mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-11-01 18:51:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 21

PEP 0492 -- Coroutines with async and await syntax. Issue #24017.

Browse source
This commit is contained in:
Yury Selivanov 2015-05-11 22:57:16 -04:00
parent 4e6bf4b3da
commit 7544508f02
72 changed files with 9261 additions and 5739 deletions
Download patch file Download diff file Expand all files Collapse all files

288
Python/compile.c
View file

@ -92,6 +92,7 @@ enum {
COMPILER_SCOPE_MODULE,
COMPILER_SCOPE_CLASS,
COMPILER_SCOPE_FUNCTION,
COMPILER_SCOPE_ASYNC_FUNCTION,
COMPILER_SCOPE_LAMBDA,
COMPILER_SCOPE_COMPREHENSION,
};
@ -193,6 +194,8 @@ static int inplace_binop(struct compiler *, operator_ty);
static int expr_constant(struct compiler *, expr_ty);
static int compiler_with(struct compiler *, stmt_ty, int);
static int compiler_async_with(struct compiler *, stmt_ty, int);
static int compiler_async_for(struct compiler *, stmt_ty);
static int compiler_call_helper(struct compiler *c, Py_ssize_t n,
asdl_seq *args,
asdl_seq *keywords);
@ -673,7 +676,9 @@ compiler_set_qualname(struct compiler *c)
parent = (struct compiler_unit *)PyCapsule_GetPointer(capsule, CAPSULE_NAME);
assert(parent);
if (u->u_scope_type == COMPILER_SCOPE_FUNCTION || u->u_scope_type == COMPILER_SCOPE_CLASS) {
if (u->u_scope_type == COMPILER_SCOPE_FUNCTION
|| u->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION
|| u->u_scope_type == COMPILER_SCOPE_CLASS) {
assert(u->u_name);
mangled = _Py_Mangle(parent->u_private, u->u_name);
if (!mangled)
@ -687,6 +692,7 @@ compiler_set_qualname(struct compiler *c)
if (!force_global) {
if (parent->u_scope_type == COMPILER_SCOPE_FUNCTION
|| parent->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION
|| parent->u_scope_type == COMPILER_SCOPE_LAMBDA) {
dot_locals_str = _PyUnicode_FromId(&dot_locals);
if (dot_locals_str == NULL)
@ -927,7 +933,9 @@ PyCompile_OpcodeStackEffect(int opcode, int oparg)
return 0;
case SETUP_WITH:
return 7;
case WITH_CLEANUP:
case WITH_CLEANUP_START:
return 1;
case WITH_CLEANUP_FINISH:
return -1; /* XXX Sometimes more */
case RETURN_VALUE:
return -1;
@ -1048,6 +1056,16 @@ PyCompile_OpcodeStackEffect(int opcode, int oparg)
return -1;
case DELETE_DEREF:
return 0;
case GET_AWAITABLE:
return 0;
case SETUP_ASYNC_WITH:
return 6;
case BEFORE_ASYNC_WITH:
return 1;
case GET_AITER:
return 0;
case GET_ANEXT:
return 1;
default:
return PY_INVALID_STACK_EFFECT;
}
@ -1642,19 +1660,43 @@ error:
}
static int
compiler_function(struct compiler *c, stmt_ty s)
compiler_function(struct compiler *c, stmt_ty s, int is_async)
{
PyCodeObject *co;
PyObject *qualname, *first_const = Py_None;
arguments_ty args = s->v.FunctionDef.args;
expr_ty returns = s->v.FunctionDef.returns;
asdl_seq* decos = s->v.FunctionDef.decorator_list;
arguments_ty args;
expr_ty returns;
identifier name;
asdl_seq* decos;
asdl_seq *body;
stmt_ty st;
Py_ssize_t i, n, arglength;
int docstring, kw_default_count = 0;
int num_annotations;
int scope_type;
assert(s->kind == FunctionDef_kind);
if (is_async) {
assert(s->kind == AsyncFunctionDef_kind);
args = s->v.AsyncFunctionDef.args;
returns = s->v.AsyncFunctionDef.returns;
decos = s->v.AsyncFunctionDef.decorator_list;
name = s->v.AsyncFunctionDef.name;
body = s->v.AsyncFunctionDef.body;
scope_type = COMPILER_SCOPE_ASYNC_FUNCTION;
} else {
assert(s->kind == FunctionDef_kind);
args = s->v.FunctionDef.args;
returns = s->v.FunctionDef.returns;
decos = s->v.FunctionDef.decorator_list;
name = s->v.FunctionDef.name;
body = s->v.FunctionDef.body;
scope_type = COMPILER_SCOPE_FUNCTION;
}
if (!compiler_decorators(c, decos))
return 0;
@ -1672,12 +1714,12 @@ compiler_function(struct compiler *c, stmt_ty s)
return 0;
assert((num_annotations & 0xFFFF) == num_annotations);
if (!compiler_enter_scope(c, s->v.FunctionDef.name,
COMPILER_SCOPE_FUNCTION, (void *)s,
if (!compiler_enter_scope(c, name,
scope_type, (void *)s,
s->lineno))
return 0;
st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, 0);
