Build error: "storing the address of local variable" in runtime/rastrace/trcmain.c

[knn-k]

Building OpenJ9 Java 17 with GCC 13.2.0 on Ubuntu 24.04.1 generates the following error:

/home/openj9/openj9-openjdk-jdk17/openj9/runtime/rastrace/trcmain.c:1045:14: error: storing the address of local variable 'tempThr' in '*thr' [-Werror=dangling-pointer=]
 1045 |         *thr = &tempThr;
      |         ~~~~~^~~~~~~~~~
/home/openj9/openj9-openjdk-jdk17/openj9/runtime/rastrace/trcmain.c:1033:23: note: 'tempThr' declared here
 1033 |         UtThreadData  tempThr;
      |                       ^~~~~~~
/home/openj9/openj9-openjdk-jdk17/openj9/runtime/rastrace/trcmain.c:1026:32: note: 'thr' declared here
 1026 | initializeTrace(UtThreadData **thr, void **gbl,
      |                 ~~~~~~~~~~~~~~~^~~

openj9/runtime/rastrace/trcmain.c

Line 1045 in 0985ff3

*thr = &tempThr;

tempThr is a local variable in initializeTrace(). thr is the first argument for initializeTrace(). The address of tempThr is used by J9VMDllMain() in trcengine.c, the caller of initializeTrace().

openj9/runtime/rastrace/trcengine.c

Line 363 in 0985ff3

rc = initializeTrace(tempThr, tempGbl, (const char **)opts, vm->omrVM, (const char **)ignore, &languageIntf);

The memory region for tempThr in the stack can be overwritten by other functions.
I think J9VMDllMain() should prepare the memory region for UtThreadData, as J9VMDllMain() seems to be the only caller of initializeTrace().

[knn-k]

Another build error with GCC 13.2.0: #20170

[knn-k]

I opened a draft PR: #20172