FFI: Add 64 bit integer comparisons and pointer comparisons.

author: Mike Pall <mike> 2011-01-13 02:35:29 +0100
committer: Mike Pall <mike> 2011-01-13 02:35:29 +0100
commit: 0ec7f5ed92b6b9720c80669b2de3aa3c40967153 (patch)
tree: d4ea028d9db343d77985df658b4370b838050523 /src/lib_ffi.c
parent: e7b08b2361dd9e3f945dfd4b7e34c4aad2243582 (diff)
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1 files changed, 98 insertions, 28 deletions
diff --git a/src/lib_ffi.c b/src/lib_ffi.c
index aeeb0bc1..89baa356 100644
--- a/src/lib_ffi.c
+++ b/src/lib_ffi.c
@@ -85,9 +85,10 @@ typedef struct FFIArith {
 } FFIArith;
 /* Check arguments for arithmetic metamethods. */
-static void ffi_checkarith(lua_State *L, CTState *cts, FFIArith *fa)
+static int ffi_checkarith(lua_State *L, CTState *cts, FFIArith *fa)
 {
  TValue *o = L->base;
+  int ok = 1;
  MSize i;
  if (o+1 >= L->top)
    lj_err_argt(L, 1, LUA_TCDATA);
@@ -105,10 +106,16 @@ static void ffi_checkarith(lua_State *L, CTState *cts, FFIArith *fa)
    } else if (tvisnum(o)) {
      fa->ct[i] = ctype_get(cts, CTID_DOUBLE);
      fa->p[i] = (uint8_t *)&o->n;
+    } else if (tvisnil(o)) {
+      fa->ct[i] = ctype_get(cts, CTID_P_VOID);
+      fa->p[i] = (uint8_t *)0;
    } else {
-      lj_err_optype(L, o, LJ_ERR_OPARITH);
+      fa->ct[i] = NULL;
+      fa->p[i] = NULL;
+      ok = 0;
    }
  }
+  return ok;
 }
 /* Pointer arithmetic. */
@@ -120,26 +127,38 @@ static int ffi_arith_ptr(lua_State *L, CTState *cts, FFIArith *fa, MMS mm)
  CTSize sz;
  CTypeID id;
  GCcdata *cd;
-  if (!(mm == MM_add || mm == MM_sub))
-    return 0;
  if (ctype_isptr(ctp->info) || ctype_isrefarray(ctp->info)) {
-    if (mm == MM_sub &&
+    if ((mm == MM_sub || mm == MM_eq || mm == MM_lt || mm == MM_le) &&
        (ctype_isptr(fa->ct[1]->info) || ctype_isrefarray(fa->ct[1]->info))) {
-      /* Pointer difference. */
+      uint8_t *pp2 = fa->p[1];
-      intptr_t diff;
+      if (mm == MM_eq) {  /* Pointer equality. Incompatible pointers are ok. */
+        setboolV(L->top-1, (pp == pp2));
+        return 1;
+      }
      if (!lj_cconv_compatptr(cts, ctp, fa->ct[1], CCF_IGNQUAL))
-        lj_err_caller(L, LJ_ERR_FFI_INVTYPE);
+        return 0;
-      sz = lj_ctype_size(cts, ctype_cid(ctp->info));  /* Element size. */
+      if (mm == MM_sub) {  /* Pointer difference. */
-      if (sz == 0 || sz == CTSIZE_INVALID)
+        intptr_t diff;
-        lj_err_caller(L, LJ_ERR_FFI_INVSIZE);
+        sz = lj_ctype_size(cts, ctype_cid(ctp->info));  /* Element size. */
-      diff = ((intptr_t)pp - (intptr_t)fa->p[1]) / (int32_t)sz;
+        if (sz == 0 || sz == CTSIZE_INVALID)
-      /* All valid pointer differences on x64 are in (-2^47, +2^47),
+          return 0;
-      ** which fits into a double without loss of precision.
+        diff = ((intptr_t)pp - (intptr_t)pp2) / (int32_t)sz;
-      */
+        /* All valid pointer differences on x64 are in (-2^47, +2^47),
-      setnumV(L->top-1, (lua_Number)diff);
+        ** which fits into a double without loss of precision.
-      return 1;
+        */
+        setnumV(L->top-1, (lua_Number)diff);
+        return 1;
+      } else if (mm == MM_lt) {  /* Pointer comparison (unsigned). */
+        setboolV(L->top-1, ((uintptr_t)pp < (uintptr_t)pp2));
+        return 1;
+      } else {
+        lua_assert(mm == MM_le);
+        setboolV(L->top-1, ((uintptr_t)pp <= (uintptr_t)pp2));
+        return 1;
+      }
    }
-    if (!ctype_isnum(fa->ct[1]->info)) return 0;
+    if (!((mm == MM_add || mm == MM_sub) &&
+          ctype_isnum(fa->ct[1]->info))) return 0;
    lj_cconv_ct_ct(cts, ctype_get(cts, CTID_INT_PSZ), fa->ct[1],
                   (uint8_t *)&idx, fa->p[1], 0);
    if (mm == MM_sub) idx = -idx;
@@ -155,7 +174,7 @@ static int ffi_arith_ptr(lua_State *L, CTState *cts, FFIArith *fa, MMS mm)
  }
  sz = lj_ctype_size(cts, ctype_cid(ctp->info));  /* Element size. */
  if (sz == CTSIZE_INVALID)
-    lj_err_caller(L, LJ_ERR_FFI_INVSIZE);
+    return 0;
  pp += idx*(int32_t)sz;  /* Compute pointer + index. */
  id = lj_ctype_intern(cts, CTINFO(CT_PTR, CTALIGN_PTR|ctype_cid(ctp->info)),
                       CTSIZE_PTR);
@@ -180,7 +199,19 @@ static int ffi_arith_int64(lua_State *L, CTState *cts, FFIArith *fa, MMS mm)
    lj_cconv_ct_ct(cts, ct, fa->ct[0], (uint8_t *)&u0, fa->p[0], 0);
    if (mm != MM_unm)
      lj_cconv_ct_ct(cts, ct, fa->ct[1], (uint8_t *)&u1, fa->p[1], 0);
-    if ((mm == MM_div || mm == MM_mod)) {
+    switch (mm) {
+    case MM_eq:
+      setboolV(L->top-1, (u0 == u1));
+      return 1;
+    case MM_lt:
+      setboolV(L->top-1,
+               id == CTID_INT64 ? ((int64_t)u0 < (int64_t)u1) : (u0 < u1));
+      return 1;
+    case MM_le:
+      setboolV(L->top-1,
+               id == CTID_INT64 ? ((int64_t)u0 <= (int64_t)u1) : (u0 <= u1));
+      return 1;
+    case MM_div: case MM_mod:
      if (u1 == 0) {  /* Division by zero. */
        if (u0 == 0)
          setnanV(L->top-1);
@@ -194,6 +225,8 @@ static int ffi_arith_int64(lua_State *L, CTState *cts, FFIArith *fa, MMS mm)
        if (mm == MM_div) id = CTID_UINT64; else u0 = 0;
        mm = MM_unm;  /* Result is 0x8000000000000000ULL or 0LL. */
      }
+      break;
+    default: break;
    }
    cd = lj_cdata_new(cts, id, 8);
    up = (uint64_t *)cdataptr(cd);
@@ -229,17 +262,27 @@ static int ffi_arith(lua_State *L)
 {
  CTState *cts = ctype_cts(L);
  FFIArith fa;
-  MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___add + (int)MM_add);
+  MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___eq + (int)MM_eq);
-  ffi_checkarith(L, cts, &fa);
+  if (ffi_checkarith(L, cts, &fa)) {
-  if (!ffi_arith_int64(L, cts, &fa, mm) &&
+    if (ffi_arith_int64(L, cts, &fa, mm) || ffi_arith_ptr(L, cts, &fa, mm))
-      !ffi_arith_ptr(L, cts, &fa, mm)) {
+      return 1;
+  }
+  /* NYI: per-cdata metamethods. */
+  {
    const char *repr[2];
    int i;
-    for (i = 0; i < 2; i++)
+    for (i = 0; i < 2; i++) {
-      repr[i] = strdata(lj_ctype_repr(L, ctype_typeid(cts, fa.ct[i]), NULL));
+      if (fa.ct[i])
-    lj_err_callerv(L, LJ_ERR_FFI_BADARITH, repr[0], repr[1]);
+        repr[i] = strdata(lj_ctype_repr(L, ctype_typeid(cts, fa.ct[i]), NULL));
+      else
+        repr[i] = typename(&L->base[i]);
+    }
+    lj_err_callerv(L, mm == MM_len ? LJ_ERR_FFI_BADLEN :
+                      mm == MM_concat ? LJ_ERR_FFI_BADCONCAT :
+                      mm < MM_add ? LJ_ERR_FFI_BADCOMP : LJ_ERR_FFI_BADARITH,
+                   repr[0], repr[1]);
  }
-  return 1;
+  return 0;  /* unreachable */
 }
 /* -- C type metamethods -------------------------------------------------- */
@@ -275,6 +318,32 @@ LJLIB_CF(ffi_meta___newindex)	LJLIB_REC(cdata_index 1)
  return 0;
 }
+/* The following functions must be in contiguous ORDER MM. */
+LJLIB_CF(ffi_meta___eq)
+{
+  return ffi_arith(L);
+}
+LJLIB_CF(ffi_meta___len)
+{
+  return ffi_arith(L);
+}
+LJLIB_CF(ffi_meta___lt)
+{
+  return ffi_arith(L);
+}
+LJLIB_CF(ffi_meta___le)
+{
+  return ffi_arith(L);
+}
+LJLIB_CF(ffi_meta___concat)
+{
+  return ffi_arith(L);
+}
 /* Forward declaration. */
 static int lj_cf_ffi_new(lua_State *L);
@@ -324,6 +393,7 @@ LJLIB_CF(ffi_meta___unm)	LJLIB_REC(cdata_arith MM_unm)
 {
  return ffi_arith(L);
 }
+/* End of contiguous ORDER MM. */
 LJLIB_CF(ffi_meta___tostring)
 {
author	Mike Pall <mike>	2011-01-13 02:35:29 +0100
committer	Mike Pall <mike>	2011-01-13 02:35:29 +0100
commit	0ec7f5ed92b6b9720c80669b2de3aa3c40967153 (patch)
tree	d4ea028d9db343d77985df658b4370b838050523 /src/lib_ffi.c
parent	e7b08b2361dd9e3f945dfd4b7e34c4aad2243582 (diff)
download	luajit-0ec7f5ed92b6b9720c80669b2de3aa3c40967153.tar.gz luajit-0ec7f5ed92b6b9720c80669b2de3aa3c40967153.tar.bz2 luajit-0ec7f5ed92b6b9720c80669b2de3aa3c40967153.zip