[TSAN] Fix test java_race_pc for MIPS

[slthakur]

Summary

For mips we reduce pc by 8 in function StackTrace::GetPreviousInstructionPc. Therefore we need to increase pc by 8 here to get the correct address in the stacktrace.

[dvyukov]

This is not specific to this particular test. Please add kPCInc constant to test.h file and use the const here.

[slthakur]

Addressed review comment.

[dvyukov]

I see that StackTrace::GetPreviousInstructionPc special cases not just mips. Please duplicate what StackTrace::GetPreviousInstructionPc does, and comment that it must be in sync with StackTrace::GetPreviousInstructionPc. Also we never increase indentation level after #if (at least not in this file), so start "const int kPCInc" from the first column.

Here is what StackTrace::GetPreviousInstructionPc does:

#if defined(powerpc) || defined(powerpc64)

// PCs are always 4 byte aligned.
return pc - 4;

#elif defined(sparc) || defined(mips)

return pc - 8;

#else

return pc - 1;

#endif

[slthakur]

Fixed indentation and duplicated code of StackTrace::GetPreviousInstructionPc in test.h

[dvyukov]

LGTM
Thanks!

[slthakur]

Committed in revision 262483.

test/tsan/java_race_pc.cc

 // RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
 // This test fails on powerpc64 on both VMA (44 and 46).
 // The Tsan report is returning wrong information about
 // the location of the race.
 // XFAIL: powerpc64
 #include "java.h"
 
 void foobar() {
 }
 
 void barbaz() {
 }
 
 void *Thread(void *p) {
   barrier_wait(&barrier);
-  __tsan_read1_pc((jptr)p, (jptr)foobar + 1);
+  __tsan_read1_pc((jptr)p, (jptr)foobar + kPCInc);
   return 0;
 }
 
 int main() {
   barrier_init(&barrier, 2);
   int const kHeapSize = 1024 * 1024;
   jptr jheap = (jptr)malloc(kHeapSize + 8) + 8;
   __tsan_java_init(jheap, kHeapSize);
   const int kBlockSize = 16;
   __tsan_java_alloc(jheap, kBlockSize);
   pthread_t th;
   pthread_create(&th, 0, Thread, (void*)jheap);
-  __tsan_write1_pc((jptr)jheap, (jptr)barbaz + 1);
+  __tsan_write1_pc((jptr)jheap, (jptr)barbaz + kPCInc);
   barrier_wait(&barrier);
   pthread_join(th, 0);
   __tsan_java_free(jheap, kBlockSize);
   fprintf(stderr, "DONE\n");
   return __tsan_java_fini();
 }
 
 // CHECK: WARNING: ThreadSanitizer: data race
 // CHECK:     #0 foobar
 // CHECK:     #0 barbaz
 // CHECK: DONE

test/tsan/test.h

 }
 #else
 unsigned long long monotonic_clock_ns() {
   struct timespec t;
   clock_gettime(CLOCK_MONOTONIC, &t);
   return (unsigned long long)t.tv_sec * 1000000000ull + t.tv_nsec;
 }
 #endif
+
+//The const kPCInc must be in sync with StackTrace::GetPreviousInstructionPc
+#if defined(__powerpc64__)
+// PCs are always 4 byte aligned.
+const int kPCInc = 4;
+#elif defined(__sparc__) || defined(__mips__)
+const int kPCInc = 8;
+#else
+const int kPCInc = 1;
+#endif