FFI: Add missing coercion when recording 64-bit bit.*().

Thanks to Peter Cawley.

(cherry picked from commit 304da39)

Before the patch, with the missed coercion from string, there is the
cast to `i64` from `p64`, where the last one is the string address. This
leads to an incorrect result of the bit operation.

This patch adds the missing coercion everywhere for bit operations
recording. Only the `recff_bit64_nary()` is affected, since all other
routines have the corresponding type check and cast emitting if
necessary. However, for the consistency, all functions have the same
checking routine `crec_bit64_arg()` now.

Sergey Kaplun:
* added the description and the test for the problem

Part of tarantool/tarantool#10709

Reviewed-by: Sergey Bronnikov <[email protected]>
Signed-off-by: Sergey Kaplun <[email protected]>
(cherry picked from commit c698ff5)

src/Makefile.dep.original

@@ -96,7 +96,7 @@ lj_crecord.o: lj_crecord.c lj_obj.h lua.h luaconf.h lj_def.h lj_arch.h \
  lj_cdata.h lj_cparse.h lj_cconv.h lj_carith.h lj_clib.h lj_ccall.h \
  lj_ff.h lj_ffdef.h lj_ir.h lj_jit.h lj_ircall.h lj_iropt.h lj_trace.h \
  lj_dispatch.h lj_traceerr.h lj_record.h lj_ffrecord.h lj_snap.h \
- lj_crecord.h lj_strfmt.h
+ lj_crecord.h lj_strfmt.h lj_strscan.h
 lj_ctype.o: lj_ctype.c lj_obj.h lua.h luaconf.h lj_def.h lj_arch.h \
  lj_gc.h lj_err.h lj_errmsg.h lj_str.h lj_tab.h lj_strfmt.h lj_ctype.h \
  lj_ccallback.h lj_buf.h

src/lj_crecord.c

@@ -32,6 +32,7 @@
 #include "lj_crecord.h"
 #include "lj_dispatch.h"
 #include "lj_strfmt.h"
+#include "lj_strscan.h"
 
 /* Some local macros to save typing. Undef'd at the end. */
 #define IR(ref)			(&J->cur.ir[(ref)])
@@ -1782,11 +1783,21 @@ static CTypeID crec_bit64_type(CTState *cts, cTValue *tv)
   return 0;  /* Use regular 32 bit ops. */
 }
 
