Fix big endian serialization (#269)

* Fix big endian serialization

Big endian serialization was broken because:
- it partially relied on `WORDS_ENDIAN` (unconditionally undef'd in cutils.h)
- endianness was not handled at all in the bc reader.
- `bc_tag_str` was missing the `"RegExp"` string
- `lre_byte_swap()` was broken for `REOP_range` and `REOP_range32`

Modifications:
- remove `WORDS_ENDIAN`
- use `bc_put_u32()` / `bc_put_u64()` in `JS_WriteBigInt()`
- use `bc_get_u32()` / `bc_get_u64()` in `JS_ReadBigInt()`
- handle host endianness in `bc_get_u16()`, `bc_get_u32()`, `bc_get_u64()` and
  `JS_ReadFunctionBytecode()`
- handle optional littleEndian argument as specified in
  `js_dataview_getValue()` and `js_dataview_setValue()`
- fix `bc_tag_str` and `lre_byte_swap()`

cutils.h

@@ -29,9 +29,6 @@
 #include <string.h>
 #include <inttypes.h>
 
-/* set if CPU is big endian */
-#undef WORDS_BIGENDIAN
-
 #if defined(_MSC_VER)
 #include <windows.h>
 #include <winsock2.h>

libregexp.c

@@ -2598,7 +2598,7 @@ const char *lre_get_groupnames(const uint8_t *bc_buf)
 void lre_byte_swap(uint8_t *buf, size_t len, BOOL is_byte_swapped)
 {
     uint8_t *p, *pe;
-    uint32_t n, r;
+    uint32_t n, r, nw;
 
     p = buf;
     if (len < RE_HEADER_LEN)
@@ -2633,16 +2633,23 @@ void lre_byte_swap(uint8_t *buf, size_t len, BOOL is_byte_swapped)
             case REOP_save_reset: // has two 8 bit arguments
                 break;
             case REOP_range32: // variable length
-                for (r = 3 + 4 * get_u16(&p[1]); n < r; n += 4)
+                nw = get_u16(&p[1]);  // number of pairs of uint32_t
+                if (is_byte_swapped)
+                    n = bswap16(n);
+                for (r = 3 + 8 * nw; n < r; n += 4)
                     inplace_bswap32(&p[n]);
                 goto doswap16;
             case REOP_range: // variable length
-                for (r = 3 + 2 * get_u16(&p[1]); n < r; n += 2)
+                nw = get_u16(&p[1]);  // number of pairs of uint16_t
+                if (is_byte_swapped)
+                    n = bswap16(n);
+                for (r = 3 + 4 * nw; n < r; n += 2)
                     inplace_bswap16(&p[n]);
                 goto doswap16;
             default:
             doswap16:
                 inplace_bswap16(&p[1]);
+                break;
             }
             break;
         case 5:

quickjs.c

@@ -32325,6 +32325,7 @@ static const char * const bc_tag_str[] = {
     "TypedArray",
     "ArrayBuffer",
     "SharedArrayBuffer",
+    "RegExp",
     "Date",
     "ObjectValue",
     "ObjectReference",
@@ -32613,20 +32614,14 @@ static int JS_WriteBigInt(BCWriterState *s, JSValue obj)
         bc_put_leb128(s, len);
         /* always saved in byte based little endian representation */
         for(j = 0; j < n1; j++) {
-            dbuf_putc(&s->dbuf, v >> (j * 8));
+            bc_put_u8(s, v >> (j * 8));
         }
         for(; i < a->len; i++) {
             limb_t v = a->tab[i];
 #if LIMB_BITS == 32
-#ifdef WORDS_BIGENDIAN
+            bc_put_u32(s, v);
-            v = bswap32(v);
-#endif
-            dbuf_put_u32(&s->dbuf, v);
 #else
-#ifdef WORDS_BIGENDIAN
+            bc_put_u64(s, v);
-            v = bswap64(v);
-#endif
-            dbuf_put_u64(&s->dbuf, v);
 #endif
         }
     }
@@ -33218,33 +33213,45 @@ static int bc_get_u8(BCReaderState *s, uint8_t *pval)
 
