summaryrefslogtreecommitdiff
path: root/Build/source/libs/luajit/LuaJIT-src/src/lj_bcwrite.c
blob: b2c097383870f8214280475140beb68640e682d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
/*
** Bytecode writer.
** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
*/

#define lj_bcwrite_c
#define LUA_CORE

#include "lj_obj.h"
#include "lj_gc.h"
#include "lj_buf.h"
#include "lj_bc.h"
#if LJ_HASFFI
#include "lj_ctype.h"
#endif
#if LJ_HASJIT
#include "lj_dispatch.h"
#include "lj_jit.h"
#endif
#include "lj_strfmt.h"
#include "lj_bcdump.h"
#include "lj_vm.h"

/* Context for bytecode writer. */
typedef struct BCWriteCtx {
  SBuf sb;			/* Output buffer. */
  GCproto *pt;			/* Root prototype. */
  lua_Writer wfunc;		/* Writer callback. */
  void *wdata;			/* Writer callback data. */
  int strip;			/* Strip debug info. */
  int status;			/* Status from writer callback. */
} BCWriteCtx;

/* -- Bytecode writer ----------------------------------------------------- */

/* Write a single constant key/value of a template table. */
static void bcwrite_ktabk(BCWriteCtx *ctx, cTValue *o, int narrow)
{
  char *p = lj_buf_more(&ctx->sb, 1+10);
  if (tvisstr(o)) {
    const GCstr *str = strV(o);
    MSize len = str->len;
    p = lj_buf_more(&ctx->sb, 5+len);
    p = lj_strfmt_wuleb128(p, BCDUMP_KTAB_STR+len);
    p = lj_buf_wmem(p, strdata(str), len);
  } else if (tvisint(o)) {
    *p++ = BCDUMP_KTAB_INT;
    p = lj_strfmt_wuleb128(p, intV(o));
  } else if (tvisnum(o)) {
    if (!LJ_DUALNUM && narrow) {  /* Narrow number constants to integers. */
      lua_Number num = numV(o);
      int32_t k = lj_num2int(num);
      if (num == (lua_Number)k) {  /* -0 is never a constant. */
	*p++ = BCDUMP_KTAB_INT;
	p = lj_strfmt_wuleb128(p, k);
	setsbufP(&ctx->sb, p);
	return;
      }
    }
    *p++ = BCDUMP_KTAB_NUM;
    p = lj_strfmt_wuleb128(p, o->u32.lo);
    p = lj_strfmt_wuleb128(p, o->u32.hi);
  } else {
    lua_assert(tvispri(o));
    *p++ = BCDUMP_KTAB_NIL+~itype(o);
  }
  setsbufP(&ctx->sb, p);
}

/* Write a template table. */
static void bcwrite_ktab(BCWriteCtx *ctx, char *p, const GCtab *t)
{
  MSize narray = 0, nhash = 0;
  if (t->asize > 0) {  /* Determine max. length of array part. */
    ptrdiff_t i;
    TValue *array = tvref(t->array);
    for (i = (ptrdiff_t)t->asize-1; i >= 0; i--)
      if (!tvisnil(&array[i]))
	break;
    narray = (MSize)(i+1);
  }
  if (t->hmask > 0) {  /* Count number of used hash slots. */
    MSize i, hmask = t->hmask;
    Node *node = noderef(t->node);
    for (i = 0; i <= hmask; i++)
      nhash += !tvisnil(&node[i].val);
  }
  /* Write number of array slots and hash slots. */
  p = lj_strfmt_wuleb128(p, narray);
  p = lj_strfmt_wuleb128(p, nhash);
  setsbufP(&ctx->sb, p);
  if (narray) {  /* Write array entries (may contain nil). */
    MSize i;
    TValue *o = tvref(t->array);
    for (i = 0; i < narray; i++, o++)
      bcwrite_ktabk(ctx, o, 1);
  }
  if (nhash) {  /* Write hash entries. */
    MSize i = nhash;
    Node *node = noderef(t->node) + t->hmask;
    for (;; node--)
      if (!tvisnil(&node->val)) {
	bcwrite_ktabk(ctx, &node->key, 0);
	bcwrite_ktabk(ctx, &node->val, 1);
	if (--i == 0) break;
      }
  }
}

/* Write GC constants of a prototype. */
static void bcwrite_kgc(BCWriteCtx *ctx, GCproto *pt)
{
  MSize i, sizekgc = pt->sizekgc;
  GCRef *kr = mref(pt->k, GCRef) - (ptrdiff_t)sizekgc;
  for (i = 0; i < sizekgc; i++, kr++) {
    GCobj *o = gcref(*kr);
    MSize tp, need = 1;
    char *p;
    /* Determine constant type and needed size. */
    if (o->gch.gct == ~LJ_TSTR) {
      tp = BCDUMP_KGC_STR + gco2str(o)->len;
      need = 5+gco2str(o)->len;
    } else if (o->gch.gct == ~LJ_TPROTO) {
      lua_assert((pt->flags & PROTO_CHILD));
      tp = BCDUMP_KGC_CHILD;
#if LJ_HASFFI
    } else if (o->gch.gct == ~LJ_TCDATA) {
      CTypeID id = gco2cd(o)->ctypeid;
      need = 1+4*5;
      if (id == CTID_INT64) {
	tp = BCDUMP_KGC_I64;
      } else if (id == CTID_UINT64) {
	tp = BCDUMP_KGC_U64;
      } else {
	lua_assert(id == CTID_COMPLEX_DOUBLE);
	tp = BCDUMP_KGC_COMPLEX;
      }
#endif
    } else {
      lua_assert(o->gch.gct == ~LJ_TTAB);
      tp = BCDUMP_KGC_TAB;
      need = 1+2*5;
    }
    /* Write constant type. */
    p = lj_buf_more(&ctx->sb, need);
    p = lj_strfmt_wuleb128(p, tp);
    /* Write constant data (if any). */
    if (tp >= BCDUMP_KGC_STR) {
      p = lj_buf_wmem(p, strdata(gco2str(o)), gco2str(o)->len);
    } else if (tp == BCDUMP_KGC_TAB) {
      bcwrite_ktab(ctx, p, gco2tab(o));
      continue;
#if LJ_HASFFI
    } else if (tp != BCDUMP_KGC_CHILD) {
      cTValue *q = (TValue *)cdataptr(gco2cd(o));
      p = lj_strfmt_wuleb128(p, q[0].u32.lo);
      p = lj_strfmt_wuleb128(p, q[0].u32.hi);
      if (tp == BCDUMP_KGC_COMPLEX) {
	p = lj_strfmt_wuleb128(p, q[1].u32.lo);
	p = lj_strfmt_wuleb128(p, q[1].u32.hi);
      }
#endif
    }
    setsbufP(&ctx->sb, p);
  }
}

/* Write number constants of a prototype. */
static void bcwrite_knum(BCWriteCtx *ctx, GCproto *pt)
{
  MSize i, sizekn = pt->sizekn;
  cTValue *o = mref(pt->k, TValue);
  char *p = lj_buf_more(&ctx->sb, 10*sizekn);
  for (i = 0; i < sizekn; i++, o++) {
    int32_t k;
    if (tvisint(o)) {
      k = intV(o);
      goto save_int;
    } else {
      /* Write a 33 bit ULEB128 for the int (lsb=0) or loword (lsb=1). */
      if (!LJ_DUALNUM) {  /* Narrow number constants to integers. */
	lua_Number num = numV(o);
	k = lj_num2int(num);
	if (num == (lua_Number)k) {  /* -0 is never a constant. */
	save_int:
	  p = lj_strfmt_wuleb128(p, 2*(uint32_t)k | ((uint32_t)k&0x80000000u));
	  if (k < 0)
	    p[-1] = (p[-1] & 7) | ((k>>27) & 0x18);
	  continue;
	}
      }
      p = lj_strfmt_wuleb128(p, 1+(2*o->u32.lo | (o->u32.lo & 0x80000000u)));
      if (o->u32.lo >= 0x80000000u)
	p[-1] = (p[-1] & 7) | ((o->u32.lo>>27) & 0x18);
      p = lj_strfmt_wuleb128(p, o->u32.hi);
    }
  }
  setsbufP(&ctx->sb, p);
}

