Reapply [IR] Lazily initialize the class to pass name mapping (NFC) (#96321) (#96462)

On MSVC the `this` uses inside `decltype` require a lambda capture. On
clang they result in an unused capture warning instead. Add the capture
and suppress the warning with `(void)this`.

-----

Initializing this map is somewhat expensive (especially for O0), so we
currently only do it if certain flags are used. I would like to make use
of it for crash dumps (#96078), where we don't know in advance whether
it will be needed or not.

This patch changes the initialization to a lazy approach, where a
callback is registered that does the actual initialization. The
callbacks will be run the first time the pass name is requested.

This way there is no compile-time impact if the mapping is not used.

19 files changed, 40 insertions, 48 deletions

diff --git a/llvm/include/llvm/IR/PassInstrumentation.h b/llvm/include/llvm/IR/PassInstrumentation.h
index ff5e544..f2eb8a9 100644
--- a/llvm/include/llvm/IR/PassInstrumentation.h
+++ b/llvm/include/llvm/IR/PassInstrumentation.h
@@ -149,6 +149,11 @@ public:
     AnalysesClearedCallbacks.emplace_back(std::move(C));
   }
 
+  template <typename CallableT>
+  void registerClassToPassNameCallback(CallableT C) {
+    ClassToPassNameCallbacks.emplace_back(std::move(C));
+  }
+
   /// Add a class name to pass name mapping for use by pass instrumentation.
   void addClassToPassName(StringRef ClassName, StringRef PassName);
   /// Get the pass name for a given pass class name.
@@ -185,6 +190,7 @@ private:
   SmallVector<llvm::unique_function<AnalysesClearedFunc>, 4>
       AnalysesClearedCallbacks;
 
+  SmallVector<llvm::unique_function<void ()>, 4> ClassToPassNameCallbacks;
   DenseMap<StringRef, std::string> ClassToPassName;
 };
 
diff --git a/llvm/include/llvm/Passes/TargetPassRegistry.inc b/llvm/include/llvm/Passes/TargetPassRegistry.inc
index b618331..521913c 100644
--- a/llvm/include/llvm/Passes/TargetPassRegistry.inc
+++ b/llvm/include/llvm/Passes/TargetPassRegistry.inc
@@ -21,9 +21,12 @@
 #error "must provide <Target>PassRegistry.def"
 #endif
 
-if (PopulateClassToPassNames) {
-  auto *PIC = PB.getPassInstrumentationCallbacks();
-
+auto *PIC = PB.getPassInstrumentationCallbacks();
+if (PIC) {
+  PIC->registerClassToPassNameCallback([this, PIC]() {
+    // MSVC requires this to be captured if it's used inside decltype.
+    // Other compilers consider it an unused lambda capture.
+    (void)this;
 #define ADD_CLASS_PASS_TO_PASS_NAME(NAME, CREATE_PASS)                         \
   PIC->addClassToPassName(decltype(CREATE_PASS)::name(), NAME);
 #define ADD_CLASS_PASS_TO_PASS_NAME_WITH_PARAMS(NAME, CLASS)                   \
@@ -69,6 +72,7 @@ if (PopulateClassToPassNames) {
 #undef MACHINE_FUNCTION_PASS_WITH_PARAMS
 #undef ADD_CLASS_PASS_TO_PASS_NAME
 #undef ADD_CLASS_PASS_TO_PASS_NAME_WITH_PARAMS
+  });
 }
 
 #define ADD_PASS(NAME, CREATE_PASS)                                            \
diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
index f09c3b2..b8e56c7 100644
--- a/llvm/include/llvm/Target/TargetMachine.h
+++ b/llvm/include/llvm/Target/TargetMachine.h
@@ -369,8 +369,7 @@ public:
 
   /// Allow the target to modify the pass pipeline.
   // TODO: Populate all pass names by using <Target>PassRegistry.def.
-  virtual void registerPassBuilderCallbacks(PassBuilder &,
-                                            bool PopulateClassToPassNames) {}
+  virtual void registerPassBuilderCallbacks(PassBuilder &) {}
 
   /// Allow the target to register alias analyses with the AAManager for use
   /// with the new pass manager. Only affects the "default" AAManager.
diff --git a/llvm/lib/IR/PassInstrumentation.cpp b/llvm/lib/IR/PassInstrumentation.cpp
index 86c82a1..0c4e769 100644
--- a/llvm/lib/IR/PassInstrumentation.cpp
+++ b/llvm/lib/IR/PassInstrumentation.cpp
@@ -24,6 +24,11 @@ void PassInstrumentationCallbacks::addClassToPassName(StringRef ClassName,
 
