| #include "Python.h" |
| #include "Python-ast.h" |
| #include "code.h" |
| #include "symtable.h" |
| #include "structmember.h" |
| |
| /* two error strings used for warnings */ |
| #define GLOBAL_AFTER_ASSIGN \ |
| "name '%.400s' is assigned to before global declaration" |
| |
| #define GLOBAL_AFTER_USE \ |
| "name '%.400s' is used prior to global declaration" |
| |
| PySTEntryObject * |
| PySTEntry_New(struct symtable *st, identifier name, block_ty block, |
| void *key, int lineno) |
| { |
| PySTEntryObject *ste = NULL; |
| PyObject *k, *v; |
| |
| k = PyLong_FromVoidPtr(key); |
| if (k == NULL) |
| goto fail; |
| ste = (PySTEntryObject *)PyObject_New(PySTEntryObject, |
| &PySTEntry_Type); |
| ste->ste_table = st; |
| ste->ste_id = k; |
| ste->ste_tmpname = 0; |
| |
| ste->ste_name = name; |
| Py_INCREF(name); |
| |
| v = PyDict_New(); |
| if (v == NULL) |
| goto fail; |
| ste->ste_symbols = v; |
| |
| v = PyList_New(0); |
| if (v == NULL) |
| goto fail; |
| ste->ste_varnames = v; |
| |
| v = PyList_New(0); |
| if (v == NULL) |
| goto fail; |
| ste->ste_children = v; |
| |
| ste->ste_type = block; |
| ste->ste_unoptimized = 0; |
| ste->ste_nested = 0; |
| ste->ste_free = 0; |
| ste->ste_varargs = 0; |
| ste->ste_varkeywords = 0; |
| ste->ste_opt_lineno = 0; |
| ste->ste_tmpname = 0; |
| ste->ste_lineno = lineno; |
| |
| if (st->st_cur != NULL && |
| (st->st_cur->ste_nested || |
| st->st_cur->ste_type == FunctionBlock)) |
| ste->ste_nested = 1; |
| ste->ste_child_free = 0; |
| ste->ste_generator = 0; |
| |
| if (PyDict_SetItem(st->st_symbols, ste->ste_id, (PyObject *)ste) < 0) |
| goto fail; |
| |
| return ste; |
| fail: |
| Py_XDECREF(ste); |
| return NULL; |
| } |
| |
| static PyObject * |
| ste_repr(PySTEntryObject *ste) |
| { |
| char buf[256]; |
| |
| PyOS_snprintf(buf, sizeof(buf), |
| "<symtable entry %.100s(%ld), line %d>", |
| PyString_AS_STRING(ste->ste_name), |
| PyInt_AS_LONG(ste->ste_id), ste->ste_lineno); |
| return PyString_FromString(buf); |
| } |
| |
| static void |
| ste_dealloc(PySTEntryObject *ste) |
| { |
| ste->ste_table = NULL; |
| Py_XDECREF(ste->ste_id); |
| Py_XDECREF(ste->ste_name); |
| Py_XDECREF(ste->ste_symbols); |
| Py_XDECREF(ste->ste_varnames); |
| Py_XDECREF(ste->ste_children); |
| PyObject_Del(ste); |
| } |
| |
| #define OFF(x) offsetof(PySTEntryObject, x) |
| |
| static PyMemberDef ste_memberlist[] = { |
| {"id", T_OBJECT, OFF(ste_id), READONLY}, |
| {"name", T_OBJECT, OFF(ste_name), READONLY}, |
| {"symbols", T_OBJECT, OFF(ste_symbols), READONLY}, |
| {"varnames", T_OBJECT, OFF(ste_varnames), READONLY}, |
| {"children", T_OBJECT, OFF(ste_children), READONLY}, |
| {"type", T_INT, OFF(ste_type), READONLY}, |
| {"lineno", T_INT, OFF(ste_lineno), READONLY}, |
| {NULL} |
| }; |
| |
| PyTypeObject PySTEntry_Type = { |
| PyObject_HEAD_INIT(&PyType_Type) |
| 0, |
| "symtable entry", |
| sizeof(PySTEntryObject), |
| 0, |
| (destructor)ste_dealloc, /* tp_dealloc */ |
| 0, /* tp_print */ |
| 0, /* tp_getattr */ |
| 0, /* tp_setattr */ |
| 0, /* tp_compare */ |
| (reprfunc)ste_repr, /* tp_repr */ |
| 0, /* tp_as_number */ |
| 0, /* tp_as_sequence */ |
| 0, /* tp_as_mapping */ |
| 0, /* tp_hash */ |
| 0, /* tp_call */ |
| 0, /* tp_str */ |
| PyObject_GenericGetAttr, /* tp_getattro */ |
| 0, /* tp_setattro */ |
| 0, /* tp_as_buffer */ |
| Py_TPFLAGS_DEFAULT, /* tp_flags */ |
| 0, /* tp_doc */ |
| 0, /* tp_traverse */ |
| 0, /* tp_clear */ |
| 0, /* tp_richcompare */ |
| 0, /* tp_weaklistoffset */ |
| 0, /* tp_iter */ |
| 0, /* tp_iternext */ |
| 0, /* tp_methods */ |
| ste_memberlist, /* tp_members */ |
| 0, /* tp_getset */ |
| 0, /* tp_base */ |
| 0, /* tp_dict */ |
| 0, /* tp_descr_get */ |
| 0, /* tp_descr_set */ |
| 0, /* tp_dictoffset */ |
| 0, /* tp_init */ |
| 0, /* tp_alloc */ |
| 0, /* tp_new */ |
| }; |
| |
| static int symtable_analyze(struct symtable *st); |
| static int symtable_warn(struct symtable *st, char *msg); |
| static int symtable_enter_block(struct symtable *st, identifier name, |
| block_ty block, void *ast, int lineno); |
| static int symtable_exit_block(struct symtable *st, void *ast); |
| static int symtable_visit_stmt(struct symtable *st, stmt_ty s); |
| static int symtable_visit_expr(struct symtable *st, expr_ty s); |
| static int symtable_visit_genexp(struct symtable *st, expr_ty s); |
| static int symtable_visit_arguments(struct symtable *st, arguments_ty); |
| static int symtable_visit_excepthandler(struct symtable *st, excepthandler_ty); |
| static int symtable_visit_alias(struct symtable *st, alias_ty); |
