1242 lines
37 KiB
C
1242 lines
37 KiB
C
/* Frame object implementation */
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#include "Python.h"
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#include "pycore_object.h"
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#include "pycore_gc.h" // _PyObject_GC_IS_TRACKED()
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#include "code.h"
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#include "frameobject.h"
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#include "opcode.h"
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#include "structmember.h" // PyMemberDef
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#define OFF(x) offsetof(PyFrameObject, x)
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static PyMemberDef frame_memberlist[] = {
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{"f_back", T_OBJECT, OFF(f_back), READONLY},
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{"f_code", T_OBJECT, OFF(f_code), READONLY},
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{"f_builtins", T_OBJECT, OFF(f_builtins), READONLY},
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{"f_globals", T_OBJECT, OFF(f_globals), READONLY},
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{"f_lasti", T_INT, OFF(f_lasti), READONLY},
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{"f_trace_lines", T_BOOL, OFF(f_trace_lines), 0},
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{"f_trace_opcodes", T_BOOL, OFF(f_trace_opcodes), 0},
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{NULL} /* Sentinel */
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};
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static struct _Py_frame_state *
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get_frame_state(void)
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{
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PyInterpreterState *interp = _PyInterpreterState_GET();
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return &interp->frame;
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}
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static PyObject *
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frame_getlocals(PyFrameObject *f, void *closure)
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{
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if (PyFrame_FastToLocalsWithError(f) < 0)
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return NULL;
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Py_INCREF(f->f_locals);
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return f->f_locals;
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}
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int
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PyFrame_GetLineNumber(PyFrameObject *f)
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{
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assert(f != NULL);
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if (f->f_trace) {
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return f->f_lineno;
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}
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else {
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return PyCode_Addr2Line(f->f_code, f->f_lasti);
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}
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}
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static PyObject *
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frame_getlineno(PyFrameObject *f, void *closure)
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{
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return PyLong_FromLong(PyFrame_GetLineNumber(f));
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}
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/* Given the index of the effective opcode,
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scan back to construct the oparg with EXTENDED_ARG */
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static unsigned int
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get_arg(const _Py_CODEUNIT *codestr, Py_ssize_t i)
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{
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_Py_CODEUNIT word;
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unsigned int oparg = _Py_OPARG(codestr[i]);
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if (i >= 1 && _Py_OPCODE(word = codestr[i-1]) == EXTENDED_ARG) {
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oparg |= _Py_OPARG(word) << 8;
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if (i >= 2 && _Py_OPCODE(word = codestr[i-2]) == EXTENDED_ARG) {
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oparg |= _Py_OPARG(word) << 16;
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if (i >= 3 && _Py_OPCODE(word = codestr[i-3]) == EXTENDED_ARG) {
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oparg |= _Py_OPARG(word) << 24;
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}
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}
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}
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return oparg;
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}
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typedef enum kind {
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With = 1,
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Loop = 2,
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Try = 3,
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Except = 4,
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} Kind;
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#define BITS_PER_BLOCK 3
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static inline int64_t
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push_block(int64_t stack, Kind kind)
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{
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assert(stack < ((int64_t)1)<<(BITS_PER_BLOCK*CO_MAXBLOCKS));
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return (stack << BITS_PER_BLOCK) | kind;
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}
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static inline int64_t
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pop_block(int64_t stack)
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{
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assert(stack > 0);
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return stack >> BITS_PER_BLOCK;
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}
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static inline Kind
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top_block(int64_t stack)
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{
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return stack & ((1<<BITS_PER_BLOCK)-1);
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}
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static int64_t *
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markblocks(PyCodeObject *code_obj, int len)
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{
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const _Py_CODEUNIT *code =
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(const _Py_CODEUNIT *)PyBytes_AS_STRING(code_obj->co_code);
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int64_t *blocks = PyMem_New(int64_t, len+1);
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int i, j, opcode;
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if (blocks == NULL) {
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PyErr_NoMemory();
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return NULL;
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}
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memset(blocks, -1, (len+1)*sizeof(int64_t));
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blocks[0] = 0;
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int todo = 1;
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while (todo) {
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todo = 0;
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for (i = 0; i < len; i++) {
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int64_t block_stack = blocks[i];
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int64_t except_stack;
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if (block_stack == -1) {
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continue;
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}
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opcode = _Py_OPCODE(code[i]);
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switch (opcode) {
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case JUMP_IF_FALSE_OR_POP:
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case JUMP_IF_TRUE_OR_POP:
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case POP_JUMP_IF_FALSE:
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case POP_JUMP_IF_TRUE:
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case JUMP_IF_NOT_EXC_MATCH:
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT);
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assert(j < len);
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if (blocks[j] == -1 && j < i) {
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todo = 1;
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}
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assert(blocks[j] == -1 || blocks[j] == block_stack);
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blocks[j] = block_stack;
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blocks[i+1] = block_stack;
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break;
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case JUMP_ABSOLUTE:
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT);
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assert(j < len);
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if (blocks[j] == -1 && j < i) {
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todo = 1;
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}
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assert(blocks[j] == -1 || blocks[j] == block_stack);
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blocks[j] = block_stack;
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break;
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case SETUP_FINALLY:
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT) + i + 1;
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assert(j < len);
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except_stack = push_block(block_stack, Except);
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assert(blocks[j] == -1 || blocks[j] == except_stack);
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blocks[j] = except_stack;
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block_stack = push_block(block_stack, Try);
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blocks[i+1] = block_stack;
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break;
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case SETUP_WITH:
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case SETUP_ASYNC_WITH:
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT) + i + 1;
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assert(j < len);
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except_stack = push_block(block_stack, Except);
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assert(blocks[j] == -1 || blocks[j] == except_stack);
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blocks[j] = except_stack;
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block_stack = push_block(block_stack, With);
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blocks[i+1] = block_stack;
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break;
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case JUMP_FORWARD:
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT) + i + 1;
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assert(j < len);
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assert(blocks[j] == -1 || blocks[j] == block_stack);
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blocks[j] = block_stack;
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break;
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case GET_ITER:
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case GET_AITER:
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block_stack = push_block(block_stack, Loop);
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blocks[i+1] = block_stack;
