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, 7 insertions, 11 deletions

diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 04141edec..f080f457b 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -35,7 +35,6 @@
 #include "py/runtime.h"
 #include "py/builtin.h"
 #include "py/stream.h"
-#include "py/pfenv.h"
 
 #if MICROPY_PY_BUILTINS_FLOAT
 #include <math.h>
@@ -413,9 +412,7 @@ STATIC mp_obj_t mp_builtin_print(mp_uint_t n_args, const mp_obj_t *args, mp_map_
         stream_obj = file_elem->value;
     }
 
-    pfenv_t pfenv;
-    pfenv.data = stream_obj;
-    pfenv.print_strn = (void (*)(void *, const char *, mp_uint_t))mp_stream_write;
+    mp_print_t print = {stream_obj, (mp_print_strn_t)mp_stream_write};
     #endif
     for (mp_uint_t i = 0; i < n_args; i++) {
         if (i > 0) {
@@ -426,7 +423,7 @@ STATIC mp_obj_t mp_builtin_print(mp_uint_t n_args, const mp_obj_t *args, mp_map_
             #endif
         }
         #if MICROPY_PY_IO
-        mp_obj_print_helper((void (*)(void *env, const char *fmt, ...))pfenv_printf, &pfenv, args[i], PRINT_STR);
+        mp_obj_print_helper(&print, args[i], PRINT_STR);
         #else
         mp_obj_print(args[i], PRINT_STR);
         #endif
@@ -443,10 +440,8 @@ MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_print_obj, 0, mp_builtin_print);
 STATIC mp_obj_t mp_builtin___repl_print__(mp_obj_t o) {
     if (o != mp_const_none) {
         #if MICROPY_PY_IO
-        pfenv_t pfenv;
-        pfenv.data = &mp_sys_stdout_obj;
-        pfenv.print_strn = (void (*)(void *, const char *, mp_uint_t))mp_stream_write;
-        mp_obj_print_helper((void (*)(void *env, const char *fmt, ...))pfenv_printf, &pfenv, o, PRINT_REPR);
+        mp_print_t print = {&mp_sys_stdout_obj, (mp_print_strn_t)mp_stream_write};
+        mp_obj_print_helper(&print, o, PRINT_REPR);
         mp_stream_write(&mp_sys_stdout_obj, "\n", 1);
         #else
         mp_obj_print(o, PRINT_REPR);
@@ -459,8 +454,9 @@ MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin___repl_print___obj, mp_builtin___repl_print
 
 STATIC mp_obj_t mp_builtin_repr(mp_obj_t o_in) {
     vstr_t vstr;
-    vstr_init(&vstr, 16);
-    mp_obj_print_helper((void (*)(void *env, const char *fmt, ...))vstr_printf, &vstr, o_in, PRINT_REPR);
+    mp_print_t print;
+    vstr_init_print(&vstr, 16, &print);
+    mp_obj_print_helper(&print, o_in, PRINT_REPR);
     return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_repr_obj, mp_builtin_repr);