Encapsulate PassManager debug flags to avoid static init and cxa_exit.

This puts all the global PassManager debugging flags, like
-print-after-all and -time-passes, behind a managed static. This
eliminates their static initializers and, more importantly, exit-time
destructors.

The only behavioral change I anticipate is that tools need to
initialize the PassManager before parsing the command line in order to
export these options, which makes sense. Tools that already initialize
the standard passes (opt/llc) don't need to do anything new.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190974 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/PassManager.h

@@ -28,6 +28,11 @@ class Module;
 class PassManagerImpl;
 class FunctionPassManagerImpl;
 
+/// Called by tools to initialize globals and register options at a particular
+/// point (before command line parsing). If this is not called, then PassManager
+/// globals are lazily initialized at first use.
+void initializePassManager();
+
 /// PassManagerBase - An abstract interface to allow code to add passes to
 /// a pass manager without having to hard-code what kind of pass manager
 /// it is.

lib/IR/Core.cpp

@@ -40,6 +40,7 @@
 using namespace llvm;
 
 void llvm::initializeCore(PassRegistry &Registry) {
+  initializePassManager();
   initializeDominatorTreePass(Registry);
   initializePrintModulePassPass(Registry);
   initializePrintFunctionPassPass(Registry);

lib/IR/PassManager.cpp

@@ -45,65 +45,94 @@ enum PassDebugLevel {
   Disabled, Arguments, Structure, Executions, Details
 };
 
-static cl::opt<enum PassDebugLevel>
-PassDebugging("debug-pass", cl::Hidden,
+bool TimePassesIsEnabled = false;
+
+/// Encapsulate PassManager debug options. These are convenient options that
+/// should be available to any LLVM-based tool. They exist purely as
+/// command-line debug options, therefore don't need to be local to an LLVM
+/// context or captured by a formal API. In all respects they are handled like
+/// global variables, but being defined in the LLVMCore library cannot have
+/// static initializers and must be destroyed only at llvm_shutdown.
+struct PassDebugOpts {
+  cl::opt<enum PassDebugLevel> PassDebugging;
+
+  typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
+  PassOptionList;
+
+  // Print IR out before/after specified passes.
+  PassOptionList PrintBefore;
+
+  PassOptionList PrintAfter;
+
+  cl::opt<bool> PrintBeforeAll;
+  cl::opt<bool> PrintAfterAll;
+
+  cl::opt<bool,true> EnableTiming;
+
+  PassDebugOpts():
+    PassDebugging("debug-pass", cl::Hidden,
                   cl::desc("Print PassManager debugging information"),
                   cl::values(
-  clEnumVal(Disabled  , "disable debug output"),
-  clEnumVal(Arguments , "print pass arguments to pass to 'opt'"),
-  clEnumVal(Structure , "print pass structure before run()"),
-  clEnumVal(Executions, "print pass name before it is executed"),
-  clEnumVal(Details   , "print pass details when it is executed"),
-                             clEnumValEnd));
+                    clEnumVal(Disabled , "disable debug output"),
+                    clEnumVal(Arguments,
+                              "print pass arguments to pass to 'opt'"),
+                    clEnumVal(Structure, "print pass structure before run()"),
+                    clEnumVal(Executions,
+                              "print pass name before it is executed"),
+                    clEnumVal(Details,
+                              "print pass details when it is executed"),
+                    clEnumValEnd)),
+    PrintBefore("print-before",
+                llvm::cl::desc("Print IR before specified passes"),
+                cl::Hidden),
+    PrintAfter("print-after",
+               llvm::cl::desc("Print IR after specified passes"),
+               cl::Hidden),
+    PrintBeforeAll("print-before-all",
+                   llvm::cl::desc("Print IR before each pass"),
+                   cl::init(false)),
+    PrintAfterAll("print-after-all",
+                  llvm::cl::desc("Print IR after each pass"),
+                  cl::init(false)),
+    EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
+                 cl::desc(
+                   "Time each pass, printing elapsed time for each on exit"))
+  {}
 
-typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
-PassOptionList;
-
-// Print IR out before/after specified passes.
-static PassOptionList
-PrintBefore("print-before",
-            llvm::cl::desc("Print IR before specified passes"),
-            cl::Hidden);
-
-static PassOptionList
-PrintAfter("print-after",
-           llvm::cl::desc("Print IR after specified passes"),
-           cl::Hidden);
-
-static cl::opt<bool>
-PrintBeforeAll("print-before-all",
-               llvm::cl::desc("Print IR before each pass"),
-               cl::init(false));
-static cl::opt<bool>
-PrintAfterAll("print-after-all",
-              llvm::cl::desc("Print IR after each pass"),
-              cl::init(false));
-
-/// This is a helper to determine whether to print IR before or
-/// after a pass.
-
-static bool ShouldPrintBeforeOrAfterPass(const PassInfo *PI,
-                                         PassOptionList &PassesToPrint) {
-  for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
-    const llvm::PassInfo *PassInf = PassesToPrint[i];
-    if (PassInf)
-      if (PassInf->getPassArgument() == PI->getPassArgument()) {
-        return true;
-      }
+  /// This is a helper to determine whether to print IR before or
+  /// after a pass.
+  bool ShouldPrintBeforeOrAfterPass(const PassInfo *PI,
+                                    PassOptionList &PassesToPrint) {
+    for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
+      const llvm::PassInfo *PassInf = PassesToPrint[i];
+      if (PassInf)
+        if (PassInf->getPassArgument() == PI->getPassArgument()) {
+          return true;
+        }
+    }
+    return false;
   }
-  return false;
-}
 
