[sanitizer] Downgrade TestPTrace() Reports to VReport

[thurstond]

Requested in #152072 (comment)

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Thurston Dang (thurstond)

Changes

Requested in #152072 (comment)

---

Full diff: https://github.com/llvm/llvm-project/pull/152350.diff

1 Files Affected:

• (modified) compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp (+7-6)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
index 5fde65ea48c42..2bf547f4a7216 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
@@ -413,11 +413,12 @@ static void TestPTrace() {
   // internal_fork() on SPARC actually calls __fork(). We can't safely fork,
   // because it's possible seccomp has been configured to disallow fork() but
   // allow clone().
-  Report("WARNING: skipping TestPTrace() because this is SPARC\n");
-  Report(
-      "If seccomp blocks ptrace, LeakSanitizer may hang without further "
-      "notice\n");
-  Report(
+  VReport(1, "WARNING: skipping TestPTrace() because this is SPARC\n");
+  VReport(1,
+          "If seccomp blocks ptrace, LeakSanitizer may hang without further "
+          "notice\n");
+  VReport(
+      1,
       "If seccomp does not block ptrace, you can safely ignore this warning\n");
 #  else
   // Heuristic: only check the first time this is called. This is not always
@@ -438,7 +439,7 @@ static void TestPTrace() {
   if (pid < 0) {
     int rverrno;
     if (internal_iserror(pid, &rverrno))
-      Report("WARNING: TestPTrace() failed to fork (errno %d)\n", rverrno);
+      VReport(0, "WARNING: TestPTrace() failed to fork (errno %d)\n", rverrno);
 
     // We don't abort the sanitizer - it's still worth letting the sanitizer
     // try.

[fmayer]

should we only run this function if verbose logging is on?

[thurstond]

The non-SPARC case has logging for verbosity >= 0. It would be ugly to add an extra check for verbosity only for SPARC.

[thurstond]

Usually, this function is only called once (for leak detection at the end of the program execution); it's rare for users to manually trigger leak detection. In any case, the overhead of calling this function is low compared to the rest of leak detection.