/* Write bytecode instructions. */
static char *bcwrite_bytecode(BCWriteCtx *ctx, char *p, GCproto *pt)
{
  MSize nbc = pt->sizebc-1;  /* Omit the [JI]FUNC* header. */
#if LJ_HASJIT
  uint8_t *q = (uint8_t *)p;
#endif
  p = lj_buf_wmem(p, proto_bc(pt)+1, nbc*(MSize)sizeof(BCIns));
  UNUSED(ctx);
#if LJ_HASJIT
  /* Unpatch modified bytecode containing ILOOP/JLOOP etc. */
  if ((pt->flags & PROTO_ILOOP) || pt->trace) {
    jit_State *J = L2J(sbufL(&ctx->sb));
    MSize i;
    for (i = 0; i < nbc; i++, q += sizeof(BCIns)) {
      BCOp op = (BCOp)q[LJ_ENDIAN_SELECT(0, 3)];
      if (op == BC_IFORL || op == BC_IITERL || op == BC_ILOOP ||
	  op == BC_JFORI) {
	q[LJ_ENDIAN_SELECT(0, 3)] = (uint8_t)(op-BC_IFORL+BC_FORL);
      } else if (op == BC_JFORL || op == BC_JITERL || op == BC_JLOOP) {
	BCReg rd = q[LJ_ENDIAN_SELECT(2, 1)] + (q[LJ_ENDIAN_SELECT(3, 0)] << 8);
	BCIns ins = traceref(J, rd)->startins;
	q[LJ_ENDIAN_SELECT(0, 3)] = (uint8_t)(op-BC_JFORL+BC_FORL);
	q[LJ_ENDIAN_SELECT(2, 1)] = bc_c(ins);
	q[LJ_ENDIAN_SELECT(3, 0)] = bc_b(ins);
      }
    }
  }
#endif
  return p;
}

/* Write prototype. */
static void bcwrite_proto(BCWriteCtx *ctx, GCproto *pt)
{
  MSize sizedbg = 0;
  char *p;

  /* Recursively write children of prototype. */
  if ((pt->flags & PROTO_CHILD)) {
    ptrdiff_t i, n = pt->sizekgc;
    GCRef *kr = mref(pt->k, GCRef) - 1;
    for (i = 0; i < n; i++, kr--) {
      GCobj *o = gcref(*kr);
      if (o->gch.gct == ~LJ_TPROTO)
	bcwrite_proto(ctx, gco2pt(o));
    }
  }

  /* Start writing the prototype info to a buffer. */
  p = lj_buf_need(&ctx->sb,
		  5+4+6*5+(pt->sizebc-1)*(MSize)sizeof(BCIns)+pt->sizeuv*2);
  p += 5;  /* Leave room for final size. */

  /* Write prototype header. */
  *p++ = (pt->flags & (PROTO_CHILD|PROTO_VARARG|PROTO_FFI));
  *p++ = pt->numparams;
  *p++ = pt->framesize;
  *p++ = pt->sizeuv;
  p = lj_strfmt_wuleb128(p, pt->sizekgc);
  p = lj_strfmt_wuleb128(p, pt->sizekn);
  p = lj_strfmt_wuleb128(p, pt->sizebc-1);
  if (!ctx->strip) {
    if (proto_lineinfo(pt))
      sizedbg = pt->sizept - (MSize)((char *)proto_lineinfo(pt) - (char *)pt);
    p = lj_strfmt_wuleb128(p, sizedbg);
    if (sizedbg) {
      p = lj_strfmt_wuleb128(p, pt->firstline);
      p = lj_strfmt_wuleb128(p, pt->numline);
    }
  }

  /* Write bytecode instructions and upvalue refs. */
  p = bcwrite_bytecode(ctx, p, pt);
  p = lj_buf_wmem(p, proto_uv(pt), pt->sizeuv*2);
  setsbufP(&ctx->sb, p);

  /* Write constants. */
  bcwrite_kgc(ctx, pt);
  bcwrite_knum(ctx, pt);

  /* Write debug info, if not stripped. */
  if (sizedbg) {
    p = lj_buf_more(&ctx->sb, sizedbg);
    p = lj_buf_wmem(p, proto_lineinfo(pt), sizedbg);
    setsbufP(&ctx->sb, p);
  }

  /* Pass buffer to writer function. */
  if (ctx->status == 0) {
    MSize n = sbuflen(&ctx->sb) - 5;
    MSize nn = (lj_fls(n)+8)*9 >> 6;
    char *q = sbufB(&ctx->sb) + (5 - nn);
    p = lj_strfmt_wuleb128(q, n);  /* Fill in final size. */
    lua_assert(p == sbufB(&ctx->sb) + 5);
    ctx->status = ctx->wfunc(sbufL(&ctx->sb), q, nn+n, ctx->wdata);
  }
}

/* Write header of bytecode dump. */
static void bcwrite_header(BCWriteCtx *ctx)
{
  GCstr *chunkname = proto_chunkname(ctx->pt);
  const char *name = strdata(chunkname);
  MSize len = chunkname->len;
  char *p = lj_buf_need(&ctx->sb, 5+5+len);
  *p++ = BCDUMP_HEAD1;
  *p++ = BCDUMP_HEAD2;
  *p++ = BCDUMP_HEAD3;
  *p++ = BCDUMP_VERSION;
  *p++ = (ctx->strip ? BCDUMP_F_STRIP : 0) +
	 LJ_BE*BCDUMP_F_BE +
	 ((ctx->pt->flags & PROTO_FFI) ? BCDUMP_F_FFI : 0) +
	 LJ_FR2*BCDUMP_F_FR2;
  if (!ctx->strip) {
    p = lj_strfmt_wuleb128(p, len);
    p = lj_buf_wmem(p, name, len);
  }
  ctx->status = ctx->wfunc(sbufL(&ctx->sb), sbufB(&ctx->sb),
			   (MSize)(p - sbufB(&ctx->sb)), ctx->wdata);
}

/* Write footer of bytecode dump. */
static void bcwrite_footer(BCWriteCtx *ctx)
{
  if (ctx->status == 0) {
    uint8_t zero = 0;
    ctx->status = ctx->wfunc(sbufL(&ctx->sb), &zero, 1, ctx->wdata);
  }
}

/* Protected callback for bytecode writer. */
static TValue *cpwriter(lua_State *L, lua_CFunction dummy, void *ud)
{
  BCWriteCtx *ctx = (BCWriteCtx *)ud;
  UNUSED(L); UNUSED(dummy);
  lj_buf_need(&ctx->sb, 1024);  /* Avoids resize for most prototypes. */
  bcwrite_header(ctx);
  bcwrite_proto(ctx, ctx->pt);
  bcwrite_footer(ctx);
  return NULL;
}

/* Write bytecode for a prototype. */
int lj_bcwrite(lua_State *L, GCproto *pt, lua_Writer writer, void *data,
	      int strip)
{
  BCWriteCtx ctx;
  int status;
  ctx.pt = pt;
  ctx.wfunc = writer;
  ctx.wdata = data;
  ctx.strip = strip;
  ctx.status = 0;
  lj_buf_init(L, &ctx.sb);
  status = lj_vm_cpcall(L, NULL, &ctx, cpwriter);
  if (status == 0) status = ctx.status;
  lj_buf_free(G(sbufL(&ctx.sb)), &ctx.sb);
  return status;
}