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break;
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case FOR_ITER:
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blocks[i+1] = block_stack;
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block_stack = pop_block(block_stack);
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j = get_arg(code, i) / sizeof(_Py_CODEUNIT) + i + 1;
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assert(j < len);
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assert(blocks[j] == -1 || blocks[j] == block_stack);
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blocks[j] = block_stack;
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break;
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case POP_BLOCK:
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case POP_EXCEPT:
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block_stack = pop_block(block_stack);
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blocks[i+1] = block_stack;
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break;
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case END_ASYNC_FOR:
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block_stack = pop_block(pop_block(block_stack));
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blocks[i+1] = block_stack;
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break;
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case RETURN_VALUE:
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case RAISE_VARARGS:
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case RERAISE:
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/* End of block */
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break;
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default:
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blocks[i+1] = block_stack;
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}
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}
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}
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return blocks;
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}
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static int
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compatible_block_stack(int64_t from_stack, int64_t to_stack)
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{
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if (to_stack < 0) {
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return 0;
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}
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while(from_stack > to_stack) {
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from_stack = pop_block(from_stack);
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}
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return from_stack == to_stack;
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}
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static const char *
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explain_incompatible_block_stack(int64_t to_stack)
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{
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Kind target_kind = top_block(to_stack);
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switch(target_kind) {
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case Except:
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return "can't jump into an 'except' block as there's no exception";
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case Try:
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return "can't jump into the body of a try statement";
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case With:
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return "can't jump into the body of a with statement";
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case Loop:
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return "can't jump into the body of a for loop";
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default:
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Py_UNREACHABLE();
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}
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}
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static int *
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marklines(PyCodeObject *code, int len)
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{
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int *linestarts = PyMem_New(int, len);
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if (linestarts == NULL) {
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return NULL;
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}
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Py_ssize_t size = PyBytes_GET_SIZE(code->co_lnotab) / 2;
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unsigned char *p = (unsigned char*)PyBytes_AS_STRING(code->co_lnotab);
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int line = code->co_firstlineno;
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int addr = 0;
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int index = 0;
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while (--size >= 0) {
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addr += *p++;
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if (index*2 < addr) {
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linestarts[index++] = line;
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}
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while (index*2 < addr) {
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linestarts[index++] = -1;
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if (index >= len) {
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break;
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}
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}
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line += (signed char)*p;
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p++;
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}
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if (index < len) {
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linestarts[index++] = line;
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}
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while (index < len) {
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linestarts[index++] = -1;
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}
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assert(index == len);
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return linestarts;
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}
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static int
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first_line_not_before(int *lines, int len, int line)
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{
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int result = INT_MAX;
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for (int i = 0; i < len; i++) {
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if (lines[i] < result && lines[i] >= line) {
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result = lines[i];
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}
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}
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if (result == INT_MAX) {
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return -1;
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}
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return result;
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}
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static void
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frame_stack_pop(PyFrameObject *f)
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{
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assert(f->f_stackdepth >= 0);
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f->f_stackdepth--;
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PyObject *v = f->f_valuestack[f->f_stackdepth];
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Py_DECREF(v);
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}
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static void
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frame_block_unwind(PyFrameObject *f)
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{
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assert(f->f_stackdepth >= 0);
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assert(f->f_iblock > 0);
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f->f_iblock--;
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PyTryBlock *b = &f->f_blockstack[f->f_iblock];
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intptr_t delta = f->f_stackdepth - b->b_level;
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while (delta > 0) {
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frame_stack_pop(f);
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delta--;
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}
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}
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/* Setter for f_lineno - you can set f_lineno from within a trace function in
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* order to jump to a given line of code, subject to some restrictions. Most
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* lines are OK to jump to because they don't make any assumptions about the
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* state of the stack (obvious because you could remove the line and the code
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* would still work without any stack errors), but there are some constructs
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* that limit jumping:
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*
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* o Lines with an 'except' statement on them can't be jumped to, because
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* they expect an exception to be on the top of the stack.
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* o Lines that live in a 'finally' block can't be jumped from or to, since
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* we cannot be sure which state the interpreter was in or would be in
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* during execution of the finally block.
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* o 'try', 'with' and 'async with' blocks can't be jumped into because
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* the blockstack needs to be set up before their code runs.
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* o 'for' and 'async for' loops can't be jumped into because the
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* iterator needs to be on the stack.
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* o Jumps cannot be made from within a trace function invoked with a
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* 'return' or 'exception' event since the eval loop has been exited at
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* that time.
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*/
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static int
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frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno, void *Py_UNUSED(ignored))
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{
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if (p_new_lineno == NULL) {
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PyErr_SetString(PyExc_AttributeError, "cannot delete attribute");
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return -1;
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}
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/* f_lineno must be an integer. */
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if (!PyLong_CheckExact(p_new_lineno)) {
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PyErr_SetString(PyExc_ValueError,
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"lineno must be an integer");
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return -1;
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}
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/*
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* This code preserves the historical restrictions on
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* setting the line number of a frame.