| static int symtable_visit_comprehension(struct symtable *st, comprehension_ty); |
| static int symtable_visit_keyword(struct symtable *st, keyword_ty); |
| static int symtable_visit_slice(struct symtable *st, slice_ty); |
| static int symtable_visit_params(struct symtable *st, asdl_seq *args, int top); |
| static int symtable_visit_params_nested(struct symtable *st, asdl_seq *args); |
| static int symtable_implicit_arg(struct symtable *st, int pos); |
| |
| |
| static identifier top = NULL, lambda = NULL; |
| |
| #define GET_IDENTIFIER(VAR) \ |
| ((VAR) ? (VAR) : ((VAR) = PyString_InternFromString(# VAR))) |
| |
| #define DUPLICATE_ARGUMENT \ |
| "duplicate argument '%s' in function definition" |
| |
| static struct symtable * |
| symtable_new(void) |
| { |
| struct symtable *st; |
| |
| st = (struct symtable *)PyMem_Malloc(sizeof(struct symtable)); |
| if (st == NULL) |
| return NULL; |
| |
| st->st_filename = NULL; |
| if ((st->st_stack = PyList_New(0)) == NULL) |
| goto fail; |
| if ((st->st_symbols = PyDict_New()) == NULL) |
| goto fail; |
| st->st_cur = NULL; |
| st->st_tmpname = 0; |
| st->st_private = NULL; |
| return st; |
| fail: |
| PySymtable_Free(st); |
| return NULL; |
| } |
| |
| struct symtable * |
| PySymtable_Build(mod_ty mod, const char *filename, PyFutureFeatures *future) |
| { |
| struct symtable *st = symtable_new(); |
| asdl_seq *seq; |
| int i; |
| |
| if (st == NULL) |
| return st; |
| st->st_filename = filename; |
| st->st_future = future; |
| symtable_enter_block(st, GET_IDENTIFIER(top), ModuleBlock, |
| (void *)mod, 0); |
| st->st_top = st->st_cur; |
| st->st_cur->ste_unoptimized = OPT_TOPLEVEL; |
| /* Any other top-level initialization? */ |
| switch (mod->kind) { |
| case Module_kind: |
| seq = mod->v.Module.body; |
| for (i = 0; i < asdl_seq_LEN(seq); i++) |
| if (!symtable_visit_stmt(st, asdl_seq_GET(seq, i))) |
| goto error; |
| break; |
| case Expression_kind: |
| if (!symtable_visit_expr(st, mod->v.Expression.body)) |
| goto error; |
| break; |
| case Interactive_kind: |
| seq = mod->v.Interactive.body; |
| for (i = 0; i < asdl_seq_LEN(seq); i++) |
| if (!symtable_visit_stmt(st, asdl_seq_GET(seq, i))) |
| goto error; |
| break; |
| case Suite_kind: |
| PyErr_SetString(PyExc_RuntimeError, |
| "this compiler does not handle Suites"); |
| return NULL; |
| } |
| if (!symtable_exit_block(st, (void *)mod)) |
| return NULL; |
| if (symtable_analyze(st)) |
| return st; |
| error: |
| PySymtable_Free(st); |
| return NULL; |
| } |
| |
| void |
| PySymtable_Free(struct symtable *st) |
| { |
| Py_XDECREF(st->st_symbols); |
| Py_XDECREF(st->st_stack); |
| PyMem_Free((void *)st); |
| } |
| |
| PySTEntryObject * |
| PySymtable_Lookup(struct symtable *st, void *key) |
| { |
| PyObject *k, *v; |
| |
| k = PyLong_FromVoidPtr(key); |
| if (k == NULL) |
| return NULL; |
| v = PyDict_GetItem(st->st_symbols, k); |
| if (v) { |
| assert(PySTEntry_Check(v)); |
| Py_DECREF(k); |
| Py_INCREF(v); |
| return (PySTEntryObject *)v; |
| } |
| else { |
| PyErr_SetString(PyExc_KeyError, |
| "unknown symbol table entry"); |
| return NULL; |
| } |
| } |
| |
| int |
| PyST_GetScope(PySTEntryObject *ste, PyObject *name) |
| { |
| PyObject *v = PyDict_GetItem(ste->ste_symbols, name); |
| if (!v) |
| return 0; |
| assert(PyInt_Check(v)); |
| return (PyInt_AS_LONG(v) >> SCOPE_OFF) & SCOPE_MASK; |
| } |
| |
| |
| /* Analyze raw symbol information to determine scope of each name. |
| |
| The next several functions are helpers for PySymtable_Analyze(), |
| which determines whether a name is local, global, or free. In addition, |
| it determines which local variables are cell variables; they provide |
| bindings that are used for free variables in enclosed blocks. |
| |
| There are also two kinds of free variables, implicit and explicit. An |
| explicit global is declared with the global statement. An implicit |
| global is a free variable for which the compiler has found no binding |
| in an enclosing function scope. The implicit global is either a global |
| or a builtin. Python's module and class blocks use the xxx_NAME opcodes |
| to handle these names to implement slightly odd semantics. In such a |
| block, the name is treated as global until it is assigned to; then it |
| is treated as a local. |
| |
| The symbol table requires two passes to determine the scope of each name. |
| The first pass collects raw facts from the AST: the name is a parameter |
| here, the name is used by not defined here, etc. The second pass analyzes |
| these facts during a pass over the PySTEntryObjects created during pass 1. |
| |
