From 3e78b1fdd92ee891ba4f6f249ce399f37eca0b87 Mon Sep 17 00:00:00 2001
From: Damien George <damien@micropython.org>
Date: Fri, 4 Mar 2022 10:40:15 +1100
Subject: [PATCH] py/qstr: Add qstr_from_strn_static.

Signed-off-by: Damien George <damien@micropython.org>
---
 py/qstr.c | 20 ++++++++++++++++++--
 py/qstr.h |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/py/qstr.c b/py/qstr.c
index 3720932250..f5c1b113df 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -309,7 +309,7 @@ qstr qstr_from_str(const char *str) {
     return qstr_from_strn(str, strlen(str));
 }
 
-qstr qstr_from_strn(const char *str, size_t len) {
+static qstr qstr_from_strn_helper(const char *str, size_t len, bool is_static) {
     QSTR_ENTER();
     qstr q = qstr_find_strn(str, len);
     if (q == 0) {
@@ -321,6 +321,11 @@ qstr qstr_from_strn(const char *str, size_t len) {
             mp_raise_msg(&mp_type_RuntimeError, MP_ERROR_TEXT("name too long"));
         }
 
+        if (is_static) {
+            assert(str[len] == '\0');
+            goto add;
+        }
+
         // compute number of bytes needed to intern this string
         size_t n_bytes = len + 1;
 
@@ -364,12 +369,23 @@ qstr qstr_from_strn(const char *str, size_t len) {
         // store the interned strings' data
         memcpy(q_ptr, str, len);
         q_ptr[len] = '\0';
-        q = qstr_add(len, q_ptr);
+        str = q_ptr;
+
+    add:
+        q = qstr_add(len, str);
     }
     QSTR_EXIT();
     return q;
 }
 
+qstr qstr_from_strn(const char *str, size_t len) {
+    return qstr_from_strn_helper(str, len, false);
+}
+
+qstr qstr_from_strn_static(const char *str, size_t len) {
+    return qstr_from_strn_helper(str, len, true);
+}
+
 mp_uint_t qstr_hash(qstr q) {
     const qstr_pool_t *pool = find_qstr(&q);
     #if MICROPY_QSTR_BYTES_IN_HASH
diff --git a/py/qstr.h b/py/qstr.h
index 58ce285fd2..69d52e85fe 100644
--- a/py/qstr.h
+++ b/py/qstr.h
@@ -101,6 +101,7 @@ qstr qstr_find_strn(const char *str, size_t str_len); // returns MP_QSTRnull if
 
 qstr qstr_from_str(const char *str);
 qstr qstr_from_strn(const char *str, size_t len);
+qstr qstr_from_strn_static(const char *str, size_t len);
 
 mp_uint_t qstr_hash(qstr q);
 const char *qstr_str(qstr q);