ports/embed: Implement additional time functions.

Optionally adds gmtime, localtime, mktime, time, time_ns to the time
module, implemented using mp_hal_time_ns(). This could also be used by
other ports.

I'm unsure where to put modtime_mphal.h, it could also be in extmod. The
important thing is that for MICROPY_PY_TIME_INCLUDEFILE to work it must be
at the same path in both the port build (original source tree) and the
application build (micropython_embed distribution), therefore not in
ports/embed/port.

It is named .h, mismatching the corresponding ports/*/modtime.c, because it
must not be compiled separately, which naming it .c would make harder for
users of the embed port - they would need to explicitly exclude it, whereas
this way they can continue to just compile all the .c files found in the
micropython_embed distribution except those in lib.

Signed-off-by: Christian Walther <cwalther@gmx.ch>

examples/embedding-full/main.c

@@ -35,6 +35,7 @@ static const char *example_2 =
     "help(random)\n"
     "import time\n"
     "help(time)\n"
+    "print('time.gmtime(736622952) = 2023-05-05T17:29:12Z:', time.gmtime(736622952))\n"
     "import math\n"
     "help(math)\n"
     "import frozenhello\n"

examples/embedding-full/micropython_embed.mk

@@ -8,6 +8,12 @@ MICROPYTHON_TOP = ../..
 # Include modules from extmod in the output.
 EMBED_EXTRA = extmod
 
+# Include helper sources for the time module in the output.
+EMBED_EXTRA += \
+	shared/timeutils/timeutils.c \
+	shared/timeutils/timeutils.h \
+	shared/timeutils/modtime_mphal.h
+
 # Freeze Python modules.
 FROZEN_MANIFEST ?= manifest.py
 

examples/embedding-full/mpconfigport.h

@@ -22,6 +22,12 @@
 // Enable floating point numbers and the math module.
 #define MICROPY_FLOAT_IMPL                      (MICROPY_FLOAT_IMPL_FLOAT)
 
+// Enable more functions in the time module. Requires additions to EMBED_EXTRA,
+// see micropython_embed.mk.
+#define MICROPY_PY_TIME_GMTIME_LOCALTIME_MKTIME (1)
+#define MICROPY_PY_TIME_TIME_TIME_NS            (1)
+#define MICROPY_PY_TIME_INCLUDEFILE             "shared/timeutils/modtime_mphal.h"
+
 // Requires shared/readline/readline.h, don't bother as we have no input.
 #define MICROPY_PY_BUILTINS_INPUT               (0)
 

examples/embedding-full/mphal.c

@@ -52,6 +52,15 @@ mp_uint_t mp_hal_ticks_cpu(void) {
 
 #endif
 
+#if MICROPY_PY_TIME_TIME_TIME_NS
+
+uint64_t mp_hal_time_ns(void) {
+	// Nanoseconds since the Epoch.
+	return 0;
+}
+
+#endif
+
 // Text-mode standard output
 void mp_hal_stdout_tx_strn_cooked(const char *str, size_t len) {
     // This is a simplistic implementation for demonstration purposes. A real

ports/embed/embed.mk

@@ -16,6 +16,12 @@ ifeq ($(filter extmod,$(EMBED_EXTRA)),extmod)
 include $(TOP)/extmod/extmod.mk
 endif
 
+# The parts of EMBED_EXTRA that name literal files and don't need special handling.
+EMBED_EXTRA_FILES = $(filter-out extmod,$(EMBED_EXTRA))
+
+# Extra files need to be searched for QSTRs.
+SRC_QSTR += $(addprefix $(TOP)/,$(EMBED_EXTRA_FILES))
+
 # Set the location of the MicroPython embed port.
 MICROPYTHON_EMBED_PORT = $(MICROPYTHON_TOP)/ports/embed
 
@@ -57,6 +63,9 @@ endif
 ifneq ($(FROZEN_MANIFEST),)
 PACKAGE_DIR_LIST += $(addprefix $(PACKAGE_DIR)/,frozen)
 endif
+ifneq ($(EMBED_EXTRA_FILES),)
+PACKAGE_DIR_LIST += $(addprefix $(PACKAGE_DIR)/,$(filter-out ./,$(sort $(dir $(EMBED_EXTRA_FILES)))))
+endif
 
 .PHONY: micropython-embed-package
 micropython-embed-package: $(GENHDR_OUTPUT) $(FROZEN_OUTPUT)
@@ -86,6 +95,10 @@ ifneq ($(FROZEN_MANIFEST),)
 endif
 	$(ECHO) "- port"
 	$(Q)$(CP) $(MICROPYTHON_EMBED_PORT)/port/*.[ch] $(PACKAGE_DIR)/port
+ifneq ($(EMBED_EXTRA_FILES),)
+	$(ECHO) "- extra"
+	$(Q)$(foreach FILE,$(EMBED_EXTRA_FILES),$(CP) $(TOP)/$(FILE) $(dir $(PACKAGE_DIR)/$(FILE)) &&) true
+endif
 
 # Include remaining core make rules.
 include $(TOP)/py/mkrules.mk

shared/timeutils/modtime_mphal.h

@@ -0,0 +1,52 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2023 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.
+ */
+
+#include "py/obj.h"
+#include "py/mphal.h"
+#include "shared/timeutils/timeutils.h"
+
+// Return the localtime as an 8-tuple.
+static mp_obj_t mp_time_localtime_get(void) {
+    mp_int_t seconds = mp_hal_time_ns() / 1000000000;
+    timeutils_struct_time_t tm;
+    timeutils_seconds_since_epoch_to_struct_time(seconds, &tm);
+    mp_obj_t tuple[8] = {
+        tuple[0] = mp_obj_new_int(tm.tm_year),
+        tuple[1] = mp_obj_new_int(tm.tm_mon),
+        tuple[2] = mp_obj_new_int(tm.tm_mday),
+        tuple[3] = mp_obj_new_int(tm.tm_hour),
+        tuple[4] = mp_obj_new_int(tm.tm_min),
+        tuple[5] = mp_obj_new_int(tm.tm_sec),
+        tuple[6] = mp_obj_new_int(tm.tm_wday),
+        tuple[7] = mp_obj_new_int(tm.tm_yday),
+    };
+    return mp_obj_new_tuple(8, tuple);
+}
+
+// Returns the number of seconds, as an integer, since the Epoch.
+static mp_obj_t mp_time_time_get(void) {
+    return mp_obj_new_int(mp_hal_time_ns() / 1000000000);
+}