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| author | Raymond Hettinger <python@rcn.com> | 2004-10-26 08:59:14 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2004-10-26 08:59:14 (GMT) |
| commit | 23109ef11e91c49b56b517ce454bcf87a4153c62 (patch) | |
| tree | 53ca2774bc93c604957f33c6229b7b240dcf7532 | |
| parent | 368c0b22f8e43709afbbc3805f55ceffed127212 (diff) | |
| download | cpython-23109ef11e91c49b56b517ce454bcf87a4153c62.zip cpython-23109ef11e91c49b56b517ce454bcf87a4153c62.tar.gz cpython-23109ef11e91c49b56b517ce454bcf87a4153c62.tar.bz2 | |
SF bug #1053819: Segfault in tuple_of_constants
Peepholer could be fooled into misidentifying a tuple_of_constants.
Added code to count consecutive occurrences of LOAD_CONST.
Use the count to weed out the misidentified cases.
Added a unittest.
| -rw-r--r-- | Lib/test/test_peepholer.py | 17 | ||||
| -rw-r--r-- | Python/compile.c | 10 |
2 files changed, 26 insertions, 1 deletions
diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py index 913f805..934b57c 100644 --- a/Lib/test/test_peepholer.py +++ b/Lib/test/test_peepholer.py @@ -83,6 +83,23 @@ class TestTranforms(unittest.TestCase): self.assert_(elem in asm) self.assert_('BUILD_TUPLE' not in asm) + # Bug 1053819: Tuple of constants misidentified when presented with: + # . . . opcode_with_arg 100 unary_opcode BUILD_TUPLE 1 . . . + # The following would segfault upon compilation + def crater(): + (~[ + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + ],) + def test_elim_extra_return(self): # RETURN LOAD_CONST None RETURN --> RETURN def f(x): diff --git a/Python/compile.c b/Python/compile.c index dfb94d3..37793ca 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -419,15 +419,16 @@ tuple_of_constants(unsigned char *codestr, int n, PyObject *consts) newconst = PyTuple_New(n); if (newconst == NULL) return 0; + len_consts = PyList_GET_SIZE(consts); for (i=0 ; i<n ; i++) { arg = GETARG(codestr, (i*3)); + assert(arg < len_consts); constant = PyList_GET_ITEM(consts, arg); Py_INCREF(constant); PyTuple_SET_ITEM(newconst, i, constant); } /* Append folded constant onto consts */ - len_consts = PyList_GET_SIZE(consts); if (PyList_Append(consts, newconst)) { Py_DECREF(newconst); return 0; @@ -501,6 +502,7 @@ optimize_code(PyObject *code, PyObject* consts, PyObject *names, PyObject *linen unsigned char *lineno; int *addrmap = NULL; int new_line, cum_orig_line, last_line, tabsiz; + int cumlc=0, lastlc=0; /* Count runs of consecutive LOAD_CONST codes */ unsigned int *blocks; char *name; @@ -536,6 +538,10 @@ optimize_code(PyObject *code, PyObject* consts, PyObject *names, PyObject *linen for (i=0, nops=0 ; i<codelen ; i += CODESIZE(codestr[i])) { addrmap[i] = i - nops; opcode = codestr[i]; + + lastlc = cumlc; + cumlc = 0; + switch (opcode) { /* Replace UNARY_NOT JUMP_IF_FALSE POP_TOP with @@ -589,6 +595,7 @@ optimize_code(PyObject *code, PyObject* consts, PyObject *names, PyObject *linen /* Skip over LOAD_CONST trueconst JUMP_IF_FALSE xx POP_TOP */ case LOAD_CONST: + cumlc = lastlc + 1; j = GETARG(codestr, i); if (codestr[i+3] != JUMP_IF_FALSE || codestr[i+6] != POP_TOP || @@ -607,6 +614,7 @@ optimize_code(PyObject *code, PyObject* consts, PyObject *names, PyObject *linen j = GETARG(codestr, i); h = i - 3 * j; if (h >= 0 && + j == lastlc && codestr[h] == LOAD_CONST && ISBASICBLOCK(blocks, h, 3*(j+1)) && tuple_of_constants(&codestr[h], j, consts)) { |