From 876b2f286b9af1a69846c84d1229014b2a885c97 Mon Sep 17 00:00:00 2001 From: Benjamin Peterson Date: Sun, 28 Jun 2009 03:18:59 +0000 Subject: [PATCH] Merged revisions 72912,72920,72940 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r72912 | benjamin.peterson | 2009-05-25 08:13:44 -0500 (Mon, 25 May 2009) | 5 lines add a SETUP_WITH opcode It speeds up the with statement and correctly looks up the special methods involved. ........ r72920 | benjamin.peterson | 2009-05-25 15:12:57 -0500 (Mon, 25 May 2009) | 1 line take into account the fact that SETUP_WITH pushes a finally block ........ r72940 | benjamin.peterson | 2009-05-26 07:49:59 -0500 (Tue, 26 May 2009) | 1 line teach the peepholer about SETUP_WITH ........ --- Doc/library/dis.rst | 12 ++++++ Doc/reference/compound_stmts.rst | 8 ++-- Include/opcode.h | 4 +- Lib/opcode.py | 6 ++- Lib/test/test_descr.py | 8 ++-- Python/ceval.c | 70 +++++++++++++++++++++++++++--- Python/compile.c | 73 ++++---------------------------- Python/import.c | 3 +- Python/opcode_targets.h | 2 +- Python/peephole.c | 3 ++ 10 files changed, 105 insertions(+), 84 deletions(-) diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst index 8d4d9561622..341beb57d80 100644 --- a/Doc/library/dis.rst +++ b/Doc/library/dis.rst @@ -436,6 +436,18 @@ the stack so that it is available for further iterations of the loop. by ``CALL_FUNCTION`` to construct a class. +.. opcode:: SETUP_WITH (delta) + + This opcode performs several operations before a with block starts. First, + it loads :meth:`~object.__exit__` from the context manager and pushes it onto + the stack for later use by :opcode:`WITH_CLEANUP`. Then, + :meth:`~object.__enter__` is called, and a finally block pointing to *delta* + is pushed. Finally, the result of calling the enter method is pushed onto + the stack. The next opcode will either ignore it (:opcode:`POP_TOP`), or + store it in (a) variable(s) (:opcode:`STORE_FAST`, :opcode:`STORE_NAME`, or + :opcode:`UNPACK_SEQUENCE`). + + .. opcode:: WITH_CLEANUP () Cleans up the stack when a :keyword:`with` statement block exits. TOS is diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst index 016ccbbc6c5..4444f182dae 100644 --- a/Doc/reference/compound_stmts.rst +++ b/Doc/reference/compound_stmts.rst @@ -354,6 +354,8 @@ The execution of the :keyword:`with` statement with one "item" proceeds as follo #. The context expression is evaluated to obtain a context manager. +#. The context manager's :meth:`__exit__` is loaded for later use. + #. The context manager's :meth:`__enter__` method is invoked. #. If a target was included in the :keyword:`with` statement, the return value @@ -363,9 +365,9 @@ The execution of the :keyword:`with` statement with one "item" proceeds as follo The :keyword:`with` statement guarantees that if the :meth:`__enter__` method returns without an error, then :meth:`__exit__` will always be - called. Thus, if an error occurs during the assignment to the target - list, it will be treated the same as an error occurring within the suite - would be. See step 5 below. + called. Thus, if an error occurs during the assignment to the target list, + it will be treated the same as an error occurring within the suite would + be. See step 6 below. #. The suite is executed. diff --git