Question

我知道这经常被问到，但我阅读了十几个问题但仍未找到解决方案。编译时我收到警告：

warning: assignment makes pointer from integer without a cast

此警告所指的代码为：

unsigned char *WebPrintReturnLine(BIO *bio) {

long int i;
unsigned int turn = 0;
unsigned char *ptr = 0;
int size;
unsigned char buffer[4096];

i = (long int) WebRead(bio, buffer, sizeof(buffer));
if( (ptr = (unsigned char *) malloc(strlen(buffer))) == 0 ) {
    printf("Error: Couldn't allocate memory in WebPrintReturnLine\n");
    return ptr;
}

//strlen does not care about '\0' but as array begin at 0 it nulifies
size = strlen(buffer);
//strcpy the buffer into the allocated memory
strcpy(ptr, buffer);
printf("%d\n", isend(buffer, sizeof(buffer)));

while( (i > 0) && (!isend(buffer, sizeof(buffer))) ) {
    i = (long int) WebRead(bio, buffer, sizeof(buffer));
    size += strlen(buffer);
    if( (ptr = (unsigned char*) realloc(ptr, size)) == 0 ) {
        printf("Error: Couldn't reallocate memory in WebPrintReturnLine\n");
        ptr = 0;
        return ptr; 
    }//End if
    //Strcat the original string and the buffer together
    strcat(ptr, buffer);
}//End while

//Now finally print the line
printf("%s", ptr);

return ptr;
}

这被称为：

unsigned char *ptr;    
if( (ptr = WebPrintReturnLine(bio)) == 0 )
    return -1;

我首先要在这个问题中缩短代码，但是我有可能会监督导致此警告的内容。

Answer 1

因此警告在您问题的第二个代码段中。当您调用它时，WebPrintReturnLine的声明不可见。在C90规则下，编译器假定它返回int（在这种情况下不正确）。根据C99规则，电话是非法的。您需要为声明#include的标头添加WebPrintReturnLine。 - 基思汤普森

警告 - 赋值使整数指针不带强制转换

1 个答案: