feat: add tiny printf implementation for embedded systems

1 files changed, 129 insertions, 0 deletions

diff --git a/na/lib/printf.h b/na/lib/printf.h
new file mode 100644
index 0000000..8aa23cf
--- /dev/null
+++ b/na/lib/printf.h
@@ -0,0 +1,129 @@
+///////////////////////////////////////////////////////////////////////////////

+// \author (c) Marco Paland (info@paland.com)

+//             2014-2019, PALANDesign Hannover, Germany

+//

+// \license The MIT License (MIT)

+//

+// 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.

+//

+// \brief Tiny printf, sprintf and snprintf implementation, optimized for speed on

+//        embedded systems with a very limited resources.

+//        Use this instead of bloated standard/newlib printf.

+//        These routines are thread safe and reentrant.

+//

+///////////////////////////////////////////////////////////////////////////////

+

+#ifndef _PRINTF_H_

+#define _PRINTF_H_

+

+#include <stdarg.h>

+

+/* LumeOS: avoid stddef.h — define types from compiler builtins directly.

+ * This works in both C and C++ and matches our types.h definition. */

+#ifndef _SIZE_T_DEFINED

+#define _SIZE_T_DEFINED

+typedef __SIZE_TYPE__    size_t;

+typedef __PTRDIFF_TYPE__ ptrdiff_t;

+typedef __INTMAX_TYPE__  intmax_t;

+#endif

+

+/* LumeOS: kernel does not need floating-point formatted output */

+#define PRINTF_DISABLE_SUPPORT_FLOAT

+#define PRINTF_DISABLE_SUPPORT_EXPONENTIAL

+

+

+#ifdef __cplusplus

+extern "C" {

+#endif

+

+

+/**

+ * Output a character to a custom device like UART, used by the printf() function

+ * This function is declared here only. You have to write your custom implementation somewhere

+ * \param character Character to output

+ */

+void _putchar(char character);

+

+

+/**

+ * Tiny printf implementation

+ * You have to implement _putchar if you use printf()

+ * To avoid conflicts with the regular printf() API it is overridden by macro defines

+ * and internal underscore-appended functions like printf_() are used

+ * \param format A string that specifies the format of the output

+ * \return The number of characters that are written into the array, not counting the terminating null character

+ */

+#define printf printf_

+int printf_(const char* format, ...);

+

+

+/**

+ * Tiny sprintf implementation

+ * Due to security reasons (buffer overflow) YOU SHOULD CONSIDER USING (V)SNPRINTF INSTEAD!

+ * \param buffer A pointer to the buffer where to store the formatted string. MUST be big enough to store the output!

+ * \param format A string that specifies the format of the output

+ * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character

+ */

+#define sprintf sprintf_

+int sprintf_(char* buffer, const char* format, ...);

+

+

+/**

+ * Tiny snprintf/vsnprintf implementation

+ * \param buffer A pointer to the buffer where to store the formatted string

+ * \param count The maximum number of characters to store in the buffer, including a terminating null character

+ * \param format A string that specifies the format of the output

+ * \param va A value identifying a variable arguments list

+ * \return The number of characters that COULD have been written into the buffer, not counting the terminating

+ *         null character. A value equal or larger than count indicates truncation. Only when the returned value

+ *         is non-negative and less than count, the string has been completely written.

+ */

+#define snprintf  snprintf_

+#define vsnprintf vsnprintf_

+int  snprintf_(char* buffer, size_t count, const char* format, ...);

+int vsnprintf_(char* buffer, size_t count, const char* format, va_list va);

+

+

+/**

+ * Tiny vprintf implementation

+ * \param format A string that specifies the format of the output

+ * \param va A value identifying a variable arguments list

+ * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character

+ */

+#define vprintf vprintf_

+int vprintf_(const char* format, va_list va);

+

+

+/**

+ * printf with output function

+ * You may use this as dynamic alternative to printf() with its fixed _putchar() output

+ * \param out An output function which takes one character and an argument pointer

+ * \param arg An argument pointer for user data passed to output function

+ * \param format A string that specifies the format of the output

+ * \return The number of characters that are sent to the output function, not counting the terminating null character

+ */

+int fctprintf(void (*out)(char character, void* arg), void* arg, const char* format, ...);

+

+

+#ifdef __cplusplus

+}

+#endif

+

+

+#endif  // _PRINTF_H_