-/// This is a utility to check whether a pass should have IR dumped
-/// before it.
-static bool ShouldPrintBeforePass(const PassInfo *PI) {
-  return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PI, PrintBefore);
-}
+  /// This is a utility to check whether a pass should have IR dumped
+  /// before it.
+  bool ShouldPrintBeforePass(const PassInfo *PI) {
+    return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PI, PrintBefore);
+  }
 
-/// This is a utility to check whether a pass should have IR dumped
-/// after it.
-static bool ShouldPrintAfterPass(const PassInfo *PI) {
-  return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PI, PrintAfter);
+  /// This is a utility to check whether a pass should have IR dumped
+  /// after it.
+  bool ShouldPrintAfterPass(const PassInfo *PI) {
+    return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PI, PrintAfter);
+  }
+};
+
+static ManagedStatic<PassDebugOpts> GlobalPassDebugOpts;
+
+/// This is called by tools to force registration of debugging options and
+/// ensure they appear in the tool's -help usage.
+void initializePassManager() {
+  // Force instantiation of PassDebugOpts.
+  *GlobalPassDebugOpts;
 }
 
 } // End of llvm namespace
@@ -111,12 +140,9 @@ static bool ShouldPrintAfterPass(const PassInfo *PI) {
 /// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
 /// or higher is specified.
 bool PMDataManager::isPassDebuggingExecutionsOrMore() const {
-  return PassDebugging >= Executions;
+  return GlobalPassDebugOpts->PassDebugging >= Executions;
 }
 
-
-
-
 void PassManagerPrettyStackEntry::print(raw_ostream &OS) const {
   if (V == 0 && M == 0)
     OS << "Releasing pass '";
@@ -668,7 +694,8 @@ void PMTopLevelManager::schedulePass(Pass *P) {
     return;
   }
 
-  if (PI && !PI->isAnalysis() && ShouldPrintBeforePass(PI)) {
+  if (PI && !PI->isAnalysis() &&
+      GlobalPassDebugOpts->ShouldPrintBeforePass(PI)) {
     Pass *PP = P->createPrinterPass(
       dbgs(), std::string("*** IR Dump Before ") + P->getPassName() + " ***");
     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
@@ -677,7 +704,8 @@ void PMTopLevelManager::schedulePass(Pass *P) {
   // Add the requested pass to the best available pass manager.
   P->assignPassManager(activeStack, getTopLevelPassManagerType());
 
-  if (PI && !PI->isAnalysis() && ShouldPrintAfterPass(PI)) {
+  if (PI && !PI->isAnalysis() &&
+      GlobalPassDebugOpts->ShouldPrintAfterPass(PI)) {
     Pass *PP = P->createPrinterPass(
       dbgs(), std::string("*** IR Dump After ") + P->getPassName() + " ***");
     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
@@ -729,7 +757,7 @@ Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {
 // Print passes managed by this top level manager.
 void PMTopLevelManager::dumpPasses() const {
 
-  if (PassDebugging < Structure)
+  if (GlobalPassDebugOpts->PassDebugging < Structure)
     return;
 
   // Print out the immutable passes
@@ -748,7 +776,7 @@ void PMTopLevelManager::dumpPasses() const {
 
 void PMTopLevelManager::dumpArguments() const {
 
-  if (PassDebugging < Arguments)
+  if (GlobalPassDebugOpts->PassDebugging < Arguments)
     return;
 
   dbgs() << "Pass Arguments: ";
@@ -881,7 +909,7 @@ void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
         std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
         PreservedSet.end()) {
       // Remove this analysis
-      if (PassDebugging >= Details) {
+      if (GlobalPassDebugOpts->PassDebugging >= Details) {
         Pass *S = Info->second;
         dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
         dbgs() << S->getPassName() << "'\n";
@@ -905,7 +933,7 @@ void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
           std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
              PreservedSet.end()) {
         // Remove this analysis
-        if (PassDebugging >= Details) {
+        if (GlobalPassDebugOpts->PassDebugging >= Details) {
           Pass *S = Info->second;
           dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
           dbgs() << S->getPassName() << "'\n";
@@ -928,7 +956,7 @@ void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
 
   TPM->collectLastUses(DeadPasses, P);
 