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* Jumps are forbidden on a 'return' trace event (except after a yield).
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* Jumps from 'call' trace events are also forbidden.
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* In addition, jumps are forbidden when not tracing,
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* as this is a debugging feature.
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*/
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switch(f->f_state) {
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case FRAME_CREATED:
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PyErr_Format(PyExc_ValueError,
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"can't jump from the 'call' trace event of a new frame");
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return -1;
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case FRAME_RETURNED:
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case FRAME_UNWINDING:
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case FRAME_RAISED:
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case FRAME_CLEARED:
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PyErr_SetString(PyExc_ValueError,
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"can only jump from a 'line' trace event");
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return -1;
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case FRAME_EXECUTING:
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case FRAME_SUSPENDED:
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/* You can only do this from within a trace function, not via
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* _getframe or similar hackery. */
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if (!f->f_trace) {
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PyErr_Format(PyExc_ValueError,
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"f_lineno can only be set by a trace function");
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return -1;
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}
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break;
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}
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int new_lineno;
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/* Fail if the line falls outside the code block and
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select first line with actual code. */
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int overflow;
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long l_new_lineno = PyLong_AsLongAndOverflow(p_new_lineno, &overflow);
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if (overflow
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#if SIZEOF_LONG > SIZEOF_INT
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|| l_new_lineno > INT_MAX
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|| l_new_lineno < INT_MIN
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#endif
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) {
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PyErr_SetString(PyExc_ValueError,
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"lineno out of range");
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return -1;
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}
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new_lineno = (int)l_new_lineno;
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if (new_lineno < f->f_code->co_firstlineno) {
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PyErr_Format(PyExc_ValueError,
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"line %d comes before the current code block",
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new_lineno);
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return -1;
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}
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/* PyCode_NewWithPosOnlyArgs limits co_code to be under INT_MAX so this
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* should never overflow. */
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int len = (int)(PyBytes_GET_SIZE(f->f_code->co_code) / sizeof(_Py_CODEUNIT));
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int *lines = marklines(f->f_code, len);
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if (lines == NULL) {
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return -1;
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}
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new_lineno = first_line_not_before(lines, len, new_lineno);
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if (new_lineno < 0) {
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PyErr_Format(PyExc_ValueError,
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"line %d comes after the current code block",
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(int)l_new_lineno);
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PyMem_Free(lines);
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return -1;
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}
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int64_t *blocks = markblocks(f->f_code, len);
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if (blocks == NULL) {
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PyMem_Free(lines);
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return -1;
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}
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int64_t target_block_stack = -1;
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int64_t best_block_stack = -1;
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int best_addr = -1;
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int64_t start_block_stack = blocks[f->f_lasti/sizeof(_Py_CODEUNIT)];
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const char *msg = "cannot find bytecode for specified line";
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for (int i = 0; i < len; i++) {
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if (lines[i] == new_lineno) {
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target_block_stack = blocks[i];
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if (compatible_block_stack(start_block_stack, target_block_stack)) {
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msg = NULL;
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if (target_block_stack > best_block_stack) {
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best_block_stack = target_block_stack;
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best_addr = i*sizeof(_Py_CODEUNIT);
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}
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}
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else if (msg) {
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if (target_block_stack >= 0) {
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msg = explain_incompatible_block_stack(target_block_stack);
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}
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else {
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msg = "code may be unreachable.";
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}
|
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}
|
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}
|
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}
|
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PyMem_Free(blocks);
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PyMem_Free(lines);
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if (msg != NULL) {
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PyErr_SetString(PyExc_ValueError, msg);
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return -1;
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}
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|
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/* Unwind block stack. */
|
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while (start_block_stack > best_block_stack) {
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Kind kind = top_block(start_block_stack);
|
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switch(kind) {
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case Loop:
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frame_stack_pop(f);
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break;
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case Try:
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frame_block_unwind(f);
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break;
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case With:
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frame_block_unwind(f);
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// Pop the exit function
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frame_stack_pop(f);
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break;
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case Except:
|
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PyErr_SetString(PyExc_ValueError,
|
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"can't jump out of an 'except' block");
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return -1;
|
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}
|
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start_block_stack = pop_block(start_block_stack);
|
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}
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|
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/* Finally set the new f_lineno and f_lasti and return OK. */
|
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f->f_lineno = new_lineno;
|
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f->f_lasti = best_addr;
|
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return 0;
|
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}
|
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|
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static PyObject *
|
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frame_gettrace(PyFrameObject *f, void *closure)
|
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{
|
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PyObject* trace = f->f_trace;
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|
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if (trace == NULL)
|
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trace = Py_None;
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|
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Py_INCREF(trace);
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|
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return trace;
|
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}
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|
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static int
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frame_settrace(PyFrameObject *f, PyObject* v, void *closure)
|
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{
|
|
/* We rely on f_lineno being accurate when f_trace is set. */
|
|
f->f_lineno = PyFrame_GetLineNumber(f);
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|
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if (v == Py_None)
|
|
v = NULL;
|
|
Py_XINCREF(v);
|
|
Py_XSETREF(f->f_trace, v);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static PyGetSetDef frame_getsetlist[] = {
|
|
{"f_locals", (getter)frame_getlocals, NULL, NULL},
|
|
{"f_lineno", (getter)frame_getlineno,
|
|
(setter)frame_setlineno, NULL},
|
|
{"f_trace", (getter)frame_gettrace, (setter)frame_settrace, NULL},
|
|
{0}
|
|
};
|
|
|
|
/* Stack frames are allocated and deallocated at a considerable rate.
