在编译“ C”语言文件时收到此警告。
In function ‘strncat’,inlined from ‘O281DC3F563F92003x’ at util.c:817:13:
/usr/arm-linux-gnueabihf/include/bits/string3.h:152:3: warning: call to
__builtin___strncat_chk might overflow destination buffer [enabled by
default]
In function ‘strncat’,inlined from ‘UFE191C0002FB606Eb’ at util.c:3231:25:
/usr/arm-linux-gnueabihf/include/bits/string3.h:152:3: warning: call to
__builtin___strncat_chk might overflow destination buffer [enabled by
default]
In function ‘strncat’,
如何删除这些警告？
答案 0 :(得分：0)
如this answer中所述，您可以轻松地将googlelogin() {
var user = firebase.auth().currentUser;
var name, email, photoUrl, uid, emailVerified;
alert('hello');
return this.afAuth.auth.signInWithRedirect(new firebase.auth.GoogleAuthProvider()).then( newUser => {
if (newUser != null) {
name = newUser.displayName;
email = newUser.email;
photoUrl = newUser.photoURL;
emailVerified = newUser.emailVerified;
uid = newUser.uid;
console.log(email);
}
}).catch( err => {
console.log("Error signing in with Google!");
console.log(err);
});
}
的用法替换为strncat，这样可以将缓冲区的位置作为参数并使其可以安全使用。
snprintf示例：
strncat更安全的#define BUF_SIZE 32
char buf[BUF_SIZE];
strncpy(buf, "foo", sizeof(buf) -1);
strncat(buf, "bar", sizeof(buf) - strlen(buf) -1);
示例：
snprintf该方法的缺点是，如果您实际上想连接为：
#define BUF_SIZE 32
char buf[BUF_SIZE];
snprintf(buf, sizeof(buf), "%s%s", "foo", "bar");
导致未定义的行为。