   available_real_regs    = NULL;
   n_available_real_regs  = 0;
   isMove                 = NULL;
   getRegUsage            = NULL;
   mapRegs                = NULL;
   genSpill               = NULL;
   genReload              = NULL;
   ppInstr                = NULL;
   ppReg                  = NULL;
   iselBB                 = NULL;
   bbToIR                 = NULL;
   emit                   = NULL;
   findHelper             = NULL;
   specHelper             = NULL;
   preciseMemExnsFn       = NULL;

   saved_verbosity = vex_verbosity;
   if (bb_verbosity > 0)
      vex_verbosity = bb_verbosity;

   vassert(vex_initdone);
   LibVEX_ClearTemporary(False);

   /* First off, check that the guest and host insn sets
      are supported. */
   switch (iset_host) {
      case InsnSetX86:
         getAllocableRegs_X86 ( &n_available_real_regs,
                                &available_real_regs );
         isMove      = (Bool(*)(HInstr*,HReg*,HReg*)) isMove_X86Instr;
         getRegUsage = (void(*)(HRegUsage*,HInstr*)) getRegUsage_X86Instr;
         mapRegs     = (void(*)(HRegRemap*,HInstr*)) mapRegs_X86Instr;
         genSpill    = (HInstr*(*)(HReg,Int)) genSpill_X86;
         genReload   = (HInstr*(*)(HReg,Int)) genReload_X86;
         ppInstr     = (void(*)(HInstr*)) ppX86Instr;
         ppReg       = (void(*)(HReg)) ppHRegX86;
         iselBB      = iselBB_X86;
         emit        = (Int(*)(UChar*,Int,HInstr*)) emit_X86Instr;
	 host_is_bigendian = False;
         break;
      default:
         vpanic("LibVEX_Translate: unsupported target insn set");
   }

   switch (iset_guest) {
      case InsnSetX86:
         preciseMemExnsFn = guest_x86_state_requires_precise_mem_exns;
         bbToIR           = bbToIR_X86Instr;
         findHelper       = x86guest_findhelper;
         specHelper       = x86guest_spechelper;
         guest_sizeB      = sizeof(VexGuestX86State);
         break;
      default:
         vpanic("LibVEX_Translate: unsupported guest insn set");
   }

   irbb = bbToIR ( guest_bytes, 
		   guest_bytes_addr,
		   guest_bytes_read,
		   byte_accessible,
		   host_is_bigendian );

   if (irbb == NULL) {
      /* Access failure. */
      LibVEX_ClearTemporary(False);
      vex_verbosity = saved_verbosity;
      return TransAccessFail;
   }

   /* If debugging, show the raw guest bytes for this bb. */
   if (vex_verbosity >= 2) {
      UChar* p = guest_bytes;
      vex_printf("\n");
      vex_printf(". 0 %llx %d\n.", guest_bytes_addr, *guest_bytes_read );
      for (i = 0; i < *guest_bytes_read; i++)
         vex_printf(" %02x", (Int)p[i] );
      vex_printf("\n");
   }

   /* Sanity check the initial IR. */
   sanityCheckIRBB(irbb, Ity_I32);

   /* Clean it up, hopefully a lot. */
   irbb = do_iropt_BB ( irbb, specHelper, preciseMemExnsFn, 
                              guest_bytes_addr );
   sanityCheckIRBB(irbb, Ity_I32);

   if (vex_verbosity > 0) {
      vex_printf("\n-------- After IR optimisation --------\n");
      ppIRBB ( irbb );
      vex_printf("\n");
   }

   /* Get the thing instrumented. */
   if (instrument)
      irbb = (*instrument)(irbb);

   /* Turn it into virtual-registerised code. */
   vcode = iselBB ( irbb, findHelper );

   if (vex_verbosity > 0) {
      vex_printf("\n-------- Virtual registerised code --------\n");
      for (i = 0; i < vcode->arr_used; i++) {
         vex_printf("%3d   ", i);
         ppInstr(vcode->arr[i]);
         vex_printf("\n");
      }
      vex_printf("\n");
   }

   /* Register allocate. */
   rcode = doRegisterAllocation ( vcode, available_real_regs,
                  	       	  n_available_real_regs,
			          isMove, getRegUsage, mapRegs, 
			          genSpill, genReload, guest_sizeB,
				  ppInstr, ppReg );

   if (vex_verbosity > 0) {
      vex_printf("\n-------- Post-regalloc code --------\n");
      for (i = 0; i < rcode->arr_used; i++) {
         vex_printf("%3d   ", i);
         ppInstr(rcode->arr[i]);
         vex_printf("\n");
      }
      vex_printf("\n");
   }

   /* Assemble */
   out_used = 0; /* tracks along the host_bytes array */
   for (i = 0; i < rcode->arr_used; i++) {
      if (vex_verbosity > 1) {
         ppInstr(rcode->arr[i]);
         vex_printf("\n");
      }
      j = (*emit)( insn_bytes, 32, rcode->arr[i] );
      if (vex_verbosity > 1) {
         for (k = 0; k < j; k++)
	    if (insn_bytes[k] < 16)
               vex_printf("0%x ",  (UInt)insn_bytes[k]);
            else
               vex_printf("%x ", (UInt)insn_bytes[k]);
         vex_printf("\n\n");
      }
      if (out_used + j > host_bytes_size) {
         LibVEX_ClearTemporary(False);
         vex_verbosity = saved_verbosity;
         return TransOutputFull;
      }
      for (k = 0; k < j; k++) {
         host_bytes[out_used] = insn_bytes[k];
         out_used++;
      }
      vassert(out_used <= host_bytes_size);
   }
   *host_bytes_used = out_used;

   //   LibVEX_ClearTemporary(True);
   LibVEX_ClearTemporary(False);

   vex_verbosity = saved_verbosity;
   return TransOK;
}



/*---------------------------------------------------------------*/
/*--- end                                     main/vex_main.c ---*/
/*---------------------------------------------------------------*/