RFR: JDK-8309219: Fix xlc17 clang 15 warnings in java.base [v3]

[Martin Doerr]

On Wed, 7 Jun 2023 11:23:26 GMT, JoKern65 <duke at openjdk.org> wrote:

>> This pr is a split off from JDK-8308288: Fix xlc17 clang warnings in shared code https://github.com/openjdk/jdk/pull/14146
>> It handles the part in java.base.
>> 
>> Compiling on AIX with xlc17 which contains the new clang 15 frontend
>> shows the following warnings.
>> 
>> built by make/modules/java.base/Lib.gmk
>> 
>> src/java.base/unix/native/libnet/DefaultProxySelector.c:378:41:22: error: passing arguments to a function without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>> proxies = (*g_proxy_resolver_lookup)(resolver, uri, NULL, &error);
>> ^
>> 
>> 
>> src/java.base/unix/native/libnet/NetworkInterface.c:1612:24: error: arithmetic on a pointer to void is a GNU extension [-Werror,-Wgnu-pointer-arith]
>> end = (void *)nddp + size;
>> 
>> src/java.base/unix/native/libnio/fs/UnixNativeDispatcher.c:1251:7: error: '_ALLBSD_SOURCE' is not defined, evaluates to 0 [-Werror,-Wundef]
>> #elif _ALLBSD_SOURCE
>> The whole file checks whether _ALLBSD_SOURCE is defined, only where #elif is used the call to defined() was forgotten.
>> 
>> built by make/modules/java.base/lib/CoreLibraries.gmk
>> 
>> src/java.base/unix/native/libjava/ProcessHandleImpl_unix.c:638 comparison of integers of different signs: 'int' and 'unsigned long'
>> if (ret < sizeof(psinfo_t)) {
>> ProcessHandleImpl_unix.c:  Just using the proper type `size_t` instead of `int`.
>> 
>> 
>> src/java.base/aix/native/libjli/java_md_aix.c:42:38: error: arithmetic on a pointer to void is a GNU extension [-Werror,-Wgnu-pointer-arith]
>> addr < p->ldinfo_textorg + p->ldinfo_textsize) {
>> we can fix this with temporary casting the `void*` pointer to `char*` or by disabling the warning in CoreLibraries.gmk
>> 
>> src/java.base/share/native/libzip/zlib/inffast.c:74:20: error: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
>> void ZLIB_INTERNAL inflate_fast(strm, start)
>> ^
>> src/java.base/share/native/libjli/java.c:2311:22: error: format string is not a string literal [-Werror,-Wformat-nonliteral]
>> vfprintf(stderr, fmt, vl);
>> ^~~
>> 
>> The test library libGetXSpace.c also shows a warning.
>> In addition, the cast in that lib is wrong, we opened "[JDK-8309216](https://bugs.openjdk.org/browse/JDK-8309216) cast from jchar* to char* in test GetXSpace.java" for that.
>
> JoKern65 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update libGetXSpace.c
>   
>   cast not necessary

Marked as reviewed by mdoerr (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/14281#pullrequestreview-1467571356