py: Protect mp_parse and mp_compile with nlr push/pop block.

To enable parsing constants more efficiently, mp_parse should be allowed
to raise an exception, and mp_compile can already raise a MemoryError.
So these functions need to be protected by an nlr push/pop block.

This patch adds that feature in all places.  This allows to simplify how
mp_parse and mp_compile are called: they now raise an exception if they
have an error and so explicit checking is not needed anymore.

1 files changed, 4 insertions, 22 deletions

diff --git a/minimal/main.c b/minimal/main.c
index d25577d62d..c6c8080ade 100644
--- a/minimal/main.c
+++ b/minimal/main.c
@@ -3,7 +3,6 @@
 #include <string.h>
 
 #include "py/nlr.h"
-#include "py/parsehelper.h"
 #include "py/compile.h"
 #include "py/runtime.h"
 #include "py/repl.h"
@@ -15,32 +14,15 @@
 void do_str(const char *src) {
     mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
     if (lex == NULL) {
-        return;
-    }
-
-    mp_parse_error_kind_t parse_error_kind;
-    mp_parse_node_t pn = mp_parse(lex, MP_PARSE_SINGLE_INPUT, &parse_error_kind);
-
-    if (pn == MP_PARSE_NODE_NULL) {
-        // parse error
-        mp_parse_show_exception(lex, parse_error_kind);
-        mp_lexer_free(lex);
-        return;
-    }
-
-    // parse okay
-    qstr source_name = lex->source_name;
-    mp_lexer_free(lex);
-    mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, true);
-
-    if (mp_obj_is_exception_instance(module_fun)) {
-        // compile error
-        mp_obj_print_exception(printf_wrapper, NULL, module_fun);
+        printf("MemoryError: lexer could not allocate memory\n");
         return;
     }
 
     nlr_buf_t nlr;
     if (nlr_push(&nlr) == 0) {
+        qstr source_name = lex->source_name;
+        mp_parse_node_t pn = mp_parse(lex, MP_PARSE_SINGLE_INPUT);
+        mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, true);
         mp_call_function_0(module_fun);
         nlr_pop();
     } else {