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, 67 insertions, 0 deletions

diff --git a/py/mpprint.h b/py/mpprint.h
new file mode 100644
index 000000000..60fa18acf
--- /dev/null
+++ b/py/mpprint.h
@@ -0,0 +1,67 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef __MICROPY_INCLUDED_PY_MPPRINT_H__
+#define __MICROPY_INCLUDED_PY_MPPRINT_H__
+
+#include "py/mpconfig.h"
+
+#define PF_FLAG_LEFT_ADJUST       (0x001)
+#define PF_FLAG_SHOW_SIGN         (0x002)
+#define PF_FLAG_SPACE_SIGN        (0x004)
+#define PF_FLAG_NO_TRAILZ         (0x008)
+#define PF_FLAG_SHOW_PREFIX       (0x010)
+#define PF_FLAG_SHOW_COMMA        (0x020)
+#define PF_FLAG_PAD_AFTER_SIGN    (0x040)
+#define PF_FLAG_CENTER_ADJUST     (0x080)
+#define PF_FLAG_ADD_PERCENT       (0x100)
+#define PF_FLAG_PAD_NAN_INF       (0x200)
+#define PF_FLAG_SHOW_OCTAL_LETTER (0x400)
+
+typedef void (*mp_print_strn_t)(void *data, const char *str, mp_uint_t len);
+
+typedef struct _mp_print_t {
+    void *data;
+    mp_print_strn_t print_strn;
+} mp_print_t;
+
+// Wrapper for platform print function, which wraps MP_PLAT_PRINT_STRN.
+// All (non-debug) prints go through this interface (except some which
+// go through mp_sys_stdout_obj if MICROPY_PY_IO is defined).
+extern const mp_print_t mp_plat_print;
+
+int mp_print_str(const mp_print_t *print, const char *str);
+int mp_print_strn(const mp_print_t *print, const char *str, mp_uint_t len, int flags, char fill, int width);
+int mp_print_int(const mp_print_t *print, mp_uint_t x, int sgn, int base, int base_char, int flags, char fill, int width);
+#if MICROPY_PY_BUILTINS_FLOAT
+int mp_print_float(const mp_print_t *print, mp_float_t f, char fmt, int flags, char fill, int width, int prec);
+#endif
+
+int mp_printf(const mp_print_t *print, const char *fmt, ...);
+#ifdef va_start
+int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args);
+#endif
+
+#endif // __MICROPY_INCLUDED_PY_MPPRINT_H__