From f2e267da68bf85f3f12fa77155e469352bdc6c09 Mon Sep 17 00:00:00 2001 From: Damien George Date: Tue, 16 Jun 2020 22:49:25 +1000 Subject: [PATCH] py/compile: Implement PEP 526, syntax for variable annotations. This addition to the grammar was introduced in Python 3.6. It allows annotating the type of a varilable, like: x: int = 123 s: str The implementation in this commit is quite simple and just ignores the annotation (the int and str bits above). The reason to implement this is to allow Python 3.6+ code that uses this feature to compile under MicroPython without change, and for users to use type checkers. In the future viper could use this syntax as a way to give types to variables, which is currently done in a bit of an ad-hoc way, eg x = int(123). And this syntax could potentially be used in the inline assembler to define labels in an way that's easier to read. --- py/compile.c | 31 ++++++++++++++++++++++++------- py/grammar.h | 8 +++++--- 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/py/compile.c b/py/compile.c index 614e851a3..53108b706 100644 --- a/py/compile.c +++ b/py/compile.c @@ -1981,7 +1981,8 @@ STATIC void compile_async_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { #endif STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { - if (MP_PARSE_NODE_IS_NULL(pns->nodes[1])) { + mp_parse_node_t pn_rhs = pns->nodes[1]; + if (MP_PARSE_NODE_IS_NULL(pn_rhs)) { if (comp->is_repl && comp->scope_cur->kind == SCOPE_MODULE) { // for REPL, evaluate then print the expression compile_load_id(comp, MP_QSTR___repl_print__); @@ -1999,10 +2000,26 @@ STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { EMIT(pop_top); // discard last result since this is a statement and leaves nothing on the stack } } - } else if (MP_PARSE_NODE_IS_STRUCT(pns->nodes[1])) { - mp_parse_node_struct_t *pns1 = (mp_parse_node_struct_t *)pns->nodes[1]; + } else if (MP_PARSE_NODE_IS_STRUCT(pn_rhs)) { + mp_parse_node_struct_t *pns1 = (mp_parse_node_struct_t *)pn_rhs; int kind = MP_PARSE_NODE_STRUCT_KIND(pns1); - if (kind == PN_expr_stmt_augassign) { + if (kind == PN_annassign) { + // the annotation is in pns1->nodes[0] and is ignored + if (MP_PARSE_NODE_IS_NULL(pns1->nodes[1])) { + // an annotation of the form "x: y" + // inside a function this declares "x" as a local + if (comp->scope_cur->kind == SCOPE_FUNCTION) { + if (MP_PARSE_NODE_IS_ID(pns->nodes[0])) { + qstr lhs = MP_PARSE_NODE_LEAF_ARG(pns->nodes[0]); + scope_find_or_add_id(comp->scope_cur, lhs, ID_INFO_KIND_LOCAL); + } + } + } else { + // an assigned annotation of the form "x: y = z" + pn_rhs = pns1->nodes[1]; + goto plain_assign; + } + } else if (kind == PN_expr_stmt_augassign) { c_assign(comp, pns->nodes[0], ASSIGN_AUG_LOAD); // lhs load for aug assign compile_node(comp, pns1->nodes[1]); // rhs assert(MP_PARSE_NODE_IS_TOKEN(pns1->nodes[0])); @@ -2027,10 +2044,10 @@ STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { } else { plain_assign: #if MICROPY_COMP_DOUBLE_TUPLE_ASSIGN - if (MP_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[1], PN_testlist_star_expr) + if (MP_PARSE_NODE_IS_STRUCT_KIND(pn_rhs, PN_testlist_star_expr) && MP_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[0], PN_testlist_star_expr)) { mp_parse_node_struct_t *pns0 = (mp_parse_node_struct_t *)pns->nodes[0]; - pns1 = (mp_parse_node_struct_t *)pns->nodes[1]; + pns1 = (mp_parse_node_struct_t *)pn_rhs; uint32_t n_pns0 = MP_PARSE_NODE_STRUCT_NUM_NODES(pns0); // Can only optimise a tuple-to-tuple assignment when all of the following hold: // - equal number of items in LHS and RHS tuples @@ -2070,7 +2087,7 @@ STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { } #endif - compile_node(comp, pns->nodes[1]); // rhs + compile_node(comp, pn_rhs); // rhs c_assign(comp, pns->nodes[0], ASSIGN_STORE); // lhs store } } else { diff --git a/py/grammar.h b/py/grammar.h index ff8e61828..285fbded2 100644 --- a/py/grammar.h +++ b/py/grammar.h @@ -98,20 +98,22 @@ DEF_RULE_NC(simple_stmt, and_ident(2), rule(simple_stmt_2), tok(NEWLINE)) DEF_RULE(simple_stmt_2, c(generic_all_nodes), list_with_end, rule(small_stmt), tok(DEL_SEMICOLON)) // small_stmt: expr_stmt | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | nonlocal_stmt | assert_stmt -// expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) | ('=' (yield_expr|testlist_star_expr))*) +// expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) | ('=' (yield_expr|testlist_star_expr))*) // testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [','] +// annassign: ':' test ['=' (yield_expr|testlist_star_expr)] // augassign: '+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' | '<<=' | '>>=' | '**=' | '//=' -// # For normal assignments, additional restrictions enforced by the interpreter +// # For normal and annotated assignments, additional restrictions enforced by the interpreter DEF_RULE_NC(small_stmt, or(8), rule(del_stmt), rule(pass_stmt), rule(flow_stmt), rule(import_stmt), rule(global_stmt), rule(nonlocal_stmt), rule(assert_stmt), rule(expr_stmt)) DEF_RULE(expr_stmt, c(expr_stmt), and(2), rule(testlist_star_expr), opt_rule(expr_stmt_2)) -DEF_RULE_NC(expr_stmt_2, or(2), rule(expr_stmt_augassign), rule(expr_stmt_assign_list)) +DEF_RULE_NC(expr_stmt_2, or(3), rule(annassign), rule(expr_stmt_augassign), rule(expr_stmt_assign_list)) DEF_RULE_NC(expr_stmt_augassign, and_ident(2), rule(augassign), rule(expr_stmt_6)) DEF_RULE_NC(expr_stmt_assign_list, one_or_more, rule(expr_stmt_assign)) DEF_RULE_NC(expr_stmt_assign, and_ident(2), tok(DEL_EQUAL), rule(expr_stmt_6)) DEF_RULE_NC(expr_stmt_6, or(2), rule(yield_expr), rule(testlist_star_expr)) DEF_RULE(testlist_star_expr, c(generic_tuple), list_with_end, rule(testlist_star_expr_2), tok(DEL_COMMA)) DEF_RULE_NC(testlist_star_expr_2, or(2), rule(star_expr), rule(test)) +DEF_RULE_NC(annassign, and(3), tok(DEL_COLON), rule(test), opt_rule(expr_stmt_assign)) DEF_RULE_NC(augassign, or(13), tok(DEL_PLUS_EQUAL), tok(DEL_MINUS_EQUAL), tok(DEL_STAR_EQUAL), tok(DEL_AT_EQUAL), tok(DEL_SLASH_EQUAL), tok(DEL_PERCENT_EQUAL), tok(DEL_AMPERSAND_EQUAL), tok(DEL_PIPE_EQUAL), tok(DEL_CARET_EQUAL), tok(DEL_DBL_LESS_EQUAL), tok(DEL_DBL_MORE_EQUAL), tok(DEL_DBL_STAR_EQUAL), tok(DEL_DBL_SLASH_EQUAL)) // del_stmt: 'del' exprlist