| When a function is entered during the second pass, the parent passes |
| the set of all name bindings visible to its children. These bindings |
| are used to determine if the variable is free or an implicit global. |
| After doing the local analysis, it analyzes each of its child blocks |
| using an updated set of name bindings. |
| |
| The children update the free variable set. If a local variable is free |
| in a child, the variable is marked as a cell. The current function must |
| provide runtime storage for the variable that may outlive the function's |
| frame. Cell variables are removed from the free set before the analyze |
| function returns to its parent. |
| |
| The sets of bound and free variables are implemented as dictionaries |
| mapping strings to None. |
| */ |
| |
| #define SET_SCOPE(DICT, NAME, I) { \ |
| PyObject *o = PyInt_FromLong(I); \ |
| if (!o) \ |
| return 0; \ |
| if (PyDict_SetItem((DICT), (NAME), o) < 0) \ |
| return 0; \ |
| } |
| |
| /* Decide on scope of name, given flags. |
| |
| The dicts passed in as arguments are modified as necessary. |
| ste is passed so that flags can be updated. |
| */ |
| |
| static int |
| analyze_name(PySTEntryObject *ste, PyObject *dict, PyObject *name, int flags, |
| PyObject *bound, PyObject *local, PyObject *free, |
| PyObject *global) |
| { |
| if (flags & DEF_GLOBAL) { |
| if (flags & DEF_PARAM) { |
| PyErr_Format(PyExc_SyntaxError, |
| "name '%s' is local and global", |
| PyString_AS_STRING(name)); |
| return 0; |
| } |
| SET_SCOPE(dict, name, GLOBAL_EXPLICIT); |
| if (PyDict_SetItem(global, name, Py_None) < 0) |
| return 0; |
| if (bound && PyDict_GetItem(bound, name)) { |
| if (PyDict_DelItem(bound, name) < 0) |
| return 0; |
| } |
| return 1; |
| } |
| if (flags & DEF_BOUND) { |
| SET_SCOPE(dict, name, LOCAL); |
| if (PyDict_SetItem(local, name, Py_None) < 0) |
| return 0; |
| if (PyDict_GetItem(global, name)) { |
| if (PyDict_DelItem(global, name) < 0) |
| return 0; |
| } |
| return 1; |
| } |
| /* If an enclosing block has a binding for this name, it |
| is a free variable rather than a global variable. |
| Note that having a non-NULL bound implies that the block |
| is nested. |
| */ |
| if (bound && PyDict_GetItem(bound, name)) { |
| SET_SCOPE(dict, name, FREE); |
| ste->ste_free = 1; |
| if (PyDict_SetItem(free, name, Py_None) < 0) |
| return 0; |
| return 1; |
| } |
| /* If a parent has a global statement, then call it global |
| explicit? It could also be global implicit. |
| */ |
| else if (global && PyDict_GetItem(global, name)) { |
| SET_SCOPE(dict, name, GLOBAL_EXPLICIT); |
| return 1; |
| } |
| else { |
| if (ste->ste_nested) |
| ste->ste_free = 1; |
| SET_SCOPE(dict, name, GLOBAL_IMPLICIT); |
| return 1; |
| } |
| return 0; /* Can't get here */ |
| } |
| |
| #undef SET_SCOPE |
| |
| /* If a name is defined in free and also in locals, then this block |
| provides the binding for the free variable. The name should be |
| marked CELL in this block and removed from the free list. |
| |
| Note that the current block's free variables are included in free. |
| That's safe because no name can be free and local in the same scope. |
| */ |
| |
| static int |
| analyze_cells(PyObject *scope, PyObject *free) |
| { |
| PyObject *name, *v, *w; |
| int flags, pos = 0, success = 0; |
| |
| w = PyInt_FromLong(CELL); |
| if (!w) |
| return 0; |
| while (PyDict_Next(scope, &pos, &name, &v)) { |
| assert(PyInt_Check(v)); |
| flags = PyInt_AS_LONG(v); |
| if (flags != LOCAL) |
| continue; |
| if (!PyDict_GetItem(free, name)) |
| continue; |
| /* Replace LOCAL with CELL for this name, and remove |
| from free. It is safe to replace the value of name |
| in the dict, because it will not cause a resize. |
| */ |
| if (PyDict_SetItem(scope, name, w) < 0) |
| goto error; |
| if (!PyDict_DelItem(free, name) < 0) |
| goto error; |
| } |
| success = 1; |
| error: |
| Py_DECREF(w); |
| return success; |
| } |
| |
| /* Check for illegal statements in unoptimized namespaces */ |
| static int |
| check_unoptimized(const PySTEntryObject* ste) { |
| char buf[300]; |
| const char* trailer; |
| |
| if (ste->ste_type != FunctionBlock || !ste->ste_unoptimized |
| || !(ste->ste_free || ste->ste_child_free)) |
| return 1; |
| |
| trailer = (ste->ste_child_free ? |
| "contains a nested function with free variables" : |
| "is a nested function"); |
| |
| switch (ste->ste_unoptimized) { |
| case OPT_TOPLEVEL: /* exec / import * at top-level is fine */ |
| case OPT_EXEC: /* qualified exec is fine */ |
| return 1; |
| case OPT_IMPORT_STAR: |
| PyOS_snprintf(buf, sizeof(buf), |
