priv/main/vex_main.c

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

#include "libvex.h"

#include "vex_globals.h"
#include "vex_util.h"
#include "host_regs.h"
#include "x86host_defs.h"
#include "x86guest_defs.h"


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

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

/* 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,
   /* verbosity level */
   Int verbosity,
   /* Are we supporting valgrind checking? */
   Bool valgrind_support,
   /* Max # guest insns per bb */
   Int guest_insns_per_bb
)
{
   vassert(!vex_initdone);
   vassert(failure_exit);
   vassert(log_bytes);
   vassert(debuglevel >= 0);
   vassert(verbosity >= 0);
   vassert(guest_insns_per_bb >= 1 && guest_insns_per_bb <= 100);

   vex_failure_exit       = failure_exit;
   vex_log_bytes          = log_bytes;
   vex_debuglevel         = debuglevel;
   vex_verbosity          = verbosity;
   vex_valgrind_support   = valgrind_support;
   vex_guest_insns_per_bb = guest_insns_per_bb;
   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 )
)
{
   /* 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* );
   IRBB*        (*bbToIR)      ( UChar*, Addr64, Int*, 
                                         Bool(*)(Addr64), Bool );
   Int          (*emit)        ( UChar*, Int, HInstr* );

   Bool         host_is_bigendian = False;
   IRBB*        irbb;
   HInstrArray* vcode;
   HInstrArray* rcode;
   Int          i, j, k, out_used;

   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:
         bbToIR = bbToIR_X86Instr;
         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);
      return TransAccessFail;
   }
   sanityCheckIRBB(irbb, Ity_I32);

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

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

   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,
				  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 */
   UChar insn_bytes[32];
   out_used = 0; /* tracks along the host_bytes array */
   for (i = 0; i < rcode->arr_used; i++) {
      if (vex_verbosity > 0) {
         ppInstr(rcode->arr[i]);
         vex_printf("\n");
      }
      j = (*emit)( insn_bytes, 32, rcode->arr[i] );
      if (vex_verbosity > 0) {
         for (k = 0; k < j; k++)
            vex_printf("0x%-2x ", (UInt)insn_bytes[k]);
         vex_printf("\n\n");
      }
      if (out_used + j > host_bytes_size) {
         LibVEX_ClearTemporary(False);
         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);

   return TransOK;
}



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