|
|
In an attempt to improve the speed of function calls, we:
|
|
|
|
1. Hold a single "zombie" frame on each code object. This retains
|
|
the allocated and initialised frame object from an invocation of
|
|
the code object. The zombie is reanimated the next time we need a
|
|
frame object for that code object. Doing this saves the malloc/
|
|
realloc required when using a free_list frame that isn't the
|
|
correct size. It also saves some field initialisation.
|
|
|
|
In zombie mode, no field of PyFrameObject holds a reference, but
|
|
the following fields are still valid:
|
|
|
|
* ob_type, ob_size, f_code, f_valuestack;
|
|
|
|
* f_locals, f_trace are NULL;
|
|
|
|
* f_localsplus does not require re-allocation and
|
|
the local variables in f_localsplus are NULL.
|
|
|
|
2. We also maintain a separate free list of stack frames (just like
|
|
floats are allocated in a special way -- see floatobject.c). When
|
|
a stack frame is on the free list, only the following members have
|
|
a meaning:
|
|
ob_type == &Frametype
|
|
f_back next item on free list, or NULL
|
|
f_stacksize size of value stack
|
|
ob_size size of localsplus
|
|
Note that the value and block stacks are preserved -- this can save
|
|
another malloc() call or two (and two free() calls as well!).
|
|
Also note that, unlike for integers, each frame object is a
|
|
malloc'ed object in its own right -- it is only the actual calls to
|
|
malloc() that we are trying to save here, not the administration.
|
|
After all, while a typical program may make millions of calls, a
|
|
call depth of more than 20 or 30 is probably already exceptional
|
|
unless the program contains run-away recursion. I hope.
|
|
|
|
Later, PyFrame_MAXFREELIST was added to bound the # of frames saved on
|
|
free_list. Else programs creating lots of cyclic trash involving
|
|
frames could provoke free_list into growing without bound.
|
|
*/
|
|
/* max value for numfree */
|
|
#define PyFrame_MAXFREELIST 200
|
|
|
|
static void _Py_HOT_FUNCTION
|
|
frame_dealloc(PyFrameObject *f)
|
|
{
|
|
if (_PyObject_GC_IS_TRACKED(f)) {
|
|
_PyObject_GC_UNTRACK(f);
|
|
}
|
|
|
|
Py_TRASHCAN_SAFE_BEGIN(f)
|
|
/* Kill all local variables */
|
|
PyObject **valuestack = f->f_valuestack;
|
|
for (PyObject **p = f->f_localsplus; p < valuestack; p++) {
|
|
Py_CLEAR(*p);
|
|
}
|
|
|
|
/* Free stack */
|
|
for (int i = 0; i < f->f_stackdepth; i++) {
|
|
Py_XDECREF(f->f_valuestack[i]);
|
|
}
|
|
f->f_stackdepth = 0;
|
|
|
|
Py_XDECREF(f->f_back);
|
|
Py_DECREF(f->f_builtins);
|
|
Py_DECREF(f->f_globals);
|
|
Py_CLEAR(f->f_locals);
|
|
Py_CLEAR(f->f_trace);
|
|
|
|
PyCodeObject *co = f->f_code;
|
|
if (co->co_zombieframe == NULL) {
|
|
co->co_zombieframe = f;
|
|
}
|
|
else {
|
|
struct _Py_frame_state *state = get_frame_state();
|
|
#ifdef Py_DEBUG
|
|
// frame_dealloc() must not be called after _PyFrame_Fini()
|
|
assert(state->numfree != -1);
|
|
#endif
|
|
if (state->numfree < PyFrame_MAXFREELIST) {
|
|
++state->numfree;
|
|
f->f_back = state->free_list;
|
|
state->free_list = f;
|
|
}
|
|
else {
|
|
PyObject_GC_Del(f);
|
|
}
|
|
}
|
|
|
|
Py_DECREF(co);
|
|
Py_TRASHCAN_SAFE_END(f)
|
|
}
|
|
|
|
static inline Py_ssize_t
|
|
frame_nslots(PyFrameObject *frame)
|
|
{
|
|
PyCodeObject *code = frame->f_code;
|
|
return (code->co_nlocals
|
|
+ PyTuple_GET_SIZE(code->co_cellvars)
|
|
+ PyTuple_GET_SIZE(code->co_freevars));
|
|
}
|
|
|
|
static int
|
|
frame_traverse(PyFrameObject *f, visitproc visit, void *arg)
|
|
{
|
|
Py_VISIT(f->f_back);
|
|
Py_VISIT(f->f_code);
|
|
Py_VISIT(f->f_builtins);
|
|
Py_VISIT(f->f_globals);
|
|
Py_VISIT(f->f_locals);
|
|
Py_VISIT(f->f_trace);
|
|
|
|
/* locals */
|
|
PyObject **fastlocals = f->f_localsplus;
|
|
for (Py_ssize_t i = frame_nslots(f); --i >= 0; ++fastlocals) {
|
|
Py_VISIT(*fastlocals);
|
|
}
|
|
|
|
/* stack */
|
|
for (int i = 0; i < f->f_stackdepth; i++) {
|
|
Py_VISIT(f->f_valuestack[i]);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
frame_tp_clear(PyFrameObject *f)
|
|
{
|
|
/* Before anything else, make sure that this frame is clearly marked
|
|
* as being defunct! Else, e.g., a generator reachable from this
|
|
* frame may also point to this frame, believe itself to still be
|
|
* active, and try cleaning up this frame again.
