examples: Refactoring bindings examples

examples/hello_d/Makefile

@@ -26,7 +26,13 @@ MAINSRC = hello_d_main.d
 
 # hello_d built-in application info
 
-DFLAGS += -oq -betterC
+# no garbage collection
+DFLAGS += -betterC
+# better informations
+DFLAGS += -vtls -verrors=context
+# like #ifdef/#define NuttX_ImportC
+# importC: need $(CC) to compile C file and -P-I to import C includes
+DFLAGS += -P-I$(TOPDIR)/include --d-version=NuttX_ImportC --gcc=$(CC)
 PROGNAME  = $(CONFIG_EXAMPLES_HELLO_D_PROGNAME)
 PRIORITY  = $(CONFIG_EXAMPLES_HELLO_D_PRIORITY)
 STACKSIZE = $(CONFIG_EXAMPLES_HELLO_D_STACKSIZE)

examples/hello_d/hello_d_main.d

@@ -26,79 +26,116 @@ module examples.hello_d_main;
 // import core.stdc.stdio : printf;
 // import core.stdc.stdlib : malloc, free;
 
-///
-pragma(printf)
-extern (C) int printf(scope const(char)* fmt, scope...) @nogc nothrow @trusted;
-///
-extern (C) void* malloc(size_t size) @nogc nothrow @trusted;
-///
-extern (C) void free(void* ptr) @nogc nothrow @trusted;
+version (D_BetterC) // no DRT
+{
+    /// if betterC and LDC, disable moduleinfo and typeinfo
+    version (LDC)
+    {
+        pragma(LDC_no_moduleinfo);
+        pragma(LDC_no_typeinfo);
+    }
+}
+
+/// use --d-version=NuttX_ImportC to define
+version (NuttX_ImportC)
+{
+    /// D compiler will not import C++ symbols
+    /// so we need to import them manually
+    /// @nogc, @trusted, @safe, nothrow - not allowed
+    /// https://issues.dlang.org/show_bug.cgi?id=23812
+    import nuttx_std : malloc, free, printf; // by default: @system (unsafe)
+}
+else
+{
+    /// Correctly FFI-import C/C++ symbols (@safe compatibility)
+    ///
+    pragma(printf)
+    extern (C) int printf(scope const(char)* fmt, scope...) @nogc nothrow @trusted;
+    ///
+    extern (C) void* malloc(size_t size) @nogc nothrow @trusted;
+    ///
+    extern (C) void free(scope void* ptr) @nogc nothrow @trusted;
+}
 
 //***************************************************************************
-// Private module content
+// Private module content (default is public)
 //***************************************************************************
 private:
 
 // based heloxx class layout
 extern (C++,class)
 struct DHelloWorld
 {
-@nogc nothrow:
-
     @disable this();
     @disable this(this);
-    this(int secret) @safe pure
-    {
-        mSecret = secret;
-        debug printf("Constructor\n");
-    }
 
-    ~this() @safe pure
+    /// use --d-version=NuttX_ImportC to define
+    version (NuttX_ImportC)
     {
-        debug printf("Destructor\n");
-    }
-
-    bool HelloWorld() @safe
-    {
-        debug printf("HelloWorld: mSecret=%d\n", mSecret);
+        this(int secret)
+        {
+            mSecret = secret;
+            printf("Constructor\n");
+        }
 
-        if (mSecret != 42)
+        ~this()
         {
-            printf("DHelloWorld.HelloWorld: CONSTRUCTION FAILED!\n");
-            return false;
+            printf("Destructor\n");
         }
-        else
+
+        bool HelloWorld()
         {
-            printf("DHelloWorld.HelloWorld: Hello, World!!\n");
-            return true;
+            printf("HelloWorld: mSecret=%d\n", mSecret);
+
+            if (mSecret != 42)
+            {
+                printf("DHelloWorld.HelloWorld: CONSTRUCTION FAILED!\n");
+                return false;
+            }
+            else
+            {
+                printf("DHelloWorld.HelloWorld: Hello, World!!\n");
+                return true;
+            }
         }
     }
+    else
+    {
+        this(int secret) @safe nothrow @nogc
+        {
+            mSecret = secret;
+            printf("Constructor\n");
+        }
 
-    private int mSecret;
-}
-
-//***************************************************************************
-// Private Data
-//***************************************************************************
+        ~this() @safe nothrow @nogc
+        {
+            printf("Destructor\n");
+        }
 
