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, 2 insertions, 2 deletions

diff --git a/stmhal/modstm.c b/stmhal/modstm.c
index 72f4c67a76..b795d296b4 100644
--- a/stmhal/modstm.c
+++ b/stmhal/modstm.c
@@ -68,9 +68,9 @@ typedef struct _stm_mem_obj_t {
     uint32_t elem_size; // in bytes
 } stm_mem_obj_t;
 
-STATIC void stm_mem_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+STATIC void stm_mem_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     stm_mem_obj_t *self = self_in;
-    print(env, "<%u-bit memory>", 8 * self->elem_size);
+    mp_printf(print, "<%u-bit memory>", 8 * self->elem_size);
 }
 
 STATIC mp_obj_t stm_mem_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {