py: Overhaul and simplify printf/pfenv mechanism.

Previous to this patch the printing mechanism was a bit of a tangled
mess.  This patch attempts to consolidate printing into one interface.

All (non-debug) printing now uses the mp_print* family of functions,
mainly mp_printf.  All these functions take an mp_print_t structure as
their first argument, and this structure defines the printing backend
through the "print_strn" function of said structure.

Printing from the uPy core can reach the platform-defined print code via
two paths: either through mp_sys_stdout_obj (defined pert port) in
conjunction with mp_stream_write; or through the mp_plat_print structure
which uses the MP_PLAT_PRINT_STRN macro to define how string are printed
on the platform.  The former is only used when MICROPY_PY_IO is defined.

With this new scheme printing is generally more efficient (less layers
to go through, less arguments to pass), and, given an mp_print_t*
structure, one can call mp_print_str for efficiency instead of
mp_printf("%s", ...).  Code size is also reduced by around 200 bytes on
Thumb2 archs.

1 files changed, 6 insertions, 6 deletions

diff --git a/py/objnamedtuple.c b/py/objnamedtuple.c
index 9cc6da1b7a..ef635a7a9c 100644
--- a/py/objnamedtuple.c
+++ b/py/objnamedtuple.c
@@ -53,19 +53,19 @@ STATIC mp_uint_t namedtuple_find_field(mp_obj_namedtuple_type_t *type, qstr name
     return -1;
 }
 
-STATIC void namedtuple_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
+STATIC void namedtuple_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
     (void)kind;
     mp_obj_namedtuple_t *o = o_in;
-    print(env, "%s(", qstr_str(o->tuple.base.type->name));
+    mp_printf(print, "%s(", qstr_str(o->tuple.base.type->name));
     const qstr *fields = ((mp_obj_namedtuple_type_t*)o->tuple.base.type)->fields;
     for (mp_uint_t i = 0; i < o->tuple.len; i++) {
         if (i > 0) {
-            print(env, ", ");
+            mp_print_str(print, ", ");
         }
-        print(env, "%s=", qstr_str(fields[i]));
-        mp_obj_print_helper(print, env, o->tuple.items[i], PRINT_REPR);
+        mp_printf(print, "%s=", qstr_str(fields[i]));
+        mp_obj_print_helper(print, o->tuple.items[i], PRINT_REPR);
     }
-    print(env, ")");
+    mp_print_str(print, ")");
 }
 
 STATIC void namedtuple_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {