py/vstr: Remove vstr.had_error flag and inline basic vstr functions.

The vstr.had_error flag was a relic from the very early days which assumed
that the malloc functions (eg m_new, m_renew) returned NULL if they failed
to allocate.  But that's no longer the case: these functions will raise an
exception if they fail.

Since it was impossible for had_error to be set, this patch introduces no
change in behaviour.

An alternative option would be to change the malloc calls to the _maybe
variants, which return NULL instead of raising, but then a lot of code
will need to explicitly check if the vstr had an error and raise if it
did.

The code-size savings for this patch are, in bytes: bare-arm:188,
minimal:456, unix(NDEBUG,x86-64):368, stmhal:228, esp8266:360.

1 files changed, 3 insertions, 5 deletions

diff --git a/py/misc.h b/py/misc.h
index 79a4c1c6e..3ed227a35 100644
--- a/py/misc.h
+++ b/py/misc.h
@@ -139,7 +139,6 @@ typedef struct _vstr_t {
     size_t alloc;
     size_t len;
     char *buf;
-    bool had_error : 1;
     bool fixed_buf : 1;
 } vstr_t;
 
@@ -155,10 +154,9 @@ void vstr_clear(vstr_t *vstr);
 vstr_t *vstr_new(void);
 vstr_t *vstr_new_size(size_t alloc);
 void vstr_free(vstr_t *vstr);
-void vstr_reset(vstr_t *vstr);
-bool vstr_had_error(vstr_t *vstr);
-char *vstr_str(vstr_t *vstr);
-size_t vstr_len(vstr_t *vstr);
+static inline void vstr_reset(vstr_t *vstr) { vstr->len = 0; }
+static inline char *vstr_str(vstr_t *vstr) { return vstr->buf; }
+static inline size_t vstr_len(vstr_t *vstr) { return vstr->len; }
 void vstr_hint_size(vstr_t *vstr, size_t size);
 char *vstr_extend(vstr_t *vstr, size_t size);
 char *vstr_add_len(vstr_t *vstr, size_t len);