[llvm] af2e549 - [Timer][Statistics] Make global constructor ordering more robust

[Nicolai Hähnle via llvm-commits]

Author: Nicolai Hähnle
Date: 2022-08-25T19:09:49+02:00
New Revision: af2e54992de969f3ec75e397f1840068c2ebd060

URL: https://github.com/llvm/llvm-project/commit/af2e54992de969f3ec75e397f1840068c2ebd060
DIFF: https://github.com/llvm/llvm-project/commit/af2e54992de969f3ec75e397f1840068c2ebd060.diff

LOG: [Timer][Statistics] Make global constructor ordering more robust

It was observed in D129117 that the subtle dependency between statistic
and timer code is not entirely robust: the global destructor
~StatisticInfo indirectly calls CreateInfoOutputFile, which requires
the LibSupportInfoOutputFilename to not have been destructed.

By constructing LibSupportInfoOutputFilename before the StatisticInfo
object, the order of destruction is guaranteed.

Differential Revision: https://reviews.llvm.org/D131059

Added: 
    

Modified: 
    llvm/include/llvm/Support/Timer.h
    llvm/lib/Support/Statistic.cpp
    llvm/lib/Support/Timer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Support/Timer.h b/llvm/include/llvm/Support/Timer.h
index 742d20ce51dd..d72af3541af0 100644
--- a/llvm/include/llvm/Support/Timer.h
+++ b/llvm/include/llvm/Support/Timer.h
@@ -231,10 +231,10 @@ class TimerGroup {
   /// Prints all timers as JSON key/value pairs.
   static const char *printAllJSONValues(raw_ostream &OS, const char *delim);
 
-  /// Ensure global timer group lists are initialized. This function is mostly
-  /// used by the Statistic code to influence the construction and destruction
-  /// order of the global timer lists.
-  static void ConstructTimerLists();
+  /// Ensure global objects required for statistics printing are initialized.
+  /// This function is used by the Statistic code to ensure correct order of
+  /// global constructors and destructors.
+  static void constructForStatistics();
 
   /// This makes the default group unmanaged, and lets the user manage the
   /// group's lifetime.

diff  --git a/llvm/lib/Support/Statistic.cpp b/llvm/lib/Support/Statistic.cpp
index df9f7c5e0be3..24ef3e9abaeb 100644
--- a/llvm/lib/Support/Statistic.cpp
+++ b/llvm/lib/Support/Statistic.cpp
@@ -120,8 +120,9 @@ void TrackingStatistic::RegisterStatistic() {
 }
 
 StatisticInfo::StatisticInfo() {
-  // Ensure timergroup lists are created first so they are destructed after us.
-  TimerGroup::ConstructTimerLists();
+  // Ensure that necessary timer global objects are created first so they are
+  // destructed after us.
+  TimerGroup::constructForStatistics();
 }
 
 // Print information when destroyed, iff command line option is specified.

diff  --git a/llvm/lib/Support/Timer.cpp b/llvm/lib/Support/Timer.cpp
index 08e1a8a0e0aa..c1b0fdbc077b 100644
--- a/llvm/lib/Support/Timer.cpp
+++ b/llvm/lib/Support/Timer.cpp
@@ -499,7 +499,8 @@ const char *TimerGroup::printAllJSONValues(raw_ostream &OS, const char *delim) {
   return delim;
 }
 
-void TimerGroup::ConstructTimerLists() {
+void TimerGroup::constructForStatistics() {
+  (void)getLibSupportInfoOutputFilename();
   (void)*NamedGroupedTimers;
 }