+static TRef crec_bit64_arg(jit_State *J, CType *d, TRef sp, TValue *sval)
+{
+  if (LJ_UNLIKELY(tref_isstr(sp))) {
+    if (lj_strscan_num(strV(sval), sval)) {
+      sp = emitir(IRTG(IR_STRTO, IRT_NUM), sp, 0);
+    }  /* else: interpreter will throw. */
+  }
+  return crec_ct_tv(J, d, 0, sp, sval);
+}
+
 void LJ_FASTCALL recff_bit64_tobit(jit_State *J, RecordFFData *rd)
 {
   CTState *cts = ctype_ctsG(J2G(J));
-  TRef tr = crec_ct_tv(J, ctype_get(cts, CTID_INT64), 0,
-		       J->base[0], &rd->argv[0]);
+  TRef tr = crec_bit64_arg(J, ctype_get(cts, CTID_INT64),
+			   J->base[0], &rd->argv[0]);
   if (!tref_isinteger(tr))
     tr = emitconv(tr, IRT_INT, tref_type(tr), 0);
   J->base[0] = tr;
@@ -1797,7 +1808,7 @@ int LJ_FASTCALL recff_bit64_unary(jit_State *J, RecordFFData *rd)
   CTState *cts = ctype_ctsG(J2G(J));
   CTypeID id = crec_bit64_type(cts, &rd->argv[0]);
   if (id) {
-    TRef tr = crec_ct_tv(J, ctype_get(cts, id), 0, J->base[0], &rd->argv[0]);
+    TRef tr = crec_bit64_arg(J, ctype_get(cts, id), J->base[0], &rd->argv[0]);
     tr = emitir(IRT(rd->data, id-CTID_INT64+IRT_I64), tr, 0);
     J->base[0] = emitir(IRTG(IR_CNEWI, IRT_CDATA), lj_ir_kint(J, id), tr);
     return 1;
@@ -1817,9 +1828,9 @@ int LJ_FASTCALL recff_bit64_nary(jit_State *J, RecordFFData *rd)
   if (id) {
     CType *ct = ctype_get(cts, id);
     uint32_t ot = IRT(rd->data, id-CTID_INT64+IRT_I64);
-    TRef tr = crec_ct_tv(J, ct, 0, J->base[0], &rd->argv[0]);
+    TRef tr = crec_bit64_arg(J, ct, J->base[0], &rd->argv[0]);
     for (i = 1; J->base[i] != 0; i++) {
-      TRef tr2 = crec_ct_tv(J, ct, 0, J->base[i], &rd->argv[i]);
+      TRef tr2 = crec_bit64_arg(J, ct, J->base[i], &rd->argv[i]);
       tr = emitir(ot, tr, tr2);
     }
     J->base[0] = emitir(IRTG(IR_CNEWI, IRT_CDATA), lj_ir_kint(J, id), tr);
@@ -1834,15 +1845,15 @@ int LJ_FASTCALL recff_bit64_shift(jit_State *J, RecordFFData *rd)
   CTypeID id;
   TRef tsh = 0;
   if (J->base[0] && tref_iscdata(J->base[1])) {
-    tsh = crec_ct_tv(J, ctype_get(cts, CTID_INT64), 0,
-		     J->base[1], &rd->argv[1]);
+    tsh = crec_bit64_arg(J, ctype_get(cts, CTID_INT64),
+			 J->base[1], &rd->argv[1]);
     if (!tref_isinteger(tsh))
       tsh = emitconv(tsh, IRT_INT, tref_type(tsh), 0);
     J->base[1] = tsh;
   }
   id = crec_bit64_type(cts, &rd->argv[0]);
   if (id) {
-    TRef tr = crec_ct_tv(J, ctype_get(cts, id), 0, J->base[0], &rd->argv[0]);
+    TRef tr = crec_bit64_arg(J, ctype_get(cts, id), J->base[0], &rd->argv[0]);
     uint32_t op = rd->data;
     if (!tsh) tsh = lj_opt_narrow_tobit(J, J->base[1]);
     if (!(op < IR_BROL ? LJ_TARGET_MASKSHIFT : LJ_TARGET_MASKROT) &&
@@ -1872,7 +1883,7 @@ TRef recff_bit64_tohex(jit_State *J, RecordFFData *rd, TRef hdr)
     CTypeID id2 = 0;
     n = (int32_t)lj_carith_check64(J->L, 2, &id2);
     if (id2)
-      trsf = crec_ct_tv(J, ctype_get(cts, CTID_INT32), 0, trsf, &rd->argv[1]);
+      trsf = crec_bit64_arg(J, ctype_get(cts, CTID_INT32), trsf, &rd->argv[1]);
     else
       trsf = lj_opt_narrow_tobit(J, trsf);
     emitir(IRTGI(IR_EQ), trsf, lj_ir_kint(J, n));  /* Specialize to n. */
@@ -1883,7 +1894,7 @@ TRef recff_bit64_tohex(jit_State *J, RecordFFData *rd, TRef hdr)
   if ((uint32_t)n > 254) n = 254;
   sf |= ((SFormat)((n+1)&255) << STRFMT_SH_PREC);
   if (id) {
-    tr = crec_ct_tv(J, ctype_get(cts, id), 0, J->base[0], &rd->argv[0]);
+    tr = crec_bit64_arg(J, ctype_get(cts, id), J->base[0], &rd->argv[0]);
     if (n < 16)
       tr = emitir(IRT(IR_BAND, IRT_U64), tr,
 		  lj_ir_kint64(J, ((uint64_t)1 << 4*n)-1));

test/tarantool-tests/lj-1252-missing-bit64-coercion.test.lua

@@ -0,0 +1,30 @@
+local tap = require('tap')
+
+-- Test file to demonstrate LuaJIT incorrect recording of
+-- `bit` library with needed coercion from string.
+-- See also: https://github.com/LuaJIT/LuaJIT/issues/1252.
+
+local test = tap.test('lj-1252-missing-bit64-coercion'):skipcond({
+  ['Test requires JIT enabled'] = not jit.status(),
+})
+
+test:plan(1)
+
+-- Simplify the `jit.dump()` output.
+local bor = bit.bor
+
+jit.opt.start('hotloop=1')
+
+-- Before the patch, with the missed coercion from string, there
+-- is the cast to `i64` from `p64`, where the last one is the
+-- string address. This leads to an incorrect result of the bit
+-- operation.
+
+local results = {}
+for i = 1, 4 do
+  results[i] = bor('0', 0LL)
+end
+
+test:samevalues(results, 'correct recording of the bit operation with coercion')
+
+test:done(true)