py: f-strings are now opt-in compile flag

klardotsh · klardotsh · commit 4ad8eb4e5c36 · 2020-05-15T17:10:31.000-07:00
diff --git a/ports/bare-arm/mpconfigport.h b/ports/bare-arm/mpconfigport.h
@@ -37,6 +37,7 @@
 #define MICROPY_PY_ARRAY            (0)
 #define MICROPY_PY_ATTRTUPLE        (0)
 #define MICROPY_PY_COLLECTIONS      (0)
+#define MICROPY_PY_FSTRING          (0)
 #define MICROPY_PY_MATH             (0)
 #define MICROPY_PY_CMATH            (0)
 #define MICROPY_PY_IO               (0)
diff --git a/ports/unix/mpconfigport.h b/ports/unix/mpconfigport.h
@@ -122,6 +122,7 @@
 #define MICROPY_PY_SYS_EXC_INFO     (1)
 #define MICROPY_PY_COLLECTIONS_DEQUE (1)
 #define MICROPY_PY_COLLECTIONS_ORDEREDDICT (1)
+#define MICROPY_PY_FSTRING          (1)
 #ifndef MICROPY_PY_MATH_SPECIAL_FUNCTIONS
 #define MICROPY_PY_MATH_SPECIAL_FUNCTIONS (1)
 #endif
diff --git a/py/lexer.c b/py/lexer.c
@@ -334,15 +334,19 @@ STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw, bool is_fstring)
     }
 
     size_t n_closing = 0;
+    # if MICROPY_PY_FSTRING
     bool in_expression = false;
     bool expression_eat = true;
+    # endif
 
     while (!is_end(lex) && (num_quotes > 1 || !is_char(lex, '\n')) && n_closing < num_quotes) {
         if (is_char(lex, quote_char)) {
             n_closing += 1;
             vstr_add_char(&lex->vstr, CUR_CHAR(lex));
         } else {
             n_closing = 0;
+
+            # if MICROPY_PY_FSTRING
             if (is_fstring && is_char(lex, '{')) {
                 vstr_add_char(&lex->vstr, CUR_CHAR(lex));
                 in_expression = !in_expression;
@@ -387,6 +391,7 @@ STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw, bool is_fstring)
                 next_char(lex);
                 continue;
             }
+            # endif
 
             if (is_char(lex, '\\')) {
                 next_char(lex);
@@ -621,18 +626,23 @@ void mp_lexer_to_next(mp_lexer_t *lex) {
                     kind = MP_TOKEN_BYTES;
                     n_char = 2;
                 }
+                # if MICROPY_PY_FSTRING
                 if (is_char_following(lex, 'f')) {
                     lex->tok_kind = MP_TOKEN_FSTRING_RAW;
                     break;
                 }
-            } else if (is_char(lex, 'f')) {
+                # endif
+            }
+            # if MICROPY_PY_FSTRING
+            else if (is_char(lex, 'f')) {
                 if (is_char_following(lex, 'r')) {
                     lex->tok_kind = MP_TOKEN_FSTRING_RAW;
                     break;
                 }
                 n_char = 1;
                 is_fstring = true;
             }
+            # endif
 
             // Set or check token kind
             if (lex->tok_kind == MP_TOKEN_END) {
diff --git a/py/mpconfig.h b/py/mpconfig.h
@@ -1108,6 +1108,12 @@ typedef double mp_float_t;
 #define MICROPY_PY_COLLECTIONS_NAMEDTUPLE__ASDICT (0)
 #endif
 
+// Whether to include support for PEP-498 f-strings
+#ifndef MICROPY_PY_FSTRING
+#define MICROPY_PY_FSTRING (0)
+#endif
+
+
 // Whether to provide "math" module
 #ifndef MICROPY_PY_MATH
 #define MICROPY_PY_MATH (1)
diff --git a/py/parse.c b/py/parse.c
@@ -1155,12 +1155,14 @@ mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) {
         } else if (lex->tok_kind == MP_TOKEN_DEDENT_MISMATCH) {
             exc = mp_obj_new_exception_msg(&mp_type_IndentationError,
                 MP_ERROR_TEXT("unindent doesn't match any outer indent level"));
+        # if MICROPY_PY_FSTRING
         } else if (lex->tok_kind == MP_TOKEN_MALFORMED_FSTRING) {
             exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
                 MP_ERROR_TEXT("malformed f-string"));
         } else if (lex->tok_kind == MP_TOKEN_FSTRING_RAW) {
             exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
                 MP_ERROR_TEXT("raw f-strings are not supported"));
+        # endif
         } else {
             exc = mp_obj_new_exception_msg(&mp_type_SyntaxError,
                 MP_ERROR_TEXT("invalid syntax"));
