[Statistic] Refactor to make getInstructionsExecuted publically available

Author: ahoppen

include/swift/Basic/Statistic.h

@@ -70,6 +70,10 @@ class Stmt;
 class TypeRepr;
 struct FingerprintAndMembers;
 
+/// Get the number of instructions executed since this process was launched.
+/// Returns 0 if the number of instructions executed could not be determined.
+uint64_t getInstructionsExecuted();
+
 // There are a handful of cases where the swift compiler can introduce
 // counter-measurement noise via nondeterminism, especially via
 // parallelism; inhibiting all such cases reliably using existing avenues

lib/Basic/Statistic.cpp

@@ -10,19 +10,17 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/AST/Decl.h"
+#include "swift/Basic/Statistic.h"
+#include "swift/Config.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
-#include "swift/Basic/Statistic.h"
-#include "swift/AST/Decl.h"
-#include "swift/AST/Expr.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include "llvm/Support/raw_ostream.h"
 #include <chrono>
 #include <limits>
 
@@ -59,6 +57,16 @@ bool environmentVariableRequestedMaximumDeterminism() {
   return false;
 }
 
+uint64_t getInstructionsExecuted() {
+#if defined(HAVE_PROC_PID_RUSAGE) && defined(RUSAGE_INFO_V4)
+  struct rusage_info_v4 ru;
+  if (proc_pid_rusage(getpid(), RUSAGE_INFO_V4, (rusage_info_t *)&ru) == 0) {
+    return ru.ri_instructions;
+  }
+#endif
+  return 0;
+}
+
 static std::string
 makeFileName(StringRef Prefix,
              StringRef ProgramName,
@@ -510,12 +518,9 @@ FrontendStatsTracer::~FrontendStatsTracer()
 // associated fields in the provided AlwaysOnFrontendCounters.
 void updateProcessWideFrontendCounters(
     UnifiedStatsReporter::AlwaysOnFrontendCounters &C) {
-#if defined(HAVE_PROC_PID_RUSAGE) && defined(RUSAGE_INFO_V4)
-  struct rusage_info_v4 ru;
-  if (0 == proc_pid_rusage(getpid(), RUSAGE_INFO_V4, (rusage_info_t *)&ru)) {
-    C.NumInstructionsExecuted = ru.ri_instructions;
+  if (auto instrExecuted = getInstructionsExecuted()) {
+    C.NumInstructionsExecuted = instrExecuted;
   }
-#endif
 
 #if defined(HAVE_MALLOC_ZONE_STATISTICS) && defined(HAVE_MALLOC_MALLOC_H)
   // On Darwin we have a lifetime max that's maintained by malloc we can