py: Implement break/continue from an exception with finally.
Still todo: break/continue from within the finally block itself.
diff --git a/py/compile.c b/py/compile.c
index c4b582e..5415757 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -50,7 +50,8 @@
int break_label;
int continue_label;
- int except_nest_level;
+ int break_continue_except_level;
+ int cur_except_level; // increased for SETUP_EXCEPT, SETUP_FINALLY; decreased for POP_BLOCK, POP_EXCEPT
int n_arg_keyword;
bool have_star_arg;
@@ -1080,18 +1081,14 @@
if (comp->break_label == 0) {
printf("ERROR: cannot break from here\n");
}
- EMIT_ARG(break_loop, comp->break_label);
+ EMIT_ARG(break_loop, comp->break_label, comp->cur_except_level - comp->break_continue_except_level);
}
void compile_continue_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
if (comp->continue_label == 0) {
printf("ERROR: cannot continue from here\n");
}
- if (comp->except_nest_level > 0) {
- EMIT_ARG(continue_loop, comp->continue_label);
- } else {
- EMIT_ARG(jump, comp->continue_label);
- }
+ EMIT_ARG(continue_loop, comp->continue_label, comp->cur_except_level - comp->break_continue_except_level);
}
void compile_return_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
@@ -1387,15 +1384,22 @@
EMIT_ARG(label_assign, l_end);
}
+#define START_BREAK_CONTINUE_BLOCK \
+ int old_break_label = comp->break_label; \
+ int old_continue_label = comp->continue_label; \
+ int break_label = comp_next_label(comp); \
+ int continue_label = comp_next_label(comp); \
+ comp->break_label = break_label; \
+ comp->continue_label = continue_label; \
+ comp->break_continue_except_level = comp->cur_except_level;
+
+#define END_BREAK_CONTINUE_BLOCK \
+ comp->break_label = old_break_label; \
+ comp->continue_label = old_continue_label; \
+ comp->break_continue_except_level = comp->cur_except_level;
+
void compile_while_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
- int old_break_label = comp->break_label;
- int old_continue_label = comp->continue_label;
-
- int break_label = comp_next_label(comp);
- int continue_label = comp_next_label(comp);
-
- comp->break_label = break_label;
- comp->continue_label = continue_label;
+ START_BREAK_CONTINUE_BLOCK
// compared to CPython, we have an optimised version of while loops
#if MICROPY_EMIT_CPYTHON
@@ -1423,8 +1427,7 @@
#endif
// break/continue apply to outer loop (if any) in the else block
- comp->break_label = old_break_label;
- comp->continue_label = old_continue_label;
+ END_BREAK_CONTINUE_BLOCK
compile_node(comp, pns->nodes[2]); // else
@@ -1434,14 +1437,7 @@
// TODO preload end and step onto stack if they are not constants
// TODO check if step is negative and do opposite test
void compile_for_stmt_optimised_range(compiler_t *comp, mp_parse_node_t pn_var, mp_parse_node_t pn_start, mp_parse_node_t pn_end, mp_parse_node_t pn_step, mp_parse_node_t pn_body, mp_parse_node_t pn_else) {
- int old_break_label = comp->break_label;
- int old_continue_label = comp->continue_label;
-
- int break_label = comp_next_label(comp);
- int continue_label = comp_next_label(comp);
-
- comp->break_label = break_label;
- comp->continue_label = continue_label;
+ START_BREAK_CONTINUE_BLOCK
int top_label = comp_next_label(comp);
int entry_label = comp_next_label(comp);
@@ -1477,8 +1473,7 @@
EMIT_ARG(pop_jump_if_true, top_label);
