issue #146 Currently Ravi's code generator assumes that #operator returns an integer value, but if user has set a metamethod for __len the operator# might return a non-integer value. This issue came to light when testing lpeg, which redefines #operator to return userdata objects. We now try to only expect integer values when # is used in fornum loops, or applied to table or array. Additionally unless the target is an array, we also emit a TOINT opcode to validate at runtime that the value in integer type

ravi-tests/matmul1_ravi.lua

@@ -13,7 +13,7 @@ function matrix.T(a: table)
 end
 
 function matrix.mul(a: table, b: table)
-	assert(#a[1] == #b);
+	assert(@integer(#a[1]) == #b);
 	local m: integer, n: integer, p: integer, x: table = #a, #a[1], #b[1], {};
 	local c: table = matrix.T(b); -- transpose for efficiency
 	for i = 1, m do

ravi-tests/ravi_tests1.ravi

@@ -634,11 +634,11 @@ z = function()
   y=x()
   y[1] = 99.67
   assert(y[1], 99.67)
-  assert(#y == 1)
+  assert(@integer (#y) == 1)
 end
 check(z, 'CLOSURE', 'GETUPVAL', 'MOVE', 'CALL',
   'MOVE', 'CALL', 'SETUPVAL', 'SETTABUP', 'GETTABUP_SK', 'GETTABUP',
-  'LOADK', 'CALL', 'GETTABUP_SK', 'GETUPVAL', 'LEN', 'EQ_II',
+  'LOADK', 'CALL', 'GETTABUP_SK', 'GETUPVAL', 'LEN', 'TOINT', 'EQ_II',
   'JMP', 'LOADBOOL', 'LOADBOOL', 'CALL', 'RETURN')
 z()
 compile(z)
@@ -665,7 +665,7 @@ z = function()
 end
 check(z, 'NEWTABLE', 'LOADK', 'LOADK', 'LOADK', 'LOADK',
   'LOADK', 'LOADK', 'LOADK', 'SETLIST', 'GETTABUP_SK', 'GETTABLE_I',
-  'EQ', 'JMP', 'LOADBOOL', 'LOADBOOL', 'CALL', 'GETTABUP_SK', 'LEN',
+  'EQ', 'JMP', 'LOADBOOL', 'LOADBOOL', 'CALL', 'GETTABUP_SK', 'LEN', 'TOINT',
   'EQ_II', 'JMP', 'LOADBOOL', 'LOADBOOL', 'CALL', 'GETTABUP_SK', 'GETTABLE_I',
   'EQ', 'JMP', 'LOADBOOL', 'LOADBOOL', 'CALL', 'GETTABLE_I', 'LOADK',
   'CONCAT', 'SETTABLE_I', 'CLOSURE', 'SETUPVAL', 'GETTABUP_SK', 'GETUPVAL',

src/lcode.c

@@ -1262,14 +1262,22 @@ static int constfolding (FuncState *fs, int op, expdesc *e1,
 ** Expression to produce final result will be encoded in 'e'.
 */
 static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
+  ravitype_t e_type = e->ravi_type;
   int r = luaK_exp2anyreg(fs, e);  /* opcodes operate only on registers */
   freeexp(fs, e);
   if (op == OP_BNOT && e->ravi_type == RAVI_TNUMINT) 
     op = OP_RAVI_BNOT_I;
   e->u.info = luaK_codeABC(fs, op, 0, r, 0);  /* generate opcode */
   e->k = VRELOCABLE;  /* all those operations are relocatable */
-  if (op == OP_LEN)
-    e->ravi_type = RAVI_TNUMINT;
+  if (op == OP_LEN) {
+	if (e_type == RAVI_TARRAYINT || e_type == RAVI_TARRAYFLT)
+      e->ravi_type = RAVI_TNUMINT;
+	else if (e_type == RAVI_TTABLE) {
+	  luaK_exp2anyreg(fs, e);
+	  luaK_codeABC(fs, OP_RAVI_TOINT, e->u.info, 0, 0);
+	  e->ravi_type = RAVI_TNUMINT;
+	}
+  }
   luaK_fixline(fs, line);
 }
 

src/lparser.c

@@ -1920,6 +1920,9 @@ static int exp1 (LexState *ls, Fornuminfo *info) {
    */
   expdesc e = {.ravi_type = RAVI_TANY, .pc = -1};
   int reg;
+  int expect_int = 0;
+  if (ls->t.token == '#')
+    expect_int = 1;
   expr(ls, &e);
   DEBUG_EXPR(raviY_printf(ls->fs, "fornum exp -> %e\n", &e));
   info->is_constant = (e.k == VKINT);
@@ -1927,7 +1930,13 @@ static int exp1 (LexState *ls, Fornuminfo *info) {
   luaK_exp2nextreg(ls->fs, &e);
   lua_assert(e.k == VNONRELOC);
   reg = e.u.info;
-  info->type = e.ravi_type;
+  if (expect_int && e.ravi_type != RAVI_TNUMINT) {
+    luaK_codeABC(ls->fs, OP_RAVI_TOINT, reg, 0, 0);
+    info->type = RAVI_TNUMINT;
+  }
+  else {
+    info->type = e.ravi_type;
+  }
   return reg;
 }