Merge branch 'master' into v2.1

Thanks to Sergey Kaplun. #1443

doc/ext_ffi_api.html

@@ -468,6 +468,8 @@ otherwise. The following parameters are currently defined:
 <td class="abiparam">uwp</td><td class="abidesc">Universal Windows Platform</td></tr>
 <tr class="even">
 <td class="abiparam">gc64</td><td class="abidesc">64 bit GC references</td></tr>
+<tr class="odd">
+<td class="abiparam">dualnum</td><td class="abidesc">Dual-number mode</td></tr>
 </table>
 
 <h3 id="ffi_os"><tt>ffi.os</tt></h3>

src/lib_ffi.c

@@ -758,6 +758,9 @@ LJLIB_CF(ffi_abi)	LJLIB_REC(.)
 #endif
 #if LJ_GC64
     "\004gc64"
+#endif
+#if LJ_DUALNUM
+    "\007dualnum"
 #endif
   ) >= 0;
   setboolV(L->top-1, b);

src/lj_clib.c

@@ -81,7 +81,7 @@ static const char *clib_extname(lua_State *L, const char *name)
 /* Check for a recognized ld script line. */
 static const char *clib_check_lds(lua_State *L, const char *buf)
 {
-  char *p, *e;
+  const char *p, *e;
   if ((!strncmp(buf, "GROUP", 5) || !strncmp(buf, "INPUT", 5)) &&
       (p = strchr(buf, '('))) {
     while (*++p == ' ') ;

src/lj_crecord.c

@@ -895,6 +895,8 @@ again:
 	  }
 	  J->base[0] = lj_ir_kint(J, (int32_t)fct->size);
 	  return;  /* Interpreter will throw for newindex. */
+	} else if (cd && cd->ctypeid == CTID_CTYPEID) {
+	  /* Only resolve constants and metamethods for constructors. */
 	} else if (ctype_isbitfield(fct->info)) {
 	  if (ofs)
 	    ptr = emitir(IRT(IR_ADD, IRT_PTR), ptr, lj_ir_kintp(J, ofs));

src/lj_ffrecord.c

@@ -854,7 +854,7 @@ static void LJ_FASTCALL recff_string_range(jit_State *J, RecordFFData *rd)
   }
   trstart = recff_string_start(J, str, &start, trstart, trlen, tr0);
   if (rd->data) {  /* Return string.sub result. */
-    if (end - start >= 0) {
+    if (start <= end) {
       /* Also handle empty range here, to avoid extra traces. */
       TRef trptr, trslen = emitir(IRTGI(IR_SUBOV), trend, trstart);
       emitir(IRTGI(IR_GE), trslen, tr0);
@@ -865,8 +865,8 @@ static void LJ_FASTCALL recff_string_range(jit_State *J, RecordFFData *rd)
       J->base[0] = lj_ir_kstr(J, &J2G(J)->strempty);
     }
   } else {  /* Return string.byte result(s). */
-    ptrdiff_t i, len = end - start;
-    if (len > 0) {
+    if (start < end) {
+      ptrdiff_t i, len = end - start;
       TRef trslen = emitir(IRTGI(IR_SUBOV), trend, trstart);
       emitir(IRTGI(IR_EQ), trslen, lj_ir_kint(J, (int32_t)len));
       if (J->baseslot + len > LJ_MAX_JSLOTS)

src/lj_record.c

@@ -526,6 +526,12 @@ static LoopEvent rec_for(jit_State *J, const BCIns *fori, int isforl)
   LoopEvent ev;
   TRef stop;
   IRType t;
+  /* Avoid semantic mismatches and always failing guards. */
+  if ((tvisnum(&tv[FORL_IDX]) && tvisnan(&tv[FORL_IDX])) ||
+      (tvisnum(&tv[FORL_STOP]) && tvisnan(&tv[FORL_STOP])) ||
+      (tvisnum(&tv[FORL_STEP]) && tvisnan(&tv[FORL_STEP])) ||
+      tvismzero(&tv[FORL_STEP]))
+    lj_trace_err(J, LJ_TRERR_GFAIL);
   if (isforl) {  /* Handle FORL/JFORL opcodes. */
     TRef idx = tr[FORL_IDX];
     if (mref(J->scev.pc, const BCIns) == fori && tref_ref(idx) == J->scev.idx) {

src/lj_state.c

@@ -72,7 +72,7 @@ static void resizestack(lua_State *L, MSize n)
   while (oldsize < realsize)  /* Clear new slots. */
     setnilV(st + oldsize++);
   L->stacksize = realsize;
-  if ((size_t)(mref(G(L)->jit_base, char) - (char *)oldst) < oldsize)
+  if ((size_t)(mref(G(L)->jit_base, char) - (char *)oldst) < (size_t)oldsize * sizeof(TValue))
     setmref(G(L)->jit_base, mref(G(L)->jit_base, char) + delta);
   L->base = (TValue *)((char *)L->base + delta);
   L->top = (TValue *)((char *)L->top + delta);