added MIN_VIRTUAL_OPCODE/MAX_ALLOWED_OPCODE etc

python · markshannon · Apr 1, 2022 · Mar 28, 2022 · Mar 30, 2022 · Mar 30, 2022
commit da4293169cb3ccb6dabfab9b25faea423d7eef4d
@@ -78,6 +78,12 @@
 #define POP_BLOCK -4
 #define JUMP -5

+#define MIN_VIRTUAL_OPCODE -5
+#define MAX_ALLOWED_OPCODE 254
+
+#define IS_WITHIN_OPCODE_RANGE(opcode) \
+        ((opcode) >= MIN_VIRTUAL_OPCODE && (opcode) <= MAX_ALLOWED_OPCODE)
+
 #define IS_VIRTUAL_OPCODE(opcode) ((opcode) < 0)

 #define IS_TOP_LEVEL_AWAIT(c) ( \
@@ -117,7 +123,7 @@ is_bit_set_in_table(const uint32_t *table, int bitindex) {
     * Word is indexed by (bitindex>>ln(size of int in bits)).
     * Bit within word is the low bits of bitindex.
     */
-    if (bitindex >= 0) {
+    if (bitindex >= 0 && bitindex < 256) {
        uint32_t word = table[bitindex >> LOG_BITS_PER_INT];
        return (word >> (bitindex & MASK_LOW_LOG_BITS)) & 1;
    }
@@ -1192,6 +1198,7 @@ static int
 compiler_addop_line(struct compiler *c, int opcode, int line,
                    int end_line, int col_offset, int end_col_offset)
 {
+    assert(IS_WITHIN_OPCODE_RANGE(opcode));
    assert(!HAS_ARG(opcode) || IS_ARTIFICIAL(opcode));

    if (compiler_use_new_implicit_block_if_needed(c) < 0) {
@@ -1434,6 +1441,7 @@ compiler_addop_i_line(struct compiler *c, int opcode, Py_ssize_t oparg,
       The argument of a concrete bytecode instruction is limited to 8-bit.
       EXTENDED_ARG is used for 16, 24, and 32-bit arguments. */

+    assert(IS_WITHIN_OPCODE_RANGE(opcode));
    assert(HAS_ARG(opcode));
    assert(0 <= oparg && oparg <= 2147483647);

@@ -1477,6 +1485,7 @@ static int add_jump_to_block(struct compiler *c, int opcode,
                             int col_offset, int end_col_offset,
                             basicblock *target)
 {
+    assert(IS_WITHIN_OPCODE_RANGE(opcode));
    assert(HAS_ARG(opcode) || IS_VIRTUAL_OPCODE(opcode));
    assert(target != NULL);