From Cppcheck:
Passing NULL after the last typed argument to a variadic function leads to
undefined behaviour. The C99 standard, in section 7.15.1.1, states that if the
type used by va_arg() is not compatible with the type of the actual next
argument (as promoted according to the default argument promotions), the
behavior is undefined. The value of the NULL macro is an implementation-defined
null pointer constant (7.17), which can be any integer constant expression with
the value 0, or such an expression casted to (void*) (6.3.2.3). This includes
values like 0, 0L, or even 0LL.In practice on common architectures, this will
cause real crashes if sizeof(int) != sizeof(void*), and NULL is defined to 0 or
any other null pointer constant that promotes to int. To reproduce you might be
able to use this little code example on 64bit platforms. If the output includes
"ERROR", the sentinel had only 4 out of 8 bytes initialized to zero and was not
detected as the final argument to stop argument processing via
va_arg(). Changing the 0 to (void*)0 or 0L will make the "ERROR" output go away.
void f(char *s, ...) {
va_list ap;
va_start(ap,s);
for (;;) {
char *p = va_arg(ap,char*);
printf("%018p, %s\n", p, (long)p & 255 ? p : "");
if(!p) break;
}
va_end(ap);
}
void g() {
char *s2 = "x";
char *s3 = "ERROR";
// changing 0 to 0L for the 7th argument (which is intended to act as
// sentinel) makes the error go away on x86_64
f("first", s2, s2, s2, s2, s2, 0, s3, (char*)0);
}
void h() {
int i;
volatile unsigned char a[1000];
for (i = 0; i<sizeof(a); i++)
a[i] = -1;
}
int main() {
h();
g();
return 0;
}
(cherry picked from commit d8879af877)
This MR changes the default Debian sid build to wrap make with bear
that creates compilation database and use the compilation database
to run Cppcheck on the source files systematically.
The job is currently set to be allowed to fail as it will take some
time to fix all the Cppcheck detected issues.
(cherry picked from commit f55dc51f42)
This MR changes the default Debian sid build to wrap make with bear
that creates compilation database and use the compilation database
to run Cppcheck on the source files systematically.
The job is currently set to be allowed to fail as it will take some
time to fix all the Cppcheck detected issues.
The libidn2 library on Ubuntu Bionic is broken and idn2_to_unicode_8zlz() does't
fail when it should. This commit ensures that we don't run the system test for
valid A-label in locale that cannot display with the buggy libidn2 as it would
break the tests.
(cherry picked from commit c42e3583f9)
It is possible dig used ACE encoded name in locale, which does not
support converting it to unicode. Instead of fatal error, fallback to
ACE name on output.
(cherry picked from commit c8a871e908)
Ondřej Surý
Mark Andrews
Ondřej Surý
Petr MenšíkandOndřej Surý