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Document how the pattern recognizer keeps all of its references in bounds.

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Add a test in case the underlying assumptions ever change (i.e. the
compiler starts generating code blocks that are not punctuated by
RETURN_VALUE).
This commit is contained in:
Raymond Hettinger 2005-02-21 20:03:14 +00:00
parent 467024ccfc
commit 07359a7fed
1 changed files with 8 additions and 0 deletions
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8
Python/compile.c
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@ -677,6 +677,14 @@ optimize_code(PyObject *code, PyObject* consts, PyObject *names, PyObject *linen
goto exitUnchanged;
codestr = memcpy(codestr, PyString_AS_STRING(code), codelen);
/* Verify that RETURN_VALUE terminates the codestring. This allows
the various transformation patterns to look ahead several
instructions without additional checks to make sure they are not
looking beyond the end of the code string.
*/
if (codestr[codelen-1] != RETURN_VALUE)
goto exitUnchanged;
/* Mapping to new jump targets after NOPs are removed */
addrmap = PyMem_Malloc(codelen * sizeof(int));
if (addrmap == NULL)