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, 1 insertions, 2 deletions

diff --git a/qemu-arm/main.c b/qemu-arm/main.c
index 860014493b..1673c82afd 100644
--- a/qemu-arm/main.c
+++ b/qemu-arm/main.c
@@ -11,7 +11,6 @@
 #include "py/stackctrl.h"
 #include "py/gc.h"
 #include "py/repl.h"
-#include "py/pfenv.h"
 
 void do_str(const char *src) {
     mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
@@ -28,7 +27,7 @@ void do_str(const char *src) {
         nlr_pop();
     } else {
         // uncaught exception
-        mp_obj_print_exception(printf_wrapper, NULL, (mp_obj_t)nlr.ret_val);
+        mp_obj_print_exception(&mp_extern_printf_wrapper, (mp_obj_t)nlr.ret_val);
     }
 }