// break/continue apply to outer loop (if any) in the else block
- comp->break_label = old_break_label;
- comp->continue_label = old_continue_label;
+ END_BREAK_CONTINUE_BLOCK
compile_node(comp, pn_else);
@@ -1531,18 +1526,11 @@
}
#endif
- int old_break_label = comp->break_label;
- int old_continue_label = comp->continue_label;
+ START_BREAK_CONTINUE_BLOCK
- int for_label = comp_next_label(comp);
int pop_label = comp_next_label(comp);
int end_label = comp_next_label(comp);
- int break_label = comp_next_label(comp);
-
- comp->continue_label = for_label;
- comp->break_label = break_label;
-
// I don't think our implementation needs SETUP_LOOP/POP_BLOCK for for-statements
#if MICROPY_EMIT_CPYTHON
EMIT_ARG(setup_loop, end_label);
@@ -1550,19 +1538,18 @@
compile_node(comp, pns->nodes[1]); // iterator
EMIT(get_iter);
- EMIT_ARG(label_assign, for_label);
+ EMIT_ARG(label_assign, continue_label);
EMIT_ARG(for_iter, pop_label);
c_assign(comp, pns->nodes[0], ASSIGN_STORE); // variable
compile_node(comp, pns->nodes[2]); // body
if (!EMIT(last_emit_was_return_value)) {
- EMIT_ARG(jump, for_label);
+ EMIT_ARG(jump, continue_label);
}
EMIT_ARG(label_assign, pop_label);
EMIT(for_iter_end);
// break/continue apply to outer loop (if any) in the else block
- comp->break_label = old_break_label;
- comp->continue_label = old_continue_label;
+ END_BREAK_CONTINUE_BLOCK
#if MICROPY_EMIT_CPYTHON
EMIT(pop_block);
@@ -1582,8 +1569,10 @@
int stack_size = EMIT(get_stack_size);
int l1 = comp_next_label(comp);
int success_label = comp_next_label(comp);
- comp->except_nest_level += 1; // for correct handling of continue
+
EMIT_ARG(setup_except, l1);
+ comp->cur_except_level += 1;
+
compile_node(comp, pn_body); // body
EMIT(pop_block);
EMIT_ARG(jump, success_label);
@@ -1634,6 +1623,7 @@
if (qstr_exception_local != 0) {
l3 = comp_next_label(comp);
EMIT_ARG(setup_finally, l3);
+ comp->cur_except_level += 1;
}
compile_node(comp, pns_except->nodes[1]);
if (qstr_exception_local != 0) {
@@ -1646,15 +1636,18 @@
EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
EMIT_ARG(store_id, qstr_exception_local);
EMIT_ARG(delete_id, qstr_exception_local);
+
+ comp->cur_except_level -= 1;
EMIT(end_finally);
}
EMIT_ARG(jump, l2);
EMIT_ARG(label_assign, end_finally_label);
}
+ comp->cur_except_level -= 1;
EMIT(end_finally);
+
EMIT_ARG(label_assign, success_label);
- comp->except_nest_level -= 1;
compile_node(comp, pn_else); // else block, can be null
EMIT_ARG(label_assign, l2);
EMIT_ARG(set_stack_size, stack_size);
@@ -1664,7 +1657,10 @@
// don't understand how the stack works with exceptions, so we force it to return to the correct value
int stack_size = EMIT(get_stack_size);
int l_finally_block = comp_next_label(comp);
+
EMIT_ARG(setup_finally, l_finally_block);
+ comp->cur_except_level += 1;
+
if (n_except == 0) {
assert(MP_PARSE_NODE_IS_NULL(pn_else));
compile_node(comp, pn_body);
@@ -1675,7 +1671,10 @@
EMIT_ARG(load_const_tok, MP_TOKEN_KW_NONE);
EMIT_ARG(label_assign, l_finally_block);
compile_node(comp, pn_finally);
+
+ comp->cur_except_level -= 1;
EMIT(end_finally);
+
EMIT_ARG(set_stack_size, stack_size);
}
@@ -3056,7 +3055,9 @@
comp->break_label = 0;
comp->continue_label = 0;
- comp->except_nest_level = 0;
+ comp->break_continue_except_level = 0;
+ comp->cur_except_level = 0;
+
comp->scope_head = NULL;
comp->scope_cur = NULL;