Remove the built-in print and the jerry_port_console port API functions (#1749)

The built-in `print` is removed from jerry-core, but an external
`print` implementation is added to jerry-main. From now on, all
embedders of the engine have to implement their own `print` if they
need such a functionality.

For printing results in REPL mode of jerry-main, the external
`print` handler is called directly instead of looking up the `print`
function registered into the global object. (The two are the same,
but the indirection is not needed anymore.)

Because jerry-core does not contain `print` anymore,
`jerry_port_console` is removed from the port API. The default port
is updated, i.e., the implementation of `jerry_port_console` is
removed. Additionally, all references to `jerry_port_console` in
jerry-main are replaced by `printf`.

Speculatively, `jerry_port_console` is also removed from all
non-default targets. Most targets implemented it for the sake of the
engine only; in those targets the removal was trivial. Where the
function was called from the embedder application as well, the
calls were replaced with equivalents (e.g., `printf`, `printk`).

NOTE 1: This is a breaking change!

NOTE 2: This patch still leaves several targets without a JS `print`
implementation.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

targets/curie_bsp/jerry_app/quark/main.c

@@ -36,6 +36,7 @@
 #include "zephyr.h"
 #include "microkernel/task.h"
 #include "os/os.h"
+#include "misc/printk.h"
 
 static T_QUEUE queue;
 
@@ -51,7 +52,7 @@ void jerry_resolve_error (jerry_value_t ret_value)
     jerry_char_t *err_str_buf = (jerry_char_t *) balloc (err_str_size, NULL);
     jerry_size_t sz = jerry_string_to_char_buffer (err_str_val, err_str_buf, err_str_size);
     err_str_buf[sz] = 0;
-    jerry_port_console ("Script Error: unhandled exception: %s\n", err_str_buf);
+    printk ("Script Error: unhandled exception: %s\n", err_str_buf);
     bfree(err_str_buf);
     jerry_release_value (err_str_val);
   }
@@ -59,9 +60,9 @@ void jerry_resolve_error (jerry_value_t ret_value)
 
 void help ()
 {
-  jerry_port_console ("Usage:\n");
-  jerry_port_console ("js e 'JavaScript Command'\n");
-  jerry_port_console ("eg. js e print ('Hello World');\n");
+  printk ("Usage:\n");
+  printk ("js e 'JavaScript Command'\n");
+  printk ("eg. js e print ('Hello World');\n");
 }
 
 void eval_jerry_script (int argc, char *argv[], struct tcmd_handler_ctx *ctx)
@@ -79,7 +80,7 @@ void eval_jerry_script (int argc, char *argv[], struct tcmd_handler_ctx *ctx)
     size_t *str_lens = (size_t *) balloc ((argc - 2) * sizeof(size_t), &err);
     if (str_lens == NULL || err != E_OS_OK)
     {
-      jerry_port_console ("%s: allocate memory failed!", __func__);
+      printk ("%s: allocate memory failed!", __func__);
       TCMD_RSP_ERROR (ctx, NULL);
       return;
     }
@@ -92,7 +93,7 @@ void eval_jerry_script (int argc, char *argv[], struct tcmd_handler_ctx *ctx)
     char *buffer = (char *) balloc (str_total_length, &err);
     if (buffer == NULL || err != E_OS_OK)
     {
-      jerry_port_console ("%s: allocate memory failed!", __func__);
+      printk ("%s: allocate memory failed!", __func__);
       TCMD_RSP_ERROR (ctx, NULL);
       return;
     }

targets/curie_bsp/source/curie-bsp-port.c

@@ -20,24 +20,6 @@
 #include <stddef.h>
 #include "jerryscript-port.h"
 
-/**
- * Provide console message implementation for the engine.
- * Curie BSP implementation
- */
-void
-jerry_port_console (const char *format, /**< format string */
-                    ...) /**< parameters */
-{
-  char buf[256];
-  int length = 0;
-  va_list args;
-  va_start (args, format);
-  length = vsnprintf (buf, 256, format, args);
-  buf[length] = '\0';
-  printk ("%s", buf);
-  va_end (args);
-} /* jerry_port_console */
-
 /**
  * Provide log message implementation for the engine.
  * Curie BSP implementation