|
|
*/
|
|
f->f_state = FRAME_CLEARED;
|
|
|
|
Py_CLEAR(f->f_trace);
|
|
|
|
/* locals */
|
|
PyObject **fastlocals = f->f_localsplus;
|
|
for (Py_ssize_t i = frame_nslots(f); --i >= 0; ++fastlocals) {
|
|
Py_CLEAR(*fastlocals);
|
|
}
|
|
|
|
/* stack */
|
|
for (int i = 0; i < f->f_stackdepth; i++) {
|
|
Py_CLEAR(f->f_valuestack[i]);
|
|
}
|
|
f->f_stackdepth = 0;
|
|
return 0;
|
|
}
|
|
|
|
static PyObject *
|
|
frame_clear(PyFrameObject *f, PyObject *Py_UNUSED(ignored))
|
|
{
|
|
if (_PyFrame_IsExecuting(f)) {
|
|
PyErr_SetString(PyExc_RuntimeError,
|
|
"cannot clear an executing frame");
|
|
return NULL;
|
|
}
|
|
if (f->f_gen) {
|
|
_PyGen_Finalize(f->f_gen);
|
|
assert(f->f_gen == NULL);
|
|
}
|
|
(void)frame_tp_clear(f);
|
|
Py_RETURN_NONE;
|
|
}
|
|
|
|
PyDoc_STRVAR(clear__doc__,
|
|
"F.clear(): clear most references held by the frame");
|
|
|
|
static PyObject *
|
|
frame_sizeof(PyFrameObject *f, PyObject *Py_UNUSED(ignored))
|
|
{
|
|
Py_ssize_t res, extras, ncells, nfrees;
|
|
|
|
PyCodeObject *code = f->f_code;
|
|
ncells = PyTuple_GET_SIZE(code->co_cellvars);
|
|
nfrees = PyTuple_GET_SIZE(code->co_freevars);
|
|
extras = code->co_stacksize + code->co_nlocals + ncells + nfrees;
|
|
/* subtract one as it is already included in PyFrameObject */
|
|
res = sizeof(PyFrameObject) + (extras-1) * sizeof(PyObject *);
|
|
|
|
return PyLong_FromSsize_t(res);
|
|
}
|
|
|
|
PyDoc_STRVAR(sizeof__doc__,
|
|
"F.__sizeof__() -> size of F in memory, in bytes");
|
|
|
|
static PyObject *
|
|
frame_repr(PyFrameObject *f)
|
|
{
|
|
int lineno = PyFrame_GetLineNumber(f);
|
|
PyCodeObject *code = f->f_code;
|
|
return PyUnicode_FromFormat(
|
|
"<frame at %p, file %R, line %d, code %S>",
|
|
f, code->co_filename, lineno, code->co_name);
|
|
}
|
|
|
|
static PyMethodDef frame_methods[] = {
|
|
{"clear", (PyCFunction)frame_clear, METH_NOARGS,
|
|
clear__doc__},
|
|
{"__sizeof__", (PyCFunction)frame_sizeof, METH_NOARGS,
|
|
sizeof__doc__},
|
|
{NULL, NULL} /* sentinel */
|
|
};
|
|
|
|
PyTypeObject PyFrame_Type = {
|
|
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
|
"frame",
|
|
sizeof(PyFrameObject),
|
|
sizeof(PyObject *),
|
|
(destructor)frame_dealloc, /* tp_dealloc */
|
|
0, /* tp_vectorcall_offset */
|
|
0, /* tp_getattr */
|
|
0, /* tp_setattr */
|
|
0, /* tp_as_async */
|
|
(reprfunc)frame_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 */
|
|
PyObject_GenericSetAttr, /* tp_setattro */
|
|
0, /* tp_as_buffer */
|
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
|
|
0, /* tp_doc */
|
|
(traverseproc)frame_traverse, /* tp_traverse */
|
|
(inquiry)frame_tp_clear, /* tp_clear */
|
|
0, /* tp_richcompare */
|
|
0, /* tp_weaklistoffset */
|
|
0, /* tp_iter */
|
|
0, /* tp_iternext */
|
|
frame_methods, /* tp_methods */
|
|
frame_memberlist, /* tp_members */
|
|
frame_getsetlist, /* tp_getset */
|
|
0, /* tp_base */
|
|
0, /* tp_dict */
|
|
};
|
|
|
|
_Py_IDENTIFIER(__builtins__);
|
|
|
|
static inline PyFrameObject*
|
|
frame_alloc(PyCodeObject *code)
|
|
{
|
|
PyFrameObject *f;
|
|
|
|
f = code->co_zombieframe;
|
|
if (f != NULL) {
|
|
code->co_zombieframe = NULL;
|
|
_Py_NewReference((PyObject *)f);
|
|
assert(f->f_code == code);
|
|
return f;
|
|
}
|
|
|
|
Py_ssize_t ncells = PyTuple_GET_SIZE(code->co_cellvars);
|
|
Py_ssize_t nfrees = PyTuple_GET_SIZE(code->co_freevars);
|
|
Py_ssize_t extras = code->co_stacksize + code->co_nlocals + ncells + nfrees;
|
|
struct _Py_frame_state *state = get_frame_state();
|
|
if (state->free_list == NULL)
|
|
{
|
|
f = PyObject_GC_NewVar(PyFrameObject, &PyFrame_Type, extras);
|
|
if (f == NULL) {
|
|
return NULL;
|
|
}
|
|
}
|
|
else {
|
|
#ifdef Py_DEBUG
|
|
// frame_alloc() must not be called after _PyFrame_Fini()
|
|
assert(state->numfree != -1);
|
|
#endif
|
|
assert(state->numfree > 0);
|
|
--state->numfree;
|
|
f = state->free_list;
|
|
state->free_list = state->free_list->f_back;
|
|
if (Py_SIZE(f) < extras) {
|
|
PyFrameObject *new_f = PyObject_GC_Resize(PyFrameObject, f, extras);
|
|
if (new_f == NULL) {
|
|
PyObject_GC_Del(f);
|
|
return NULL;
|
|
}
|
|
f = new_f;
|
|
}
|
|
_Py_NewReference((PyObject *)f);
|
|
}
|
|
|
|
f->f_code = code;
|
|
extras = code->co_nlocals + ncells + nfrees;
|
|
f->f_valuestack = f->f_localsplus + extras;
|
|
for (Py_ssize_t i=0; i<extras; i++) {
|
|
f->f_localsplus[i] = NULL;
|
|
}
|
|
f->f_locals = NULL;
|
|
f->f_trace = NULL;
|
|
return f;
|
|
}
|
|
|
|
|
|
static inline PyObject *
|
|
frame_get_builtins(PyFrameObject *back, PyObject *globals)
|
|
{
|
|
PyObject *builtins;
|
|
|
|
if (back != NULL && back->f_globals == globals) {
|
|
/* If we share the globals, we share the builtins.
