Build error with GCC 10 in NetworkInterface.c and k_standard.c

[Yasumasa Suenaga]

Hi Koichi,

On 2020/07/17 20:26, Koichi Sakata wrote:
> Hi Daniel,
> 
>  > The changes to NetworkInterface.c look good to me.
> 
> Thank you.
> 
>  > You'll need to find a reviewer that understands what that
>  > method is supposed to do in that case, that's not me ;-)
> 
> I understand. This ML is suitable for finding a reviewer, isn't it?
> Or, there is another way. We can avoid the error by the accepting maybe-uninitialized warning in libfdlibm instead of fixing k_standard.c.
> 
> diff --git a/make/modules/java.base/lib/CoreLibraries.gmk b/make/modules/java.base/lib/CoreLibraries.gmk
> --- a/make/modules/java.base/lib/CoreLibraries.gmk
> +++ b/make/modules/java.base/lib/CoreLibraries.gmk
> @@ -48,7 +48,7 @@
>       CFLAGS := $(CFLAGS_JDKLIB) $(LIBFDLIBM_CFLAGS), \
>       CFLAGS_windows_debug := -DLOGGING, \
>       CFLAGS_aix := -qfloat=nomaf, \
> -    DISABLED_WARNINGS_gcc := sign-compare misleading-indentation array-bounds, \
> +    DISABLED_WARNINGS_gcc := sign-compare misleading-indentation array-bounds maybe-uninitialized, \
>       DISABLED_WARNINGS_clang := sign-compare, \
>       DISABLED_WARNINGS_microsoft := 4146 4244 4018, \
>       ARFLAGS := $(ARFLAGS), \

This change affects all of C sources in core-libs.
So I think it is better affect to k_standard.c only as below:

```
diff --git a/make/modules/java.base/lib/CoreLibraries.gmk b/make/modules/java.base/lib/CoreLibraries.gmk
--- a/make/modules/java.base/lib/CoreLibraries.gmk
+++ b/make/modules/java.base/lib/CoreLibraries.gmk
@@ -39,6 +39,10 @@
  LIBFDLIBM_SRC := $(TOPDIR)/src/java.base/share/native/libfdlibm
  LIBFDLIBM_CFLAGS := -I$(LIBFDLIBM_SRC) $(FDLIBM_CFLAGS)

+ifeq ($(call isTargetOs, linux), true)
+  BUILD_LIBFDLIBM_k_standard.c_CFLAGS += -Wno-maybe-uninitialized
+endif
+
  $(eval $(call SetupNativeCompilation, BUILD_LIBFDLIBM, \
      NAME := fdlibm, \
      TYPE := STATIC_LIBRARY, \
```

You can pass compiler option to specified file.


Thanks,

Yasumasa


> Thanks,
> Koichi
> 
> On 2020/07/15 3:36, Daniel Fuchs wrote:
>> Hi Koichi,
>>
>> On 13/07/2020 08:03, Koichi Sakata wrote:
>>  > I understand that. I respect your idea.
>>  > I fixed the patch as follows.
>> The changes to NetworkInterface.c look good to me.
>>
>>  >
>>  > By the way, k_standard.c still remains. Is there a way to proceed with it?
>>
>> You'll need to find a reviewer that understands what that
>> method is supposed to do in that case, that's not me ;-)
>>
>> best regards,
>>
>> -- daniel
>>
>>> Thanks, > Koichi
>>>
>>> ===== PATCH =====
>>> diff --git a/src/java.base/unix/native/libnet/NetworkInterface.c b/src/java.base/unix/native/libnet/NetworkInterface.c
>>> --- a/src/java.base/unix/native/libnet/NetworkInterface.c
>>> +++ b/src/java.base/unix/native/libnet/NetworkInterface.c
>>> @@ -1296,7 +1296,8 @@
>>>   static int getIndex(int sock, const char *name) {
>>>       struct ifreq if2;
>>>       memset((char *)&if2, 0, sizeof(if2));
>>> -    strncpy(if2.ifr_name, name, sizeof(if2.ifr_name) - 1);
>>> +    strncpy(if2.ifr_name, name, sizeof(if2.ifr_name));
>>> +    if2.ifr_name[sizeof(if2.ifr_name) - 1] = 0;
>>>
>>>       if (ioctl(sock, SIOCGIFINDEX, (char *)&if2) < 0) {
>>>           return -1;
>>> @@ -1359,7 +1360,8 @@
>>>   static int getFlags(int sock, const char *ifname, int *flags) {
>>>       struct ifreq if2;
>>>       memset((char *)&if2, 0, sizeof(if2));
>>> -    strncpy(if2.ifr_name, ifname, sizeof(if2.ifr_name) - 1);
>>> +    strncpy(if2.ifr_name, ifname, sizeof(if2.ifr_name));
>>> +    if2.ifr_name[sizeof(if2.ifr_name) - 1] = 0;
>>>
>>>       if (ioctl(sock, SIOCGIFFLAGS, (char *)&if2) < 0) {
>>>           return -1;
>>> diff --git a/src/java.base/share/native/libfdlibm/k_standard.c b/src/java.base/share/native/libfdlibm/k_standard.c
>>> --- a/src/java.base/share/native/libfdlibm/k_standard.c
>>> +++ b/src/java.base/share/native/libfdlibm/k_standard.c
>>> @@ -739,6 +739,10 @@
>>>                           errno = EDOM;
>>>                   }
>>>                   break;
>>> +            default:
>>> +                exc.retval = zero;
>>> +                errno = EINVAL;
>>> +                break;
>>>           }
>>>           return exc.retval;
>>>   }
>>>
>>>
>>