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, 4 insertions, 4 deletions

diff --git a/stmhal/i2c.c b/stmhal/i2c.c
index 80b40b887..e742b2100 100644
--- a/stmhal/i2c.c
+++ b/stmhal/i2c.c
@@ -183,7 +183,7 @@ STATIC const pyb_i2c_obj_t pyb_i2c_obj[] = {
     {{&pyb_i2c_type}, &I2CHandle2}
 };
 
-STATIC void pyb_i2c_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
+STATIC void pyb_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     pyb_i2c_obj_t *self = self_in;
 
     uint i2c_num;
@@ -191,12 +191,12 @@ STATIC void pyb_i2c_print(void (*print)(void *env, const char *fmt, ...), void *
     else { i2c_num = 2; }
 
     if (self->i2c->State == HAL_I2C_STATE_RESET) {
-        print(env, "I2C(%u)", i2c_num);
+        mp_printf(print, "I2C(%u)", i2c_num);
     } else {
         if (in_master_mode(self)) {
-            print(env, "I2C(%u, I2C.MASTER, baudrate=%u)", i2c_num, self->i2c->Init.ClockSpeed);
+            mp_printf(print, "I2C(%u, I2C.MASTER, baudrate=%u)", i2c_num, self->i2c->Init.ClockSpeed);
         } else {
-            print(env, "I2C(%u, I2C.SLAVE, addr=0x%02x)", i2c_num, (self->i2c->Instance->OAR1 >> 1) & 0x7f);
+            mp_printf(print, "I2C(%u, I2C.SLAVE, addr=0x%02x)", i2c_num, (self->i2c->Instance->OAR1 >> 1) & 0x7f);
         }
     }
 }