 StringRef
 PassInstrumentationCallbacks::getPassNameForClassName(StringRef ClassName) {
+  if (!ClassToPassNameCallbacks.empty()) {
+    for (auto &Fn : ClassToPassNameCallbacks)
+      Fn();
+    ClassToPassNameCallbacks.clear();
+  }
   return ClassToPassName[ClassName];
 }
 
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index f819345..c19d5a7 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -325,18 +325,6 @@ AnalysisKey NoOpLoopAnalysis::Key;
 
 namespace {
 
-/// Whether or not we should populate a PassInstrumentationCallbacks's class to
-/// pass name map.
-///
-/// This is for optimization purposes so we don't populate it if we never use
-/// it. This should be updated if new pass instrumentation wants to use the map.
-/// We currently only use this for --print-before/after.
-bool shouldPopulateClassToPassNames() {
-  return PrintPipelinePasses || !printBeforePasses().empty() ||
-         !printAfterPasses().empty() || !isFilterPassesEmpty() ||
-         TargetPassConfig::hasLimitedCodeGenPipeline();
-}
-
 // A pass for testing -print-on-crash.
 // DO NOT USE THIS EXCEPT FOR TESTING!
 class TriggerCrashPass : public PassInfoMixin<TriggerCrashPass> {
@@ -416,10 +404,13 @@ PassBuilder::PassBuilder(TargetMachine *TM, PipelineTuningOptions PTO,
                          std::optional<PGOOptions> PGOOpt,
                          PassInstrumentationCallbacks *PIC)
     : TM(TM), PTO(PTO), PGOOpt(PGOOpt), PIC(PIC) {
-  bool ShouldPopulateClassToPassNames = PIC && shouldPopulateClassToPassNames();
   if (TM)
-    TM->registerPassBuilderCallbacks(*this, ShouldPopulateClassToPassNames);
-  if (ShouldPopulateClassToPassNames) {
+    TM->registerPassBuilderCallbacks(*this);
+  if (PIC) {
+    PIC->registerClassToPassNameCallback([this, PIC]() {
+      // MSVC requires this to be captured if it's used inside decltype.
+      // Other compilers consider it an unused lambda capture.
+      (void)this;
 #define MODULE_PASS(NAME, CREATE_PASS)                                         \
   PIC->addClassToPassName(decltype(CREATE_PASS)::name(), NAME);
 #define MODULE_PASS_WITH_PARAMS(NAME, CLASS, CREATE_PASS, PARSER, PARAMS)      \
@@ -453,6 +444,7 @@ PassBuilder::PassBuilder(TargetMachine *TM, PipelineTuningOptions PTO,
 #define MACHINE_FUNCTION_PASS(NAME, CREATE_PASS)                               \
   PIC->addClassToPassName(decltype(CREATE_PASS)::name(), NAME);
 #include "llvm/Passes/MachinePassRegistry.def"
+    });
   }
 }
 
diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 8c924e7..37ce07d 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -554,8 +554,7 @@ public:
 
 } // end anonymous namespace
 
-void AArch64TargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void AArch64TargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 
   PB.registerLateLoopOptimizationsEPCallback(
       [=](LoopPassManager &LPM, OptimizationLevel Level) {
diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.h b/llvm/lib/Target/AArch64/AArch64TargetMachine.h
index e396d92..1a470ca 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.h
@@ -43,8 +43,7 @@ public:
   // Pass Pipeline Configuration
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
 
   TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
 
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 3e21d8e..9162e11 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -658,8 +658,7 @@ Error AMDGPUTargetMachine::buildCodeGenPipeline(
   return CGPB.buildPipeline(MPM, Out, DwoOut, FileType);
 }
 
-void AMDGPUTargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void AMDGPUTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 
 #define GET_PASS_REGISTRY "AMDGPUPassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
index 98b0bc0..0f74fbc 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
@@ -58,8 +58,7 @@ public:
                              const CGPassBuilderOption &Opts,
                              PassInstrumentationCallbacks *PIC) override;
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
   void registerDefaultAliasAnalyses(AAManager &) override;
 
   /// Get the integer value of a null pointer in the given address space.
diff --git a/llvm/lib/Target/BPF/BPFTargetMachine.cpp b/llvm/lib/Target/BPF/BPFTargetMachine.cpp
index 7b73c9f..7d91fa8 100644
--- a/llvm/lib/Target/BPF/BPFTargetMachine.cpp
+++ b/llvm/lib/Target/BPF/BPFTargetMachine.cpp
@@ -113,8 +113,7 @@ static Expected<bool> parseBPFPreserveStaticOffsetOptions(StringRef Params) {
                                             "BPFPreserveStaticOffsetPass");
 }
 
