WebAssembly01--c代码调用js
编译选项
emcc test.c --js-library pkg.js -o test.js
pkg.js
mergeInto(LibraryManager.library,{
js_add:function(a,b) {
console.log("js_add");
return a+b;
},
js_console_log_int:function(param){
console.log("js_console_log_in:"+param);
}
})
test.c
#ifndef EM_PORT_API
# if defined(__EMSCRIPTEN__)
# include <emscripten.h>
# if defined(__cplusplus)
# define EM_PORT_API(rettype) extern "C" rettype EMSCRIPTEN_KEEPALIVE
# else
# define EM_PORT_API(rettype) rettype EMSCRIPTEN_KEEPALIVE
# endif
# else
# if defined(__cplusplus)
# define EM_PORT_API(rettype) extern "C" rettype
# else
# define EM_PORT_API(rettype) rettype
# endif
# endif
#endif
#include<stdio.h>
#include<emscripten.h>
#include<stdlib.h>
#include<string.h>
EM_PORT_API(int) js_add(int a,int b);
EM_PORT_API(void) js_console_log_int(int param);
EM_PORT_API(void) print_the_answer(){
int i=js_add(21,21);
js_console_log_int(i);
}
EM_PORT_API(char*) str_merge(char* str1,char* str2)
{
int str1_len = 0;
int str2_len = 0;
int size = 0;
char *buf = NULL;
if(str1) str1_len = strlen(str1);
if(str2) str2_len = strlen(str2);
size = str1_len+str2_len;
buf = (char*)malloc(size);
memset(buf,0,size);
if(str1_len>0)strncpy(buf,str1,str1_len);
if(str2_len>0)strncpy(buf+str1_len,str2,str2_len);
return buf;//return merge result
}
EM_PORT_API(int) add(int a,int b)
{
return a+b;
}
int main(int argc,char** argv)
{
return add(1,2);
}
<html>
<head>
<title>test page</title>
</head>
<body>
<script >
Module={}
Module.onRuntimeInitialized=function(){
Module._print_the_answer();
}
</script>
<script src="test.js"></script>
</body>
</html>
emrun --no_browser --port 8000 test.html