| "import * is not allowed in function '%.100s' " |
| "because it is %s", |
| PyString_AS_STRING(ste->ste_name), trailer); |
| break; |
| case OPT_BARE_EXEC: |
| PyOS_snprintf(buf, sizeof(buf), |
| "unqualified exec is not allowed in function " |
| "'%.100s' it %s", |
| PyString_AS_STRING(ste->ste_name), trailer); |
| break; |
| default: |
| PyOS_snprintf(buf, sizeof(buf), |
| "function '%.100s' uses import * and bare exec, " |
| "which are illegal because it %s", |
| PyString_AS_STRING(ste->ste_name), trailer); |
| break; |
| } |
| |
| PyErr_SetString(PyExc_SyntaxError, buf); |
| PyErr_SyntaxLocation(ste->ste_table->st_filename, |
| ste->ste_opt_lineno); |
| return 0; |
| } |
| |
| /* Enter the final scope information into the st_symbols dict. |
| * |
| * All arguments are dicts. Modifies symbols, others are read-only. |
| */ |
| static int |
| update_symbols(PyObject *symbols, PyObject *scope, |
| PyObject *bound, PyObject *free, int class) |
| { |
| PyObject *name, *v, *u, *w, *free_value = NULL; |
| int i, flags, pos = 0; |
| |
| while (PyDict_Next(symbols, &pos, &name, &v)) { |
| assert(PyInt_Check(v)); |
| flags = PyInt_AS_LONG(v); |
| w = PyDict_GetItem(scope, name); |
| assert(w && PyInt_Check(w)); |
| i = PyInt_AS_LONG(w); |
| flags |= (i << SCOPE_OFF); |
| u = PyInt_FromLong(flags); |
| if (PyDict_SetItem(symbols, name, u) < 0) { |
| Py_DECREF(u); |
| return 0; |
| } |
| Py_DECREF(u); |
| } |
| |
| free_value = PyInt_FromLong(FREE << SCOPE_OFF); |
| if (!free_value) |
| return 0; |
| |
| /* add a free variable when it's only use is for creating a closure */ |
| pos = 0; |
| while (PyDict_Next(free, &pos, &name, &v)) { |
| PyObject *o = PyDict_GetItem(symbols, name); |
| |
| if (o) { |
| /* It could be a free variable in a method of |
| the class that has the same name as a local |
| or global in the class scope. |
| */ |
| if (class && |
| PyInt_AS_LONG(o) & (DEF_BOUND | DEF_GLOBAL)) { |
| int i = PyInt_AS_LONG(o) | DEF_FREE_CLASS; |
| o = PyInt_FromLong(i); |
| if (!o) { |
| Py_DECREF(free_value); |
| return 0; |
| } |
| if (PyDict_SetItem(symbols, name, o) < 0) { |
| Py_DECREF(o); |
| Py_DECREF(free_value); |
| return 0; |
| } |
| } |
| /* else it's not free, probably a cell */ |
| continue; |
| } |
| if (!PyDict_GetItem(bound, name)) |
| continue; /* it's a global */ |
| |
| if (PyDict_SetItem(symbols, name, free_value) < 0) { |
| Py_DECREF(free_value); |
| return 0; |
| } |
| } |
| Py_DECREF(free_value); |
| return 1; |
| } |
| |
| /* Make final symbol table decisions for block of ste. |
| Arguments: |
| ste -- current symtable entry (input/output) |
| bound -- set of variables bound in enclosing scopes (input) |
| free -- set of free variables in enclosed scopes (output) |
| globals -- set of declared global variables in enclosing scopes (input) |
| */ |
| |
| static int |
| analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free, |
| PyObject *global) |
| { |
| PyObject *name, *v, *local = NULL, *scope = NULL, *newbound = NULL; |
| PyObject *newglobal = NULL, *newfree = NULL; |
| int i, flags, pos = 0, success = 0; |
| |
| local = PyDict_New(); |
| if (!local) |
| goto error; |
| scope = PyDict_New(); |
| if (!scope) |
| goto error; |
| newglobal = PyDict_New(); |
| if (!newglobal) |
| goto error; |
| newfree = PyDict_New(); |
| if (!newfree) |
| goto error; |
| newbound = PyDict_New(); |
| if (!newbound) |
| goto error; |
| |
| if (ste->ste_type == ClassBlock) { |
| /* make a copy of globals before calling analyze_name(), |
| because global statements in the class have no effect |
| on nested functions. |
| */ |
| if (PyDict_Update(newglobal, global) < 0) |
| goto error; |
| if (bound) |
| if (PyDict_Update(newbound, bound) < 0) |
| goto error; |
| } |
| |
| assert(PySTEntry_Check(ste)); |
| assert(PyDict_Check(ste->ste_symbols)); |
| while (PyDict_Next(ste->ste_symbols, &pos, &name, &v)) { |
| flags = PyInt_AS_LONG(v); |
| if (!analyze_name(ste, scope, name, flags, bound, local, free, |
| global)) |
| goto error; |
| } |
| |
| if (ste->ste_type != ClassBlock) { |
| if (ste->ste_type == FunctionBlock) { |
| if (PyDict_Update(newbound, local) < 0) |
| goto error; |
| } |
| if (bound) { |
| if (PyDict_Update(newbound, bound) < 0) |
| goto error; |
| } |
| if (PyDict_Update(newglobal, global) < 0) |
| goto error; |
| } |
| |
| /* Recursively call analyze_block() on each child block */ |
| for (i = 0; i < PyList_GET_SIZE(ste->ste_children); ++i) { |
| PyObject *c = PyList_GET_ITEM(ste->ste_children, i); |
| PySTEntryObject* entry; |
| assert(c && PySTEntry_Check(c)); |
