[tsan]: rename RunningOnValgrind to __tsan_RunningOnValgrind

[sugak]

Summary

RunningOnValgrind is a common name, used in several projects (gperftools for instance).
Add the namespace __tsan_ prefix to avoid errors when linking with
other libraries that define a symbol with this name.

The change is mechanical, induced by the following command:

git grep -lw RunningOnValgrind | \
xargs perl -pi -e 's/\b(RunningOnValgrind)\b/__tsan_$1/g'

[kcc]

I am not sure we still need this, let Dmitry comment.
But if we do, it clearly should remain as is -- that's the whole purpose :)

[dvyukov]

We still use it and it must be named RunningOnValgrind to override definitions in projects. Other projects are meant to disable their definitions when building for tsan.

What do you use from gperftools? tcmalloc/heapchecker/heapprofiler are not compatible with sanitizers. What's left is cpuprofiler, but it does not use RunningOnValgrind as far as I see.

[sugak]

Thank you for the explanation @dvyukov! I don't remember exactly how gperftools was used in a project where I noticed the symbol name conflict. I'll try to reproduce it, and will post here for the record.
Abandoning this.

lib/tsan/rtl/tsan.syms.extra

 __tsan_init
 __tsan_read*
 __tsan_write*
 __tsan_vptr*
 __tsan_func*
 __tsan_atomic*
 __tsan_java*
 __tsan_unaligned*
 __tsan_release
 __tsan_acquire
+__tsan_RunningOnValgrind
 __ubsan_*
 Annotate*
 WTFAnnotate*
-RunningOnValgrind
 ValgrindSlowdown

lib/tsan/rtl/tsan_flags.inc

 TSAN_FLAG(int, flush_symbolizer_ms, 5000, "Flush symbolizer caches every X ms.")
 TSAN_FLAG(
     int, memory_limit_mb, 0,
     "Resident memory limit in MB to aim at."
     "If the process consumes more memory, then TSan will flush shadow memory.")
 TSAN_FLAG(bool, stop_on_start, false,
           "Stops on start until __tsan_resume() is called (for debugging).")
 TSAN_FLAG(bool, running_on_valgrind, false,
-          "Controls whether RunningOnValgrind() returns true or false.")
+          "Controls whether __tsan_RunningOnValgrind() returns true or false.")
 TSAN_FLAG(
     int, history_size, kGoMode ? 1 : 3, // There are a lot of goroutines in Go.
     "Per-thread history size, controls how many previous memory accesses "
     "are remembered per thread.  Possible values are [0..7]. "
     "history_size=0 amounts to 32K memory accesses.  Each next value doubles "
     "the amount of memory accesses, up to history_size=7 that amounts to "
     "4M memory accesses.  The default value is 2 (128K memory accesses).")
 TSAN_FLAG(int, io_sync, 1,

lib/tsan/rtl/tsan_interface_ann.cc

 }
 
 void INTERFACE_ATTRIBUTE WTFAnnotateBenignRaceSized(
     char *f, int l, uptr mem, uptr sz, char *desc) {
   SCOPED_ANNOTATION(AnnotateBenignRaceSized);
   BenignRaceImpl(f, l, mem, sz, desc);
 }
 
-int INTERFACE_ATTRIBUTE RunningOnValgrind() {
+int INTERFACE_ATTRIBUTE __tsan_RunningOnValgrind() {
   return flags()->running_on_valgrind;
 }
 
 double __attribute__((weak)) INTERFACE_ATTRIBUTE ValgrindSlowdown(void) {
   return 10.0;
 }
 
 const char INTERFACE_ATTRIBUTE* ThreadSanitizerQuery(const char *query) {