-void BPFTargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void BPFTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 #define GET_PASS_REGISTRY "BPFPassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
 
diff --git a/llvm/lib/Target/BPF/BPFTargetMachine.h b/llvm/lib/Target/BPF/BPFTargetMachine.h
index 0a28394..4e6adc7 100644
--- a/llvm/lib/Target/BPF/BPFTargetMachine.h
+++ b/llvm/lib/Target/BPF/BPFTargetMachine.h
@@ -42,8 +42,7 @@ public:
     return TLOF.get();
   }
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
 };
 }
 
diff --git a/llvm/lib/Target/DirectX/DirectXTargetMachine.cpp b/llvm/lib/Target/DirectX/DirectXTargetMachine.cpp
index c853393..e6dbb25 100644
--- a/llvm/lib/Target/DirectX/DirectXTargetMachine.cpp
+++ b/llvm/lib/Target/DirectX/DirectXTargetMachine.cpp
@@ -102,8 +102,7 @@ DirectXTargetMachine::DirectXTargetMachine(const Target &T, const Triple &TT,
 
 DirectXTargetMachine::~DirectXTargetMachine() {}
 
-void DirectXTargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void DirectXTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 #define GET_PASS_REGISTRY "DirectXPassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
 }
diff --git a/llvm/lib/Target/DirectX/DirectXTargetMachine.h b/llvm/lib/Target/DirectX/DirectXTargetMachine.h
index 428beaf..d04c375 100644
--- a/llvm/lib/Target/DirectX/DirectXTargetMachine.h
+++ b/llvm/lib/Target/DirectX/DirectXTargetMachine.h
@@ -47,8 +47,7 @@ public:
   }
 
   TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
 };
 } // namespace llvm
 
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
index e488650..b362285 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -312,8 +312,7 @@ HexagonTargetMachine::getSubtargetImpl(const Function &F) const {
   return I.get();
 }
 
-void HexagonTargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void HexagonTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 #define GET_PASS_REGISTRY "HexagonPassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
 
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.h b/llvm/lib/Target/Hexagon/HexagonTargetMachine.h
index 34ff45b..6e9a78b 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetMachine.h
+++ b/llvm/lib/Target/Hexagon/HexagonTargetMachine.h
@@ -35,8 +35,7 @@ public:
   ~HexagonTargetMachine() override;
   const HexagonSubtarget *getSubtargetImpl(const Function &F) const override;
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
   TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
 
diff --git a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
index b60a1d7..152f200 100644
--- a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.cpp
@@ -224,8 +224,7 @@ void NVPTXTargetMachine::registerDefaultAliasAnalyses(AAManager &AAM) {
   AAM.registerFunctionAnalysis<NVPTXAA>();
 }
 
-void NVPTXTargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void NVPTXTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 #define GET_PASS_REGISTRY "NVPTXPassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
 
diff --git a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
index 870ea20..2b88da6 100644
--- a/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
+++ b/llvm/lib/Target/NVPTX/NVPTXTargetMachine.h
@@ -66,8 +66,7 @@ public:
 
   void registerDefaultAliasAnalyses(AAManager &AAM) override;
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
 
   TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
 
diff --git a/llvm/lib/Target/X86/X86CodeGenPassBuilder.cpp b/llvm/lib/Target/X86/X86CodeGenPassBuilder.cpp
index 9819bfd..d979517 100644
--- a/llvm/lib/Target/X86/X86CodeGenPassBuilder.cpp
+++ b/llvm/lib/Target/X86/X86CodeGenPassBuilder.cpp
@@ -50,8 +50,7 @@ Error X86CodeGenPassBuilder::addInstSelector(AddMachinePass &addPass) const {
 
 } // namespace
 
-void X86TargetMachine::registerPassBuilderCallbacks(
-    PassBuilder &PB, bool PopulateClassToPassNames) {
+void X86TargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
 #define GET_PASS_REGISTRY "X86PassRegistry.def"
 #include "llvm/Passes/TargetPassRegistry.inc"
 }
diff --git a/llvm/lib/Target/X86/X86TargetMachine.h b/llvm/lib/Target/X86/X86TargetMachine.h
index 916445c..ec4a93e9 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.h
+++ b/llvm/lib/Target/X86/X86TargetMachine.h
@@ -66,8 +66,7 @@ public:
                                 SMDiagnostic &Error,
                                 SMRange &SourceRange) const override;
 
-  void registerPassBuilderCallbacks(PassBuilder &PB,
-                                    bool PopulateClassToPassNames) override;
+  void registerPassBuilderCallbacks(PassBuilder &PB) override;
 
   Error buildCodeGenPipeline(ModulePassManager &, raw_pwrite_stream &,
                              raw_pwrite_stream *, CodeGenFileType,