a/Include/opcode.h b/Include/opcode.h index 2b1c59da9a8..7ffa359bca0 100644 --- a/Include/opcode.h +++ b/Include/opcode.h @@ -130,8 +130,10 @@ extern "C" { #define CALL_FUNCTION_KW 141 /* #args + (#kwargs<<8) */ #define CALL_FUNCTION_VAR_KW 142 /* #args + (#kwargs<<8) */ +#define SETUP_WITH 143 + /* Support for opargs more than 16 bits long */ -#define EXTENDED_ARG 143 +#define EXTENDED_ARG 144 #define LIST_APPEND 145 #define SET_ADD 146 diff --git a/Lib/opcode.py b/Lib/opcode.py index 86ebc5c564d..e8cccc32ea1 100644 --- a/Lib/opcode.py +++ b/Lib/opcode.py @@ -166,12 +166,14 @@ hasfree.append(137) def_op('CALL_FUNCTION_VAR', 140) # #args + (#kwargs << 8) def_op('CALL_FUNCTION_KW', 141) # #args + (#kwargs << 8) def_op('CALL_FUNCTION_VAR_KW', 142) # #args + (#kwargs << 8) -def_op('EXTENDED_ARG', 143) -EXTENDED_ARG = 143 + +jrel_op('SETUP_WITH', 143) def_op('LIST_APPEND', 145) def_op('SET_ADD', 146) def_op('MAP_ADD', 147) +def_op('EXTENDED_ARG', 144) +EXTENDED_ARG = 144 del def_op, name_op, jrel_op, jabs_op diff --git a/Lib/test/test_descr.py b/Lib/test/test_descr.py index 5c505715a8e..ac5ab6832b9 100644 --- a/Lib/test/test_descr.py +++ b/Lib/test/test_descr.py @@ -1569,6 +1569,7 @@ order (MRO) for bases """ def some_number(self_, key): self.assertEqual(key, "hi") return 4 + def swallow(*args): pass # It would be nice to have every special method tested here, but I'm # only listing the ones I can remember outside of typeobject.c, since it @@ -1584,11 +1585,8 @@ order (MRO) for bases """ set(("__class__",)), {}), ("__subclasscheck__", do_issubclass, return_true, set(("__bases__",)), {}), - # These two fail because the compiler generates LOAD_ATTR to look - # them up. We'd have to add a new opcode to fix this, and it's - # probably not worth it. - # ("__enter__", run_context, iden), - # ("__exit__", run_context, iden), + ("__enter__", run_context, iden, set(), {"__exit__" : swallow}), + ("__exit__", run_context, swallow, set(), {"__enter__" : iden}), ] class Checker(object): diff --git a/Python/ceval.c b/Python/ceval.c index b5b5c272721..b689f3de28b 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -119,6 +119,7 @@ static int import_all_from(PyObject *, PyObject *); static void format_exc_check_arg(PyObject *, const char *, PyObject *); static PyObject * unicode_concatenate(PyObject *, PyObject *, PyFrameObject *, unsigned char *); +static PyObject * special_lookup(PyObject *, char *, PyObject **); #define NAME_ERROR_MSG \ "name '%.200s' is not defined" @@ -2455,6 +2456,33 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) STACK_LEVEL()); DISPATCH(); + TARGET(SETUP_WITH) + { + static PyObject *exit, *enter; + w = TOP(); + x = special_lookup(w, "__exit__", &exit); + if (!x) + break; + SET_TOP(x); + u = special_lookup(w, "__enter__", &enter); + Py_DECREF(w); + if (!u) { + x = NULL; + break; + } + x = PyObject_CallFunctionObjArgs(u, NULL); + Py_DECREF(u); + if (!x) + break; + /* Setup the finally block before pushing the result + of __enter__ on the stack. */ + PyFrame_BlockSetup(f, SETUP_FINALLY, INSTR_OFFSET() + oparg, + STACK_LEVEL()); + + PUSH(x); + DISPATCH(); + } + TARGET(WITH_CLEANUP) { /* At the top of the stack are 1-3 values indicating @@ -2479,17 +2507,36 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) should still be resumed.) */ - PyObject *exit_func = POP(); + PyObject *exit_func; u = TOP(); if (u == Py_None) { + POP(); + exit_func = TOP(); + SET_TOP(u); v = w = Py_None; } else if (PyLong_Check(u)) { + POP(); + switch(PyLong_AsLong(u)) { + case WHY_RETURN: + case WHY_CONTINUE: + /* Retval in TOP. */ + exit_func = SECOND(); + SET_SECOND(TOP()); + SET_TOP(u); + break; + default: + exit_func = TOP(); + SET_TOP(u); + break; + } u = v = w = Py_None; } else { - v = SECOND(); + v = SECOND(); w = THIRD(); + exit_func = stack_pointer[-7]; + stack_pointer[-7] = NULL; } /* XXX Not the fastest way to call it... */ x = PyObject_CallFunctionObjArgs(exit_func, u, v, w, @@ -2509,11 +2556,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag) else if (err > 0) { err = 0; /* There was an exception and a True return */ - STACKADJ(-2); - SET_TOP(PyLong_FromLong((long) WHY_SILENCED)); - Py_DECREF(u); - Py_DECREF(v); - Py_DECREF(w); + PUSH(PyLong_FromLong((long) WHY_SILENCED)); } PREDICT(END_FINALLY); break; @@ -3194,6 +3237,19 @@ fail: /* Jump here from prelude on failure */ } +static PyObject * +special_lookup(PyObject *o, char *meth, PyObject **cache) +{ + PyObject *res; + res = _PyObject_LookupSpecial(o, meth, cache); + if (res == NULL && !PyErr_Occurred()) { + PyErr_SetObject(PyExc_AttributeError, *cache); + return NULL; + } + return res; +} + + /* Logic for the raise statement (too complicated for inlining). This *consumes* a reference count to each of its arguments. */ static enum why_code diff --git a/Python/compile.c b/Python/compile.c index c78949d8878..490137f3db1 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -761,6 +761,8 @@ opcode_stack_effect(int opcode, int oparg) return -1; case BREAK_LOOP: return 0; + case SETUP_WITH: + return 7; case WITH_CLEANUP: return -1; /* XXX Sometimes more */ case STORE_LOCALS: @@ -3085,85 +3087,31 @@ expr_constant(expr_ty e) static int compiler_with(struct compiler *c, stmt_ty s) { - static identifier enter_attr, exit_attr; basicblock *block, *finally; - identifier tmpvalue = NULL, tmpexit = NULL; assert(s->kind == With_kind); - if (!enter_attr) { - enter_attr = PyUnicode_InternFromString("__enter__"); - if (!enter_attr) - return 0; - } - if (!exit_attr) { - exit_attr = PyUnicode_InternFromString("__exit__"); - if (!exit_attr) - return 0; - } - block = compiler_new_block(c); finally = compiler_new_block(c); if (!block || !finally) return 0; - if (s->v.With.optional_vars) { - /* Create a temporary variable to hold context.__enter__(). - We need to do this rather than preserving it on the stack - because SETUP_FINALLY remembers the stack level. - We need to do the assignment *inside* the try/finally - so that context.__exit__() is called when the assignment - fails. But we need to call context.__enter__() *before* - the try/finally so that if it fails we won't call - context.__exit__(). - */ - tmpvalue = compiler_new_tmpname(c); - if (tmpvalue == NULL) - return 0; - PyArena_AddPyObject(c->c_arena, tmpvalue); - } - tmpexit = compiler_new_tmpname(c); - if (tmpexit == NULL) - return 0; - PyArena_AddPyObject(c->c_arena, tmpexit); - /* Evaluate EXPR */ VISIT(c, expr, s->v.With.context_expr); + ADDOP_JREL(c, SETUP_WITH, finally); - /* Squirrel away context.__exit__ by stuffing it under context */ - ADDOP(c, DUP_TOP); - ADDOP_O(c, LOAD_ATTR, exit_attr, names); - if (!compiler_nameop(c, tmpexit, Store)) - return 0; - - /* Call context.__enter__() */ - ADDOP_O(c, LOAD_ATTR, enter_attr, names); - ADDOP_I(c, CALL_FUNCTION, 0); - - if (s->v.With.optional_vars) { - /* Store it in tmpvalue */ - if (!compiler_nameop(c, tmpvalue, Store)) - return 0; - } - else { - /* Discard result from context.__enter__() */ - ADDOP(c, POP_TOP); - } - - /* Start the try block */ - ADDOP_JREL(c, SETUP_FINALLY, finally); - + /* SETUP_WITH pushes a finally block. */ compiler_use_next_block(c, block); if (!compiler_push_fblock(c, FINALLY_TRY, block)) { return 0; } if (s->v.With.optional_vars) { - /* Bind saved result of context.__enter__() to VAR */ - if (!compiler_nameop(c, tmpvalue, Load) || - !compiler_nameop(c, tmpvalue, Del)) - return 0; - VISIT(c, expr, s->v.With.optional_vars); + VISIT(c, expr, s->v.With.optional_vars); + } + else { + /* Discard result from context.__enter__() */ + ADDOP(c, POP_TOP); } /* BLOCK code */ @@ -3181,9 +3129,6 @@ compiler_with(struct compiler *c, stmt_ty s) /* Finally block starts; context.__exit__ is on the stack under the exception or return information. Just issue our magic opcode. */ - if (!compiler_nameop(c, tmpexit, Load) || - !compiler_nameop(c, tmpexit, Del)) - return 0; ADDOP(c, WITH_CLEANUP); /* Finally block ends. */ diff --git a/Python/import.c b/Python/import.c index bccb9711fb0..23dd7b4d089 100644 --- a/Python/import.c +++ b/Python/import.c @@ -89,9 +89,10 @@ typedef unsigned short mode_t; change LIST_APPEND and SET_ADD, add MAP_ADD) Python 3.1a0: 3150 (optimize conditional branches: introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) + Python 3.2a0: 3160 (add SETUP_WITH) */ -#define MAGIC (3150 | ((long)'\r'<<16) | ((long)'\n'<<24)) +#define MAGIC (3160 | ((long)'\r'<<16) | ((long)'\n'<<24)) /* Magic word as global; note that _PyImport_Init() can change the value of this global to accommodate for alterations of how the compiler works which are enabled by command line switches. */ diff --git a/Python/opcode_targets.h b/Python/opcode_targets.h index 043e42a30a5..deaf0a31b71 100644 --- a/Python/opcode_targets.h +++ b/Python/opcode_targets.h @@ -142,8 +142,8 @@ static void *opcode_targets[256] = { &&TARGET_CALL_FUNCTION_VAR, &&TARGET_CALL_FUNCTION_KW, &&TARGET_CALL_FUNCTION_VAR_KW, + &&TARGET_SETUP_WITH, &&TARGET_EXTENDED_ARG, - &&_unknown_opcode, &&TARGET_LIST_APPEND, &&TARGET_SET_ADD, &&TARGET_MAP_ADD, diff --git a/Python/peephole.c b/Python/peephole.c index de1b2aca0d8..23735b0a31a 100644 --- a/Python/peephole.c +++ b/Python/peephole.c @@ -251,6 +251,7 @@ markblocks(unsigned char *code, Py_ssize_t len) case SETUP_LOOP: case SETUP_EXCEPT: case SETUP_FINALLY: + case SETUP_WITH: j = GETJUMPTGT(code, i); blocks[j] = 1; break; @@ -566,6 +567,7 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names, case SETUP_LOOP: case SETUP_EXCEPT: case SETUP_FINALLY: + case SETUP_WITH: tgt = GETJUMPTGT(codestr, i); /* Replace JUMP_* to a RETURN into just a RETURN */ if (UNCONDITIONAL_JUMP(opcode) && @@ -648,6 +650,7 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names, case SETUP_LOOP: case SETUP_EXCEPT: case SETUP_FINALLY: + case SETUP_WITH: j = addrmap[GETARG(codestr, i) + i + 3] - addrmap[i] - 3; SETARG(codestr, i, j); break;