diff options
| author | nkozlovskiy <nmk@ydb.tech> | 2023-09-29 12:24:06 +0300 |
|---|---|---|
| committer | nkozlovskiy <nmk@ydb.tech> | 2023-09-29 12:41:34 +0300 |
| commit | e0e3e1717e3d33762ce61950504f9637a6e669ed (patch) | |
| tree | bca3ff6939b10ed60c3d5c12439963a1146b9711 /contrib/tools/python/src/Python/compile.c | |
| parent | 38f2c5852db84c7b4d83adfcb009eb61541d1ccd (diff) | |
| download | ydb-e0e3e1717e3d33762ce61950504f9637a6e669ed.tar.gz | |
add ydb deps
Diffstat (limited to 'contrib/tools/python/src/Python/compile.c')
| -rw-r--r-- | contrib/tools/python/src/Python/compile.c | 3976 |
1 files changed, 3976 insertions, 0 deletions
diff --git a/contrib/tools/python/src/Python/compile.c b/contrib/tools/python/src/Python/compile.c new file mode 100644 index 0000000000..7f8babc12b --- /dev/null +++ b/contrib/tools/python/src/Python/compile.c @@ -0,0 +1,3976 @@ +/* + * This file compiles an abstract syntax tree (AST) into Python bytecode. + * + * The primary entry point is PyAST_Compile(), which returns a + * PyCodeObject. The compiler makes several passes to build the code + * object: + * 1. Checks for future statements. See future.c + * 2. Builds a symbol table. See symtable.c. + * 3. Generate code for basic blocks. See compiler_mod() in this file. + * 4. Assemble the basic blocks into final code. See assemble() in + * this file. + * 5. Optimize the byte code (peephole optimizations). See peephole.c + * + * Note that compiler_mod() suggests module, but the module ast type + * (mod_ty) has cases for expressions and interactive statements. + * + * CAUTION: The VISIT_* macros abort the current function when they + * encounter a problem. So don't invoke them when there is memory + * which needs to be released. Code blocks are OK, as the compiler + * structure takes care of releasing those. Use the arena to manage + * objects. + */ + +#include "Python.h" + +#include "Python-ast.h" +#include "node.h" +#include "pyarena.h" +#include "ast.h" +#include "code.h" +#include "compile.h" +#include "symtable.h" +#include "opcode.h" + +int Py_OptimizeFlag = 0; + +#define DEFAULT_BLOCK_SIZE 16 +#define DEFAULT_BLOCKS 8 +#define DEFAULT_CODE_SIZE 128 +#define DEFAULT_LNOTAB_SIZE 16 + +#define COMP_GENEXP 0 +#define COMP_SETCOMP 1 +#define COMP_DICTCOMP 2 + +struct instr { + unsigned i_jabs : 1; + unsigned i_jrel : 1; + unsigned i_hasarg : 1; + unsigned char i_opcode; + int i_oparg; + struct basicblock_ *i_target; /* target block (if jump instruction) */ + int i_lineno; +}; + +typedef struct basicblock_ { + /* Each basicblock in a compilation unit is linked via b_list in the + reverse order that the block are allocated. b_list points to the next + block, not to be confused with b_next, which is next by control flow. */ + struct basicblock_ *b_list; + /* number of instructions used */ + int b_iused; + /* length of instruction array (b_instr) */ + int b_ialloc; + /* pointer to an array of instructions, initially NULL */ + struct instr *b_instr; + /* If b_next is non-NULL, it is a pointer to the next + block reached by normal control flow. */ + struct basicblock_ *b_next; + /* b_seen is used to perform a DFS of basicblocks. */ + unsigned b_seen : 1; + /* b_return is true if a RETURN_VALUE opcode is inserted. */ + unsigned b_return : 1; + /* depth of stack upon entry of block, computed by stackdepth() */ + int b_startdepth; + /* instruction offset for block, computed by assemble_jump_offsets() */ + int b_offset; +} basicblock; + +/* fblockinfo tracks the current frame block. + +A frame block is used to handle loops, try/except, and try/finally. +It's called a frame block to distinguish it from a basic block in the +compiler IR. +*/ + +enum fblocktype { LOOP, EXCEPT, FINALLY_TRY, FINALLY_END }; + +struct fblockinfo { + enum fblocktype fb_type; + basicblock *fb_block; +}; + +/* The following items change on entry and exit of code blocks. + They must be saved and restored when returning to a block. +*/ +struct compiler_unit { + PySTEntryObject *u_ste; + + PyObject *u_name; + /* The following fields are dicts that map objects to + the index of them in co_XXX. The index is used as + the argument for opcodes that refer to those collections. + */ + PyObject *u_consts; /* all constants */ + PyObject *u_names; /* all names */ + PyObject *u_varnames; /* local variables */ + PyObject *u_cellvars; /* cell variables */ + PyObject *u_freevars; /* free variables */ + + PyObject *u_private; /* for private name mangling */ + + int u_argcount; /* number of arguments for block */ + /* Pointer to the most recently allocated block. By following b_list + members, you can reach all early allocated blocks. */ + basicblock *u_blocks; + basicblock *u_curblock; /* pointer to current block */ + + int u_nfblocks; + struct fblockinfo u_fblock[CO_MAXBLOCKS]; + + int u_firstlineno; /* the first lineno of the block */ + int u_lineno; /* the lineno for the current stmt */ + bool u_lineno_set; /* boolean to indicate whether instr + has been generated with current lineno */ +}; + +/* This struct captures the global state of a compilation. + +The u pointer points to the current compilation unit, while units +for enclosing blocks are stored in c_stack. The u and c_stack are +managed by compiler_enter_scope() and compiler_exit_scope(). +*/ + +struct compiler { + const char *c_filename; + struct symtable *c_st; + PyFutureFeatures *c_future; /* pointer to module's __future__ */ + PyCompilerFlags *c_flags; + + int c_interactive; /* true if in interactive mode */ + int c_nestlevel; + + struct compiler_unit *u; /* compiler state for current block */ + PyObject *c_stack; /* Python list holding compiler_unit ptrs */ + PyArena *c_arena; /* pointer to memory allocation arena */ +}; + +static int compiler_enter_scope(struct compiler *, identifier, void *, int); +static void compiler_free(struct compiler *); +static basicblock *compiler_new_block(struct compiler *); +static int compiler_next_instr(struct compiler *, basicblock *); +static int compiler_addop(struct compiler *, int); +static int compiler_addop_o(struct compiler *, int, PyObject *, PyObject *); +static int compiler_addop_i(struct compiler *, int, int); +static int compiler_addop_j(struct compiler *, int, basicblock *, int); +static basicblock *compiler_use_new_block(struct compiler *); +static int compiler_error(struct compiler *, const char *); +static int compiler_nameop(struct compiler *, identifier, expr_context_ty); + +static PyCodeObject *compiler_mod(struct compiler *, mod_ty); +static int compiler_visit_stmt(struct compiler *, stmt_ty); +static int compiler_visit_keyword(struct compiler *, keyword_ty); +static int compiler_visit_expr(struct compiler *, expr_ty); +static int compiler_augassign(struct compiler *, stmt_ty); +static int compiler_visit_slice(struct compiler *, slice_ty, + expr_context_ty); + +static int compiler_push_fblock(struct compiler *, enum fblocktype, + basicblock *); +static void compiler_pop_fblock(struct compiler *, enum fblocktype, + basicblock *); +/* Returns true if there is a loop on the fblock stack. */ +static int compiler_in_loop(struct compiler *); + +static int inplace_binop(struct compiler *, operator_ty); +static int expr_constant(expr_ty e); + +static int compiler_with(struct compiler *, stmt_ty); + +static PyCodeObject *assemble(struct compiler *, int addNone); +static PyObject *__doc__; + +#define COMPILER_CAPSULE_NAME_COMPILER_UNIT "compile.c compiler unit" + +PyObject * +_Py_Mangle(PyObject *privateobj, PyObject *ident) +{ + /* Name mangling: __private becomes _classname__private. + This is independent from how the name is used. */ + const char *p, *name = PyString_AsString(ident); + char *buffer; + size_t nlen, plen; + if (privateobj == NULL || !PyString_Check(privateobj) || + name == NULL || name[0] != '_' || name[1] != '_') { + Py_INCREF(ident); + return ident; + } + p = PyString_AsString(privateobj); + nlen = strlen(name); + /* Don't mangle __id__ or names with dots. + + The only time a name with a dot can occur is when + we are compiling an import statement that has a + package name. + + TODO(jhylton): Decide whether we want to support + mangling of the module name, e.g. __M.X. + */ + if ((name[nlen-1] == '_' && name[nlen-2] == '_') + || strchr(name, '.')) { + Py_INCREF(ident); + return ident; /* Don't mangle __whatever__ */ + } + /* Strip leading underscores from class name */ + while (*p == '_') + p++; + if (*p == '\0') { + Py_INCREF(ident); + return ident; /* Don't mangle if class is just underscores */ + } + plen = strlen(p); + + if (plen + nlen >= PY_SSIZE_T_MAX - 1) { + PyErr_SetString(PyExc_OverflowError, + "private identifier too large to be mangled"); + return NULL; + } + + ident = PyString_FromStringAndSize(NULL, 1 + nlen + plen); + if (!ident) + return 0; + /* ident = "_" + p[:plen] + name # i.e. 1+plen+nlen bytes */ + buffer = PyString_AS_STRING(ident); + buffer[0] = '_'; + strncpy(buffer+1, p, plen); + strcpy(buffer+1+plen, name); + return ident; +} + +static int +compiler_init(struct compiler *c) +{ + memset(c, 0, sizeof(struct compiler)); + + c->c_stack = PyList_New(0); + if (!c->c_stack) + return 0; + + return 1; +} + +PyCodeObject * +PyAST_Compile(mod_ty mod, const char *filename, PyCompilerFlags *flags, + PyArena *arena) +{ + struct compiler c; + PyCodeObject *co = NULL; + PyCompilerFlags local_flags; + int merged; + + if (!__doc__) { + __doc__ = PyString_InternFromString("__doc__"); + if (!__doc__) + return NULL; + } + + if (!compiler_init(&c)) + return NULL; + c.c_filename = filename; + c.c_arena = arena; + c.c_future = PyFuture_FromAST(mod, filename); + if (c.c_future == NULL) + goto finally; + if (!flags) { + local_flags.cf_flags = 0; + flags = &local_flags; + } + merged = c.c_future->ff_features | flags->cf_flags; + c.c_future->ff_features = merged; + flags->cf_flags = merged; + c.c_flags = flags; + c.c_nestlevel = 0; + + c.c_st = PySymtable_Build(mod, filename, c.c_future); + if (c.c_st == NULL) { + if (!PyErr_Occurred()) + PyErr_SetString(PyExc_SystemError, "no symtable"); + goto finally; + } + + co = compiler_mod(&c, mod); + + finally: + compiler_free(&c); + assert(co || PyErr_Occurred()); + return co; +} + +PyCodeObject * +PyNode_Compile(struct _node *n, const char *filename) +{ + PyCodeObject *co = NULL; + mod_ty mod; + PyArena *arena = PyArena_New(); + if (!arena) + return NULL; + mod = PyAST_FromNode(n, NULL, filename, arena); + if (mod) + co = PyAST_Compile(mod, filename, NULL, arena); + PyArena_Free(arena); + return co; +} + +static void +compiler_free(struct compiler *c) +{ + if (c->c_st) + PySymtable_Free(c->c_st); + if (c->c_future) + PyObject_Free(c->c_future); + Py_DECREF(c->c_stack); +} + +static PyObject * +list2dict(PyObject *list) +{ + Py_ssize_t i, n; + PyObject *v, *k; + PyObject *dict = PyDict_New(); + if (!dict) return NULL; + + n = PyList_Size(list); + for (i = 0; i < n; i++) { + v = PyInt_FromLong(i); + if (!v) { + Py_DECREF(dict); + return NULL; + } + k = PyList_GET_ITEM(list, i); + k = _PyCode_ConstantKey(k); + if (k == NULL || PyDict_SetItem(dict, k, v) < 0) { + Py_XDECREF(k); + Py_DECREF(v); + Py_DECREF(dict); + return NULL; + } + Py_DECREF(k); + Py_DECREF(v); + } + return dict; +} + +/* Return new dict containing names from src that match scope(s). + +src is a symbol table dictionary. If the scope of a name matches +either scope_type or flag is set, insert it into the new dict. The +values are integers, starting at offset and increasing by one for +each key. +*/ + +static PyObject * +dictbytype(PyObject *src, int scope_type, int flag, int offset) +{ + Py_ssize_t i = offset, scope, num_keys, key_i; + PyObject *k, *v, *dest = PyDict_New(); + PyObject *sorted_keys; + + assert(offset >= 0); + if (dest == NULL) + return NULL; + + /* Sort the keys so that we have a deterministic order on the indexes + saved in the returned dictionary. These indexes are used as indexes + into the free and cell var storage. Therefore if they aren't + deterministic, then the generated bytecode is not deterministic. + */ + sorted_keys = PyDict_Keys(src); + if (sorted_keys == NULL) + return NULL; + if (PyList_Sort(sorted_keys) != 0) { + Py_DECREF(sorted_keys); + return NULL; + } + num_keys = PyList_GET_SIZE(sorted_keys); + + for (key_i = 0; key_i < num_keys; key_i++) { + k = PyList_GET_ITEM(sorted_keys, key_i); + v = PyDict_GetItem(src, k); + /* XXX this should probably be a macro in symtable.h */ + assert(PyInt_Check(v)); + scope = (PyInt_AS_LONG(v) >> SCOPE_OFF) & SCOPE_MASK; + + if (scope == scope_type || PyInt_AS_LONG(v) & flag) { + PyObject *tuple, *item = PyInt_FromLong(i); + if (item == NULL) { + Py_DECREF(sorted_keys); + Py_DECREF(dest); + return NULL; + } + i++; + tuple = _PyCode_ConstantKey(k); + if (!tuple || PyDict_SetItem(dest, tuple, item) < 0) { + Py_DECREF(sorted_keys); + Py_DECREF(item); + Py_DECREF(dest); + Py_XDECREF(tuple); + return NULL; + } + Py_DECREF(item); + Py_DECREF(tuple); + } + } + Py_DECREF(sorted_keys); + return dest; +} + +static void +compiler_unit_check(struct compiler_unit *u) +{ + basicblock *block; + for (block = u->u_blocks; block != NULL; block = block->b_list) { + assert((void *)block != (void *)0xcbcbcbcb); + assert((void *)block != (void *)0xfbfbfbfb); + assert((void *)block != (void *)0xdbdbdbdb); + if (block->b_instr != NULL) { + assert(block->b_ialloc > 0); + assert(block->b_iused > 0); + assert(block->b_ialloc >= block->b_iused); + } + else { + assert (block->b_iused == 0); + assert (block->b_ialloc == 0); + } + } +} + +static void +compiler_unit_free(struct compiler_unit *u) +{ + basicblock *b, *next; + + compiler_unit_check(u); + b = u->u_blocks; + while (b != NULL) { + if (b->b_instr) + PyObject_Free((void *)b->b_instr); + next = b->b_list; + PyObject_Free((void *)b); + b = next; + } + Py_CLEAR(u->u_ste); + Py_CLEAR(u->u_name); + Py_CLEAR(u->u_consts); + Py_CLEAR(u->u_names); + Py_CLEAR(u->u_varnames); + Py_CLEAR(u->u_freevars); + Py_CLEAR(u->u_cellvars); + Py_CLEAR(u->u_private); + PyObject_Free(u); +} + +static int +compiler_enter_scope(struct compiler *c, identifier name, void *key, + int lineno) +{ + struct compiler_unit *u; + + u = (struct compiler_unit *)PyObject_Malloc(sizeof( + struct compiler_unit)); + if (!u) { + PyErr_NoMemory(); + return 0; + } + memset(u, 0, sizeof(struct compiler_unit)); + u->u_argcount = 0; + u->u_ste = PySymtable_Lookup(c->c_st, key); + if (!u->u_ste) { + compiler_unit_free(u); + return 0; + } + Py_INCREF(name); + u->u_name = name; + u->u_varnames = list2dict(u->u_ste->ste_varnames); + u->u_cellvars = dictbytype(u->u_ste->ste_symbols, CELL, 0, 0); + if (!u->u_varnames || !u->u_cellvars) { + compiler_unit_free(u); + return 0; + } + + u->u_freevars = dictbytype(u->u_ste->ste_symbols, FREE, DEF_FREE_CLASS, + PyDict_Size(u->u_cellvars)); + if (!u->u_freevars) { + compiler_unit_free(u); + return 0; + } + + u->u_blocks = NULL; + u->u_nfblocks = 0; + u->u_firstlineno = lineno; + u->u_lineno = 0; + u->u_lineno_set = false; + u->u_consts = PyDict_New(); + if (!u->u_consts) { + compiler_unit_free(u); + return 0; + } + u->u_names = PyDict_New(); + if (!u->u_names) { + compiler_unit_free(u); + return 0; + } + + u->u_private = NULL; + + /* Push the old compiler_unit on the stack. */ + if (c->u) { + PyObject *capsule = PyCapsule_New(c->u, COMPILER_CAPSULE_NAME_COMPILER_UNIT, NULL); + if (!capsule || PyList_Append(c->c_stack, capsule) < 0) { + Py_XDECREF(capsule); + compiler_unit_free(u); + return 0; + } + Py_DECREF(capsule); + u->u_private = c->u->u_private; + Py_XINCREF(u->u_private); + } + c->u = u; + + c->c_nestlevel++; + if (compiler_use_new_block(c) == NULL) + return 0; + + return 1; +} + +static void +compiler_exit_scope(struct compiler *c) +{ + int n; + PyObject *capsule; + + c->c_nestlevel--; + compiler_unit_free(c->u); + /* Restore c->u to the parent unit. */ + n = PyList_GET_SIZE(c->c_stack) - 1; + if (n >= 0) { + capsule = PyList_GET_ITEM(c->c_stack, n); + c->u = (struct compiler_unit *)PyCapsule_GetPointer(capsule, COMPILER_CAPSULE_NAME_COMPILER_UNIT); + assert(c->u); + /* we are deleting from a list so this really shouldn't fail */ + if (PySequence_DelItem(c->c_stack, n) < 0) + Py_FatalError("compiler_exit_scope()"); + compiler_unit_check(c->u); + } + else + c->u = NULL; + +} + +/* Allocate a new block and return a pointer to it. + Returns NULL on error. +*/ + +static basicblock * +compiler_new_block(struct compiler *c) +{ + basicblock *b; + struct compiler_unit *u; + + u = c->u; + b = (basicblock *)PyObject_Malloc(sizeof(basicblock)); + if (b == NULL) { + PyErr_NoMemory(); + return NULL; + } + memset((void *)b, 0, sizeof(basicblock)); + /* Extend the singly linked list of blocks with new block. */ + b->b_list = u->u_blocks; + u->u_blocks = b; + return b; +} + +static basicblock * +compiler_use_new_block(struct compiler *c) +{ + basicblock *block = compiler_new_block(c); + if (block == NULL) + return NULL; + c->u->u_curblock = block; + return block; +} + +static basicblock * +compiler_next_block(struct compiler *c) +{ + basicblock *block = compiler_new_block(c); + if (block == NULL) + return NULL; + c->u->u_curblock->b_next = block; + c->u->u_curblock = block; + return block; +} + +static basicblock * +compiler_use_next_block(struct compiler *c, basicblock *block) +{ + assert(block != NULL); + c->u->u_curblock->b_next = block; + c->u->u_curblock = block; + return block; +} + +/* Returns the offset of the next instruction in the current block's + b_instr array. Resizes the b_instr as necessary. + Returns -1 on failure. +*/ + +static int +compiler_next_instr(struct compiler *c, basicblock *b) +{ + assert(b != NULL); + if (b->b_instr == NULL) { + b->b_instr = (struct instr *)PyObject_Malloc( + sizeof(struct instr) * DEFAULT_BLOCK_SIZE); + if (b->b_instr == NULL) { + PyErr_NoMemory(); + return -1; + } + b->b_ialloc = DEFAULT_BLOCK_SIZE; + memset((char *)b->b_instr, 0, + sizeof(struct instr) * DEFAULT_BLOCK_SIZE); + } + else if (b->b_iused == b->b_ialloc) { + struct instr *tmp; + size_t oldsize, newsize; + oldsize = b->b_ialloc * sizeof(struct instr); + newsize = oldsize << 1; + + if (oldsize > (PY_SIZE_MAX >> 1)) { + PyErr_NoMemory(); + return -1; + } + + if (newsize == 0) { + PyErr_NoMemory(); + return -1; + } + b->b_ialloc <<= 1; + tmp = (struct instr *)PyObject_Realloc( + (void *)b->b_instr, newsize); + if (tmp == NULL) { + PyErr_NoMemory(); + return -1; + } + b->b_instr = tmp; + memset((char *)b->b_instr + oldsize, 0, newsize - oldsize); + } + return b->b_iused++; +} + +/* Set the i_lineno member of the instruction at offset off if the + line number for the current expression/statement has not + already been set. If it has been set, the call has no effect. + + The line number is reset in the following cases: + - when entering a new scope + - on each statement + - on each expression that start a new line + - before the "except" clause + - before the "for" and "while" expressions +*/ + +static void +compiler_set_lineno(struct compiler *c, int off) +{ + basicblock *b; + if (c->u->u_lineno_set) + return; + c->u->u_lineno_set = true; + b = c->u->u_curblock; + b->b_instr[off].i_lineno = c->u->u_lineno; +} + +static int +opcode_stack_effect(int opcode, int oparg) +{ + switch (opcode) { + case POP_TOP: + return -1; + case ROT_TWO: + case ROT_THREE: + return 0; + case DUP_TOP: + return 1; + case ROT_FOUR: + return 0; + + case UNARY_POSITIVE: + case UNARY_NEGATIVE: + case UNARY_NOT: + case UNARY_CONVERT: + case UNARY_INVERT: + return 0; + + case SET_ADD: + case LIST_APPEND: + return -1; + + case MAP_ADD: + return -2; + + case BINARY_POWER: + case BINARY_MULTIPLY: + case BINARY_DIVIDE: + case BINARY_MODULO: + case BINARY_ADD: + case BINARY_SUBTRACT: + case BINARY_SUBSCR: + case BINARY_FLOOR_DIVIDE: + case BINARY_TRUE_DIVIDE: + return -1; + case INPLACE_FLOOR_DIVIDE: + case INPLACE_TRUE_DIVIDE: + return -1; + + case SLICE+0: + return 0; + case SLICE+1: + return -1; + case SLICE+2: + return -1; + case SLICE+3: + return -2; + + case STORE_SLICE+0: + return -2; + case STORE_SLICE+1: + return -3; + case STORE_SLICE+2: + return -3; + case STORE_SLICE+3: + return -4; + + case DELETE_SLICE+0: + return -1; + case DELETE_SLICE+1: + return -2; + case DELETE_SLICE+2: + return -2; + case DELETE_SLICE+3: + return -3; + + case INPLACE_ADD: + case INPLACE_SUBTRACT: + case INPLACE_MULTIPLY: + case INPLACE_DIVIDE: + case INPLACE_MODULO: + return -1; + case STORE_SUBSCR: + return -3; + case STORE_MAP: + return -2; + case DELETE_SUBSCR: + return -2; + + case BINARY_LSHIFT: + case BINARY_RSHIFT: + case BINARY_AND: + case BINARY_XOR: + case BINARY_OR: + return -1; + case INPLACE_POWER: + return -1; + case GET_ITER: + return 0; + + case PRINT_EXPR: + return -1; + case PRINT_ITEM: + return -1; + case PRINT_NEWLINE: + return 0; + case PRINT_ITEM_TO: + return -2; + case PRINT_NEWLINE_TO: + return -1; + case INPLACE_LSHIFT: + case INPLACE_RSHIFT: + case INPLACE_AND: + case INPLACE_XOR: + case INPLACE_OR: + return -1; + case BREAK_LOOP: + return 0; + case SETUP_WITH: + return 4; + case WITH_CLEANUP: + return -1; /* XXX Sometimes more */ + case LOAD_LOCALS: + return 1; + case RETURN_VALUE: + return -1; + case IMPORT_STAR: + return -1; + case EXEC_STMT: + return -3; + case YIELD_VALUE: + return 0; + + case POP_BLOCK: + return 0; + case END_FINALLY: + return -3; /* or -1 or -2 if no exception occurred or + return/break/continue */ + case BUILD_CLASS: + return -2; + + case STORE_NAME: + return -1; + case DELETE_NAME: + return 0; + case UNPACK_SEQUENCE: + return oparg-1; + case FOR_ITER: + return 1; /* or -1, at end of iterator */ + + case STORE_ATTR: + return -2; + case DELETE_ATTR: + return -1; + case STORE_GLOBAL: + return -1; + case DELETE_GLOBAL: + return 0; + case DUP_TOPX: + return oparg; + case LOAD_CONST: + return 1; + case LOAD_NAME: + return 1; + case BUILD_TUPLE: + case BUILD_LIST: + case BUILD_SET: + return 1-oparg; + case BUILD_MAP: + return 1; + case LOAD_ATTR: + return 0; + case COMPARE_OP: + return -1; + case IMPORT_NAME: + return -1; + case IMPORT_FROM: + return 1; + + case JUMP_FORWARD: + case JUMP_IF_TRUE_OR_POP: /* -1 if jump not taken */ + case JUMP_IF_FALSE_OR_POP: /* "" */ + case JUMP_ABSOLUTE: + return 0; + + case POP_JUMP_IF_FALSE: + case POP_JUMP_IF_TRUE: + return -1; + + case LOAD_GLOBAL: + return 1; + + case CONTINUE_LOOP: + return 0; + case SETUP_LOOP: + case SETUP_EXCEPT: + case SETUP_FINALLY: + return 0; + + case LOAD_FAST: + return 1; + case STORE_FAST: + return -1; + case DELETE_FAST: + return 0; + + case RAISE_VARARGS: + return -oparg; +#define NARGS(o) (((o) % 256) + 2*((o) / 256)) + case CALL_FUNCTION: + return -NARGS(oparg); + case CALL_FUNCTION_VAR: + case CALL_FUNCTION_KW: + return -NARGS(oparg)-1; + case CALL_FUNCTION_VAR_KW: + return -NARGS(oparg)-2; +#undef NARGS + case MAKE_FUNCTION: + return -oparg; + case BUILD_SLICE: + if (oparg == 3) + return -2; + else + return -1; + + case MAKE_CLOSURE: + return -oparg-1; + case LOAD_CLOSURE: + return 1; + case LOAD_DEREF: + return 1; + case STORE_DEREF: + return -1; + default: + fprintf(stderr, "opcode = %d\n", opcode); + Py_FatalError("opcode_stack_effect()"); + + } + return 0; /* not reachable */ +} + +/* Add an opcode with no argument. + Returns 0 on failure, 1 on success. +*/ + +static int +compiler_addop(struct compiler *c, int opcode) +{ + basicblock *b; + struct instr *i; + int off; + off = compiler_next_instr(c, c->u->u_curblock); + if (off < 0) + return 0; + b = c->u->u_curblock; + i = &b->b_instr[off]; + i->i_opcode = opcode; + i->i_hasarg = 0; + if (opcode == RETURN_VALUE) + b->b_return = 1; + compiler_set_lineno(c, off); + return 1; +} + +static int +compiler_add_o(struct compiler *c, PyObject *dict, PyObject *o) +{ + PyObject *t, *v; + Py_ssize_t arg; + + t = _PyCode_ConstantKey(o); + if (t == NULL) + return -1; + + v = PyDict_GetItem(dict, t); + if (!v) { + arg = PyDict_Size(dict); + v = PyInt_FromLong(arg); + if (!v) { + Py_DECREF(t); + return -1; + } + if (PyDict_SetItem(dict, t, v) < 0) { + Py_DECREF(t); + Py_DECREF(v); + return -1; + } + Py_DECREF(v); + } + else + arg = PyInt_AsLong(v); + Py_DECREF(t); + return arg; +} + +static int +compiler_addop_o(struct compiler *c, int opcode, PyObject *dict, + PyObject *o) +{ + int arg = compiler_add_o(c, dict, o); + if (arg < 0) + return 0; + return compiler_addop_i(c, opcode, arg); +} + +static int +compiler_addop_name(struct compiler *c, int opcode, PyObject *dict, + PyObject *o) +{ + int arg; + PyObject *mangled = _Py_Mangle(c->u->u_private, o); + if (!mangled) + return 0; + arg = compiler_add_o(c, dict, mangled); + Py_DECREF(mangled); + if (arg < 0) + return 0; + return compiler_addop_i(c, opcode, arg); +} + +/* Add an opcode with an integer argument. + Returns 0 on failure, 1 on success. +*/ + +static int +compiler_addop_i(struct compiler *c, int opcode, int oparg) +{ + struct instr *i; + int off; + off = compiler_next_instr(c, c->u->u_curblock); + if (off < 0) + return 0; + i = &c->u->u_curblock->b_instr[off]; + i->i_opcode = opcode; + i->i_oparg = oparg; + i->i_hasarg = 1; + compiler_set_lineno(c, off); + return 1; +} + +static int +compiler_addop_j(struct compiler *c, int opcode, basicblock *b, int absolute) +{ + struct instr *i; + int off; + + assert(b != NULL); + off = compiler_next_instr(c, c->u->u_curblock); + if (off < 0) + return 0; + i = &c->u->u_curblock->b_instr[off]; + i->i_opcode = opcode; + i->i_target = b; + i->i_hasarg = 1; + if (absolute) + i->i_jabs = 1; + else + i->i_jrel = 1; + compiler_set_lineno(c, off); + return 1; +} + +/* The distinction between NEW_BLOCK and NEXT_BLOCK is subtle. (I'd + like to find better names.) NEW_BLOCK() creates a new block and sets + it as the current block. NEXT_BLOCK() also creates an implicit jump + from the current block to the new block. +*/ + +/* The returns inside these macros make it impossible to decref objects + created in the local function. Local objects should use the arena. +*/ + + +#define NEW_BLOCK(C) { \ + if (compiler_use_new_block((C)) == NULL) \ + return 0; \ +} + +#define NEXT_BLOCK(C) { \ + if (compiler_next_block((C)) == NULL) \ + return 0; \ +} + +#define ADDOP(C, OP) { \ + if (!compiler_addop((C), (OP))) \ + return 0; \ +} + +#define ADDOP_IN_SCOPE(C, OP) { \ + if (!compiler_addop((C), (OP))) { \ + compiler_exit_scope(c); \ + return 0; \ + } \ +} + +#define ADDOP_O(C, OP, O, TYPE) { \ + if (!compiler_addop_o((C), (OP), (C)->u->u_ ## TYPE, (O))) \ + return 0; \ +} + +/* Same as ADDOP_O, but steals a reference. */ +#define ADDOP_N(C, OP, O, TYPE) { \ + if (!compiler_addop_o((C), (OP), (C)->u->u_ ## TYPE, (O))) { \ + Py_DECREF((O)); \ + return 0; \ + } \ + Py_DECREF((O)); \ +} + +#define ADDOP_NAME(C, OP, O, TYPE) { \ + if (!compiler_addop_name((C), (OP), (C)->u->u_ ## TYPE, (O))) \ + return 0; \ +} + +#define ADDOP_I(C, OP, O) { \ + if (!compiler_addop_i((C), (OP), (O))) \ + return 0; \ +} + +#define ADDOP_JABS(C, OP, O) { \ + if (!compiler_addop_j((C), (OP), (O), 1)) \ + return 0; \ +} + +#define ADDOP_JREL(C, OP, O) { \ + if (!compiler_addop_j((C), (OP), (O), 0)) \ + return 0; \ +} + +/* VISIT and VISIT_SEQ takes an ASDL type as their second argument. They use + the ASDL name to synthesize the name of the C type and the visit function. +*/ + +#define VISIT(C, TYPE, V) {\ + if (!compiler_visit_ ## TYPE((C), (V))) \ + return 0; \ +} + +#define VISIT_IN_SCOPE(C, TYPE, V) {\ + if (!compiler_visit_ ## TYPE((C), (V))) { \ + compiler_exit_scope(c); \ + return 0; \ + } \ +} + +#define VISIT_SLICE(C, V, CTX) {\ + if (!compiler_visit_slice((C), (V), (CTX))) \ + return 0; \ +} + +#define VISIT_SEQ(C, TYPE, SEQ) { \ + int _i; \ + asdl_seq *seq = (SEQ); /* avoid variable capture */ \ + for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \ + TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \ + if (!compiler_visit_ ## TYPE((C), elt)) \ + return 0; \ + } \ +} + +#define VISIT_SEQ_IN_SCOPE(C, TYPE, SEQ) { \ + int _i; \ + asdl_seq *seq = (SEQ); /* avoid variable capture */ \ + for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \ + TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \ + if (!compiler_visit_ ## TYPE((C), elt)) { \ + compiler_exit_scope(c); \ + return 0; \ + } \ + } \ +} + +static int +compiler_isdocstring(stmt_ty s) +{ + if (s->kind != Expr_kind) + return 0; + return s->v.Expr.value->kind == Str_kind; +} + +/* Compile a sequence of statements, checking for a docstring. */ + +static int +compiler_body(struct compiler *c, asdl_seq *stmts) +{ + int i = 0; + stmt_ty st; + + if (!asdl_seq_LEN(stmts)) + return 1; + st = (stmt_ty)asdl_seq_GET(stmts, 0); + if (compiler_isdocstring(st) && Py_OptimizeFlag < 2) { + /* don't generate docstrings if -OO */ + i = 1; + VISIT(c, expr, st->v.Expr.value); + if (!compiler_nameop(c, __doc__, Store)) + return 0; + } + for (; i < asdl_seq_LEN(stmts); i++) + VISIT(c, stmt, (stmt_ty)asdl_seq_GET(stmts, i)); + return 1; +} + +static PyCodeObject * +compiler_mod(struct compiler *c, mod_ty mod) +{ + PyCodeObject *co; + int addNone = 1; + static PyObject *module; + if (!module) { + module = PyString_InternFromString("<module>"); + if (!module) + return NULL; + } + /* Use 0 for firstlineno initially, will fixup in assemble(). */ + if (!compiler_enter_scope(c, module, mod, 0)) + return NULL; + switch (mod->kind) { + case Module_kind: + if (!compiler_body(c, mod->v.Module.body)) { + compiler_exit_scope(c); + return 0; + } + break; + case Interactive_kind: + c->c_interactive = 1; + VISIT_SEQ_IN_SCOPE(c, stmt, + mod->v.Interactive.body); + break; + case Expression_kind: + VISIT_IN_SCOPE(c, expr, mod->v.Expression.body); + addNone = 0; + break; + case Suite_kind: + PyErr_SetString(PyExc_SystemError, + "suite should not be possible"); + return 0; + default: + PyErr_Format(PyExc_SystemError, + "module kind %d should not be possible", + mod->kind); + return 0; + } + co = assemble(c, addNone); + compiler_exit_scope(c); + return co; +} + +/* The test for LOCAL must come before the test for FREE in order to + handle classes where name is both local and free. The local var is + a method and the free var is a free var referenced within a method. +*/ + +static int +get_ref_type(struct compiler *c, PyObject *name) +{ + int scope = PyST_GetScope(c->u->u_ste, name); + if (scope == 0) { + char buf[350]; + PyOS_snprintf(buf, sizeof(buf), + "unknown scope for %.100s in %.100s(%s) in %s\n" + "symbols: %s\nlocals: %s\nglobals: %s", + PyString_AS_STRING(name), + PyString_AS_STRING(c->u->u_name), + PyString_AS_STRING(PyObject_Repr(c->u->u_ste->ste_id)), + c->c_filename, + PyString_AS_STRING(PyObject_Repr(c->u->u_ste->ste_symbols)), + PyString_AS_STRING(PyObject_Repr(c->u->u_varnames)), + PyString_AS_STRING(PyObject_Repr(c->u->u_names)) + ); + Py_FatalError(buf); + } + + return scope; +} + +static int +compiler_lookup_arg(PyObject *dict, PyObject *name) +{ + PyObject *k, *v; + k = _PyCode_ConstantKey(name); + if (k == NULL) + return -1; + v = PyDict_GetItem(dict, k); + Py_DECREF(k); + if (v == NULL) + return -1; + return PyInt_AS_LONG(v); +} + +static int +compiler_make_closure(struct compiler *c, PyCodeObject *co, int args) +{ + int i, free = PyCode_GetNumFree(co); + if (free == 0) { + ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts); + ADDOP_I(c, MAKE_FUNCTION, args); + return 1; + } + for (i = 0; i < free; ++i) { + /* Bypass com_addop_varname because it will generate + LOAD_DEREF but LOAD_CLOSURE is needed. + */ + PyObject *name = PyTuple_GET_ITEM(co->co_freevars, i); + int arg, reftype; + + /* Special case: If a class contains a method with a + free variable that has the same name as a method, + the name will be considered free *and* local in the + class. It should be handled by the closure, as + well as by the normal name loookup logic. + */ + reftype = get_ref_type(c, name); + if (reftype == CELL) + arg = compiler_lookup_arg(c->u->u_cellvars, name); + else /* (reftype == FREE) */ + arg = compiler_lookup_arg(c->u->u_freevars, name); + if (arg == -1) { + printf("lookup %s in %s %d %d\n" + "freevars of %s: %s\n", + PyString_AS_STRING(PyObject_Repr(name)), + PyString_AS_STRING(c->u->u_name), + reftype, arg, + PyString_AS_STRING(co->co_name), + PyString_AS_STRING(PyObject_Repr(co->co_freevars))); + Py_FatalError("compiler_make_closure()"); + } + ADDOP_I(c, LOAD_CLOSURE, arg); + } + ADDOP_I(c, BUILD_TUPLE, free); + ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts); + ADDOP_I(c, MAKE_CLOSURE, args); + return 1; +} + +static int +compiler_decorators(struct compiler *c, asdl_seq* decos) +{ + int i; + + if (!decos) + return 1; + + for (i = 0; i < asdl_seq_LEN(decos); i++) { + VISIT(c, expr, (expr_ty)asdl_seq_GET(decos, i)); + } + return 1; +} + +static int +compiler_arguments(struct compiler *c, arguments_ty args) +{ + int i; + int n = asdl_seq_LEN(args->args); + /* Correctly handle nested argument lists */ + for (i = 0; i < n; i++) { + expr_ty arg = (expr_ty)asdl_seq_GET(args->args, i); + if (arg->kind == Tuple_kind) { + PyObject *id = PyString_FromFormat(".%d", i); + if (id == NULL) { + return 0; + } + if (!compiler_nameop(c, id, Load)) { + Py_DECREF(id); + return 0; + } + Py_DECREF(id); + VISIT(c, expr, arg); + } + } + return 1; +} + +static int +compiler_function(struct compiler *c, stmt_ty s) +{ + PyCodeObject *co; + PyObject *first_const = Py_None; + arguments_ty args = s->v.FunctionDef.args; + asdl_seq* decos = s->v.FunctionDef.decorator_list; + stmt_ty st; + int i, n, docstring; + + assert(s->kind == FunctionDef_kind); + + if (!compiler_decorators(c, decos)) + return 0; + if (args->defaults) + VISIT_SEQ(c, expr, args->defaults); + if (!compiler_enter_scope(c, s->v.FunctionDef.name, (void *)s, + s->lineno)) + return 0; + + st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, 0); + docstring = compiler_isdocstring(st); + if (docstring && Py_OptimizeFlag < 2) + first_const = st->v.Expr.value->v.Str.s; + if (compiler_add_o(c, c->u->u_consts, first_const) < 0) { + compiler_exit_scope(c); + return 0; + } + + /* unpack nested arguments */ + compiler_arguments(c, args); + + c->u->u_argcount = asdl_seq_LEN(args->args); + n = asdl_seq_LEN(s->v.FunctionDef.body); + /* if there was a docstring, we need to skip the first statement */ + for (i = docstring; i < n; i++) { + st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, i); + VISIT_IN_SCOPE(c, stmt, st); + } + co = assemble(c, 1); + compiler_exit_scope(c); + if (co == NULL) + return 0; + + compiler_make_closure(c, co, asdl_seq_LEN(args->defaults)); + Py_DECREF(co); + + for (i = 0; i < asdl_seq_LEN(decos); i++) { + ADDOP_I(c, CALL_FUNCTION, 1); + } + + return compiler_nameop(c, s->v.FunctionDef.name, Store); +} + +static int +compiler_class(struct compiler *c, stmt_ty s) +{ + int n, i; + PyCodeObject *co; + PyObject *str; + asdl_seq* decos = s->v.ClassDef.decorator_list; + + if (!compiler_decorators(c, decos)) + return 0; + + /* push class name on stack, needed by BUILD_CLASS */ + ADDOP_O(c, LOAD_CONST, s->v.ClassDef.name, consts); + /* push the tuple of base classes on the stack */ + n = asdl_seq_LEN(s->v.ClassDef.bases); + if (n > 0) + VISIT_SEQ(c, expr, s->v.ClassDef.bases); + ADDOP_I(c, BUILD_TUPLE, n); + if (!compiler_enter_scope(c, s->v.ClassDef.name, (void *)s, + s->lineno)) + return 0; + Py_INCREF(s->v.ClassDef.name); + Py_XSETREF(c->u->u_private, s->v.ClassDef.name); + str = PyString_InternFromString("__name__"); + if (!str || !compiler_nameop(c, str, Load)) { + Py_XDECREF(str); + compiler_exit_scope(c); + return 0; + } + + Py_DECREF(str); + str = PyString_InternFromString("__module__"); + if (!str || !compiler_nameop(c, str, Store)) { + Py_XDECREF(str); + compiler_exit_scope(c); + return 0; + } + Py_DECREF(str); + + if (!compiler_body(c, s->v.ClassDef.body)) { + compiler_exit_scope(c); + return 0; + } + + ADDOP_IN_SCOPE(c, LOAD_LOCALS); + ADDOP_IN_SCOPE(c, RETURN_VALUE); + co = assemble(c, 1); + compiler_exit_scope(c); + if (co == NULL) + return 0; + + compiler_make_closure(c, co, 0); + Py_DECREF(co); + + ADDOP_I(c, CALL_FUNCTION, 0); + ADDOP(c, BUILD_CLASS); + /* apply decorators */ + for (i = 0; i < asdl_seq_LEN(decos); i++) { + ADDOP_I(c, CALL_FUNCTION, 1); + } + if (!compiler_nameop(c, s->v.ClassDef.name, Store)) + return 0; + return 1; +} + +static int +compiler_ifexp(struct compiler *c, expr_ty e) +{ + basicblock *end, *next; + + assert(e->kind == IfExp_kind); + end = compiler_new_block(c); + if (end == NULL) + return 0; + next = compiler_new_block(c); + if (next == NULL) + return 0; + VISIT(c, expr, e->v.IfExp.test); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, next); + VISIT(c, expr, e->v.IfExp.body); + ADDOP_JREL(c, JUMP_FORWARD, end); + compiler_use_next_block(c, next); + VISIT(c, expr, e->v.IfExp.orelse); + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_lambda(struct compiler *c, expr_ty e) +{ + PyCodeObject *co; + static identifier name; + arguments_ty args = e->v.Lambda.args; + assert(e->kind == Lambda_kind); + + if (!name) { + name = PyString_InternFromString("<lambda>"); + if (!name) + return 0; + } + + if (args->defaults) + VISIT_SEQ(c, expr, args->defaults); + if (!compiler_enter_scope(c, name, (void *)e, e->lineno)) + return 0; + + /* unpack nested arguments */ + compiler_arguments(c, args); + + /* Make None the first constant, so the lambda can't have a + docstring. */ + if (compiler_add_o(c, c->u->u_consts, Py_None) < 0) + return 0; + + c->u->u_argcount = asdl_seq_LEN(args->args); + VISIT_IN_SCOPE(c, expr, e->v.Lambda.body); + if (c->u->u_ste->ste_generator) { + ADDOP_IN_SCOPE(c, POP_TOP); + } + else { + ADDOP_IN_SCOPE(c, RETURN_VALUE); + } + co = assemble(c, 1); + compiler_exit_scope(c); + if (co == NULL) + return 0; + + compiler_make_closure(c, co, asdl_seq_LEN(args->defaults)); + Py_DECREF(co); + + return 1; +} + +static int +compiler_print(struct compiler *c, stmt_ty s) +{ + int i, n; + bool dest; + + assert(s->kind == Print_kind); + n = asdl_seq_LEN(s->v.Print.values); + dest = false; + if (s->v.Print.dest) { + VISIT(c, expr, s->v.Print.dest); + dest = true; + } + for (i = 0; i < n; i++) { + expr_ty e = (expr_ty)asdl_seq_GET(s->v.Print.values, i); + if (dest) { + ADDOP(c, DUP_TOP); + VISIT(c, expr, e); + ADDOP(c, ROT_TWO); + ADDOP(c, PRINT_ITEM_TO); + } + else { + VISIT(c, expr, e); + ADDOP(c, PRINT_ITEM); + } + } + if (s->v.Print.nl) { + if (dest) + ADDOP(c, PRINT_NEWLINE_TO) + else + ADDOP(c, PRINT_NEWLINE) + } + else if (dest) + ADDOP(c, POP_TOP); + return 1; +} + +static int +compiler_if(struct compiler *c, stmt_ty s) +{ + basicblock *end, *next; + int constant; + assert(s->kind == If_kind); + end = compiler_new_block(c); + if (end == NULL) + return 0; + + constant = expr_constant(s->v.If.test); + /* constant = 0: "if 0" + * constant = 1: "if 1", "if 2", ... + * constant = -1: rest */ + if (constant == 0) { + if (s->v.If.orelse) + VISIT_SEQ(c, stmt, s->v.If.orelse); + } else if (constant == 1) { + VISIT_SEQ(c, stmt, s->v.If.body); + } else { + if (s->v.If.orelse) { + next = compiler_new_block(c); + if (next == NULL) + return 0; + } + else + next = end; + VISIT(c, expr, s->v.If.test); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, next); + VISIT_SEQ(c, stmt, s->v.If.body); + ADDOP_JREL(c, JUMP_FORWARD, end); + if (s->v.If.orelse) { + compiler_use_next_block(c, next); + VISIT_SEQ(c, stmt, s->v.If.orelse); + } + } + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_for(struct compiler *c, stmt_ty s) +{ + basicblock *start, *cleanup, *end; + + start = compiler_new_block(c); + cleanup = compiler_new_block(c); + end = compiler_new_block(c); + if (start == NULL || end == NULL || cleanup == NULL) + return 0; + ADDOP_JREL(c, SETUP_LOOP, end); + if (!compiler_push_fblock(c, LOOP, start)) + return 0; + VISIT(c, expr, s->v.For.iter); + ADDOP(c, GET_ITER); + compiler_use_next_block(c, start); + ADDOP_JREL(c, FOR_ITER, cleanup); + VISIT(c, expr, s->v.For.target); + VISIT_SEQ(c, stmt, s->v.For.body); + ADDOP_JABS(c, JUMP_ABSOLUTE, start); + compiler_use_next_block(c, cleanup); + ADDOP(c, POP_BLOCK); + compiler_pop_fblock(c, LOOP, start); + VISIT_SEQ(c, stmt, s->v.For.orelse); + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_while(struct compiler *c, stmt_ty s) +{ + basicblock *loop, *orelse, *end, *anchor = NULL; + int constant = expr_constant(s->v.While.test); + + if (constant == 0) { + if (s->v.While.orelse) + VISIT_SEQ(c, stmt, s->v.While.orelse); + return 1; + } + loop = compiler_new_block(c); + end = compiler_new_block(c); + if (constant == -1) { + anchor = compiler_new_block(c); + if (anchor == NULL) + return 0; + } + if (loop == NULL || end == NULL) + return 0; + if (s->v.While.orelse) { + orelse = compiler_new_block(c); + if (orelse == NULL) + return 0; + } + else + orelse = NULL; + + ADDOP_JREL(c, SETUP_LOOP, end); + compiler_use_next_block(c, loop); + if (!compiler_push_fblock(c, LOOP, loop)) + return 0; + if (constant == -1) { + VISIT(c, expr, s->v.While.test); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, anchor); + } + VISIT_SEQ(c, stmt, s->v.While.body); + ADDOP_JABS(c, JUMP_ABSOLUTE, loop); + + /* XXX should the two POP instructions be in a separate block + if there is no else clause ? + */ + + if (constant == -1) + compiler_use_next_block(c, anchor); + ADDOP(c, POP_BLOCK); + compiler_pop_fblock(c, LOOP, loop); + if (orelse != NULL) /* what if orelse is just pass? */ + VISIT_SEQ(c, stmt, s->v.While.orelse); + compiler_use_next_block(c, end); + + return 1; +} + +static int +compiler_continue(struct compiler *c) +{ + static const char LOOP_ERROR_MSG[] = "'continue' not properly in loop"; + static const char IN_FINALLY_ERROR_MSG[] = + "'continue' not supported inside 'finally' clause"; + int i; + + if (!c->u->u_nfblocks) + return compiler_error(c, LOOP_ERROR_MSG); + i = c->u->u_nfblocks - 1; + switch (c->u->u_fblock[i].fb_type) { + case LOOP: + ADDOP_JABS(c, JUMP_ABSOLUTE, c->u->u_fblock[i].fb_block); + break; + case EXCEPT: + case FINALLY_TRY: + while (--i >= 0 && c->u->u_fblock[i].fb_type != LOOP) { + /* Prevent continue anywhere under a finally + even if hidden in a sub-try or except. */ + if (c->u->u_fblock[i].fb_type == FINALLY_END) + return compiler_error(c, IN_FINALLY_ERROR_MSG); + } + if (i == -1) + return compiler_error(c, LOOP_ERROR_MSG); + ADDOP_JABS(c, CONTINUE_LOOP, c->u->u_fblock[i].fb_block); + break; + case FINALLY_END: + return compiler_error(c, IN_FINALLY_ERROR_MSG); + } + + return 1; +} + +/* Code generated for "try: <body> finally: <finalbody>" is as follows: + + SETUP_FINALLY L + <code for body> + POP_BLOCK + LOAD_CONST <None> + L: <code for finalbody> + END_FINALLY + + The special instructions use the block stack. Each block + stack entry contains the instruction that created it (here + SETUP_FINALLY), the level of the value stack at the time the + block stack entry was created, and a label (here L). + + SETUP_FINALLY: + Pushes the current value stack level and the label + onto the block stack. + POP_BLOCK: + Pops en entry from the block stack, and pops the value + stack until its level is the same as indicated on the + block stack. (The label is ignored.) + END_FINALLY: + Pops a variable number of entries from the *value* stack + and re-raises the exception they specify. The number of + entries popped depends on the (pseudo) exception type. + + The block stack is unwound when an exception is raised: + when a SETUP_FINALLY entry is found, the exception is pushed + onto the value stack (and the exception condition is cleared), + and the interpreter jumps to the label gotten from the block + stack. +*/ + +static int +compiler_try_finally(struct compiler *c, stmt_ty s) +{ + basicblock *body, *end; + body = compiler_new_block(c); + end = compiler_new_block(c); + if (body == NULL || end == NULL) + return 0; + + ADDOP_JREL(c, SETUP_FINALLY, end); + compiler_use_next_block(c, body); + if (!compiler_push_fblock(c, FINALLY_TRY, body)) + return 0; + VISIT_SEQ(c, stmt, s->v.TryFinally.body); + ADDOP(c, POP_BLOCK); + compiler_pop_fblock(c, FINALLY_TRY, body); + + ADDOP_O(c, LOAD_CONST, Py_None, consts); + compiler_use_next_block(c, end); + if (!compiler_push_fblock(c, FINALLY_END, end)) + return 0; + VISIT_SEQ(c, stmt, s->v.TryFinally.finalbody); + ADDOP(c, END_FINALLY); + compiler_pop_fblock(c, FINALLY_END, end); + + return 1; +} + +/* + Code generated for "try: S except E1, V1: S1 except E2, V2: S2 ...": + (The contents of the value stack is shown in [], with the top + at the right; 'tb' is trace-back info, 'val' the exception's + associated value, and 'exc' the exception.) + + Value stack Label Instruction Argument + [] SETUP_EXCEPT L1 + [] <code for S> + [] POP_BLOCK + [] JUMP_FORWARD L0 + + [tb, val, exc] L1: DUP ) + [tb, val, exc, exc] <evaluate E1> ) + [tb, val, exc, exc, E1] COMPARE_OP EXC_MATCH ) only if E1 + [tb, val, exc, 1-or-0] POP_JUMP_IF_FALSE L2 ) + [tb, val, exc] POP + [tb, val] <assign to V1> (or POP if no V1) + [tb] POP + [] <code for S1> + JUMP_FORWARD L0 + + [tb, val, exc] L2: DUP + .............................etc....................... + + [tb, val, exc] Ln+1: END_FINALLY # re-raise exception + + [] L0: <next statement> + + Of course, parts are not generated if Vi or Ei is not present. +*/ +static int +compiler_try_except(struct compiler *c, stmt_ty s) +{ + basicblock *body, *orelse, *except, *end; + int i, n; + + body = compiler_new_block(c); + except = compiler_new_block(c); + orelse = compiler_new_block(c); + end = compiler_new_block(c); + if (body == NULL || except == NULL || orelse == NULL || end == NULL) + return 0; + ADDOP_JREL(c, SETUP_EXCEPT, except); + compiler_use_next_block(c, body); + if (!compiler_push_fblock(c, EXCEPT, body)) + return 0; + VISIT_SEQ(c, stmt, s->v.TryExcept.body); + ADDOP(c, POP_BLOCK); + compiler_pop_fblock(c, EXCEPT, body); + ADDOP_JREL(c, JUMP_FORWARD, orelse); + n = asdl_seq_LEN(s->v.TryExcept.handlers); + compiler_use_next_block(c, except); + for (i = 0; i < n; i++) { + excepthandler_ty handler = (excepthandler_ty)asdl_seq_GET( + s->v.TryExcept.handlers, i); + if (!handler->v.ExceptHandler.type && i < n-1) + return compiler_error(c, "default 'except:' must be last"); + c->u->u_lineno_set = false; + c->u->u_lineno = handler->lineno; + except = compiler_new_block(c); + if (except == NULL) + return 0; + if (handler->v.ExceptHandler.type) { + ADDOP(c, DUP_TOP); + VISIT(c, expr, handler->v.ExceptHandler.type); + ADDOP_I(c, COMPARE_OP, PyCmp_EXC_MATCH); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, except); + } + ADDOP(c, POP_TOP); + if (handler->v.ExceptHandler.name) { + VISIT(c, expr, handler->v.ExceptHandler.name); + } + else { + ADDOP(c, POP_TOP); + } + ADDOP(c, POP_TOP); + VISIT_SEQ(c, stmt, handler->v.ExceptHandler.body); + ADDOP_JREL(c, JUMP_FORWARD, end); + compiler_use_next_block(c, except); + } + ADDOP(c, END_FINALLY); + compiler_use_next_block(c, orelse); + VISIT_SEQ(c, stmt, s->v.TryExcept.orelse); + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_import_as(struct compiler *c, identifier name, identifier asname) +{ + /* The IMPORT_NAME opcode was already generated. This function + merely needs to bind the result to a name. + + If there is a dot in name, we need to split it and emit a + LOAD_ATTR for each name. + */ + const char *src = PyString_AS_STRING(name); + const char *dot = strchr(src, '.'); + if (dot) { + /* Consume the base module name to get the first attribute */ + src = dot + 1; + while (dot) { + /* NB src is only defined when dot != NULL */ + PyObject *attr; + dot = strchr(src, '.'); + attr = PyString_FromStringAndSize(src, + dot ? dot - src : strlen(src)); + if (!attr) + return 0; + ADDOP_N(c, LOAD_ATTR, attr, names); + src = dot + 1; + } + } + return compiler_nameop(c, asname, Store); +} + +static int +compiler_import(struct compiler *c, stmt_ty s) +{ + /* The Import node stores a module name like a.b.c as a single + string. This is convenient for all cases except + import a.b.c as d + where we need to parse that string to extract the individual + module names. + XXX Perhaps change the representation to make this case simpler? + */ + int i, n = asdl_seq_LEN(s->v.Import.names); + + for (i = 0; i < n; i++) { + alias_ty alias = (alias_ty)asdl_seq_GET(s->v.Import.names, i); + int r; + PyObject *level; + + if (c->c_flags && (c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT)) + level = PyInt_FromLong(0); + else + level = PyInt_FromLong(-1); + + if (level == NULL) + return 0; + + ADDOP_N(c, LOAD_CONST, level, consts); + ADDOP_O(c, LOAD_CONST, Py_None, consts); + ADDOP_NAME(c, IMPORT_NAME, alias->name, names); + + if (alias->asname) { + r = compiler_import_as(c, alias->name, alias->asname); + if (!r) + return r; + } + else { + identifier tmp = alias->name; + const char *base = PyString_AS_STRING(alias->name); + char *dot = strchr(base, '.'); + if (dot) { + tmp = PyString_FromStringAndSize(base, + dot - base); + if (tmp == NULL) + return 0; + } + r = compiler_nameop(c, tmp, Store); + if (dot) { + Py_DECREF(tmp); + } + if (!r) + return r; + } + } + return 1; +} + +static int +compiler_from_import(struct compiler *c, stmt_ty s) +{ + int i, n = asdl_seq_LEN(s->v.ImportFrom.names); + + PyObject *level, *names; + static PyObject *empty_string; + + if (!empty_string) { + empty_string = PyString_FromString(""); + if (!empty_string) + return 0; + } + + if (s->v.ImportFrom.level == 0 && c->c_flags && + !(c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT)) + level = PyInt_FromLong(-1); + else + level = PyInt_FromLong(s->v.ImportFrom.level); + + if (!level) { + return 0; + } + ADDOP_N(c, LOAD_CONST, level, consts); + + names = PyTuple_New(n); + if (!names) + return 0; + + /* build up the names */ + for (i = 0; i < n; i++) { + alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i); + Py_INCREF(alias->name); + PyTuple_SET_ITEM(names, i, alias->name); + } + + if (s->lineno > c->c_future->ff_lineno && s->v.ImportFrom.module && + !strcmp(PyString_AS_STRING(s->v.ImportFrom.module), "__future__")) { + Py_DECREF(names); + return compiler_error(c, "from __future__ imports must occur " + "at the beginning of the file"); + } + ADDOP_N(c, LOAD_CONST, names, consts); + + if (s->v.ImportFrom.module) { + ADDOP_NAME(c, IMPORT_NAME, s->v.ImportFrom.module, names); + } + else { + ADDOP_NAME(c, IMPORT_NAME, empty_string, names); + } + for (i = 0; i < n; i++) { + alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i); + identifier store_name; + + if (i == 0 && *PyString_AS_STRING(alias->name) == '*') { + assert(n == 1); + ADDOP(c, IMPORT_STAR); + return 1; + } + + ADDOP_NAME(c, IMPORT_FROM, alias->name, names); + store_name = alias->name; + if (alias->asname) + store_name = alias->asname; + + if (!compiler_nameop(c, store_name, Store)) { + return 0; + } + } + /* remove imported module */ + ADDOP(c, POP_TOP); + return 1; +} + +static int +compiler_assert(struct compiler *c, stmt_ty s) +{ + static PyObject *assertion_error = NULL; + basicblock *end; + + if (Py_OptimizeFlag) + return 1; + if (assertion_error == NULL) { + assertion_error = PyString_InternFromString("AssertionError"); + if (assertion_error == NULL) + return 0; + } + if (s->v.Assert.test->kind == Tuple_kind && + asdl_seq_LEN(s->v.Assert.test->v.Tuple.elts) > 0) { + const char* msg = + "assertion is always true, perhaps remove parentheses?"; + if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, c->c_filename, + c->u->u_lineno, NULL, NULL) == -1) + return 0; + } + VISIT(c, expr, s->v.Assert.test); + end = compiler_new_block(c); + if (end == NULL) + return 0; + ADDOP_JABS(c, POP_JUMP_IF_TRUE, end); + ADDOP_O(c, LOAD_GLOBAL, assertion_error, names); + if (s->v.Assert.msg) { + VISIT(c, expr, s->v.Assert.msg); + ADDOP_I(c, CALL_FUNCTION, 1); + } + ADDOP_I(c, RAISE_VARARGS, 1); + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_visit_stmt(struct compiler *c, stmt_ty s) +{ + int i, n; + + /* Always assign a lineno to the next instruction for a stmt. */ + c->u->u_lineno = s->lineno; + c->u->u_lineno_set = false; + + switch (s->kind) { + case FunctionDef_kind: + return compiler_function(c, s); + case ClassDef_kind: + return compiler_class(c, s); + case Return_kind: + if (c->u->u_ste->ste_type != FunctionBlock) + return compiler_error(c, "'return' outside function"); + if (s->v.Return.value) { + VISIT(c, expr, s->v.Return.value); + } + else + ADDOP_O(c, LOAD_CONST, Py_None, consts); + ADDOP(c, RETURN_VALUE); + break; + case Delete_kind: + VISIT_SEQ(c, expr, s->v.Delete.targets) + break; + case Assign_kind: + n = asdl_seq_LEN(s->v.Assign.targets); + VISIT(c, expr, s->v.Assign.value); + for (i = 0; i < n; i++) { + if (i < n - 1) + ADDOP(c, DUP_TOP); + VISIT(c, expr, + (expr_ty)asdl_seq_GET(s->v.Assign.targets, i)); + } + break; + case AugAssign_kind: + return compiler_augassign(c, s); + case Print_kind: + return compiler_print(c, s); + case For_kind: + return compiler_for(c, s); + case While_kind: + return compiler_while(c, s); + case If_kind: + return compiler_if(c, s); + case Raise_kind: + n = 0; + if (s->v.Raise.type) { + VISIT(c, expr, s->v.Raise.type); + n++; + if (s->v.Raise.inst) { + VISIT(c, expr, s->v.Raise.inst); + n++; + if (s->v.Raise.tback) { + VISIT(c, expr, s->v.Raise.tback); + n++; + } + } + } + ADDOP_I(c, RAISE_VARARGS, n); + break; + case TryExcept_kind: + return compiler_try_except(c, s); + case TryFinally_kind: + return compiler_try_finally(c, s); + case Assert_kind: + return compiler_assert(c, s); + case Import_kind: + return compiler_import(c, s); + case ImportFrom_kind: + return compiler_from_import(c, s); + case Exec_kind: + VISIT(c, expr, s->v.Exec.body); + if (s->v.Exec.globals) { + VISIT(c, expr, s->v.Exec.globals); + if (s->v.Exec.locals) { + VISIT(c, expr, s->v.Exec.locals); + } else { + ADDOP(c, DUP_TOP); + } + } else { + ADDOP_O(c, LOAD_CONST, Py_None, consts); + ADDOP(c, DUP_TOP); + } + ADDOP(c, EXEC_STMT); + break; + case Global_kind: + break; + case Expr_kind: + if (c->c_interactive && c->c_nestlevel <= 1) { + VISIT(c, expr, s->v.Expr.value); + ADDOP(c, PRINT_EXPR); + } + else if (s->v.Expr.value->kind != Str_kind && + s->v.Expr.value->kind != Num_kind) { + VISIT(c, expr, s->v.Expr.value); + ADDOP(c, POP_TOP); + } + break; + case Pass_kind: + break; + case Break_kind: + if (!compiler_in_loop(c)) + return compiler_error(c, "'break' outside loop"); + ADDOP(c, BREAK_LOOP); + break; + case Continue_kind: + return compiler_continue(c); + case With_kind: + return compiler_with(c, s); + } + return 1; +} + +static int +unaryop(unaryop_ty op) +{ + switch (op) { + case Invert: + return UNARY_INVERT; + case Not: + return UNARY_NOT; + case UAdd: + return UNARY_POSITIVE; + case USub: + return UNARY_NEGATIVE; + default: + PyErr_Format(PyExc_SystemError, + "unary op %d should not be possible", op); + return 0; + } +} + +static int +binop(struct compiler *c, operator_ty op) +{ + switch (op) { + case Add: + return BINARY_ADD; + case Sub: + return BINARY_SUBTRACT; + case Mult: + return BINARY_MULTIPLY; + case Div: + if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION) + return BINARY_TRUE_DIVIDE; + else + return BINARY_DIVIDE; + case Mod: + return BINARY_MODULO; + case Pow: + return BINARY_POWER; + case LShift: + return BINARY_LSHIFT; + case RShift: + return BINARY_RSHIFT; + case BitOr: + return BINARY_OR; + case BitXor: + return BINARY_XOR; + case BitAnd: + return BINARY_AND; + case FloorDiv: + return BINARY_FLOOR_DIVIDE; + default: + PyErr_Format(PyExc_SystemError, + "binary op %d should not be possible", op); + return 0; + } +} + +static int +cmpop(cmpop_ty op) +{ + switch (op) { + case Eq: + return PyCmp_EQ; + case NotEq: + return PyCmp_NE; + case Lt: + return PyCmp_LT; + case LtE: + return PyCmp_LE; + case Gt: + return PyCmp_GT; + case GtE: + return PyCmp_GE; + case Is: + return PyCmp_IS; + case IsNot: + return PyCmp_IS_NOT; + case In: + return PyCmp_IN; + case NotIn: + return PyCmp_NOT_IN; + default: + return PyCmp_BAD; + } +} + +static int +inplace_binop(struct compiler *c, operator_ty op) +{ + switch (op) { + case Add: + return INPLACE_ADD; + case Sub: + return INPLACE_SUBTRACT; + case Mult: + return INPLACE_MULTIPLY; + case Div: + if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION) + return INPLACE_TRUE_DIVIDE; + else + return INPLACE_DIVIDE; + case Mod: + return INPLACE_MODULO; + case Pow: + return INPLACE_POWER; + case LShift: + return INPLACE_LSHIFT; + case RShift: + return INPLACE_RSHIFT; + case BitOr: + return INPLACE_OR; + case BitXor: + return INPLACE_XOR; + case BitAnd: + return INPLACE_AND; + case FloorDiv: + return INPLACE_FLOOR_DIVIDE; + default: + PyErr_Format(PyExc_SystemError, + "inplace binary op %d should not be possible", op); + return 0; + } +} + +static int +compiler_nameop(struct compiler *c, identifier name, expr_context_ty ctx) +{ + int op, scope, arg; + enum { OP_FAST, OP_GLOBAL, OP_DEREF, OP_NAME } optype; + + PyObject *dict = c->u->u_names; + PyObject *mangled; + /* XXX AugStore isn't used anywhere! */ + + mangled = _Py_Mangle(c->u->u_private, name); + if (!mangled) + return 0; + + op = 0; + optype = OP_NAME; + scope = PyST_GetScope(c->u->u_ste, mangled); + switch (scope) { + case FREE: + dict = c->u->u_freevars; + optype = OP_DEREF; + break; + case CELL: + dict = c->u->u_cellvars; + optype = OP_DEREF; + break; + case LOCAL: + if (c->u->u_ste->ste_type == FunctionBlock) + optype = OP_FAST; + break; + case GLOBAL_IMPLICIT: + if (c->u->u_ste->ste_type == FunctionBlock && + !c->u->u_ste->ste_unoptimized) + optype = OP_GLOBAL; + break; + case GLOBAL_EXPLICIT: + optype = OP_GLOBAL; + break; + default: + /* scope can be 0 */ + break; + } + + /* XXX Leave assert here, but handle __doc__ and the like better */ + assert(scope || PyString_AS_STRING(name)[0] == '_'); + + switch (optype) { + case OP_DEREF: + switch (ctx) { + case Load: op = LOAD_DEREF; break; + case Store: op = STORE_DEREF; break; + case AugLoad: + case AugStore: + break; + case Del: + PyErr_Format(PyExc_SyntaxError, + "can not delete variable '%s' referenced " + "in nested scope", + PyString_AS_STRING(name)); + Py_DECREF(mangled); + return 0; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid for deref variable"); + return 0; + } + break; + case OP_FAST: + switch (ctx) { + case Load: op = LOAD_FAST; break; + case Store: op = STORE_FAST; break; + case Del: op = DELETE_FAST; break; + case AugLoad: + case AugStore: + break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid for local variable"); + return 0; + } + ADDOP_N(c, op, mangled, varnames); + return 1; + case OP_GLOBAL: + switch (ctx) { + case Load: op = LOAD_GLOBAL; break; + case Store: op = STORE_GLOBAL; break; + case Del: op = DELETE_GLOBAL; break; + case AugLoad: + case AugStore: + break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid for global variable"); + return 0; + } + break; + case OP_NAME: + switch (ctx) { + case Load: op = LOAD_NAME; break; + case Store: op = STORE_NAME; break; + case Del: op = DELETE_NAME; break; + case AugLoad: + case AugStore: + break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid for name variable"); + return 0; + } + break; + } + + assert(op); + arg = compiler_add_o(c, dict, mangled); + Py_DECREF(mangled); + if (arg < 0) + return 0; + return compiler_addop_i(c, op, arg); +} + +static int +compiler_boolop(struct compiler *c, expr_ty e) +{ + basicblock *end; + int jumpi, i, n; + asdl_seq *s; + + assert(e->kind == BoolOp_kind); + if (e->v.BoolOp.op == And) + jumpi = JUMP_IF_FALSE_OR_POP; + else + jumpi = JUMP_IF_TRUE_OR_POP; + end = compiler_new_block(c); + if (end == NULL) + return 0; + s = e->v.BoolOp.values; + n = asdl_seq_LEN(s) - 1; + assert(n >= 0); + for (i = 0; i < n; ++i) { + VISIT(c, expr, (expr_ty)asdl_seq_GET(s, i)); + ADDOP_JABS(c, jumpi, end); + } + VISIT(c, expr, (expr_ty)asdl_seq_GET(s, n)); + compiler_use_next_block(c, end); + return 1; +} + +static int +compiler_list(struct compiler *c, expr_ty e) +{ + int n = asdl_seq_LEN(e->v.List.elts); + if (e->v.List.ctx == Store) { + ADDOP_I(c, UNPACK_SEQUENCE, n); + } + VISIT_SEQ(c, expr, e->v.List.elts); + if (e->v.List.ctx == Load) { + ADDOP_I(c, BUILD_LIST, n); + } + return 1; +} + +static int +compiler_tuple(struct compiler *c, expr_ty e) +{ + int n = asdl_seq_LEN(e->v.Tuple.elts); + if (e->v.Tuple.ctx == Store) { + ADDOP_I(c, UNPACK_SEQUENCE, n); + } + VISIT_SEQ(c, expr, e->v.Tuple.elts); + if (e->v.Tuple.ctx == Load) { + ADDOP_I(c, BUILD_TUPLE, n); + } + return 1; +} + +static int +compiler_compare(struct compiler *c, expr_ty e) +{ + int i, n; + basicblock *cleanup = NULL; + + /* XXX the logic can be cleaned up for 1 or multiple comparisons */ + VISIT(c, expr, e->v.Compare.left); + n = asdl_seq_LEN(e->v.Compare.ops); + assert(n > 0); + if (n > 1) { + cleanup = compiler_new_block(c); + if (cleanup == NULL) + return 0; + VISIT(c, expr, + (expr_ty)asdl_seq_GET(e->v.Compare.comparators, 0)); + } + for (i = 1; i < n; i++) { + ADDOP(c, DUP_TOP); + ADDOP(c, ROT_THREE); + ADDOP_I(c, COMPARE_OP, + cmpop((cmpop_ty)(asdl_seq_GET( + e->v.Compare.ops, i - 1)))); + ADDOP_JABS(c, JUMP_IF_FALSE_OR_POP, cleanup); + NEXT_BLOCK(c); + if (i < (n - 1)) + VISIT(c, expr, + (expr_ty)asdl_seq_GET(e->v.Compare.comparators, i)); + } + VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n - 1)); + ADDOP_I(c, COMPARE_OP, + cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, n - 1)))); + if (n > 1) { + basicblock *end = compiler_new_block(c); + if (end == NULL) + return 0; + ADDOP_JREL(c, JUMP_FORWARD, end); + compiler_use_next_block(c, cleanup); + ADDOP(c, ROT_TWO); + ADDOP(c, POP_TOP); + compiler_use_next_block(c, end); + } + return 1; +} + +static int +compiler_call(struct compiler *c, expr_ty e) +{ + int n, code = 0; + + VISIT(c, expr, e->v.Call.func); + n = asdl_seq_LEN(e->v.Call.args); + VISIT_SEQ(c, expr, e->v.Call.args); + if (e->v.Call.keywords) { + VISIT_SEQ(c, keyword, e->v.Call.keywords); + n |= asdl_seq_LEN(e->v.Call.keywords) << 8; + } + if (e->v.Call.starargs) { + VISIT(c, expr, e->v.Call.starargs); + code |= 1; + } + if (e->v.Call.kwargs) { + VISIT(c, expr, e->v.Call.kwargs); + code |= 2; + } + switch (code) { + case 0: + ADDOP_I(c, CALL_FUNCTION, n); + break; + case 1: + ADDOP_I(c, CALL_FUNCTION_VAR, n); + break; + case 2: + ADDOP_I(c, CALL_FUNCTION_KW, n); + break; + case 3: + ADDOP_I(c, CALL_FUNCTION_VAR_KW, n); + break; + } + return 1; +} + +static int +compiler_listcomp_generator(struct compiler *c, asdl_seq *generators, + int gen_index, expr_ty elt) +{ + /* generate code for the iterator, then each of the ifs, + and then write to the element */ + + comprehension_ty l; + basicblock *start, *anchor, *skip, *if_cleanup; + int i, n; + + start = compiler_new_block(c); + skip = compiler_new_block(c); + if_cleanup = compiler_new_block(c); + anchor = compiler_new_block(c); + + if (start == NULL || skip == NULL || if_cleanup == NULL || + anchor == NULL) + return 0; + + l = (comprehension_ty)asdl_seq_GET(generators, gen_index); + VISIT(c, expr, l->iter); + ADDOP(c, GET_ITER); + compiler_use_next_block(c, start); + ADDOP_JREL(c, FOR_ITER, anchor); + NEXT_BLOCK(c); + VISIT(c, expr, l->target); + + /* XXX this needs to be cleaned up...a lot! */ + n = asdl_seq_LEN(l->ifs); + for (i = 0; i < n; i++) { + expr_ty e = (expr_ty)asdl_seq_GET(l->ifs, i); + VISIT(c, expr, e); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup); + NEXT_BLOCK(c); + } + + if (++gen_index < asdl_seq_LEN(generators)) + if (!compiler_listcomp_generator(c, generators, gen_index, elt)) + return 0; + + /* only append after the last for generator */ + if (gen_index >= asdl_seq_LEN(generators)) { + VISIT(c, expr, elt); + ADDOP_I(c, LIST_APPEND, gen_index+1); + + compiler_use_next_block(c, skip); + } + compiler_use_next_block(c, if_cleanup); + ADDOP_JABS(c, JUMP_ABSOLUTE, start); + compiler_use_next_block(c, anchor); + + return 1; +} + +static int +compiler_listcomp(struct compiler *c, expr_ty e) +{ + assert(e->kind == ListComp_kind); + ADDOP_I(c, BUILD_LIST, 0); + return compiler_listcomp_generator(c, e->v.ListComp.generators, 0, + e->v.ListComp.elt); +} + +/* Dict and set comprehensions and generator expressions work by creating a + nested function to perform the actual iteration. This means that the + iteration variables don't leak into the current scope. + The defined function is called immediately following its definition, with the + result of that call being the result of the expression. + The LC/SC version returns the populated container, while the GE version is + flagged in symtable.c as a generator, so it returns the generator object + when the function is called. + This code *knows* that the loop cannot contain break, continue, or return, + so it cheats and skips the SETUP_LOOP/POP_BLOCK steps used in normal loops. + + Possible cleanups: + - iterate over the generator sequence instead of using recursion +*/ + +static int +compiler_comprehension_generator(struct compiler *c, + asdl_seq *generators, int gen_index, + expr_ty elt, expr_ty val, int type) +{ + /* generate code for the iterator, then each of the ifs, + and then write to the element */ + + comprehension_ty gen; + basicblock *start, *anchor, *skip, *if_cleanup; + int i, n; + + start = compiler_new_block(c); + skip = compiler_new_block(c); + if_cleanup = compiler_new_block(c); + anchor = compiler_new_block(c); + + if (start == NULL || skip == NULL || if_cleanup == NULL || + anchor == NULL) + return 0; + + gen = (comprehension_ty)asdl_seq_GET(generators, gen_index); + + if (gen_index == 0) { + /* Receive outermost iter as an implicit argument */ + c->u->u_argcount = 1; + ADDOP_I(c, LOAD_FAST, 0); + } + else { + /* Sub-iter - calculate on the fly */ + VISIT(c, expr, gen->iter); + ADDOP(c, GET_ITER); + } + compiler_use_next_block(c, start); + ADDOP_JREL(c, FOR_ITER, anchor); + NEXT_BLOCK(c); + VISIT(c, expr, gen->target); + + /* XXX this needs to be cleaned up...a lot! */ + n = asdl_seq_LEN(gen->ifs); + for (i = 0; i < n; i++) { + expr_ty e = (expr_ty)asdl_seq_GET(gen->ifs, i); + VISIT(c, expr, e); + ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup); + NEXT_BLOCK(c); + } + + if (++gen_index < asdl_seq_LEN(generators)) + if (!compiler_comprehension_generator(c, + generators, gen_index, + elt, val, type)) + return 0; + + /* only append after the last for generator */ + if (gen_index >= asdl_seq_LEN(generators)) { + /* comprehension specific code */ + switch (type) { + case COMP_GENEXP: + VISIT(c, expr, elt); + ADDOP(c, YIELD_VALUE); + ADDOP(c, POP_TOP); + break; + case COMP_SETCOMP: + VISIT(c, expr, elt); + ADDOP_I(c, SET_ADD, gen_index + 1); + break; + case COMP_DICTCOMP: + /* With 'd[k] = v', v is evaluated before k, so we do + the same. */ + VISIT(c, expr, val); + VISIT(c, expr, elt); + ADDOP_I(c, MAP_ADD, gen_index + 1); + break; + default: + return 0; + } + + compiler_use_next_block(c, skip); + } + compiler_use_next_block(c, if_cleanup); + ADDOP_JABS(c, JUMP_ABSOLUTE, start); + compiler_use_next_block(c, anchor); + + return 1; +} + +static int +compiler_comprehension(struct compiler *c, expr_ty e, int type, identifier name, + asdl_seq *generators, expr_ty elt, expr_ty val) +{ + PyCodeObject *co = NULL; + expr_ty outermost_iter; + + outermost_iter = ((comprehension_ty) + asdl_seq_GET(generators, 0))->iter; + + if (!compiler_enter_scope(c, name, (void *)e, e->lineno)) + goto error; + + if (type != COMP_GENEXP) { + int op; + switch (type) { + case COMP_SETCOMP: + op = BUILD_SET; + break; + case COMP_DICTCOMP: + op = BUILD_MAP; + break; + default: + PyErr_Format(PyExc_SystemError, + "unknown comprehension type %d", type); + goto error_in_scope; + } + + ADDOP_I(c, op, 0); + } + + if (!compiler_comprehension_generator(c, generators, 0, elt, + val, type)) + goto error_in_scope; + + if (type != COMP_GENEXP) { + ADDOP(c, RETURN_VALUE); + } + + co = assemble(c, 1); + compiler_exit_scope(c); + if (co == NULL) + goto error; + + if (!compiler_make_closure(c, co, 0)) + goto error; + Py_DECREF(co); + + VISIT(c, expr, outermost_iter); + ADDOP(c, GET_ITER); + ADDOP_I(c, CALL_FUNCTION, 1); + return 1; +error_in_scope: + compiler_exit_scope(c); +error: + Py_XDECREF(co); + return 0; +} + +static int +compiler_genexp(struct compiler *c, expr_ty e) +{ + static identifier name; + if (!name) { + name = PyString_FromString("<genexpr>"); + if (!name) + return 0; + } + assert(e->kind == GeneratorExp_kind); + return compiler_comprehension(c, e, COMP_GENEXP, name, + e->v.GeneratorExp.generators, + e->v.GeneratorExp.elt, NULL); +} + +static int +compiler_setcomp(struct compiler *c, expr_ty e) +{ + static identifier name; + if (!name) { + name = PyString_FromString("<setcomp>"); + if (!name) + return 0; + } + assert(e->kind == SetComp_kind); + return compiler_comprehension(c, e, COMP_SETCOMP, name, + e->v.SetComp.generators, + e->v.SetComp.elt, NULL); +} + +static int +compiler_dictcomp(struct compiler *c, expr_ty e) +{ + static identifier name; + if (!name) { + name = PyString_FromString("<dictcomp>"); + if (!name) + return 0; + } + assert(e->kind == DictComp_kind); + return compiler_comprehension(c, e, COMP_DICTCOMP, name, + e->v.DictComp.generators, + e->v.DictComp.key, e->v.DictComp.value); +} + +static int +compiler_visit_keyword(struct compiler *c, keyword_ty k) +{ + ADDOP_O(c, LOAD_CONST, k->arg, consts); + VISIT(c, expr, k->value); + return 1; +} + +/* Test whether expression is constant. For constants, report + whether they are true or false. + + Return values: 1 for true, 0 for false, -1 for non-constant. + */ + +static int +expr_constant(expr_ty e) +{ + switch (e->kind) { + case Num_kind: + return PyObject_IsTrue(e->v.Num.n); + case Str_kind: + return PyObject_IsTrue(e->v.Str.s); + case Name_kind: + /* __debug__ is not assignable, so we can optimize + * it away in if and while statements */ + if (strcmp(PyString_AS_STRING(e->v.Name.id), + "__debug__") == 0) + return ! Py_OptimizeFlag; + /* fall through */ + default: + return -1; + } +} + +/* + Implements the with statement from PEP 343. + + The semantics outlined in that PEP are as follows: + + with EXPR as VAR: + BLOCK + + It is implemented roughly as: + + context = EXPR + exit = context.__exit__ # not calling it + value = context.__enter__() + try: + VAR = value # if VAR present in the syntax + BLOCK + finally: + if an exception was raised: + exc = copy of (exception, instance, traceback) + else: + exc = (None, None, None) + exit(*exc) + */ +static int +compiler_with(struct compiler *c, stmt_ty s) +{ + basicblock *block, *finally; + + assert(s->kind == With_kind); + + block = compiler_new_block(c); + finally = compiler_new_block(c); + if (!block || !finally) + return 0; + + /* Evaluate EXPR */ + VISIT(c, expr, s->v.With.context_expr); + ADDOP_JREL(c, SETUP_WITH, finally); + + /* SETUP_WITH pushes a finally block. */ + compiler_use_next_block(c, block); + /* Note that the block is actually called SETUP_WITH in ceval.c, but + functions the same as SETUP_FINALLY except that exceptions are + normalized. */ + if (!compiler_push_fblock(c, FINALLY_TRY, block)) { + return 0; + } + + if (s->v.With.optional_vars) { + VISIT(c, expr, s->v.With.optional_vars); + } + else { + /* Discard result from context.__enter__() */ + ADDOP(c, POP_TOP); + } + + /* BLOCK code */ + VISIT_SEQ(c, stmt, s->v.With.body); + + /* End of try block; start the finally block */ + ADDOP(c, POP_BLOCK); + compiler_pop_fblock(c, FINALLY_TRY, block); + + ADDOP_O(c, LOAD_CONST, Py_None, consts); + compiler_use_next_block(c, finally); + if (!compiler_push_fblock(c, FINALLY_END, finally)) + return 0; + + /* Finally block starts; context.__exit__ is on the stack under + the exception or return information. Just issue our magic + opcode. */ + ADDOP(c, WITH_CLEANUP); + + /* Finally block ends. */ + ADDOP(c, END_FINALLY); + compiler_pop_fblock(c, FINALLY_END, finally); + return 1; +} + +static int +compiler_visit_expr(struct compiler *c, expr_ty e) +{ + int i, n; + + /* If expr e has a different line number than the last expr/stmt, + set a new line number for the next instruction. + */ + if (e->lineno > c->u->u_lineno) { + c->u->u_lineno = e->lineno; + c->u->u_lineno_set = false; + } + switch (e->kind) { + case BoolOp_kind: + return compiler_boolop(c, e); + case BinOp_kind: + VISIT(c, expr, e->v.BinOp.left); + VISIT(c, expr, e->v.BinOp.right); + ADDOP(c, binop(c, e->v.BinOp.op)); + break; + case UnaryOp_kind: + VISIT(c, expr, e->v.UnaryOp.operand); + ADDOP(c, unaryop(e->v.UnaryOp.op)); + break; + case Lambda_kind: + return compiler_lambda(c, e); + case IfExp_kind: + return compiler_ifexp(c, e); + case Dict_kind: + n = asdl_seq_LEN(e->v.Dict.values); + ADDOP_I(c, BUILD_MAP, (n>0xFFFF ? 0xFFFF : n)); + for (i = 0; i < n; i++) { + VISIT(c, expr, + (expr_ty)asdl_seq_GET(e->v.Dict.values, i)); + VISIT(c, expr, + (expr_ty)asdl_seq_GET(e->v.Dict.keys, i)); + ADDOP(c, STORE_MAP); + } + break; + case Set_kind: + n = asdl_seq_LEN(e->v.Set.elts); + VISIT_SEQ(c, expr, e->v.Set.elts); + ADDOP_I(c, BUILD_SET, n); + break; + case ListComp_kind: + return compiler_listcomp(c, e); + case SetComp_kind: + return compiler_setcomp(c, e); + case DictComp_kind: + return compiler_dictcomp(c, e); + case GeneratorExp_kind: + return compiler_genexp(c, e); + case Yield_kind: + if (c->u->u_ste->ste_type != FunctionBlock) + return compiler_error(c, "'yield' outside function"); + if (e->v.Yield.value) { + VISIT(c, expr, e->v.Yield.value); + } + else { + ADDOP_O(c, LOAD_CONST, Py_None, consts); + } + ADDOP(c, YIELD_VALUE); + break; + case Compare_kind: + return compiler_compare(c, e); + case Call_kind: + return compiler_call(c, e); + case Repr_kind: + VISIT(c, expr, e->v.Repr.value); + ADDOP(c, UNARY_CONVERT); + break; + case Num_kind: + ADDOP_O(c, LOAD_CONST, e->v.Num.n, consts); + break; + case Str_kind: + ADDOP_O(c, LOAD_CONST, e->v.Str.s, consts); + break; + /* The following exprs can be assignment targets. */ + case Attribute_kind: + if (e->v.Attribute.ctx != AugStore) + VISIT(c, expr, e->v.Attribute.value); + switch (e->v.Attribute.ctx) { + case AugLoad: + ADDOP(c, DUP_TOP); + /* Fall through to load */ + case Load: + ADDOP_NAME(c, LOAD_ATTR, e->v.Attribute.attr, names); + break; + case AugStore: + ADDOP(c, ROT_TWO); + /* Fall through to save */ + case Store: + ADDOP_NAME(c, STORE_ATTR, e->v.Attribute.attr, names); + break; + case Del: + ADDOP_NAME(c, DELETE_ATTR, e->v.Attribute.attr, names); + break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid in attribute expression"); + return 0; + } + break; + case Subscript_kind: + switch (e->v.Subscript.ctx) { + case AugLoad: + VISIT(c, expr, e->v.Subscript.value); + VISIT_SLICE(c, e->v.Subscript.slice, AugLoad); + break; + case Load: + VISIT(c, expr, e->v.Subscript.value); + VISIT_SLICE(c, e->v.Subscript.slice, Load); + break; + case AugStore: + VISIT_SLICE(c, e->v.Subscript.slice, AugStore); + break; + case Store: + VISIT(c, expr, e->v.Subscript.value); + VISIT_SLICE(c, e->v.Subscript.slice, Store); + break; + case Del: + VISIT(c, expr, e->v.Subscript.value); + VISIT_SLICE(c, e->v.Subscript.slice, Del); + break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid in subscript expression"); + return 0; + } + break; + case Name_kind: + return compiler_nameop(c, e->v.Name.id, e->v.Name.ctx); + /* child nodes of List and Tuple will have expr_context set */ + case List_kind: + return compiler_list(c, e); + case Tuple_kind: + return compiler_tuple(c, e); + } + return 1; +} + +static int +compiler_augassign(struct compiler *c, stmt_ty s) +{ + expr_ty e = s->v.AugAssign.target; + expr_ty auge; + + assert(s->kind == AugAssign_kind); + + switch (e->kind) { + case Attribute_kind: + auge = Attribute(e->v.Attribute.value, e->v.Attribute.attr, + AugLoad, e->lineno, e->col_offset, c->c_arena); + if (auge == NULL) + return 0; + VISIT(c, expr, auge); + VISIT(c, expr, s->v.AugAssign.value); + ADDOP(c, inplace_binop(c, s->v.AugAssign.op)); + auge->v.Attribute.ctx = AugStore; + VISIT(c, expr, auge); + break; + case Subscript_kind: + auge = Subscript(e->v.Subscript.value, e->v.Subscript.slice, + AugLoad, e->lineno, e->col_offset, c->c_arena); + if (auge == NULL) + return 0; + VISIT(c, expr, auge); + VISIT(c, expr, s->v.AugAssign.value); + ADDOP(c, inplace_binop(c, s->v.AugAssign.op)); + auge->v.Subscript.ctx = AugStore; + VISIT(c, expr, auge); + break; + case Name_kind: + if (!compiler_nameop(c, e->v.Name.id, Load)) + return 0; + VISIT(c, expr, s->v.AugAssign.value); + ADDOP(c, inplace_binop(c, s->v.AugAssign.op)); + return compiler_nameop(c, e->v.Name.id, Store); + default: + PyErr_Format(PyExc_SystemError, + "invalid node type (%d) for augmented assignment", + e->kind); + return 0; + } + return 1; +} + +static int +compiler_push_fblock(struct compiler *c, enum fblocktype t, basicblock *b) +{ + struct fblockinfo *f; + if (c->u->u_nfblocks >= CO_MAXBLOCKS) { + PyErr_SetString(PyExc_SyntaxError, + "too many statically nested blocks"); + return 0; + } + f = &c->u->u_fblock[c->u->u_nfblocks++]; + f->fb_type = t; + f->fb_block = b; + return 1; +} + +static void +compiler_pop_fblock(struct compiler *c, enum fblocktype t, basicblock *b) +{ + struct compiler_unit *u = c->u; + assert(u->u_nfblocks > 0); + u->u_nfblocks--; + assert(u->u_fblock[u->u_nfblocks].fb_type == t); + assert(u->u_fblock[u->u_nfblocks].fb_block == b); +} + +static int +compiler_in_loop(struct compiler *c) { + int i; + struct compiler_unit *u = c->u; + for (i = 0; i < u->u_nfblocks; ++i) { + if (u->u_fblock[i].fb_type == LOOP) + return 1; + } + return 0; +} +/* Raises a SyntaxError and returns 0. + If something goes wrong, a different exception may be raised. +*/ + +static int +compiler_error(struct compiler *c, const char *errstr) +{ + PyObject *loc; + PyObject *u = NULL, *v = NULL; + + loc = PyErr_ProgramText(c->c_filename, c->u->u_lineno); + if (!loc) { + Py_INCREF(Py_None); + loc = Py_None; + } + u = Py_BuildValue("(ziOO)", c->c_filename, c->u->u_lineno, + Py_None, loc); + if (!u) + goto exit; + v = Py_BuildValue("(zO)", errstr, u); + if (!v) + goto exit; + PyErr_SetObject(PyExc_SyntaxError, v); + exit: + Py_DECREF(loc); + Py_XDECREF(u); + Py_XDECREF(v); + return 0; +} + +static int +compiler_handle_subscr(struct compiler *c, const char *kind, + expr_context_ty ctx) +{ + int op = 0; + + /* XXX this code is duplicated */ + switch (ctx) { + case AugLoad: /* fall through to Load */ + case Load: op = BINARY_SUBSCR; break; + case AugStore:/* fall through to Store */ + case Store: op = STORE_SUBSCR; break; + case Del: op = DELETE_SUBSCR; break; + case Param: + PyErr_Format(PyExc_SystemError, + "invalid %s kind %d in subscript\n", + kind, ctx); + return 0; + } + if (ctx == AugLoad) { + ADDOP_I(c, DUP_TOPX, 2); + } + else if (ctx == AugStore) { + ADDOP(c, ROT_THREE); + } + ADDOP(c, op); + return 1; +} + +static int +compiler_slice(struct compiler *c, slice_ty s, expr_context_ty ctx) +{ + int n = 2; + assert(s->kind == Slice_kind); + + /* only handles the cases where BUILD_SLICE is emitted */ + if (s->v.Slice.lower) { + VISIT(c, expr, s->v.Slice.lower); + } + else { + ADDOP_O(c, LOAD_CONST, Py_None, consts); + } + + if (s->v.Slice.upper) { + VISIT(c, expr, s->v.Slice.upper); + } + else { + ADDOP_O(c, LOAD_CONST, Py_None, consts); + } + + if (s->v.Slice.step) { + n++; + VISIT(c, expr, s->v.Slice.step); + } + ADDOP_I(c, BUILD_SLICE, n); + return 1; +} + +static int +compiler_simple_slice(struct compiler *c, slice_ty s, expr_context_ty ctx) +{ + int op = 0, slice_offset = 0, stack_count = 0; + + assert(s->v.Slice.step == NULL); + if (s->v.Slice.lower) { + slice_offset++; + stack_count++; + if (ctx != AugStore) + VISIT(c, expr, s->v.Slice.lower); + } + if (s->v.Slice.upper) { + slice_offset += 2; + stack_count++; + if (ctx != AugStore) + VISIT(c, expr, s->v.Slice.upper); + } + + if (ctx == AugLoad) { + switch (stack_count) { + case 0: ADDOP(c, DUP_TOP); break; + case 1: ADDOP_I(c, DUP_TOPX, 2); break; + case 2: ADDOP_I(c, DUP_TOPX, 3); break; + } + } + else if (ctx == AugStore) { + switch (stack_count) { + case 0: ADDOP(c, ROT_TWO); break; + case 1: ADDOP(c, ROT_THREE); break; + case 2: ADDOP(c, ROT_FOUR); break; + } + } + + switch (ctx) { + case AugLoad: /* fall through to Load */ + case Load: op = SLICE; break; + case AugStore:/* fall through to Store */ + case Store: op = STORE_SLICE; break; + case Del: op = DELETE_SLICE; break; + case Param: + default: + PyErr_SetString(PyExc_SystemError, + "param invalid in simple slice"); + return 0; + } + + ADDOP(c, op + slice_offset); + return 1; +} + +static int +compiler_visit_nested_slice(struct compiler *c, slice_ty s, + expr_context_ty ctx) +{ + switch (s->kind) { + case Ellipsis_kind: + ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts); + break; + case Slice_kind: + return compiler_slice(c, s, ctx); + case Index_kind: + VISIT(c, expr, s->v.Index.value); + break; + case ExtSlice_kind: + default: + PyErr_SetString(PyExc_SystemError, + "extended slice invalid in nested slice"); + return 0; + } + return 1; +} + +static int +compiler_visit_slice(struct compiler *c, slice_ty s, expr_context_ty ctx) +{ + char * kindname = NULL; + switch (s->kind) { + case Index_kind: + kindname = "index"; + if (ctx != AugStore) { + VISIT(c, expr, s->v.Index.value); + } + break; + case Ellipsis_kind: + kindname = "ellipsis"; + if (ctx != AugStore) { + ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts); + } + break; + case Slice_kind: + kindname = "slice"; + if (!s->v.Slice.step) + return compiler_simple_slice(c, s, ctx); + if (ctx != AugStore) { + if (!compiler_slice(c, s, ctx)) + return 0; + } + break; + case ExtSlice_kind: + kindname = "extended slice"; + if (ctx != AugStore) { + int i, n = asdl_seq_LEN(s->v.ExtSlice.dims); + for (i = 0; i < n; i++) { + slice_ty sub = (slice_ty)asdl_seq_GET( + s->v.ExtSlice.dims, i); + if (!compiler_visit_nested_slice(c, sub, ctx)) + return 0; + } + ADDOP_I(c, BUILD_TUPLE, n); + } + break; + default: + PyErr_Format(PyExc_SystemError, + "invalid subscript kind %d", s->kind); + return 0; + } + return compiler_handle_subscr(c, kindname, ctx); +} + + +/* End of the compiler section, beginning of the assembler section */ + +/* do depth-first search of basic block graph, starting with block. + post records the block indices in post-order. + + XXX must handle implicit jumps from one block to next +*/ + +struct assembler { + PyObject *a_bytecode; /* string containing bytecode */ + int a_offset; /* offset into bytecode */ + int a_nblocks; /* number of reachable blocks */ + basicblock **a_postorder; /* list of blocks in dfs postorder */ + PyObject *a_lnotab; /* string containing lnotab */ + int a_lnotab_off; /* offset into lnotab */ + int a_lineno; /* last lineno of emitted instruction */ + int a_lineno_off; /* bytecode offset of last lineno */ +}; + +static void +dfs(struct compiler *c, basicblock *b, struct assembler *a) +{ + int i; + struct instr *instr = NULL; + + if (b->b_seen) + return; + b->b_seen = 1; + if (b->b_next != NULL) + dfs(c, b->b_next, a); + for (i = 0; i < b->b_iused; i++) { + instr = &b->b_instr[i]; + if (instr->i_jrel || instr->i_jabs) + dfs(c, instr->i_target, a); + } + a->a_postorder[a->a_nblocks++] = b; +} + +static int +stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth) +{ + int i, target_depth; + struct instr *instr; + if (b->b_seen || b->b_startdepth >= depth) + return maxdepth; + b->b_seen = 1; + b->b_startdepth = depth; + for (i = 0; i < b->b_iused; i++) { + instr = &b->b_instr[i]; + depth += opcode_stack_effect(instr->i_opcode, instr->i_oparg); + if (depth > maxdepth) + maxdepth = depth; + assert(depth >= 0); /* invalid code or bug in stackdepth() */ + if (instr->i_jrel || instr->i_jabs) { + target_depth = depth; + if (instr->i_opcode == FOR_ITER) { + target_depth = depth-2; + } + else if (instr->i_opcode == SETUP_FINALLY || + instr->i_opcode == SETUP_EXCEPT) { + target_depth = depth+3; + if (target_depth > maxdepth) + maxdepth = target_depth; + } + else if (instr->i_opcode == JUMP_IF_TRUE_OR_POP || + instr->i_opcode == JUMP_IF_FALSE_OR_POP) + depth = depth - 1; + maxdepth = stackdepth_walk(c, instr->i_target, + target_depth, maxdepth); + if (instr->i_opcode == JUMP_ABSOLUTE || + instr->i_opcode == JUMP_FORWARD) { + goto out; /* remaining code is dead */ + } + } + } + if (b->b_next) + maxdepth = stackdepth_walk(c, b->b_next, depth, maxdepth); +out: + b->b_seen = 0; + return maxdepth; +} + +/* Find the flow path that needs the largest stack. We assume that + * cycles in the flow graph have no net effect on the stack depth. + */ +static int +stackdepth(struct compiler *c) +{ + basicblock *b, *entryblock; + entryblock = NULL; + for (b = c->u->u_blocks; b != NULL; b = b->b_list) { + b->b_seen = 0; + b->b_startdepth = INT_MIN; + entryblock = b; + } + if (!entryblock) + return 0; + return stackdepth_walk(c, entryblock, 0, 0); +} + +static int +assemble_init(struct assembler *a, int nblocks, int firstlineno) +{ + memset(a, 0, sizeof(struct assembler)); + a->a_lineno = firstlineno; + a->a_bytecode = PyString_FromStringAndSize(NULL, DEFAULT_CODE_SIZE); + if (!a->a_bytecode) + return 0; + a->a_lnotab = PyString_FromStringAndSize(NULL, DEFAULT_LNOTAB_SIZE); + if (!a->a_lnotab) + return 0; + if (nblocks > PY_SIZE_MAX / sizeof(basicblock *)) { + PyErr_NoMemory(); + return 0; + } + a->a_postorder = (basicblock **)PyObject_Malloc( + sizeof(basicblock *) * nblocks); + if (!a->a_postorder) { + PyErr_NoMemory(); + return 0; + } + return 1; +} + +static void +assemble_free(struct assembler *a) +{ + Py_XDECREF(a->a_bytecode); + Py_XDECREF(a->a_lnotab); + if (a->a_postorder) + PyObject_Free(a->a_postorder); +} + +/* Return the size of a basic block in bytes. */ + +static int +instrsize(struct instr *instr) +{ + if (!instr->i_hasarg) + return 1; /* 1 byte for the opcode*/ + if (instr->i_oparg > 0xffff) + return 6; /* 1 (opcode) + 1 (EXTENDED_ARG opcode) + 2 (oparg) + 2(oparg extended) */ + return 3; /* 1 (opcode) + 2 (oparg) */ +} + +static int +blocksize(basicblock *b) +{ + int i; + int size = 0; + + for (i = 0; i < b->b_iused; i++) + size += instrsize(&b->b_instr[i]); + return size; +} + +/* Appends a pair to the end of the line number table, a_lnotab, representing + the instruction's bytecode offset and line number. See + Objects/lnotab_notes.txt for the description of the line number table. */ + +static int +assemble_lnotab(struct assembler *a, struct instr *i) +{ + int d_bytecode, d_lineno; + int len; + unsigned char *lnotab; + + d_bytecode = a->a_offset - a->a_lineno_off; + d_lineno = i->i_lineno - a->a_lineno; + + assert(d_bytecode >= 0); + + if(d_bytecode == 0 && d_lineno == 0) + return 1; + + if (d_bytecode > 255) { + int j, nbytes, ncodes = d_bytecode / 255; + nbytes = a->a_lnotab_off + 2 * ncodes; + len = PyString_GET_SIZE(a->a_lnotab); + if (nbytes >= len) { + if ((len <= INT_MAX / 2) && (len * 2 < nbytes)) + len = nbytes; + else if (len <= INT_MAX / 2) + len *= 2; + else { + PyErr_NoMemory(); + return 0; + } + if (_PyString_Resize(&a->a_lnotab, len) < 0) + return 0; + } + lnotab = (unsigned char *) + PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off; + for (j = 0; j < ncodes; j++) { + *lnotab++ = 255; + *lnotab++ = 0; + } + d_bytecode -= ncodes * 255; + a->a_lnotab_off += ncodes * 2; + } + assert(0 <= d_bytecode && d_bytecode <= 255); + + if (d_lineno < -128 || 127 < d_lineno) { + int j, nbytes, ncodes, k; + if (d_lineno < 0) { + k = -128; + /* use division on positive numbers */ + ncodes = (-d_lineno) / 128; + } + else { + k = 127; + ncodes = d_lineno / 127; + } + d_lineno -= ncodes * k; + assert(ncodes >= 1); + nbytes = a->a_lnotab_off + 2 * ncodes; + len = PyString_GET_SIZE(a->a_lnotab); + if (nbytes >= len) { + if ((len <= INT_MAX / 2) && len * 2 < nbytes) + len = nbytes; + else if (len <= INT_MAX / 2) + len *= 2; + else { + PyErr_NoMemory(); + return 0; + } + if (_PyString_Resize(&a->a_lnotab, len) < 0) + return 0; + } + lnotab = (unsigned char *) + PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off; + *lnotab++ = d_bytecode; + *lnotab++ = k; + d_bytecode = 0; + for (j = 1; j < ncodes; j++) { + *lnotab++ = 0; + *lnotab++ = k; + } + a->a_lnotab_off += ncodes * 2; + } + assert(-128 <= d_lineno && d_lineno <= 127); + + len = PyString_GET_SIZE(a->a_lnotab); + if (a->a_lnotab_off + 2 >= len) { + if (_PyString_Resize(&a->a_lnotab, len * 2) < 0) + return 0; + } + lnotab = (unsigned char *) + PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off; + + a->a_lnotab_off += 2; + if (d_bytecode) { + *lnotab++ = d_bytecode; + *lnotab++ = d_lineno; + } + else { /* First line of a block; def stmt, etc. */ + *lnotab++ = 0; + *lnotab++ = d_lineno; + } + a->a_lineno = i->i_lineno; + a->a_lineno_off = a->a_offset; + return 1; +} + +/* assemble_emit() + Extend the bytecode with a new instruction. + Update lnotab if necessary. +*/ + +static int +assemble_emit(struct assembler *a, struct instr *i) +{ + int size, arg = 0, ext = 0; + Py_ssize_t len = PyString_GET_SIZE(a->a_bytecode); + char *code; + + size = instrsize(i); + if (i->i_hasarg) { + arg = i->i_oparg; + ext = arg >> 16; + } + if (i->i_lineno && !assemble_lnotab(a, i)) + return 0; + if (a->a_offset + size >= len) { + if (len > PY_SSIZE_T_MAX / 2) + return 0; + if (_PyString_Resize(&a->a_bytecode, len * 2) < 0) + return 0; + } + code = PyString_AS_STRING(a->a_bytecode) + a->a_offset; + a->a_offset += size; + if (size == 6) { + assert(i->i_hasarg); + *code++ = (char)EXTENDED_ARG; + *code++ = ext & 0xff; + *code++ = ext >> 8; + arg &= 0xffff; + } + *code++ = i->i_opcode; + if (i->i_hasarg) { + assert(size == 3 || size == 6); + *code++ = arg & 0xff; + *code++ = arg >> 8; + } + return 1; +} + +static void +assemble_jump_offsets(struct assembler *a, struct compiler *c) +{ + basicblock *b; + int bsize, totsize, extended_arg_count = 0, last_extended_arg_count; + int i; + + /* Compute the size of each block and fixup jump args. + Replace block pointer with position in bytecode. */ + do { + totsize = 0; + for (i = a->a_nblocks - 1; i >= 0; i--) { + b = a->a_postorder[i]; + bsize = blocksize(b); + b->b_offset = totsize; + totsize += bsize; + } + last_extended_arg_count = extended_arg_count; + extended_arg_count = 0; + for (b = c->u->u_blocks; b != NULL; b = b->b_list) { + bsize = b->b_offset; + for (i = 0; i < b->b_iused; i++) { + struct instr *instr = &b->b_instr[i]; + /* Relative jumps are computed relative to + the instruction pointer after fetching + the jump instruction. + */ + bsize += instrsize(instr); + if (instr->i_jabs) + instr->i_oparg = instr->i_target->b_offset; + else if (instr->i_jrel) { + int delta = instr->i_target->b_offset - bsize; + instr->i_oparg = delta; + } + else + continue; + if (instr->i_oparg > 0xffff) + extended_arg_count++; + } + } + + /* XXX: This is an awful hack that could hurt performance, but + on the bright side it should work until we come up + with a better solution. + + The issue is that in the first loop blocksize() is called + which calls instrsize() which requires i_oparg be set + appropriately. There is a bootstrap problem because + i_oparg is calculated in the second loop above. + + So we loop until we stop seeing new EXTENDED_ARGs. + The only EXTENDED_ARGs that could be popping up are + ones in jump instructions. So this should converge + fairly quickly. + */ + } while (last_extended_arg_count != extended_arg_count); +} + +static PyObject * +dict_keys_inorder(PyObject *dict, int offset) +{ + PyObject *tuple, *k, *v; + Py_ssize_t i, pos = 0, size = PyDict_Size(dict); + + tuple = PyTuple_New(size); + if (tuple == NULL) + return NULL; + while (PyDict_Next(dict, &pos, &k, &v)) { + i = PyInt_AS_LONG(v); + /* The keys of the dictionary are tuples. (see compiler_add_o) + The object we want is always first, though. */ + k = PyTuple_GET_ITEM(k, 1); + Py_INCREF(k); + assert((i - offset) < size); + assert((i - offset) >= 0); + PyTuple_SET_ITEM(tuple, i - offset, k); + } + return tuple; +} + +static int +compute_code_flags(struct compiler *c) +{ + PySTEntryObject *ste = c->u->u_ste; + int flags = 0, n; + if (ste->ste_type != ModuleBlock) + flags |= CO_NEWLOCALS; + if (ste->ste_type == FunctionBlock) { + if (!ste->ste_unoptimized) + flags |= CO_OPTIMIZED; + if (ste->ste_nested) + flags |= CO_NESTED; + if (ste->ste_generator) + flags |= CO_GENERATOR; + if (ste->ste_varargs) + flags |= CO_VARARGS; + if (ste->ste_varkeywords) + flags |= CO_VARKEYWORDS; + } + + /* (Only) inherit compilerflags in PyCF_MASK */ + flags |= (c->c_flags->cf_flags & PyCF_MASK); + + n = PyDict_Size(c->u->u_freevars); + if (n < 0) + return -1; + if (n == 0) { + n = PyDict_Size(c->u->u_cellvars); + if (n < 0) + return -1; + if (n == 0) { + flags |= CO_NOFREE; + } + } + + return flags; +} + +static PyCodeObject * +makecode(struct compiler *c, struct assembler *a) +{ + PyObject *tmp; + PyCodeObject *co = NULL; + PyObject *consts = NULL; + PyObject *names = NULL; + PyObject *varnames = NULL; + PyObject *filename = NULL; + PyObject *name = NULL; + PyObject *freevars = NULL; + PyObject *cellvars = NULL; + PyObject *bytecode = NULL; + int nlocals, flags; + + tmp = dict_keys_inorder(c->u->u_consts, 0); + if (!tmp) + goto error; + consts = PySequence_List(tmp); /* optimize_code requires a list */ + Py_DECREF(tmp); + + names = dict_keys_inorder(c->u->u_names, 0); + varnames = dict_keys_inorder(c->u->u_varnames, 0); + if (!consts || !names || !varnames) + goto error; + + cellvars = dict_keys_inorder(c->u->u_cellvars, 0); + if (!cellvars) + goto error; + freevars = dict_keys_inorder(c->u->u_freevars, PyTuple_Size(cellvars)); + if (!freevars) + goto error; + filename = PyString_FromString(c->c_filename); + if (!filename) + goto error; + + nlocals = PyDict_Size(c->u->u_varnames); + flags = compute_code_flags(c); + if (flags < 0) + goto error; + + bytecode = PyCode_Optimize(a->a_bytecode, consts, names, a->a_lnotab); + if (!bytecode) + goto error; + + tmp = PyList_AsTuple(consts); /* PyCode_New requires a tuple */ + if (!tmp) + goto error; + Py_DECREF(consts); + consts = tmp; + + co = PyCode_New(c->u->u_argcount, nlocals, stackdepth(c), flags, + bytecode, consts, names, varnames, + freevars, cellvars, + filename, c->u->u_name, + c->u->u_firstlineno, + a->a_lnotab); + error: + Py_XDECREF(consts); + Py_XDECREF(names); + Py_XDECREF(varnames); + Py_XDECREF(filename); + Py_XDECREF(name); + Py_XDECREF(freevars); + Py_XDECREF(cellvars); + Py_XDECREF(bytecode); + return co; +} + + +/* For debugging purposes only */ +#if 0 +static void +dump_instr(const struct instr *i) +{ + const char *jrel = i->i_jrel ? "jrel " : ""; + const char *jabs = i->i_jabs ? "jabs " : ""; + char arg[128]; + + *arg = '\0'; + if (i->i_hasarg) + sprintf(arg, "arg: %d ", i->i_oparg); + + fprintf(stderr, "line: %d, opcode: %d %s%s%s\n", + i->i_lineno, i->i_opcode, arg, jabs, jrel); +} + +static void +dump_basicblock(const basicblock *b) +{ + const char *seen = b->b_seen ? "seen " : ""; + const char *b_return = b->b_return ? "return " : ""; + fprintf(stderr, "used: %d, depth: %d, offset: %d %s%s\n", + b->b_iused, b->b_startdepth, b->b_offset, seen, b_return); + if (b->b_instr) { + int i; + for (i = 0; i < b->b_iused; i++) { + fprintf(stderr, " [%02d] ", i); + dump_instr(b->b_instr + i); + } + } +} +#endif + +static PyCodeObject * +assemble(struct compiler *c, int addNone) +{ + basicblock *b, *entryblock; + struct assembler a; + int i, j, nblocks; + PyCodeObject *co = NULL; + + /* Make sure every block that falls off the end returns None. + XXX NEXT_BLOCK() isn't quite right, because if the last + block ends with a jump or return b_next shouldn't set. + */ + if (!c->u->u_curblock->b_return) { + NEXT_BLOCK(c); + if (addNone) + ADDOP_O(c, LOAD_CONST, Py_None, consts); + ADDOP(c, RETURN_VALUE); + } + + nblocks = 0; + entryblock = NULL; + for (b = c->u->u_blocks; b != NULL; b = b->b_list) { + nblocks++; + entryblock = b; + } + + /* Set firstlineno if it wasn't explicitly set. */ + if (!c->u->u_firstlineno) { + if (entryblock && entryblock->b_instr) + c->u->u_firstlineno = entryblock->b_instr->i_lineno; + else + c->u->u_firstlineno = 1; + } + if (!assemble_init(&a, nblocks, c->u->u_firstlineno)) + goto error; + dfs(c, entryblock, &a); + + /* Can't modify the bytecode after computing jump offsets. */ + assemble_jump_offsets(&a, c); + + /* Emit code in reverse postorder from dfs. */ + for (i = a.a_nblocks - 1; i >= 0; i--) { + b = a.a_postorder[i]; + for (j = 0; j < b->b_iused; j++) + if (!assemble_emit(&a, &b->b_instr[j])) + goto error; + } + + if (_PyString_Resize(&a.a_lnotab, a.a_lnotab_off) < 0) + goto error; + if (_PyString_Resize(&a.a_bytecode, a.a_offset) < 0) + goto error; + + co = makecode(c, &a); + error: + assemble_free(&a); + return co; +} |