|
|
Save a lookup and a call. */
|
|
builtins = back->f_builtins;
|
|
assert(builtins != NULL);
|
|
Py_INCREF(builtins);
|
|
return builtins;
|
|
}
|
|
|
|
builtins = _PyDict_GetItemIdWithError(globals, &PyId___builtins__);
|
|
if (builtins != NULL && PyModule_Check(builtins)) {
|
|
builtins = PyModule_GetDict(builtins);
|
|
assert(builtins != NULL);
|
|
}
|
|
if (builtins != NULL) {
|
|
Py_INCREF(builtins);
|
|
return builtins;
|
|
}
|
|
|
|
if (PyErr_Occurred()) {
|
|
return NULL;
|
|
}
|
|
|
|
/* No builtins! Make up a minimal one.
|
|
Give them 'None', at least. */
|
|
builtins = PyDict_New();
|
|
if (builtins == NULL) {
|
|
return NULL;
|
|
}
|
|
if (PyDict_SetItemString(builtins, "None", Py_None) < 0) {
|
|
Py_DECREF(builtins);
|
|
return NULL;
|
|
}
|
|
return builtins;
|
|
}
|
|
|
|
|
|
PyFrameObject* _Py_HOT_FUNCTION
|
|
_PyFrame_New_NoTrack(PyThreadState *tstate, PyCodeObject *code,
|
|
PyObject *globals, PyObject *locals)
|
|
{
|
|
#ifdef Py_DEBUG
|
|
if (code == NULL || globals == NULL || !PyDict_Check(globals) ||
|
|
(locals != NULL && !PyMapping_Check(locals))) {
|
|
PyErr_BadInternalCall();
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
PyFrameObject *back = tstate->frame;
|
|
PyObject *builtins = frame_get_builtins(back, globals);
|
|
if (builtins == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
PyFrameObject *f = frame_alloc(code);
|
|
if (f == NULL) {
|
|
Py_DECREF(builtins);
|
|
return NULL;
|
|
}
|
|
|
|
f->f_stackdepth = 0;
|
|
f->f_builtins = builtins;
|
|
Py_XINCREF(back);
|
|
f->f_back = back;
|
|
Py_INCREF(code);
|
|
Py_INCREF(globals);
|
|
f->f_globals = globals;
|
|
/* Most functions have CO_NEWLOCALS and CO_OPTIMIZED set. */
|
|
if ((code->co_flags & (CO_NEWLOCALS | CO_OPTIMIZED)) ==
|
|
(CO_NEWLOCALS | CO_OPTIMIZED))
|
|
; /* f_locals = NULL; will be set by PyFrame_FastToLocals() */
|
|
else if (code->co_flags & CO_NEWLOCALS) {
|
|
locals = PyDict_New();
|
|
if (locals == NULL) {
|
|
Py_DECREF(f);
|
|
return NULL;
|
|
}
|
|
f->f_locals = locals;
|
|
}
|
|
else {
|
|
if (locals == NULL)
|
|
locals = globals;
|
|
Py_INCREF(locals);
|
|
f->f_locals = locals;
|
|
}
|
|
|
|
f->f_lasti = -1;
|
|
f->f_lineno = code->co_firstlineno;
|
|
f->f_iblock = 0;
|
|
f->f_state = FRAME_CREATED;
|
|
f->f_gen = NULL;
|
|
f->f_trace_opcodes = 0;
|
|
f->f_trace_lines = 1;
|
|
|
|
assert(f->f_code != NULL);
|
|
|
|
return f;
|
|
}
|
|
|
|
PyFrameObject*
|
|
PyFrame_New(PyThreadState *tstate, PyCodeObject *code,
|
|
PyObject *globals, PyObject *locals)
|
|
{
|
|
PyFrameObject *f = _PyFrame_New_NoTrack(tstate, code, globals, locals);
|
|
if (f)
|
|
_PyObject_GC_TRACK(f);
|
|
return f;
|
|
}
|
|
|
|
|
|
/* Block management */
|
|
|
|
void
|
|
PyFrame_BlockSetup(PyFrameObject *f, int type, int handler, int level)
|
|
{
|
|
PyTryBlock *b;
|
|
if (f->f_iblock >= CO_MAXBLOCKS) {
|
|
Py_FatalError("block stack overflow");
|
|
}
|
|
b = &f->f_blockstack[f->f_iblock++];
|
|
b->b_type = type;
|
|
b->b_level = level;
|
|
b->b_handler = handler;
|
|
}
|
|
|
|
PyTryBlock *
|
|
PyFrame_BlockPop(PyFrameObject *f)
|
|
{
|
|
PyTryBlock *b;
|
|
if (f->f_iblock <= 0) {
|
|
Py_FatalError("block stack underflow");
|
|
}
|
|
b = &f->f_blockstack[--f->f_iblock];
|
|
return b;
|
|
}
|
|
|
|
/* Convert between "fast" version of locals and dictionary version.