 static int bc_get_u16(BCReaderState *s, uint16_t *pval)
 {
+    uint16_t v;
     if (unlikely(s->buf_end - s->ptr < 2)) {
         *pval = 0; /* avoid warning */
         return bc_read_error_end(s);
     }
-    *pval = get_u16(s->ptr);
+    v = get_u16(s->ptr);
+    if (is_be())
+        v = bswap16(v);
+    *pval = v;
     s->ptr += 2;
     return 0;
 }
 
 static __maybe_unused int bc_get_u32(BCReaderState *s, uint32_t *pval)
 {
+    uint32_t v;
     if (unlikely(s->buf_end - s->ptr < 4)) {
         *pval = 0; /* avoid warning */
         return bc_read_error_end(s);
     }
-    *pval = get_u32(s->ptr);
+    v = get_u32(s->ptr);
+    if (is_be())
+        v = bswap32(v);
+    *pval = v;
     s->ptr += 4;
     return 0;
 }
 
 static int bc_get_u64(BCReaderState *s, uint64_t *pval)
 {
+    uint64_t v;
     if (unlikely(s->buf_end - s->ptr < 8)) {
         *pval = 0; /* avoid warning */
         return bc_read_error_end(s);
     }
-    *pval = get_u64(s->ptr);
+    v = get_u64(s->ptr);
+    if (is_be())
+        v = bswap64(v);
+    *pval = v;
     s->ptr += 8;
     return 0;
 }
@@ -33387,6 +33394,9 @@ static int JS_ReadFunctionBytecode(BCReaderState *s, JSFunctionBytecode *b,
         return -1;
     b->byte_code_buf = bc_buf;
 
+    if (is_be())
+        bc_byte_swap(bc_buf, bc_len);
+
     pos = 0;
     while (pos < bc_len) {
         op = bc_buf[pos];
@@ -33481,15 +33491,9 @@ static JSValue JS_ReadBigInt(BCReaderState *s)
 #if LIMB_BITS == 32
             if (bc_get_u32(s, &v))
                 goto fail;
-#ifdef WORDS_BIGENDIAN
-            v = bswap32(v);
-#endif
 #else
             if (bc_get_u64(s, &v))
                 goto fail;
-#ifdef WORDS_BIGENDIAN
-            v = bswap64(v);
-#endif
 #endif
             a->tab[i] = v;
         }
@@ -50561,7 +50565,8 @@ static JSValue js_dataview_getValue(JSContext *ctx,
 {
     JSTypedArray *ta;
     JSArrayBuffer *abuf;
-    int is_swap, size;
+    BOOL littleEndian, is_swap;
+    int size;
     uint8_t *ptr;
     uint32_t v;
     uint64_t pos;
@@ -50572,12 +50577,8 @@ static JSValue js_dataview_getValue(JSContext *ctx,
     size = 1 << typed_array_size_log2(class_id);
     if (JS_ToIndex(ctx, &pos, argv[0]))
         return JS_EXCEPTION;
-    is_swap = FALSE;
+    littleEndian = argc > 1 && JS_ToBool(ctx, argv[1]);
-    if (argc > 1)
+    is_swap = littleEndian ^ !is_be();
-        is_swap = JS_ToBool(ctx, argv[1]);
-#ifndef WORDS_BIGENDIAN
-    is_swap ^= 1;
-#endif
     abuf = ta->buffer->u.array_buffer;
     if (abuf->detached)
         return JS_ThrowTypeErrorDetachedArrayBuffer(ctx);
@@ -50663,7 +50664,8 @@ static JSValue js_dataview_setValue(JSContext *ctx,
 {
     JSTypedArray *ta;
     JSArrayBuffer *abuf;
-    int is_swap, size;
+    BOOL littleEndian, is_swap;
+    int size;
     uint8_t *ptr;
     uint64_t v64;
     uint32_t v;
@@ -50703,12 +50705,8 @@ static JSValue js_dataview_setValue(JSContext *ctx,
             v64 = u.u64;
         }
     }
-    is_swap = FALSE;
+    littleEndian = argc > 2 && JS_ToBool(ctx, argv[2]);
-    if (argc > 2)
+    is_swap = littleEndian ^ !is_be();
-        is_swap = JS_ToBool(ctx, argv[2]);
-#ifndef WORDS_BIGENDIAN
-    is_swap ^= 1;
-#endif
     abuf = ta->buffer->u.array_buffer;
     if (abuf->detached)
         return JS_ThrowTypeErrorDetachedArrayBuffer(ctx);