We (SAP) try to introduce the ‘IBM Open XL C/C++ for AIX 17.1.2’ (based on
clang 17) as a feasible compiler for jdk25, because in combination with the
17.1.3 runtime this would enable the support for ubsan.
Unfortunately, the new compiler comes along with a new set of compiler warnings
turned into errors by -Werror.
One of the warnings is -Wtentative-definitions. It is fired when a variable
definition in a header is found:
/jdk/src/java.desktop/share/native/libawt/awt/image/imageInitIDs.h:36:20:
error: possible missing 'extern' on global variable definition in header
[-Werror,-Wtentative-definitions]
36 | IMGEXTERN jfieldID g_BImgRasterID;
| ^
>From now on headers allow only extern declarations of variables. The
>definition must take place in a c/cpp file. This means e.g.
imageInitIDs.h:36:20
36 extern jfieldID g_BImgRasterID;
and the corresponding c-File
jfieldID g_BImgRasterID;
The other possible solution would be to compile everything with
-Wno-tentative-definitions
which could be set in flags-cflags.m4, if compiling with clang 17.
-------------
Commit messages:
- JDK-8348286
Changes: https://git.openjdk.org/jdk/pull/23236/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23236&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8348286
Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
Patch: https://git.openjdk.org/jdk/pull/23236.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/23236/head:pull/23236
PR: https://git.openjdk.org/jdk/pull/23236