|
|
|
|
map and values are input arguments. map is a tuple of strings.
|
|
values is an array of PyObject*. At index i, map[i] is the name of
|
|
the variable with value values[i]. The function copies the first
|
|
nmap variable from map/values into dict. If values[i] is NULL,
|
|
the variable is deleted from dict.
|
|
|
|
If deref is true, then the values being copied are cell variables
|
|
and the value is extracted from the cell variable before being put
|
|
in dict.
|
|
*/
|
|
|
|
static int
|
|
map_to_dict(PyObject *map, Py_ssize_t nmap, PyObject *dict, PyObject **values,
|
|
int deref)
|
|
{
|
|
Py_ssize_t j;
|
|
assert(PyTuple_Check(map));
|
|
assert(PyDict_Check(dict));
|
|
assert(PyTuple_Size(map) >= nmap);
|
|
for (j=0; j < nmap; j++) {
|
|
PyObject *key = PyTuple_GET_ITEM(map, j);
|
|
PyObject *value = values[j];
|
|
assert(PyUnicode_Check(key));
|
|
if (deref && value != NULL) {
|
|
assert(PyCell_Check(value));
|
|
value = PyCell_GET(value);
|
|
}
|
|
if (value == NULL) {
|
|
if (PyObject_DelItem(dict, key) != 0) {
|
|
if (PyErr_ExceptionMatches(PyExc_KeyError))
|
|
PyErr_Clear();
|
|
else
|
|
return -1;
|
|
}
|
|
}
|
|
else {
|
|
if (PyObject_SetItem(dict, key, value) != 0)
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy values from the "locals" dict into the fast locals.
|
|
|
|
dict is an input argument containing string keys representing
|
|
variables names and arbitrary PyObject* as values.
|
|
|
|
map and values are input arguments. map is a tuple of strings.
|
|
values is an array of PyObject*. At index i, map[i] is the name of
|
|
the variable with value values[i]. The function copies the first
|
|
nmap variable from map/values into dict. If values[i] is NULL,
|
|
the variable is deleted from dict.
|
|
|
|
If deref is true, then the values being copied are cell variables
|
|
and the value is extracted from the cell variable before being put
|
|
in dict. If clear is true, then variables in map but not in dict
|
|
are set to NULL in map; if clear is false, variables missing in
|
|
dict are ignored.
|
|
|
|
Exceptions raised while modifying the dict are silently ignored,
|
|
because there is no good way to report them.
|
|
*/
|
|
|
|
static void
|
|
dict_to_map(PyObject *map, Py_ssize_t nmap, PyObject *dict, PyObject **values,
|
|
int deref, int clear)
|
|
{
|
|
Py_ssize_t j;
|
|
assert(PyTuple_Check(map));
|
|
assert(PyDict_Check(dict));
|
|
assert(PyTuple_Size(map) >= nmap);
|
|
for (j=0; j < nmap; j++) {
|
|
PyObject *key = PyTuple_GET_ITEM(map, j);
|
|
PyObject *value = PyObject_GetItem(dict, key);
|
|
assert(PyUnicode_Check(key));
|
|
/* We only care about NULLs if clear is true. */
|
|
if (value == NULL) {
|
|
PyErr_Clear();
|
|
if (!clear)
|
|
continue;
|
|
}
|
|
if (deref) {
|
|
assert(PyCell_Check(values[j]));
|
|
if (PyCell_GET(values[j]) != value) {
|
|
if (PyCell_Set(values[j], value) < 0)
|
|
PyErr_Clear();
|
|
}
|
|
} else if (values[j] != value) {
|
|
Py_XINCREF(value);
|
|
Py_XSETREF(values[j], value);
|
|
}
|
|
Py_XDECREF(value);
|
|
}
|
|
}
|
|
|
|
int
|
|
PyFrame_FastToLocalsWithError(PyFrameObject *f)
|
|
{
|
|
/* Merge fast locals into f->f_locals */
|
|
PyObject *locals, *map;
|
|
PyObject **fast;
|
|
PyCodeObject *co;
|
|
Py_ssize_t j;
|
|
Py_ssize_t ncells, nfreevars;
|
|
|
|
if (f == NULL) {
|
|
PyErr_BadInternalCall();
|
|
return -1;
|
|
}
|
|
locals = f->f_locals;
|
|
if (locals == NULL) {
|
|
locals = f->f_locals = PyDict_New();
|
|
if (locals == NULL)
|
|
return -1;
|
|
}
|
|
co = f->f_code;
|
|
map = co->co_varnames;
|
|
if (!PyTuple_Check(map)) {
|
|
PyErr_Format(PyExc_SystemError,
|
|
"co_varnames must be a tuple, not %s",
|
|
Py_TYPE(map)->tp_name);
|
|
return -1;
|
|
}
|
|
fast = f->f_localsplus;
|
|
j = PyTuple_GET_SIZE(map);
|
|
if (j > co->co_nlocals)
|
|
j = co->co_nlocals;
|
|
if (co->co_nlocals) {
|
|
if (map_to_dict(map, j, locals, fast, 0) < 0)
|
|
return -1;
|
|
}
|
|
ncells = PyTuple_GET_SIZE(co->co_cellvars);
|
|
nfreevars = PyTuple_GET_SIZE(co->co_freevars);
|
|
if (ncells || nfreevars) {
|
|
if (map_to_dict(co->co_cellvars, ncells,
|
|
locals, fast + co->co_nlocals, 1))
|
|
return -1;
|
|
|
|
/* If the namespace is unoptimized, then one of the
|
|
following cases applies:
|
|
1. It does not contain free variables, because it
|
|
uses import * or is a top-level namespace.
