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/objexcept.c b/py/objexcept.c
index 2d23f160a..8a008d1ff 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -90,28 +90,28 @@ mp_obj_t mp_alloc_emergency_exception_buf(mp_obj_t size_in) {
 // definition module-private so far, have it here.
 const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, 0, 0, MP_OBJ_NULL, mp_const_empty_tuple};
 
-STATIC void mp_obj_exception_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
+STATIC void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_exception_t *o = o_in;
     mp_print_kind_t k = kind & ~PRINT_EXC_SUBCLASS;
     bool is_subclass = kind & PRINT_EXC_SUBCLASS;
     if (!is_subclass && (k == PRINT_REPR || k == PRINT_EXC)) {
-        print(env, "%s", qstr_str(o->base.type->name));
+        mp_printf(print, "%s", qstr_str(o->base.type->name));
     }
 
     if (k == PRINT_EXC) {
-        print(env, ": ");
+        mp_print_str(print, ": ");
     }
 
     if (k == PRINT_STR || k == PRINT_EXC) {
         if (o->args == NULL || o->args->len == 0) {
-            print(env, "");
+            mp_print_str(print, "");
             return;
         } else if (o->args->len == 1) {
-            mp_obj_print_helper(print, env, o->args->items[0], PRINT_STR);
+            mp_obj_print_helper(print, o->args->items[0], PRINT_STR);
             return;
         }
     }
-    mp_obj_tuple_print(print, env, o->args, kind);
+    mp_obj_tuple_print(print, o->args, kind);
 }
 
 mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {