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Android 10.0 AOSP源码编译：

        AOSP源码开发环境搭建教学视频-百问100ask   

       Android系统 10.0 AOSP源码编译--CSDN程序员研修院

 Android 10.0 根文件系统和编译系统：

        Android根文件系统和编译系统教学视频-百问100ask

        Android 10.0 根文件系统和编译系统-CSDN程序员研修院

---

说明

系统：AOSP Android10.0

设备：Android模拟器

前言

本文章重点讲解Android.mk如何控制编译静态，以及链接该静态库

---

一， 静态程序代码

在Anroid层目录新建mytest/lib_test/目录, 并创建文件名：

mytest/lib_test/libcjson/cJSON.h

#ifndef cJSON__h
#define cJSON__h

#ifdef __cplusplus
extern "C"
{
#endif


#define cJSON_False 0
#define cJSON_True 1
#define cJSON_NULL 2
#define cJSON_Number 3
#define cJSON_String 4
#define cJSON_Array 5
#define cJSON_Object 6
	
#define cJSON_IsReference 256
#define cJSON_StringIsConst 512


typedef struct cJSON {
	struct cJSON *next,*prev;	
	struct cJSON *child;		

	int type;					

	char *valuestring;			
	int valueint;				
	double valuedouble;			

	char *string;				
} cJSON;

typedef struct cJSON_Hooks {
      void *(*malloc_fn)(size_t sz);
      void (*free_fn)(void *ptr);
} cJSON_Hooks;


extern void cJSON_InitHooks(cJSON_Hooks* hooks);



extern cJSON *cJSON_Parse(const char *value);

extern char  *cJSON_Print(cJSON *item);

extern char  *cJSON_PrintUnformatted(cJSON *item);

extern char *cJSON_PrintBuffered(cJSON *item,int prebuffer,int fmt);

extern void   cJSON_Delete(cJSON *c);


extern int	  cJSON_GetArraySize(cJSON *array);

extern cJSON *cJSON_GetArrayItem(cJSON *array,int item);

extern cJSON *cJSON_GetObjectItem(cJSON *object,const char *string);


extern const char *cJSON_GetErrorPtr(void);
	

extern cJSON *cJSON_CreateNull(void);
extern cJSON *cJSON_CreateTrue(void);
extern cJSON *cJSON_CreateFalse(void);
extern cJSON *cJSON_CreateBool(int b);
extern cJSON *cJSON_CreateNumber(double num);
extern cJSON *cJSON_CreateString(const char *string);
extern cJSON *cJSON_CreateArray(void);
extern cJSON *cJSON_CreateObject(void);


extern cJSON *cJSON_CreateIntArray(const int *numbers,int count);
extern cJSON *cJSON_CreateFloatArray(const float *numbers,int count);
extern cJSON *cJSON_CreateDoubleArray(const double *numbers,int count);
extern cJSON *cJSON_CreateStringArray(const char **strings,int count);


extern void cJSON_AddItemToArray(cJSON *array, cJSON *item);
extern void	cJSON_AddItemToObject(cJSON *object,const char *string,cJSON *item);
extern void	cJSON_AddItemToObjectCS(cJSON *object,const char *string,cJSON *item);	

extern void cJSON_AddItemReferenceToArray(cJSON *array, cJSON *item);
extern void	cJSON_AddItemReferenceToObject(cJSON *object,const char *string,cJSON *item);


extern cJSON *cJSON_DetachItemFromArray(cJSON *array,int which);
extern void   cJSON_DeleteItemFromArray(cJSON *array,int which);
extern cJSON *cJSON_DetachItemFromObject(cJSON *object,const char *string);
extern void   cJSON_DeleteItemFromObject(cJSON *object,const char *string);
	

extern void cJSON_InsertItemInArray(cJSON *array,int which,cJSON *newitem);	
extern void cJSON_ReplaceItemInArray(cJSON *array,int which,cJSON *newitem);
extern void cJSON_ReplaceItemInObject(cJSON *object,const char *string,cJSON *newitem);


extern cJSON *cJSON_Duplicate(cJSON *item,int recurse);



extern cJSON *cJSON_ParseWithOpts(const char *value,const char **return_parse_end,int require_null_terminated);

extern void cJSON_Minify(char *json);