|
|
2. It is a class namespace.
|
|
We don't want to accidentally copy free variables
|
|
into the locals dict used by the class.
|
|
*/
|
|
if (co->co_flags & CO_OPTIMIZED) {
|
|
if (map_to_dict(co->co_freevars, nfreevars,
|
|
locals, fast + co->co_nlocals + ncells, 1) < 0)
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
PyFrame_FastToLocals(PyFrameObject *f)
|
|
{
|
|
int res;
|
|
|
|
assert(!PyErr_Occurred());
|
|
|
|
res = PyFrame_FastToLocalsWithError(f);
|
|
if (res < 0)
|
|
PyErr_Clear();
|
|
}
|
|
|
|
void
|
|
PyFrame_LocalsToFast(PyFrameObject *f, int clear)
|
|
{
|
|
/* Merge f->f_locals into fast locals */
|
|
PyObject *locals, *map;
|
|
PyObject **fast;
|
|
PyObject *error_type, *error_value, *error_traceback;
|
|
PyCodeObject *co;
|
|
Py_ssize_t j;
|
|
Py_ssize_t ncells, nfreevars;
|
|
if (f == NULL)
|
|
return;
|
|
locals = f->f_locals;
|
|
co = f->f_code;
|
|
map = co->co_varnames;
|
|
if (locals == NULL)
|
|
return;
|
|
if (!PyTuple_Check(map))
|
|
return;
|
|
PyErr_Fetch(&error_type, &error_value, &error_traceback);
|
|
fast = f->f_localsplus;
|
|
j = PyTuple_GET_SIZE(map);
|
|
if (j > co->co_nlocals)
|
|
j = co->co_nlocals;
|
|
if (co->co_nlocals)
|
|
dict_to_map(co->co_varnames, j, locals, fast, 0, clear);
|
|
ncells = PyTuple_GET_SIZE(co->co_cellvars);
|
|
nfreevars = PyTuple_GET_SIZE(co->co_freevars);
|
|
if (ncells || nfreevars) {
|
|
dict_to_map(co->co_cellvars, ncells,
|
|
locals, fast + co->co_nlocals, 1, clear);
|
|
/* Same test as in PyFrame_FastToLocals() above. */
|
|
if (co->co_flags & CO_OPTIMIZED) {
|
|
dict_to_map(co->co_freevars, nfreevars,
|
|
locals, fast + co->co_nlocals + ncells, 1,
|
|
clear);
|
|
}
|
|
}
|
|
PyErr_Restore(error_type, error_value, error_traceback);
|
|
}
|
|
|
|
/* Clear out the free list */
|
|
void
|
|
_PyFrame_ClearFreeList(PyThreadState *tstate)
|
|
{
|
|
struct _Py_frame_state *state = &tstate->interp->frame;
|
|
while (state->free_list != NULL) {
|
|
PyFrameObject *f = state->free_list;
|
|
state->free_list = state->free_list->f_back;
|
|
PyObject_GC_Del(f);
|
|
--state->numfree;
|
|
}
|
|
assert(state->numfree == 0);
|
|
}
|
|
|
|
void
|
|
_PyFrame_Fini(PyThreadState *tstate)
|
|
{
|
|
_PyFrame_ClearFreeList(tstate);
|
|
#ifdef Py_DEBUG
|
|
struct _Py_frame_state *state = &tstate->interp->frame;
|
|
state->numfree = -1;
|
|
#endif
|
|
}
|
|
|
|
/* Print summary info about the state of the optimized allocator */
|
|
void
|
|
_PyFrame_DebugMallocStats(FILE *out)
|
|
{
|
|
struct _Py_frame_state *state = get_frame_state();
|
|
_PyDebugAllocatorStats(out,
|
|
"free PyFrameObject",
|
|
state->numfree, sizeof(PyFrameObject));
|
|
}
|
|
|
|
|
|
PyCodeObject *
|
|
PyFrame_GetCode(PyFrameObject *frame)
|
|
{
|
|
assert(frame != NULL);
|
|
PyCodeObject *code = frame->f_code;
|
|
assert(code != NULL);
|
|
Py_INCREF(code);
|
|
return code;
|
|
}
|
|
|
|
|
|
PyFrameObject*
|
|
PyFrame_GetBack(PyFrameObject *frame)
|
|
{
|
|
assert(frame != NULL);
|
|
PyFrameObject *back = frame->f_back;
|
|
Py_XINCREF(back);
|
|
return back;
|
|
}
|