| entry = (PySTEntryObject*)c; |
| if (!analyze_block(entry, newbound, newfree, newglobal)) |
| goto error; |
| if (entry->ste_free || entry->ste_child_free) |
| ste->ste_child_free = 1; |
| } |
| |
| if (ste->ste_type == FunctionBlock && !analyze_cells(scope, newfree)) |
| goto error; |
| if (!update_symbols(ste->ste_symbols, scope, bound, newfree, |
| ste->ste_type == ClassBlock)) |
| goto error; |
| if (!check_unoptimized(ste)) |
| goto error; |
| |
| if (PyDict_Update(free, newfree) < 0) |
| goto error; |
| success = 1; |
| error: |
| Py_XDECREF(local); |
| Py_XDECREF(scope); |
| Py_XDECREF(newbound); |
| Py_XDECREF(newglobal); |
| Py_XDECREF(newfree); |
| if (!success) |
| assert(PyErr_Occurred()); |
| return success; |
| } |
| |
| static int |
| symtable_analyze(struct symtable *st) |
| { |
| PyObject *free, *global; |
| int r; |
| |
| free = PyDict_New(); |
| if (!free) |
| return 0; |
| global = PyDict_New(); |
| if (!global) { |
| Py_DECREF(global); |
| return 0; |
| } |
| r = analyze_block(st->st_top, NULL, free, global); |
| Py_DECREF(free); |
| Py_DECREF(global); |
| return r; |
| } |
| |
| |
| static int |
| symtable_warn(struct symtable *st, char *msg) |
| { |
| if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, st->st_filename, |
| st->st_cur->ste_lineno, NULL, NULL) < 0) { |
| if (PyErr_ExceptionMatches(PyExc_SyntaxWarning)) { |
| PyErr_SetString(PyExc_SyntaxError, msg); |
| PyErr_SyntaxLocation(st->st_filename, |
| st->st_cur->ste_lineno); |
| } |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* symtable_enter_block() gets a reference via PySTEntry_New(). |
| This reference is released when the block is exited, via the DECREF |
| in symtable_exit_block(). |
| */ |
| |
| static int |
| symtable_exit_block(struct symtable *st, void *ast) |
| { |
| int end; |
| |
| Py_DECREF(st->st_cur); |
| end = PyList_GET_SIZE(st->st_stack) - 1; |
| if (end >= 0) { |
| st->st_cur = (PySTEntryObject *)PyList_GET_ITEM(st->st_stack, |
| end); |
| Py_INCREF(st->st_cur); |
| if (PySequence_DelItem(st->st_stack, end) < 0) |
| return 0; |
| } |
| return 1; |
| } |
| |
| static int |
| symtable_enter_block(struct symtable *st, identifier name, block_ty block, |
| void *ast, int lineno) |
| { |
| PySTEntryObject *prev = NULL; |
| |
| if (st->st_cur) { |
| prev = st->st_cur; |
| if (PyList_Append(st->st_stack, (PyObject *)st->st_cur) < 0) { |
| Py_DECREF(st->st_cur); |
| return 0; |
| } |
| Py_DECREF(st->st_cur); |
| } |
| st->st_cur = PySTEntry_New(st, name, block, ast, lineno); |
| if (name == GET_IDENTIFIER(top)) |
| st->st_global = st->st_cur->ste_symbols; |
| if (prev) { |
| if (PyList_Append(prev->ste_children, |
| (PyObject *)st->st_cur) < 0) { |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| static int |
| symtable_lookup(struct symtable *st, PyObject *name) |
| { |
| PyObject *o; |
| PyObject *mangled = _Py_Mangle(st->st_private, name); |
| if (!mangled) |
| return 0; |
| o = PyDict_GetItem(st->st_cur->ste_symbols, mangled); |
| Py_DECREF(mangled); |
| if (!o) |
| return 0; |
| return PyInt_AsLong(o); |
| } |
| |
| static int |
| symtable_add_def(struct symtable *st, PyObject *name, int flag) |
| { |
| PyObject *o; |
| PyObject *dict; |
| int val; |
| PyObject *mangled = _Py_Mangle(st->st_private, name); |
| |
| if (!mangled) |
| return 0; |
| dict = st->st_cur->ste_symbols; |
| if ((o = PyDict_GetItem(dict, mangled))) { |
| val = PyInt_AS_LONG(o); |
| if ((flag & DEF_PARAM) && (val & DEF_PARAM)) { |
| /* Is it better to use 'mangled' or 'name' here? */ |
| PyErr_Format(PyExc_SyntaxError, DUPLICATE_ARGUMENT, |
| PyString_AsString(name)); |
| PyErr_SyntaxLocation(st->st_filename, |
| st->st_cur->ste_lineno); |
| goto error; |
| } |
| val |= flag; |
| } else |
| val = flag; |
| o = PyInt_FromLong(val); |
| if (o == NULL) |
| goto error; |
| if (PyDict_SetItem(dict, mangled, o) < 0) { |
| Py_DECREF(o); |
| goto error; |
| } |
| Py_DECREF(o); |
| |
| if (flag & DEF_PARAM) { |
| if (PyList_Append(st->st_cur->ste_varnames, mangled) < 0) |
| goto error; |
| } else if (flag & DEF_GLOBAL) { |
| /* XXX need to update DEF_GLOBAL for other flags too; |
| perhaps only DEF_FREE_GLOBAL */ |
| val = flag; |
| if ((o = PyDict_GetItem(st->st_global, mangled))) { |
| val |= PyInt_AS_LONG(o); |
| } |
| o = PyInt_FromLong(val); |
| if (o == NULL) |
| goto error; |
| if (PyDict_SetItem(st->st_global, mangled, o) < 0) { |
| Py_DECREF(o); |
| goto error; |
| } |
| Py_DECREF(o); |
| } |
| return 1; |
| |
| error: |
| Py_DECREF(mangled); |
| return 0; |
| } |
| |
| /* VISIT, VISIT_SEQ and VIST_SEQ_TAIL take an ASDL type as their second argument. |