#define cJSON_AddNullToObject(object,name)		cJSON_AddItemToObject(object, name, cJSON_CreateNull())
#define cJSON_AddTrueToObject(object,name)		cJSON_AddItemToObject(object, name, cJSON_CreateTrue())
#define cJSON_AddFalseToObject(object,name)		cJSON_AddItemToObject(object, name, cJSON_CreateFalse())
#define cJSON_AddBoolToObject(object,name,b)	cJSON_AddItemToObject(object, name, cJSON_CreateBool(b))
#define cJSON_AddNumberToObject(object,name,n)	cJSON_AddItemToObject(object, name, cJSON_CreateNumber(n))
#define cJSON_AddStringToObject(object,name,s)	cJSON_AddItemToObject(object, name, cJSON_CreateString(s))


#define cJSON_SetIntValue(object,val)			((object)?(object)->valueint=(object)->valuedouble=(val):(val))
#define cJSON_SetNumberValue(object,val)		((object)?(object)->valueint=(object)->valuedouble=(val):(val))

#ifdef __cplusplus
}
#endif

#endif

mytest/lib_test/libcjson/cJSON.c

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "cJSON.h"


static const char *ep;

const char *cJSON_GetErrorPtr(void) {return ep;}

static int cJSON_strcasecmp(const char *s1,const char *s2)
{
	if (!s1) return (s1==s2)?0:1;
	if (!s2) return 1;
	for(; tolower(*s1) == tolower(*s2); ++s1, ++s2)	if(*s1 == 0)	return 0;
	return tolower(*(const unsigned char *)s1) - tolower(*(const unsigned char *)s2);
}

static void *(*cJSON_malloc)(size_t sz) = malloc;
static void (*cJSON_free)(void *ptr) = free;

static char* cJSON_strdup(const char* str)
{
      size_t len;
      char* copy;

      len = strlen(str) + 1;
      if (!(copy = (char*)cJSON_malloc(len))) return 0;
      memcpy(copy,str,len);
      return copy;
}

void cJSON_InitHooks(cJSON_Hooks* hooks)
{
    if (!hooks) { 
        cJSON_malloc = malloc;
        cJSON_free = free;
        return;
    }

	cJSON_malloc = (hooks->malloc_fn)?hooks->malloc_fn:malloc;
	cJSON_free	 = (hooks->free_fn)?hooks->free_fn:free;
}


static cJSON *cJSON_New_Item(void)
{
	cJSON* node = (cJSON*)cJSON_malloc(sizeof(cJSON));
	if (node) memset(node,0,sizeof(cJSON));
	return node;
}


void cJSON_Delete(cJSON *c)
{
	cJSON *next;
	while (c)
	{
		next=c->next;
		if (!(c->type&cJSON_IsReference) && c->child) cJSON_Delete(c->child);
		if (!(c->type&cJSON_IsReference) && c->valuestring) cJSON_free(c->valuestring);
		if (!(c->type&cJSON_StringIsConst) && c->string) cJSON_free(c->string);
		cJSON_free(c);
		c=next;
	}
}


static const char *parse_number(cJSON *item,const char *num)
{
	double n=0,sign=1,scale=0;int subscale=0,signsubscale=1;

	if (*num=='-') sign=-1,num++;	
	if (*num=='0') num++;			
	if (*num>='1' && *num<='9')	do	n=(n*10.0)+(*num++ -'0');	while (*num>='0' && *num<='9');	
	if (*num=='.' && num[1]>='0' && num[1]<='9') {num++;		do	n=(n*10.0)+(*num++ -'0'),scale--; while (*num>='0' && *num<='9');}	
	if (*num=='e' || *num=='E')		
	{	num++;if (*num=='+') num++;	else if (*num=='-') signsubscale=-1,num++;		
		while (*num>='0' && *num<='9') subscale=(subscale*10)+(*num++ - '0');	
	}

	n=sign*n*pow(10.0,(scale+subscale*signsubscale));	
	
	item->valuedouble=n;
	item->valueint=(int)n;
	item->type=cJSON_Number;
	return num;
}

static int pow2gt (int x)	{	--x;	x|=x>>1;	x|=x>>2;	x|=x>>4;	x|=x>>8;	x|=x>>16;	return x+1;	}

typedef struct {char *buffer; int length; int offset; } printbuffer;

static char* ensure(printbuffer *p,int needed)
{
	char *newbuffer;int newsize;
	if (!p || !p->buffer) return 0;
	needed+=p->offset;
	if (needed<=p->length) return p->buffer+p->offset;

	newsize=pow2gt(needed);
	newbuffer=(char*)cJSON_malloc(newsize);
	if (!newbuffer) {cJSON_free(p->buffer);p->length=0,p->buffer=0;return 0;}
	if (newbuffer) memcpy(newbuffer,p->buffer,p->length);
	cJSON_free(p->buffer);
	p->length=newsize;
	p->buffer=newbuffer;
	return newbuffer+p->offset;
}

static int update(printbuffer *p)
{
	char *str;
	if (!p || !p->buffer) return 0;
	str=p->buffer+p->offset;
	return p->offset+strlen(str);
}


static char *print_number(cJSON *item,printbuffer *p)
{
	char *str=0;
	double d=item->valuedouble;
	if (d==0)
	{
		if (p)	str=ensure(p,2);
		else	str=(char*)cJSON_malloc(2);	
		if (str) strcpy(str,"0");
	}
	else if (fabs(((double)item->valueint)-d)<=DBL_EPSILON && d<=INT_MAX && d>=INT_MIN)
	{
		if (p)	str=ensure(p,21);
		else	str=(char*)cJSON_malloc(21);	
		if (str)	sprintf(str,"%d",item->valueint);
	}
	else
	{
		if (p)	str=ensure(p,64);
		else	str=(char*)cJSON_malloc(64);	
		if (str)
		{
			if (fabs(floor(d)-d)<=DBL_EPSILON && fabs(d)<1.0e60)sprintf(str,"%.0f",d);
			else if (fabs(d)<1.0e-6 || fabs(d)>1.0e9)			sprintf(str,"%e",d);
			else												sprintf(str,"%f",d);
		}
	}
	return str;
}

static unsigned parse_hex4(const char *str)
{
	unsigned h=0;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	h=h<<4;str++;
	if (*str>='0' && *str<='9') h+=(*str)-'0'; else if (*str>='A' && *str<='F') h+=10+(*str)-'A'; else if (*str>='a' && *str<='f') h+=10+(*str)-'a'; else return 0;
	return h;
}


static const unsigned char firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
static const char *parse_string(cJSON *item,const char *str)
{
	const char *ptr=str+1;char *ptr2;char *out;int len=0;unsigned uc,uc2;
	if (*str!='"') {ep=str;return 0;}	
	
	while (*ptr!='"' && *ptr && ++len) if (*ptr++ == '\') ptr++;	
	
	out=(char*)cJSON_malloc(len+1);	
	if (!out) return 0;
	
	ptr=str+1;ptr2=out;
	while (*ptr!='"' && *ptr)
	{
		if (*ptr!='\') *ptr2++=*ptr++;
		else
		{
			ptr++;
			switch (*ptr)
			{
				case 'b': *ptr2++='b';	break;
				case 'f': *ptr2++='f';	break;
				case 'n': *ptr2++='n';	break;
				case 'r': *ptr2++='r';	break;
				case 't': *ptr2++='t';	break;
				case 'u':	 
					uc=parse_hex4(ptr+1);ptr+=4;	

					if ((uc>=0xDC00 && uc<=0xDFFF) || uc==0)	break;	

					if (uc>=0xD800 && uc<=0xDBFF)	
					{
						if (ptr[1]!='\' || ptr[2]!='u')	break;	
						uc2=parse_hex4(ptr+3);ptr+=6;
						if (uc2<0xDC00 || uc2>0xDFFF)		break;	
						uc=0x10000 + (((uc&0x3FF)<<10) | (uc2&0x3FF));
					}

					len=4;if (uc<0x80) len=1;else if (uc<0x800) len=2;else if (uc<0x10000) len=3; ptr2+=len;
					
					switch (len) {
						case 4: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 3: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 2: *--ptr2 =((uc | 0x80) & 0xBF); uc >>= 6;
						case 1: *--ptr2 =(uc | firstByteMark[len]);
					}
					ptr2+=len;
					break;
				default:  *ptr2++=*ptr; break;
			}
			ptr++;
		}
	}
	*ptr2=0;
	if (*ptr=='"') ptr++;
	item->valuestring=out;
	item->type=cJSON_String;
	return ptr;
}


static char *print_string_ptr(const char *str,printbuffer *p)
{
	const char *ptr;char *ptr2,*out;int len=0,flag=0;unsigned char token;
	
	for (ptr=str;*ptr;ptr++) flag|=((*ptr>0 && *ptr<32)||(*ptr=='"')||(*ptr=='\'))?1:0;
	if (!flag)
	{
		len=ptr-str;
		if (p) out=ensure(p,len+3);
		else		out=(char*)cJSON_malloc(len+3);
		if (!out) return 0;
		ptr2=out;*ptr2++='"';
		strcpy(ptr2,str);
		ptr2[len]='"';
		ptr2[len+1]=0;
		return out;
	}
	
