lua/ldump.c

/*
** $Id: ldump.c,v 2.39 2017/06/27 14:21:12 roberto Exp roberto $
** save precompiled Lua chunks
** See Copyright Notice in lua.h
*/

#define ldump_c
#define LUA_CORE

#include "lprefix.h"


#include <stddef.h>

#include "lua.h"

#include "lobject.h"
#include "lstate.h"
#include "lundump.h"


typedef struct {
  lua_State *L;
  lua_Writer writer;
  void *data;
  int strip;
  int status;
} DumpState;


/*
** All high-level dumps go through DumpVector; you can change it to
** change the endianness of the result
*/
#define DumpVector(v,n,D)	DumpBlock(v,(n)*sizeof((v)[0]),D)

#define DumpLiteral(s,D)	DumpBlock(s, sizeof(s) - sizeof(char), D)


static void DumpBlock (const void *b, size_t size, DumpState *D) {
  if (D->status == 0 && size > 0) {
    lua_unlock(D->L);
    D->status = (*D->writer)(D->L, b, size, D->data);
    lua_lock(D->L);
  }
}


#define DumpVar(x,D)		DumpVector(&x,1,D)


static void DumpByte (int y, DumpState *D) {
  lu_byte x = (lu_byte)y;
  DumpVar(x, D);
}


/* DumpInt Buff Size */
#define DIBS    ((sizeof(size_t) * 8 / 7) + 1)

static void DumpSize (size_t x, DumpState *D) {
  lu_byte buff[DIBS];
  int n = 0;
  do {
    buff[DIBS - (++n)] = x & 0x7f;  /* fill buffer in reverse order */
    x >>= 7;
  } while (x != 0);
  buff[DIBS - 1] |= 0x80;  /* mark last byte */
  DumpVector(buff + DIBS - n, n, D);
}


static void DumpInt (int x, DumpState *D) {
  DumpSize(x, D);
}


static void DumpNumber (lua_Number x, DumpState *D) {
  DumpVar(x, D);
}


static void DumpInteger (lua_Integer x, DumpState *D) {
  DumpVar(x, D);
}


static void DumpString (const TString *s, DumpState *D) {
  if (s == NULL)
    DumpSize(0, D);
  else {
    size_t size = tsslen(s);
    const char *str = getstr(s);
    DumpSize(size + 1, D);
    DumpVector(str, size, D);
  }
}


static void DumpCode (const Proto *f, DumpState *D) {
  DumpInt(f->sizecode, D);
  DumpVector(f->code, f->sizecode, D);
}


static void DumpFunction(const Proto *f, TString *psource, DumpState *D);

static void DumpConstants (const Proto *f, DumpState *D) {
  int i;
  int n = f->sizek;
  DumpInt(n, D);
  for (i = 0; i < n; i++) {
    const TValue *o = &f->k[i];
    DumpByte(ttype(o), D);
    switch (ttype(o)) {
      case LUA_TNIL:
        break;
      case LUA_TBOOLEAN:
        DumpByte(bvalue(o), D);
        break;
      case LUA_TNUMFLT:
        DumpNumber(fltvalue(o), D);
        break;
      case LUA_TNUMINT:
        DumpInteger(ivalue(o), D);
        break;
      case LUA_TSHRSTR:
      case LUA_TLNGSTR:
        DumpString(tsvalue(o), D);
        break;
      default: lua_assert(0);
    }
  }
}


static void DumpProtos (const Proto *f, DumpState *D) {
  int i;
  int n = f->sizep;
  DumpInt(n, D);
  for (i = 0; i < n; i++)
    DumpFunction(f->p[i], f->source, D);
}


static void DumpUpvalues (const Proto *f, DumpState *D) {
  int i, n = f->sizeupvalues;
  DumpInt(n, D);
  for (i = 0; i < n; i++) {
    DumpByte(f->upvalues[i].instack, D);
    DumpByte(f->upvalues[i].idx, D);
  }
}


static void DumpDebug (const Proto *f, DumpState *D) {
  int i, n;
  n = (D->strip) ? 0 : f->sizelineinfo;
  DumpInt(n, D);
  DumpVector(f->lineinfo, n, D);
  n = (D->strip) ? 0 : f->sizeabslineinfo;
  DumpInt(n, D);
  for (i = 0; i < n; i++) {
    DumpInt(f->abslineinfo[i].pc, D);
    DumpInt(f->abslineinfo[i].line, D);
  }
  n = (D->strip) ? 0 : f->sizelocvars;
  DumpInt(n, D);
  for (i = 0; i < n; i++) {
    DumpString(f->locvars[i].varname, D);
    DumpInt(f->locvars[i].startpc, D);
    DumpInt(f->locvars[i].endpc, D);
  }
  n = (D->strip) ? 0 : f->sizeupvalues;
  DumpInt(n, D);
  for (i = 0; i < n; i++)
    DumpString(f->upvalues[i].name, D);
}


static void DumpFunction (const Proto *f, TString *psource, DumpState *D) {
  if (D->strip || f->source == psource)
    DumpString(NULL, D);  /* no debug info or same source as its parent */
  else
    DumpString(f->source, D);
  DumpInt(f->linedefined, D);
  DumpInt(f->lastlinedefined, D);
  DumpByte(f->numparams, D);
  DumpByte(f->is_vararg, D);
  DumpByte(f->maxstacksize, D);
  DumpCode(f, D);
  DumpConstants(f, D);
  DumpUpvalues(f, D);
  DumpProtos(f, D);
  DumpDebug(f, D);
}


static void DumpHeader (DumpState *D) {
  DumpLiteral(LUA_SIGNATURE, D);
  DumpByte(LUAC_VERSION, D);
  DumpByte(LUAC_FORMAT, D);
  DumpLiteral(LUAC_DATA, D);
  DumpByte(sizeof(int), D);
  DumpByte(sizeof(size_t), D);
  DumpByte(sizeof(Instruction), D);
  DumpByte(sizeof(lua_Integer), D);
  DumpByte(sizeof(lua_Number), D);
  DumpInteger(LUAC_INT, D);
  DumpNumber(LUAC_NUM, D);
}


/*
** dump Lua function as precompiled chunk
*/
int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data,
              int strip) {
  DumpState D;
  D.L = L;
  D.writer = w;
  D.data = data;
  D.strip = strip;
  D.status = 0;
  DumpHeader(&D);
  DumpByte(f->sizeupvalues, &D);
  DumpFunction(f, NULL, &D);
  return D.status;
}