| They use the ASDL name to synthesize the name of the C type and the visit |
| function. |
| |
| VISIT_SEQ_TAIL permits the start of an ASDL sequence to be skipped, which is |
| useful if the first node in the sequence requires special treatment. |
| */ |
| |
| #define VISIT(ST, TYPE, V) \ |
| if (!symtable_visit_ ## TYPE((ST), (V))) \ |
| return 0; |
| |
| #define VISIT_SEQ(ST, TYPE, SEQ) { \ |
| int i; \ |
| asdl_seq *seq = (SEQ); /* avoid variable capture */ \ |
| for (i = 0; i < asdl_seq_LEN(seq); i++) { \ |
| TYPE ## _ty elt = asdl_seq_GET(seq, i); \ |
| if (!symtable_visit_ ## TYPE((ST), elt)) \ |
| return 0; \ |
| } \ |
| } |
| |
| #define VISIT_SEQ_TAIL(ST, TYPE, SEQ, START) { \ |
| int i; \ |
| asdl_seq *seq = (SEQ); /* avoid variable capture */ \ |
| for (i = (START); i < asdl_seq_LEN(seq); i++) { \ |
| TYPE ## _ty elt = asdl_seq_GET(seq, i); \ |
| if (!symtable_visit_ ## TYPE((ST), elt)) \ |
| return 0; \ |
| } \ |
| } |
| |
| static int |
| symtable_visit_stmt(struct symtable *st, stmt_ty s) |
| { |
| switch (s->kind) { |
| case FunctionDef_kind: |
| if (!symtable_add_def(st, s->v.FunctionDef.name, DEF_LOCAL)) |
| return 0; |
| if (s->v.FunctionDef.args->defaults) |
| VISIT_SEQ(st, expr, s->v.FunctionDef.args->defaults); |
| if (s->v.FunctionDef.decorators) |
| VISIT_SEQ(st, expr, s->v.FunctionDef.decorators); |
| if (!symtable_enter_block(st, s->v.FunctionDef.name, |
| FunctionBlock, (void *)s, s->lineno)) |
| return 0; |
| VISIT(st, arguments, s->v.FunctionDef.args); |
| VISIT_SEQ(st, stmt, s->v.FunctionDef.body); |
| if (!symtable_exit_block(st, s)) |
| return 0; |
| break; |
| case ClassDef_kind: { |
| PyObject *tmp; |
| if (!symtable_add_def(st, s->v.ClassDef.name, DEF_LOCAL)) |
| return 0; |
| VISIT_SEQ(st, expr, s->v.ClassDef.bases); |
| if (!symtable_enter_block(st, s->v.ClassDef.name, ClassBlock, |
| (void *)s, s->lineno)) |
| return 0; |
| tmp = st->st_private; |
| st->st_private = s->v.ClassDef.name; |
| VISIT_SEQ(st, stmt, s->v.ClassDef.body); |
| st->st_private = tmp; |
| if (!symtable_exit_block(st, s)) |
| return 0; |
| break; |
| } |
| case Return_kind: |
| if (s->v.Return.value) |
| VISIT(st, expr, s->v.Return.value); |
| break; |
| case Delete_kind: |
| VISIT_SEQ(st, expr, s->v.Delete.targets); |
| break; |
| case Assign_kind: |
| VISIT_SEQ(st, expr, s->v.Assign.targets); |
| VISIT(st, expr, s->v.Assign.value); |
| break; |
| case AugAssign_kind: |
| VISIT(st, expr, s->v.AugAssign.target); |
| VISIT(st, expr, s->v.AugAssign.value); |
| break; |
| case Print_kind: |
| if (s->v.Print.dest) |
| VISIT(st, expr, s->v.Print.dest); |
| VISIT_SEQ(st, expr, s->v.Print.values); |
| break; |
| case For_kind: |
| VISIT(st, expr, s->v.For.target); |
| VISIT(st, expr, s->v.For.iter); |
| VISIT_SEQ(st, stmt, s->v.For.body); |
| if (s->v.For.orelse) |
| VISIT_SEQ(st, stmt, s->v.For.orelse); |
| break; |
| case While_kind: |
| VISIT(st, expr, s->v.While.test); |
| VISIT_SEQ(st, stmt, s->v.While.body); |
| if (s->v.While.orelse) |
| VISIT_SEQ(st, stmt, s->v.While.orelse); |
| break; |
| case If_kind: |
| /* XXX if 0: and lookup_yield() hacks */ |
| VISIT(st, expr, s->v.If.test); |
| VISIT_SEQ(st, stmt, s->v.If.body); |
| if (s->v.If.orelse) |
| VISIT_SEQ(st, stmt, s->v.If.orelse); |
| break; |
| case Raise_kind: |
| if (s->v.Raise.type) { |
| VISIT(st, expr, s->v.Raise.type); |
| if (s->v.Raise.inst) { |
| VISIT(st, expr, s->v.Raise.inst); |
| if (s->v.Raise.tback) |
| VISIT(st, expr, s->v.Raise.tback); |
| } |
| } |
| break; |
| case TryExcept_kind: |
| VISIT_SEQ(st, stmt, s->v.TryExcept.body); |
| VISIT_SEQ(st, stmt, s->v.TryExcept.orelse); |
| VISIT_SEQ(st, excepthandler, s->v.TryExcept.handlers); |
| break; |
| case TryFinally_kind: |
| VISIT_SEQ(st, stmt, s->v.TryFinally.body); |
| VISIT_SEQ(st, stmt, s->v.TryFinally.finalbody); |
| break; |
| case Assert_kind: |
| VISIT(st, expr, s->v.Assert.test); |
| if (s->v.Assert.msg) |
| VISIT(st, expr, s->v.Assert.msg); |
| break; |
| case Import_kind: |
| VISIT_SEQ(st, alias, s->v.Import.names); |
| /* XXX Don't have the lineno available inside |
| visit_alias */ |
| if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno) |
| st->st_cur->ste_opt_lineno = s->lineno; |
| break; |
| case ImportFrom_kind: |
| VISIT_SEQ(st, alias, s->v.ImportFrom.names); |
| /* XXX Don't have the lineno available inside |
| visit_alias */ |
| if (st->st_cur->ste_unoptimized && !st->st_cur->ste_opt_lineno) |
| st->st_cur->ste_opt_lineno = s->lineno; |
| break; |
| case Exec_kind: |
| VISIT(st, expr, s->v.Exec.body); |