-  if (PassDebugging >= Details && !DeadPasses.empty()) {
+  if (GlobalPassDebugOpts->PassDebugging >= Details && !DeadPasses.empty()) {
     dbgs() << " -*- '" <<  P->getPassName();
     dbgs() << "' is the last user of following pass instances.";
     dbgs() << " Free these instances\n";
@@ -1146,7 +1174,7 @@ void PMDataManager::dumpPassArguments() const {
 void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
                                  enum PassDebuggingString S2,
                                  StringRef Msg) {
-  if (PassDebugging < Executions)
+  if (GlobalPassDebugOpts->PassDebugging < Executions)
     return;
   dbgs() << (void*)this << std::string(getDepth()*2+1, ' ');
   switch (S1) {
@@ -1187,7 +1215,7 @@ void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
 }
 
 void PMDataManager::dumpRequiredSet(const Pass *P) const {
-  if (PassDebugging < Details)
+  if (GlobalPassDebugOpts->PassDebugging < Details)
     return;
 
   AnalysisUsage analysisUsage;
@@ -1196,7 +1224,7 @@ void PMDataManager::dumpRequiredSet(const Pass *P) const {
 }
 
 void PMDataManager::dumpPreservedSet(const Pass *P) const {
-  if (PassDebugging < Details)
+  if (GlobalPassDebugOpts->PassDebugging < Details)
     return;
 
   AnalysisUsage analysisUsage;
@@ -1206,7 +1234,7 @@ void PMDataManager::dumpPreservedSet(const Pass *P) const {
 
 void PMDataManager::dumpAnalysisUsage(StringRef Msg, const Pass *P,
                                    const AnalysisUsage::VectorType &Set) const {
-  assert(PassDebugging >= Details);
+  assert(GlobalPassDebugOpts->PassDebugging >= Details);
   if (Set.empty())
     return;
   dbgs() << (const void*)P << std::string(getDepth()*2+3, ' ') << Msg << " Analyses:";
@@ -1741,11 +1769,6 @@ bool PassManager::run(Module &M) {
 //===----------------------------------------------------------------------===//
 // TimingInfo implementation
 
-bool llvm::TimePassesIsEnabled = false;
-static cl::opt<bool,true>
-EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
-            cl::desc("Time each pass, printing elapsed time for each on exit"));
-
 // createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
 // a non null value (if the -time-passes option is enabled) or it leaves it
 // null.  It may be called multiple times.

tools/llvm-as/llvm-as.cpp

@@ -20,6 +20,7 @@
 #include "llvm/Assembly/Parser.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Module.h"
+#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/PrettyStackTrace.h"
@@ -89,6 +90,10 @@ int main(int argc, char **argv) {
   PrettyStackTraceProgram X(argc, argv);
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm .ll -> .bc assembler\n");
 
   // Parse the file now...

tools/llvm-diff/llvm-diff.cpp

@@ -20,6 +20,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IRReader/IRReader.h"
+#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
@@ -67,6 +68,9 @@ static cl::list<std::string> GlobalsToCompare(cl::Positional,
                                               cl::desc("<globals to compare>"));
 
 int main(int argc, char **argv) {
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv);
 
   LLVMContext Context;

tools/llvm-dis/llvm-dis.cpp

@@ -23,6 +23,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
+#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/DataStream.h"
 #include "llvm/Support/FormattedStream.h"
@@ -119,6 +120,8 @@ int main(int argc, char **argv) {
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
 
   cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .ll disassembler\n");
 

tools/llvm-extract/llvm-extract.cpp

@@ -96,6 +96,10 @@ int main(int argc, char **argv) {
 
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");
 
   // Use lazy loading, since we only care about selected global values.

tools/llvm-link/llvm-link.cpp

@@ -18,6 +18,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IRReader/IRReader.h"
+#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Path.h"
@@ -73,6 +74,10 @@ int main(int argc, char **argv) {
 
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm linker\n");
 
   unsigned BaseArg = 0;

tools/llvm-nm/llvm-nm.cpp

@@ -22,6 +22,7 @@
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Format.h"
@@ -446,6 +447,10 @@ int main(int argc, char **argv) {
   PrettyStackTraceProgram X(argc, argv);
 
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm symbol table dumper\n");
 
   // llvm-nm only reads binary files.

tools/llvm-prof/llvm-prof.cpp

@@ -260,6 +260,9 @@ int main(int argc, char **argv) {
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm profile dump decoder\n");
 
   // Read in the bitcode file...

tools/llvm-stress/llvm-stress.cpp

@@ -681,6 +681,10 @@ void IntroduceControlFlow(Function *F, Random &R) {
 int main(int argc, char **argv) {
   // Init LLVM, call llvm_shutdown() on exit, parse args, etc.
   llvm::PrettyStackTraceProgram X(argc, argv);
+
+  // Initialize PassManager for -time-passes support.
+  initializePassManager();
+
   cl::ParseCommandLineOptions(argc, argv, "llvm codegen stress-tester\n");
   llvm_shutdown_obj Y;