	if (!str)
	{
		if (p)	out=ensure(p,3);
		else	out=(char*)cJSON_malloc(3);
		if (!out) return 0;
		strcpy(out,"""");
		return out;
	}
	ptr=str;while ((token=*ptr) && ++len) {if (strchr(""\bfnrt",token)) len++; else if (token<32) len+=5;ptr++;}
	
	if (p)	out=ensure(p,len+3);
	else	out=(char*)cJSON_malloc(len+3);
	if (!out) return 0;

	ptr2=out;ptr=str;
	*ptr2++='"';
	while (*ptr)
	{
		if ((unsigned char)*ptr>31 && *ptr!='"' && *ptr!='\') *ptr2++=*ptr++;
		else
		{
			*ptr2++='\';
			switch (token=*ptr++)
			{
				case '\':	*ptr2++='\';	break;
				case '"':	*ptr2++='"';	break;
				case 'b':	*ptr2++='b';	break;
				case 'f':	*ptr2++='f';	break;
				case 'n':	*ptr2++='n';	break;
				case 'r':	*ptr2++='r';	break;
				case 't':	*ptr2++='t';	break;
				default: sprintf(ptr2,"u%04x",token);ptr2+=5;	break;	
			}
		}
	}
	*ptr2++='"';*ptr2++=0;
	return out;
}

static char *print_string(cJSON *item,printbuffer *p)	{return print_string_ptr(item->valuestring,p);}


static const char *parse_value(cJSON *item,const char *value);
static char *print_value(cJSON *item,int depth,int fmt,printbuffer *p);
static const char *parse_array(cJSON *item,const char *value);
static char *print_array(cJSON *item,int depth,int fmt,printbuffer *p);
static const char *parse_object(cJSON *item,const char *value);
static char *print_object(cJSON *item,int depth,int fmt,printbuffer *p);


static const char *skip(const char *in) {while (in && *in && (unsigned char)*in<=32) in++; return in;}


cJSON *cJSON_ParseWithOpts(const char *value,const char **return_parse_end,int require_null_terminated)
{
	const char *end=0;
	cJSON *c=cJSON_New_Item();
	ep=0;
	if (!c) return 0;       

	end=parse_value(c,skip(value));
	if (!end)	{cJSON_Delete(c);return 0;}	

	
	if (require_null_terminated) {end=skip(end);if (*end) {cJSON_Delete(c);ep=end;return 0;}}
	if (return_parse_end) *return_parse_end=end;
	return c;
}

cJSON *cJSON_Parse(const char *value) {return cJSON_ParseWithOpts(value,0,0);}


char *cJSON_Print(cJSON *item)				{return print_value(item,0,1,0);}
char *cJSON_PrintUnformatted(cJSON *item)	{return print_value(item,0,0,0);}

char *cJSON_PrintBuffered(cJSON *item,int prebuffer,int fmt)
{
	printbuffer p;
	p.buffer=(char*)cJSON_malloc(prebuffer);
	p.length=prebuffer;
	p.offset=0;
	return print_value(item,0,fmt,&p);
	return p.buffer;
}



static const char *parse_value(cJSON *item,const char *value)
{
	if (!value)						return 0;	
	if (!strncmp(value,"null",4))	{ item->type=cJSON_NULL;  return value+4; }
	if (!strncmp(value,"false",5))	{ item->type=cJSON_False; return value+5; }
	if (!strncmp(value,"true",4))	{ item->type=cJSON_True; item->valueint=1;	return value+4; }
	if (*value=='"')				{ return parse_string(item,value); }
	if (*value=='-' || (*value>='0' && *value<='9'))	{ return parse_number(item,value); }
	if (*value=='[')				{ return parse_array(item,value); }
	if (*value=='{')				{ return parse_object(item,value); }

	ep=value;return 0;	
}


static char *print_value(cJSON *item,int depth,int fmt,printbuffer *p)
{
	char *out=0;
	if (!item) return 0;
	if (p)
	{
		switch ((item->type)&255)
		{
			case cJSON_NULL:	{out=ensure(p,5);	if (out) strcpy(out,"null");	break;}
			case cJSON_False:	{out=ensure(p,6);	if (out) strcpy(out,"false");	break;}
			case cJSON_True:	{out=ensure(p,5);	if (out) strcpy(out,"true");	break;}
			case cJSON_Number:	out=print_number(item,p);break;
			case cJSON_String:	out=print_string(item,p);break;
			case cJSON_Array:	out=print_array(item,depth,fmt,p);break;
			case cJSON_Object:	out=print_object(item,depth,fmt,p);break;
		}
	}
	else
	{
		switch ((item->type)&255)
		{
			case cJSON_NULL:	out=cJSON_strdup("null");	break;
			case cJSON_False:	out=cJSON_strdup("false");break;
			case cJSON_True:	out=cJSON_strdup("true"); break;
			case cJSON_Number:	out=print_number(item,0);break;
			case cJSON_String:	out=print_string(item,0);break;
			case cJSON_Array:	out=print_array(item,depth,fmt,0);break;
			case cJSON_Object:	out=print_object(item,depth,fmt,0);break;
		}
	}
	return out;
}


static const char *parse_array(cJSON *item,const char *value)
{
	cJSON *child;
	if (*value!='[')	{ep=value;return 0;}	

	item->type=cJSON_Array;
	value=skip(value+1);
	if (*value==']') return value+1;	

	item->child=child=cJSON_New_Item();
	if (!item->child) return 0;		 
	value=skip(parse_value(child,skip(value)));	
	if (!value) return 0;

	while (*value==',')
	{
		cJSON *new_item;
		if (!(new_item=cJSON_New_Item())) return 0; 	
		child->next=new_item;new_item->prev=child;child=new_item;
		value=skip(parse_value(child,skip(value+1)));
		if (!value) return 0;	
	}

	if (*value==']') return value+1;	
	ep=value;return 0;	
}


static char *print_array(cJSON *item,int depth,int fmt,printbuffer *p)
{
	char **entries;
	char *out=0,*ptr,*ret;int len=5;
	cJSON *child=item->child;
	int numentries=0,i=0,fail=0;
	size_t tmplen=0;
	
	
	while (child) numentries++,child=child->next;
	
	if (!numentries)
	{
		if (p)	out=ensure(p,3);
		else	out=(char*)cJSON_malloc(3);
		if (out) strcpy(out,"[]");
		return out;
	}

	if (p)
	{
		
		i=p->offset;
		ptr=ensure(p,1);if (!ptr) return 0;	*ptr='[';	p->offset++;
		child=item->child;
		while (child && !fail)
		{
			print_value(child,depth+1,fmt,p);
			p->offset=update(p);
			if (child->next) {len=fmt?2:1;ptr=ensure(p,len+1);if (!ptr) return 0;*ptr++=',';if(fmt)*ptr++=' ';*ptr=0;p->offset+=len;}
			child=child->next;
		}
		ptr=ensure(p,2);if (!ptr) return 0;	*ptr++=']';*ptr=0;
		out=(p->buffer)+i;
	}
	else
	{
		
		entries=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!entries) return 0;
		memset(entries,0,numentries*sizeof(char*));
		
		child=item->child;
		while (child && !fail)
		{
			ret=print_value(child,depth+1,fmt,0);
			entries[i++]=ret;
			if (ret) len+=strlen(ret)+2+(fmt?1:0); else fail=1;
			child=child->next;
		}
		
		
		if (!fail)	out=(char*)cJSON_malloc(len);
		
		if (!out) fail=1;

		
		if (fail)
		{
			for (i=0;itype=cJSON_Object;
	value=skip(value+1);
	if (*value=='}') return value+1;	
	
	item->child=child=cJSON_New_Item();
	if (!item->child) return 0;
	value=skip(parse_string(child,skip(value)));
	if (!value) return 0;
	child->string=child->valuestring;child->valuestring=0;
	if (*value!=':') {ep=value;return 0;}	
	value=skip(parse_value(child,skip(value+1)));	
	if (!value) return 0;
	
	while (*value==',')
	{
		cJSON *new_item;
		if (!(new_item=cJSON_New_Item()))	return 0; 
		child->next=new_item;new_item->prev=child;child=new_item;
		value=skip(parse_string(child,skip(value+1)));
		if (!value) return 0;
		child->string=child->valuestring;child->valuestring=0;
		if (*value!=':') {ep=value;return 0;}	
		value=skip(parse_value(child,skip(value+1)));	
		if (!value) return 0;
	}
	
	if (*value=='}') return value+1;	
	ep=value;return 0;	
}


static char *print_object(cJSON *item,int depth,int fmt,printbuffer *p)
{
	char **entries=0,**names=0;
	char *out=0,*ptr,*ret,*str;int len=7,i=0,j;
	cJSON *child=item->child;
	int numentries=0,fail=0;
	size_t tmplen=0;
	
	while (child) numentries++,child=child->next;
	
	if (!numentries)
	{
		if (p) out=ensure(p,fmt?depth+4:3);
		else	out=(char*)cJSON_malloc(fmt?depth+4:3);
		if (!out)	return 0;
		ptr=out;*ptr++='{';
		if (fmt) {*ptr++='n';for (i=0;ioffset;
		len=fmt?2:1;	ptr=ensure(p,len+1);	if (!ptr) return 0;
		*ptr++='{';	if (fmt) *ptr++='n';	*ptr=0;	p->offset+=len;
		child=item->child;depth++;
		while (child)
		{
			if (fmt)
			{
				ptr=ensure(p,depth);	if (!ptr) return 0;
				for (j=0;joffset+=depth;
			}
			print_string_ptr(child->string,p);
			p->offset=update(p);
			
			len=fmt?2:1;
			ptr=ensure(p,len);	if (!ptr) return 0;
			*ptr++=':';if (fmt) *ptr++='t';
			p->offset+=len;
			
			print_value(child,depth,fmt,p);
			p->offset=update(p);

			len=(fmt?1:0)+(child->next?1:0);
			ptr=ensure(p,len+1); if (!ptr) return 0;
			if (child->next) *ptr++=',';
			if (fmt) 
			*ptr++='n';
			*ptr=0;
			p->offset+=len;
			child=child->next;
		}
		ptr=ensure(p,fmt?(depth+1):2);	 if (!ptr) return 0;
		if (fmt)	for (i=0;ibuffer)+i;
	}
	else
	{
		
		entries=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!entries) return 0;
		names=(char**)cJSON_malloc(numentries*sizeof(char*));
		if (!names) {cJSON_free(entries);return 0;}
		memset(entries,0,sizeof(char*)*numentries);
		memset(names,0,sizeof(char*)*numentries);

		
		child=item->child;depth++;if (fmt) len+=depth;
		while (child)
		{
			names[i]=str=print_string_ptr(child->string,0);
			entries[i++]=ret=print_value(child,depth,fmt,0);
			if (str && ret) len+=strlen(ret)+strlen(str)+2+(fmt?2+depth:0); else fail=1;
			child=child->next;
		}
		
		
		if (!fail)	out=(char*)cJSON_malloc(len);
		if (!out) fail=1;

		
		if (fail)
		{
			for (i=0;ichild;int i=0;while(c)i++,c=c->next;return i;}
cJSON *cJSON_GetArrayItem(cJSON *array,int item)				{cJSON *c=array->child;  while (c && item>0) item--,c=c->next; return c;}
cJSON *cJSON_GetObjectItem(cJSON *object,const char *string)	{cJSON *c=object->child; while (c && cJSON_strcasecmp(c->string,string)) c=c->next; return c;}


static void suffix_object(cJSON *prev,cJSON *item) {prev->next=item;item->prev=prev;}

static cJSON *create_reference(cJSON *item) {cJSON *ref=cJSON_New_Item();if (!ref) return 0;memcpy(ref,item,sizeof(cJSON));ref->string=0;ref->type|=cJSON_IsReference;ref->next=ref->prev=0;return ref;}


void   cJSON_AddItemToArray(cJSON *array, cJSON *item)						{cJSON *c=array->child;if (!item) return; if (!c) {array->child=item;} else {while (c && c->next) c=c->next; suffix_object(c,item);}}
void   cJSON_AddItemToObject(cJSON *object,const char *string,cJSON *item)	{if (!item) return; if (item->string) cJSON_free(item->string);item->string=cJSON_strdup(string);cJSON_AddItemToArray(object,item);}
void   cJSON_AddItemToObjectCS(cJSON *object,const char *string,cJSON *item)	{if (!item) return; if (!(item->type&cJSON_StringIsConst) && item->string) cJSON_free(item->string);item->string=(char*)string;item->type|=cJSON_StringIsConst;cJSON_AddItemToArray(object,item);}
void	cJSON_AddItemReferenceToArray(cJSON *array, cJSON *item)						{cJSON_AddItemToArray(array,create_reference(item));}
void	cJSON_AddItemReferenceToObject(cJSON *object,const char *string,cJSON *item)	{cJSON_AddItemToObject(object,string,create_reference(item));}

cJSON *cJSON_DetachItemFromArray(cJSON *array,int which)			{cJSON *c=array->child;while (c && which>0) c=c->next,which--;if (!c) return 0;
	if (c->prev) c->prev->next=c->next;
	if (c->next) c->next->prev=c->prev;
	if (c==array->child) array->child=c->next;
	c->prev=c->next=0;
	return c;}
void   cJSON_DeleteItemFromArray(cJSON *array,int which)			{cJSON_Delete(cJSON_DetachItemFromArray(array,which));}
cJSON *cJSON_DetachItemFromObject(cJSON *object,const char *string) {int i=0;cJSON *c=object->child;while (c && cJSON_strcasecmp(c->string,string)) i++,c=c->next;if (c) return cJSON_DetachItemFromArray(object,i);return 0;}
void   cJSON_DeleteItemFromObject(cJSON *object,const char *string) {cJSON_Delete(cJSON_DetachItemFromObject(object,string));}


void   cJSON_InsertItemInArray(cJSON *array,int which,cJSON *newitem)		{cJSON *c=array->child;while (c && which>0) c=c->next,which--;if (!c) {cJSON_AddItemToArray(array,newitem);return;}
	newitem->next=c;newitem->prev=c->prev;c->prev=newitem;if (c==array->child) array->child=newitem; else newitem->prev->next=newitem;}
void   cJSON_ReplaceItemInArray(cJSON *array,int which,cJSON *newitem)		{cJSON *c=array->child;while (c && which>0) c=c->next,which--;if (!c) return;
	newitem->next=c->next;newitem->prev=c->prev;if (newitem->next) newitem->next->prev=newitem;
	if (c==array->child) array->child=newitem; else newitem->prev->next=newitem;c->next=c->prev=0;cJSON_Delete(c);}
void   cJSON_ReplaceItemInObject(cJSON *object,const char *string,cJSON *newitem){int i=0;cJSON *c=object->child;while(c && cJSON_strcasecmp(c->string,string))i++,c=c->next;if(c){newitem->string=cJSON_strdup(string);cJSON_ReplaceItemInArray(object,i,newitem);}}


cJSON *cJSON_CreateNull(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_NULL;return item;}
cJSON *cJSON_CreateTrue(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_True;return item;}
cJSON *cJSON_CreateFalse(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_False;return item;}
cJSON *cJSON_CreateBool(int b)					{cJSON *item=cJSON_New_Item();if(item)item->type=b?cJSON_True:cJSON_False;return item;}
cJSON *cJSON_CreateNumber(double num)			{cJSON *item=cJSON_New_Item();if(item){item->type=cJSON_Number;item->valuedouble=num;item->valueint=(int)num;}return item;}
cJSON *cJSON_CreateString(const char *string)	{cJSON *item=cJSON_New_Item();if(item){item->type=cJSON_String;item->valuestring=cJSON_strdup(string);}return item;}
cJSON *cJSON_CreateArray(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_Array;return item;}
cJSON *cJSON_CreateObject(void)					{cJSON *item=cJSON_New_Item();if(item)item->type=cJSON_Object;return item;}


cJSON *cJSON_CreateIntArray(const int *numbers,int count)		{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && ichild=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateFloatArray(const float *numbers,int count)	{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && ichild=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateDoubleArray(const double *numbers,int count)	{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && ichild=n;else suffix_object(p,n);p=n;}return a;}
cJSON *cJSON_CreateStringArray(const char **strings,int count)	{int i;cJSON *n=0,*p=0,*a=cJSON_CreateArray();for(i=0;a && ichild=n;else suffix_object(p,n);p=n;}return a;}


cJSON *cJSON_Duplicate(cJSON *item,int recurse)
{
	cJSON *newitem,*cptr,*nptr=0,*newchild;
	
	if (!item) return 0;
	
	newitem=cJSON_New_Item();
	if (!newitem) return 0;
	
	newitem->type=item->type&(~cJSON_IsReference),newitem->valueint=item->valueint,newitem->valuedouble=item->valuedouble;
	if (item->valuestring)	{newitem->valuestring=cJSON_strdup(item->valuestring);	if (!newitem->valuestring)	{cJSON_Delete(newitem);return 0;}}
	if (item->string)		{newitem->string=cJSON_strdup(item->string);			if (!newitem->string)		{cJSON_Delete(newitem);return 0;}}
	
	if (!recurse) return newitem;
	
	cptr=item->child;
	while (cptr)
	{
		newchild=cJSON_Duplicate(cptr,1);		
		if (!newchild) {cJSON_Delete(newitem);return 0;}
		if (nptr)	{nptr->next=newchild,newchild->prev=nptr;nptr=newchild;}	
		else		{newitem->child=newchild;nptr=newchild;}					
		cptr=cptr->next;
	}
	return newitem;
}

void cJSON_Minify(char *json)
{
	char *into=json;
	while (*json)
	{
		if (*json==' ') json++;
		else if (*json=='t') json++;	
		else if (*json=='r') json++;
		else if (*json=='n') json++;
		else if (*json=='/' && json[1]=='/')  while (*json && *json!='n') json++;	
		else if (*json=='/' && json[1]=='*') {while (*json && !(*json=='*' && json[1]=='/')) json++;json+=2;}	
		else if (*json=='"'){*into++=*json++;while (*json && *json!='"'){if (*json=='\') *into++=*json++;*into++=*json++;}*into++=*json++;} 
		else *into++=*json++;			
	}
	*into=0;	
}

二, 静态库Android.mk编写

Android源码参考模板： system/core/healthd/Android.mk

mytest/lib_test/libcjson/Android.mk
 

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)

LOCAL_SRC_FILES:= 
    cJSON.c 

LOCAL_MODULE:= libmycjson
LOCAL_MULTILIB := 64

include $(BUILD_STATIC_LIBRARY)

三， 编译静态库

source build/env_setup.sh

lunch  aosp_x86_64-eng

mmm  mytest/lib_test/libcjson/

生成的目标文件有如下：

中间文件：

out/target/product/产品名/obj/STATIC_LIBRARIES/libmycjson_intermediates

目标文件： 

out/target/product/产品名/obj/STATIC_LIBRARIES/libmycjson_intermediates/ libmycjson.a

四，主程序使用链接库代码

新建文件mytest/lib_test/main/main.c

#include 
#include "cJSON.h"
#include "my_math.h"

int main(int argc, char *argv[])
{
	
	printf("a + b = %dn", my_add(30, 40));
	
	cJSON* root = cJSON_CreateObject();
    cJSON_AddItemToObject(root,"id	",cJSON_CreateNumber(102));
	
	cJSON* message = cJSON_CreateObject();
    cJSON_AddItemToObject(message,"score",cJSON_CreateNumber(90));
    cJSON_AddItemToObject(message,"name",cJSON_CreateString("peter"));
    cJSON_AddItemToObject(root,"message",message);
		
	char *msg = cJSON_PrintUnformatted(root);
    
	printf("msg = %sn", msg);
	
	cJSON_Delete(root);	
	
	return 0;

}

 mytest/lib_test/main/Android.mk编写如下：

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_SRC_FILES:= 
		main.c

LOCAL_C_INCLUDES += 
		$(LOCAL_PATH)/../libcjson 
		$(LOCAL_PATH)/../libmath


LOCAL_SHARED_LIBRARIES += 
	libmymath 

LOCAL_STATIC_LIBRARIES += 
	libmycjson 


LOCAL_CFLAGS += 
		-Wno-error 
		-Wno-unused-parameter

LOCAL_MODULE:= cjson_test

LOCAL_MODULE_TAGS := optional


LOCAL_MULTILIB := 64


include $(BUILD_EXECUTABLE)

主程序编译：

source build/env_setup.sh

lunch  aosp_x86_64-eng

mmm  mytest/lib_test/main

生成的目标文件有如下：

中间文件： out/target/product/产品名/obj/EXECUTABLES/math_main_test_intermediates/

目标文件：out/target/product/产品名/system/bin/math_main_test

此处产品名并没有特别说明是哪一个， 大家未来开发的时候， 产品可以选择不同， 这个产品名就根据自己实际的来定。

五，运行

启动emulator时需要加参数： -writable-system， 如：

emulator -no-snapshot -verbose -show-kernel -writable-system -cores 4

这样才能使用adb remount, 将system或者vendor重新挂载成可读写分区 ，　执行如下命令实现运行：

cd  out/target/product/产品名/

adb  remount 

adb push  system/bin/math_main_test  /system/bin/

adb shell

math_main_test   #执行主程序

 总结

对于程序运行，不一定是要放到虚机的/system/bin目录， 可以放在其他路径， 如/data/目录， 只要权限和分区读写属性允许即可。