| if (!st->st_cur->ste_opt_lineno) |
| st->st_cur->ste_opt_lineno = s->lineno; |
| if (s->v.Exec.globals) { |
| st->st_cur->ste_unoptimized |= OPT_EXEC; |
| VISIT(st, expr, s->v.Exec.globals); |
| if (s->v.Exec.locals) |
| VISIT(st, expr, s->v.Exec.locals); |
| } else { |
| st->st_cur->ste_unoptimized |= OPT_BARE_EXEC; |
| } |
| break; |
| case Global_kind: { |
| int i; |
| asdl_seq *seq = s->v.Global.names; |
| for (i = 0; i < asdl_seq_LEN(seq); i++) { |
| identifier name = asdl_seq_GET(seq, i); |
| char *c_name = PyString_AS_STRING(name); |
| int cur = symtable_lookup(st, name); |
| if (cur < 0) |
| return 0; |
| if (cur & (DEF_LOCAL | USE)) { |
| char buf[1000]; |
| if (cur & DEF_LOCAL) |
| PyOS_snprintf(buf, sizeof(buf), |
| GLOBAL_AFTER_ASSIGN, |
| c_name); |
| else |
| PyOS_snprintf(buf, sizeof(buf), |
| GLOBAL_AFTER_USE, |
| c_name); |
| if (!symtable_warn(st, buf)) |
| return 0; |
| } |
| if (!symtable_add_def(st, name, DEF_GLOBAL)) |
| return 0; |
| |
| } |
| |
| break; |
| } |
| case Expr_kind: |
| VISIT(st, expr, s->v.Expr.value); |
| break; |
| case Pass_kind: |
| case Break_kind: |
| case Continue_kind: |
| /* nothing to do here */ |
| break; |
| } |
| return 1; |
| } |
| |
| static int |
| symtable_visit_expr(struct symtable *st, expr_ty e) |
| { |
| switch (e->kind) { |
| case BoolOp_kind: |
| VISIT_SEQ(st, expr, e->v.BoolOp.values); |
| break; |
| case BinOp_kind: |
| VISIT(st, expr, e->v.BinOp.left); |
| VISIT(st, expr, e->v.BinOp.right); |
| break; |
| case UnaryOp_kind: |
| VISIT(st, expr, e->v.UnaryOp.operand); |
| break; |
| case Lambda_kind: { |
| if (!symtable_add_def(st, GET_IDENTIFIER(lambda), DEF_LOCAL)) |
| return 0; |
| if (e->v.Lambda.args->defaults) |
| VISIT_SEQ(st, expr, e->v.Lambda.args->defaults); |
| /* XXX how to get line numbers for expressions */ |
| if (!symtable_enter_block(st, GET_IDENTIFIER(lambda), |
| FunctionBlock, (void *)e, 0)) |
| return 0; |
| VISIT(st, arguments, e->v.Lambda.args); |
| VISIT(st, expr, e->v.Lambda.body); |
| if (!symtable_exit_block(st, (void *)e)) |
| return 0; |
| break; |
| } |
| case Dict_kind: |
| VISIT_SEQ(st, expr, e->v.Dict.keys); |
| VISIT_SEQ(st, expr, e->v.Dict.values); |
| break; |
| case ListComp_kind: { |
| char tmpname[256]; |
| identifier tmp; |
| |
| PyOS_snprintf(tmpname, sizeof(tmpname), "_[%d]", |
| ++st->st_cur->ste_tmpname); |
| tmp = PyString_FromString(tmpname); |
| if (!symtable_add_def(st, tmp, DEF_LOCAL)) |
| return 0; |
| VISIT(st, expr, e->v.ListComp.elt); |
| VISIT_SEQ(st, comprehension, e->v.ListComp.generators); |
| break; |
| } |
| case GeneratorExp_kind: { |
| if (!symtable_visit_genexp(st, e)) { |
| return 0; |
| } |
| break; |
| } |
| case Yield_kind: |
| if (e->v.Yield.value) |
| VISIT(st, expr, e->v.Yield.value); |
| st->st_cur->ste_generator = 1; |
| break; |
| case Compare_kind: |
| VISIT(st, expr, e->v.Compare.left); |
| VISIT_SEQ(st, expr, e->v.Compare.comparators); |
| break; |
| case Call_kind: |
| VISIT(st, expr, e->v.Call.func); |
| VISIT_SEQ(st, expr, e->v.Call.args); |
| VISIT_SEQ(st, keyword, e->v.Call.keywords); |
| if (e->v.Call.starargs) |
| VISIT(st, expr, e->v.Call.starargs); |
| if (e->v.Call.kwargs) |
| VISIT(st, expr, e->v.Call.kwargs); |
| break; |
| case Repr_kind: |
| VISIT(st, expr, e->v.Repr.value); |
| break; |
| case Num_kind: |
| case Str_kind: |
| /* Nothing to do here. */ |
| break; |
| /* The following exprs can be assignment targets. */ |
| case Attribute_kind: |
| VISIT(st, expr, e->v.Attribute.value); |
| break; |
| case Subscript_kind: |
| VISIT(st, expr, e->v.Subscript.value); |
| VISIT(st, slice, e->v.Subscript.slice); |
| break; |
| case Name_kind: |
| if (!symtable_add_def(st, e->v.Name.id, |
| e->v.Name.ctx == Load ? USE : DEF_LOCAL)) |
| return 0; |
| break; |
| /* child nodes of List and Tuple will have expr_context set */ |
| case List_kind: |
| VISIT_SEQ(st, expr, e->v.List.elts); |
| break; |
| case Tuple_kind: |
| VISIT_SEQ(st, expr, e->v.Tuple.elts); |
| break; |
| } |
| return 1; |
| } |
| |
| static int |
| symtable_implicit_arg(struct symtable *st, int pos) |
| { |
| PyObject *id = PyString_FromFormat(".%d", pos); |
| if (id == NULL) |
| return 0; |
| if (!symtable_add_def(st, id, DEF_PARAM)) { |
| Py_DECREF(id); |
| return 0; |
| } |
| Py_DECREF(id); |
| return 1; |
| } |
| |
| static int |
| symtable_visit_params(struct symtable *st, asdl_seq *args, int toplevel) |
| { |
| int i, complex = 0; |
| |
| /* go through all the toplevel arguments first */ |
| for (i = 0; i < asdl_seq_LEN(args); i++) { |
| expr_ty arg = asdl_seq_GET(args, i); |