st = (stmt_ty)asdl_seq_GET(body, 0);
docstring = compiler_isdocstring(st);
if (docstring && c->c_optimize < 2)
first_const = st->v.Expr.value->v.Str.s;
@ -1688,10 +1730,10 @@ compiler_function(struct compiler *c, stmt_ty s)
c->u->u_argcount = asdl_seq_LEN(args->args);
c->u->u_kwonlyargcount = asdl_seq_LEN(args->kwonlyargs);
n = asdl_seq_LEN(s->v.FunctionDef.body);
n = asdl_seq_LEN(body);
/* if there was a docstring, we need to skip the first statement */
for (i = docstring; i < n; i++) {
st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, i);
st = (stmt_ty)asdl_seq_GET(body, i);
VISIT_IN_SCOPE(c, stmt, st);
}
co = assemble(c, 1);
@ -1711,12 +1753,19 @@ compiler_function(struct compiler *c, stmt_ty s)
Py_DECREF(qualname);
Py_DECREF(co);
if (is_async) {
co->co_flags |= CO_COROUTINE;
/* An async function is always a generator, even
if there is no 'yield' expressions in it. */
co->co_flags |= CO_GENERATOR;
}
/* decorators */
for (i = 0; i < asdl_seq_LEN(decos); i++) {
ADDOP_I(c, CALL_FUNCTION, 1);
}
return compiler_nameop(c, s->v.FunctionDef.name, Store);
return compiler_nameop(c, name, Store);
}
static int
@ -1989,6 +2038,92 @@ compiler_for(struct compiler *c, stmt_ty s)
return 1;
}
static int
compiler_async_for(struct compiler *c, stmt_ty s)
{
static PyObject *stopiter_error = NULL;
basicblock *try, *except, *end, *after_try, *try_cleanup,
*after_loop, *after_loop_else;
if (stopiter_error == NULL) {
stopiter_error = PyUnicode_InternFromString("StopAsyncIteration");
if (stopiter_error == NULL)
return 0;
}
try = compiler_new_block(c);
except = compiler_new_block(c);
end = compiler_new_block(c);
after_try = compiler_new_block(c);
try_cleanup = compiler_new_block(c);
after_loop = compiler_new_block(c);
after_loop_else = compiler_new_block(c);
if (try == NULL || except == NULL || end == NULL
|| after_try == NULL || try_cleanup == NULL)
return 0;
ADDOP_JREL(c, SETUP_LOOP, after_loop);
if (!compiler_push_fblock(c, LOOP, try))
return 0;
VISIT(c, expr, s->v.AsyncFor.iter);
ADDOP(c, GET_AITER);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
compiler_use_next_block(c, try);
ADDOP_JREL(c, SETUP_EXCEPT, except);
if (!compiler_push_fblock(c, EXCEPT, try))
return 0;
ADDOP(c, GET_ANEXT);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
VISIT(c, expr, s->v.AsyncFor.target);
ADDOP(c, POP_BLOCK);
compiler_pop_fblock(c, EXCEPT, try);
ADDOP_JREL(c, JUMP_FORWARD, after_try);
compiler_use_next_block(c, except);
ADDOP(c, DUP_TOP);
ADDOP_O(c, LOAD_GLOBAL, stopiter_error, names);
ADDOP_I(c, COMPARE_OP, PyCmp_EXC_MATCH);
ADDOP_JABS(c, POP_JUMP_IF_FALSE, try_cleanup);
ADDOP(c, POP_TOP);
ADDOP(c, POP_TOP);
ADDOP(c, POP_TOP);
ADDOP(c, POP_EXCEPT); /* for SETUP_EXCEPT */
ADDOP(c, POP_BLOCK); /* for SETUP_LOOP */
ADDOP_JABS(c, JUMP_ABSOLUTE, after_loop_else);
compiler_use_next_block(c, try_cleanup);
ADDOP(c, END_FINALLY);
compiler_use_next_block(c, after_try);
VISIT_SEQ(c, stmt, s->v.AsyncFor.body);
ADDOP_JABS(c, JUMP_ABSOLUTE, try);
ADDOP(c, POP_BLOCK); /* for SETUP_LOOP */
compiler_pop_fblock(c, LOOP, try);
compiler_use_next_block(c, after_loop);
ADDOP_JABS(c, JUMP_ABSOLUTE, end);
compiler_use_next_block(c, after_loop_else);
VISIT_SEQ(c, stmt, s->v.For.orelse);
compiler_use_next_block(c, end);
return 1;
}
static int
compiler_while(struct compiler *c, stmt_ty s)
{
@ -2515,7 +2650,7 @@ compiler_visit_stmt(struct compiler *c, stmt_ty s)
switch (s->kind) {
case FunctionDef_kind:
return compiler_function(c, s);
return compiler_function(c, s, 0);
case ClassDef_kind:
return compiler_class(c, s);
case Return_kind:
@ -2594,7 +2729,14 @@ compiler_visit_stmt(struct compiler *c, stmt_ty s)
return compiler_continue(c);
case With_kind:
return compiler_with(c, s, 0);
case AsyncFunctionDef_kind:
return compiler_function(c, s, 1);
case AsyncWith_kind:
return compiler_async_with(c, s, 0);
case AsyncFor_kind:
return compiler_async_for(c, s);
}
return 1;
}
@ -3471,6 +3613,102 @@ expr_constant(struct compiler *c, expr_ty e)
}
}
/*
Implements the async with statement.
The semantics outlined in that PEP are as follows:
async with EXPR as VAR:
BLOCK
It is implemented roughly as:
context = EXPR
exit = context.__aexit__ # not calling it
value = await context.__aenter__()
try:
VAR = value # if VAR present in the syntax
BLOCK
finally:
if an exception was raised:
exc = copy of (exception, instance, traceback)
else:
exc = (None, None, None)
if not (await exit(*exc)):
raise
*/
static int
compiler_async_with(struct compiler *c, stmt_ty s, int pos)
{
basicblock *block, *finally;
withitem_ty item = asdl_seq_GET(s->v.AsyncWith.items, pos);
assert(s->kind == AsyncWith_kind);
block = compiler_new_block(c);
finally = compiler_new_block(c);
if (!block || !finally)
return 0;
/* Evaluate EXPR */
VISIT(c, expr, item->context_expr);
ADDOP(c, BEFORE_ASYNC_WITH);
ADDOP(c, GET_AWAITABLE);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
ADDOP_JREL(c, SETUP_ASYNC_WITH, finally);
/* SETUP_ASYNC_WITH pushes a finally block. */
compiler_use_next_block(c, block);
if (!compiler_push_fblock(c, FINALLY_TRY, block)) {
return 0;
}
if (item->optional_vars) {
VISIT(c, expr, item->optional_vars);
}
else {
/* Discard result from context.__aenter__() */
ADDOP(c, POP_TOP);
}
pos++;
if (pos == asdl_seq_LEN(s->v.AsyncWith.items))
/* BLOCK code */
VISIT_SEQ(c, stmt, s->v.AsyncWith.body)
else if (!compiler_async_with(c, s, pos))
return 0;
/* End of try block; start the finally block */
ADDOP(c, POP_BLOCK);
compiler_pop_fblock(c, FINALLY_TRY, block);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
compiler_use_next_block(c, finally);
if (!compiler_push_fblock(c, FINALLY_END, finally))
return 0;
/* Finally block starts; context.__exit__ is on the stack under
the exception or return information. Just issue our magic
opcode. */
ADDOP(c, WITH_CLEANUP_START);
ADDOP(c, GET_AWAITABLE);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
ADDOP(c, WITH_CLEANUP_FINISH);
/* Finally block ends. */
ADDOP(c, END_FINALLY);
compiler_pop_fblock(c, FINALLY_END, finally);
return 1;
}
/*
Implements the with statement from PEP 343.
@ -3544,7 +3782,8 @@ compiler_with(struct compiler *c, stmt_ty s, int pos)
/* Finally block starts; context.__exit__ is on the stack under
the exception or return information. Just issue our magic
opcode. */
ADDOP(c, WITH_CLEANUP);
ADDOP(c, WITH_CLEANUP_START);
ADDOP(c, WITH_CLEANUP_FINISH);
/* Finally block ends. */
ADDOP(c, END_FINALLY);
@ -3595,6 +3834,8 @@ compiler_visit_expr(struct compiler *c, expr_ty e)
case Yield_kind:
if (c->u->u_ste->ste_type != FunctionBlock)
return compiler_error(c, "'yield' outside function");
if (c->u->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION)
return compiler_error(c, "'yield' inside async function");
if (e->v.Yield.value) {
VISIT(c, expr, e->v.Yield.value);
}
@ -3606,11 +3847,28 @@ compiler_visit_expr(struct compiler *c, expr_ty e)
case YieldFrom_kind:
if (c->u->u_ste->ste_type != FunctionBlock)
return compiler_error(c, "'yield' outside function");
if (c->u->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION)
return compiler_error(c, "'yield from' inside async function");
VISIT(c, expr, e->v.YieldFrom.value);
ADDOP(c, GET_ITER);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
break;
case Await_kind:
if (c->u->u_ste->ste_type != FunctionBlock)
return compiler_error(c, "'await' outside function");
/* this check won't be triggered while we have AWAIT token */
if (c->u->u_scope_type != COMPILER_SCOPE_ASYNC_FUNCTION)
return compiler_error(c, "'await' outside async function");
VISIT(c, expr, e->v.Await.value);
ADDOP(c, GET_AWAITABLE);
ADDOP_O(c, LOAD_CONST, Py_None, consts);
ADDOP(c, YIELD_FROM);
break;
case Compare_kind:
return compiler_compare(c, e);
case Call_kind: