Jesseyx · March 22, 2020 06:14
diff --git a/helloworld_emcc_connect_to_js_pointer.log b/helloworld_emcc_connect_to_js_pointer.log
 $emacs libtest.c

 #include <math.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>

 //                                                                                                                                                                                
 // int                                                                                                                                                                            
 int int_sqrt(int x) {
  return sqrt(x);
 }

 //                                                                                                                                                                                
 // string                                                                                                                                                                         
 char* chars_hello(char* src) {
  return strcat( "Hello ", src );
 }


 //                                                                                                                                                                                
 // pointer                                                                                                                                                                        

 typedef struct {
  char* name;
 } Hello;

 Hello* new_hello(char *name, int length) {
  Hello *obj = (Hello*)calloc(1, sizeof(Hello));
  obj->name = (char*)calloc(1, sizeof(char)*(length+1));
  for(int i=0;i<length;i++) {
    obj->name[i] = name[i];
  }
  return obj;
 }

 char* hello_getName(Hello* obj) {
  return obj->name;
 }

 void free_hello(Hello* obj) {
  if(obj == NULL) {
    return;
  }
  free(obj->name);
  free(obj);
 }


 $ emcc libtest.c  -o libtest.js -s EXPORTED_FUNCTIONS='["_int_sqrt","_chars_hello", "_new_hello","_hello_getName", "_hello_getName", "_free_hello"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'
 $ emacs main.html

 <html>
  <head>
    <title></title>
  </head>
  <body>
    <script src="libtest.js"></script>
    <script>
      //
      // int
      int_sqrt = Module.cwrap('int_sqrt', 'number', ['number']);
      console.log("#int_sqrt : "+int_sqrt(12));

      //
      // string
      chars_hello = Module.cwrap('chars_hello', 'string', ['string']);
      console.log("#chars_hello : " + chars_hello('test'));

      //
      // uint8array
      helloArray = [];
      helloSrc = "hello";
      for(i=0;i<helloSrc.length;i++){
        helloArray.push(helloSrc.charCodeAt(i));
      }
      hello = chars_hello(new Uint8Array('helloArray'));
      console.log("#chars_hello : " + hello);


      //
      // pointer
      new_hello = Module.cwrap('new_hello', 'number', ['string', 'number']);
      hello_getName = Module.cwrap('hello_getName', 'string', ['number']);
      free_hello = Module.cwrap('free_hello', '', ['number']);

      helloObj = new_hello("test", 4);
      console.log("#pointer:" + hello_getName(helloObj));
      free_hello(helloObj);
    </script>
  </body>
 </html>


 $ python -m SimpleHTTPServer
 Serving HTTP on 0.0.0.0 port 8000 ...
 $ open http://0.0.0.0:8000/
	$emacs libtest.c

	#include <math.h>
	#include <string.h>
	#include <stdio.h>
	#include <stdlib.h>

	//
	// int
	int int_sqrt(int x) {
	return sqrt(x);
	}

	//
	// string
	char* chars_hello(char* src) {
	return strcat( "Hello ", src );
	}


	//
	// pointer

	typedef struct {
	char* name;
	} Hello;

	Hello* new_hello(char *name, int length) {
	Hello obj = (Hello)calloc(1, sizeof(Hello));
	obj->name = (char)calloc(1, sizeof(char)(length+1));
	for(int i=0;i<length;i++) {
	obj->name[i] = name[i];
	}
	return obj;
	}

	char* hello_getName(Hello* obj) {
	return obj->name;
	}

	void free_hello(Hello* obj) {
	if(obj == NULL) {
	return;
	}
	free(obj->name);
	free(obj);
	}


	$ emcc libtest.c -o libtest.js -s EXPORTED_FUNCTIONS='["_int_sqrt","_chars_hello", "_new_hello","_hello_getName", "_hello_getName", "_free_hello"]' -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'
	$ emacs main.html

	<html>
	<head>
	<title></title>
	</head>
	<body>
	<script src="libtest.js"></script>
	<script>
	//
	// int
	int_sqrt = Module.cwrap('int_sqrt', 'number', ['number']);
	console.log("#int_sqrt : "+int_sqrt(12));

	//
	// string
	chars_hello = Module.cwrap('chars_hello', 'string', ['string']);
	console.log("#chars_hello : " + chars_hello('test'));

	//
	// uint8array
	helloArray = [];
	helloSrc = "hello";
	for(i=0;i<helloSrc.length;i++){
	helloArray.push(helloSrc.charCodeAt(i));
	}
	hello = chars_hello(new Uint8Array('helloArray'));
	console.log("#chars_hello : " + hello);


	//
	// pointer
	new_hello = Module.cwrap('new_hello', 'number', ['string', 'number']);
	hello_getName = Module.cwrap('hello_getName', 'string', ['number']);
	free_hello = Module.cwrap('free_hello', '', ['number']);

	helloObj = new_hello("test", 4);
	console.log("#pointer:" + hello_getName(helloObj));
	free_hello(helloObj);
	</script>
	</body>
	</html>


	$ python -m SimpleHTTPServer
	Serving HTTP on 0.0.0.0 port 8000 ...
	$ open http://0.0.0.0:8000/