| if (arg->kind == Name_kind) { |
| assert(arg->v.Name.ctx == Param || |
| (arg->v.Name.ctx == Store && !toplevel)); |
| if (!symtable_add_def(st, arg->v.Name.id, DEF_PARAM)) |
| return 0; |
| } |
| else if (arg->kind == Tuple_kind) { |
| assert(arg->v.Tuple.ctx == Store); |
| complex = 1; |
| if (toplevel) { |
| if (!symtable_implicit_arg(st, i)) |
| return 0; |
| } |
| } |
| else { |
| /* syntax error */ |
| fprintf(stderr, "unexpected expr in parameter list\n"); |
| return 0; |
| } |
| } |
| |
| if (!toplevel) { |
| if (!symtable_visit_params_nested(st, args)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static int |
| symtable_visit_params_nested(struct symtable *st, asdl_seq *args) |
| { |
| int i; |
| for (i = 0; i < asdl_seq_LEN(args); i++) { |
| expr_ty arg = asdl_seq_GET(args, i); |
| if (arg->kind == Tuple_kind && |
| !symtable_visit_params(st, arg->v.Tuple.elts, 0)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static int |
| symtable_visit_arguments(struct symtable *st, arguments_ty a) |
| { |
| /* skip default arguments inside function block |
| XXX should ast be different? |
| */ |
| if (a->args && !symtable_visit_params(st, a->args, 1)) |
| return 0; |
| if (a->vararg) { |
| if (!symtable_add_def(st, a->vararg, DEF_PARAM)) |
| return 0; |
| st->st_cur->ste_varargs = 1; |
| } |
| if (a->kwarg) { |
| if (!symtable_add_def(st, a->kwarg, DEF_PARAM)) |
| return 0; |
| st->st_cur->ste_varkeywords = 1; |
| } |
| if (a->args && !symtable_visit_params_nested(st, a->args)) |
| return 0; |
| return 1; |
| } |
| |
| |
| static int |
| symtable_visit_excepthandler(struct symtable *st, excepthandler_ty eh) |
| { |
| if (eh->type) |
| VISIT(st, expr, eh->type); |
| if (eh->name) |
| VISIT(st, expr, eh->name); |
| VISIT_SEQ(st, stmt, eh->body); |
| return 1; |
| } |
| |
| |
| static int |
| symtable_visit_alias(struct symtable *st, alias_ty a) |
| { |
| /* Compute store_name, the name actually bound by the import |
| operation. It is diferent than a->name when a->name is a |
| dotted package name (e.g. spam.eggs) |
| */ |
| PyObject *store_name; |
| PyObject *name = (a->asname == NULL) ? a->name : a->asname; |
| const char *base = PyString_AS_STRING(name); |
| char *dot = strchr(base, '.'); |
| if (dot) |
| store_name = PyString_FromStringAndSize(base, dot - base); |
| else { |
| store_name = name; |
| Py_INCREF(store_name); |
| } |
| if (strcmp(PyString_AS_STRING(name), "*")) { |
| int r = symtable_add_def(st, store_name, DEF_IMPORT); |
| Py_DECREF(store_name); |
| return r; |
| } |
| else { |
| if (st->st_cur->ste_type != ModuleBlock) { |
| if (!symtable_warn(st, |
| "import * only allowed at module level")) |
| return 0; |
| } |
| st->st_cur->ste_unoptimized |= OPT_IMPORT_STAR; |
| return 1; |
| } |
| } |
| |
| |
| static int |
| symtable_visit_comprehension(struct symtable *st, comprehension_ty lc) |
| { |
| VISIT(st, expr, lc->target); |
| VISIT(st, expr, lc->iter); |
| VISIT_SEQ(st, expr, lc->ifs); |
| return 1; |
| } |
| |
| |
| static int |
| symtable_visit_keyword(struct symtable *st, keyword_ty k) |
| { |
| VISIT(st, expr, k->value); |
| return 1; |
| } |
| |
| |
| static int |
| symtable_visit_slice(struct symtable *st, slice_ty s) |
| { |
| switch (s->kind) { |
| case Slice_kind: |
| if (s->v.Slice.lower) |
| VISIT(st, expr, s->v.Slice.lower) |
| if (s->v.Slice.upper) |
| VISIT(st, expr, s->v.Slice.upper) |
| if (s->v.Slice.step) |
| VISIT(st, expr, s->v.Slice.step) |
| break; |
| case ExtSlice_kind: |
| VISIT_SEQ(st, slice, s->v.ExtSlice.dims) |
| break; |
| case Index_kind: |
| VISIT(st, expr, s->v.Index.value) |
| break; |
| case Ellipsis_kind: |
| break; |
| } |
| return 1; |
| } |
| |
| static int |
| symtable_visit_genexp(struct symtable *st, expr_ty e) |
| { |
| identifier tmp; |
| comprehension_ty outermost = ((comprehension_ty) |
| (asdl_seq_GET(e->v.GeneratorExp.generators, 0))); |
| /* Outermost iterator is evaluated in current scope */ |
| VISIT(st, expr, outermost->iter); |
| /* Create generator scope for the rest */ |
| tmp = PyString_FromString("<genexpr>"); |
| if (!symtable_enter_block(st, tmp, FunctionBlock, (void *)e, 0)) { |
| return 0; |
| } |
| st->st_cur->ste_generator = 1; |
| /* Outermost iter is received as an argument */ |
| if (!symtable_implicit_arg(st, 0)) { |
| return 0; |
| } |
| VISIT(st, expr, outermost->target); |
| VISIT_SEQ(st, expr, outermost->ifs); |
| VISIT_SEQ_TAIL(st, comprehension, e->v.GeneratorExp.generators, 1); |
| VISIT(st, expr, e->v.GeneratorExp.elt); |
| if (!symtable_exit_block(st, (void *)e)) |
| return 0; |
| return 1; |
| } |