-// Define a statically constructed DHellowWorld instance if D static
-// initializers are supported by the platform
-// --d-version=D_Initialize
-version (D_Initialize)
-{
-    static DHelloWorld g_HelloWorld;
+        bool HelloWorld() @safe nothrow @nogc
+        {
+            printf("HelloWorld: mSecret=%d\n", mSecret);
+
+            if (mSecret != 42)
+            {
+                printf("DHelloWorld.HelloWorld: CONSTRUCTION FAILED!\n");
+                return false;
+            }
+            else
+            {
+                printf("DHelloWorld.HelloWorld: Hello, World!!\n");
+                return true;
+            }
+        }
+    }
+    private int mSecret = 0;
 }
 
-//***************************************************************************
-// Public Functions
-//***************************************************************************
-
 /****************************************************************************
  * Name: hello_d_main
  ****************************************************************************/
 // betterC need main function no-mangle.
-extern (C)
-int hello_d_main(int argc, char*[] argv) nothrow @nogc
+extern (C) int hello_d_main(int argc, char*[] argv)
 {
     version (LDC)
     {
@@ -118,5 +155,6 @@ int hello_d_main(int argc, char*[] argv) nothrow @nogc
 
     printf("hello_d_main: Saying hello from the instance constructed on the stack\n");
     HelloWorld.HelloWorld();
+
     return 0;
 }

examples/hello_d/nuttx_std.c

@@ -0,0 +1,39 @@
+/****************************************************************************
+ * apps/examples/hello_d/nuttx_std.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+/****************************************************************************
+ * This is imported to d source using importC
+ * https://dlang.org/spec/importc.html
+ ****************************************************************************/
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * hello_d_main
+ ****************************************************************************/

examples/hello_zig/Makefile

@@ -25,7 +25,7 @@ include $(APPDIR)/Make.defs
 MAINSRC = hello_zig.zig
 
 # Hello, Zig! built-in application info
-
+ZIGFLAGS += -lc -I$(TOPDIR)/include
 PROGNAME  = $(CONFIG_EXAMPLES_HELLO_ZIG_PROGNAME)
 PRIORITY  = $(CONFIG_EXAMPLES_HELLO_ZIG_PRIORITY)
 STACKSIZE = $(CONFIG_EXAMPLES_HELLO_ZIG_STACKSIZE)

examples/hello_zig/hello_zig.zig

@@ -24,17 +24,35 @@
 const std = @import("std");
 
 //****************************************************************************
-//* Externs
+//* C API - need libc linking (freestanding libc is stubs only)
 //****************************************************************************
+// NuttX namespace
+const NuttX = struct {
+    pub const c = @cImport({
+        @cInclude("nuttx/config.h");
+        @cInclude("stdio.h");
+    });
+    pub fn print(comptime fmt: [*:0]const u8, args: anytype) void {
+        _ = printf(std.fmt.comptimePrint(std.mem.span(fmt), args));
+    }
+};
 
-pub extern fn printf(_format: [*:0]const u8) c_int;
+// or (optional) const c = std.c; // from std library (non-full libc)
 
+// typedef alias
+const printf = NuttX.c.printf;
 //****************************************************************************
 //* hello_zig_main
 //****************************************************************************
-pub export fn main(_argc: c_int, _argv: [*]const [*]const u8) u8 {
-    _ = _argc;
-    _ = _argv;
-    _ = printf("Hello, Zig!\n");
+comptime {
+    // rename to hello_zig_main entry point for nuttx
+    @export(hello_zig, .{
+        .name = "hello_zig_main",
+        .linkage = .weak,
+    });
+}
+
+fn hello_zig(_: c_int, _: ?[*]const [*]const u8) callconv(.C) c_int {
+    NuttX.print("[{s}]: Hello, Zig!\n", .{NuttX.c.CONFIG_ARCH_BOARD});
     return 0;
 }

examples/leds_zig/Kconfig

@@ -0,0 +1,30 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config EXAMPLES_LEDS_ZIG
+	tristate "\"LEDs Zig\" example"
+	default n
+	depends on USERLED
+	---help---
+		Enable the \"LEDs Zig\" example
+
+if EXAMPLES_LEDS_ZIG
+
+config EXAMPLES_LEDS_ZIG_PROGNAME
+	string "Program name"
+	default "leds_zig"
+	---help---
+		This is the name of the program that will be used when the
+		program is installed.
+
+config EXAMPLES_LEDS_ZIG_PRIORITY
+	int "LEDs Zig task priority"
+	default 100
+
+config EXAMPLES_LEDS_ZIG_STACKSIZE
+	int "LEDs Zig stack size"
+	default DEFAULT_TASK_STACKSIZE
+
+endif

examples/leds_zig/Make.defs

@@ -0,0 +1,23 @@
+############################################################################
+# apps/examples/leds_zig/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+ifneq ($(CONFIG_EXAMPLES_LEDS_ZIG),)
+CONFIGURED_APPS += $(APPDIR)/examples/leds_zig
+endif