Move DroppedVariableStats to CodeGen lib (#120650)

To get Dropped variable statistics for MIR, we need to move the base
class DroppedVariableStats code to the CodeGen library because we cannot
have CodeGen link against Passes.

Also moved the code for the virtual functions to the header because
clang/lib/CodeGen doesn't link against llvm/lib/CodeGen however it does
link against Passes which contains the `class StandardInstrumentations`
code but not the definition for the virtual functions leading to the
error about not finding vtable for `class DroppedVariableStatsIR`

Author: rastogishubham

llvm/include/llvm/Passes/DroppedVariableStats.h renamed to llvm/include/llvm/CodeGen/DroppedVariableStats.h

@@ -18,6 +18,7 @@
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassInstrumentation.h"
 
@@ -206,12 +207,33 @@ class DroppedVariableStatsIR : public DroppedVariableStats {
   virtual void
   visitEveryInstruction(unsigned &DroppedCount,
                         DenseMap<VarID, DILocation *> &InlinedAtsMap,
-                        VarID Var) override;
+                        VarID Var) override {
+    const DIScope *DbgValScope = std::get<0>(Var);
+    for (const auto &I : instructions(Func)) {
+      auto *DbgLoc = I.getDebugLoc().get();
+      if (!DbgLoc)
+        continue;
+      if (updateDroppedCount(DbgLoc, DbgLoc->getScope(), DbgValScope,
+                             InlinedAtsMap, Var, DroppedCount))
+        break;
+    }
+  }
   /// Override base class method to run on #dbg_values specifically.
   virtual void visitEveryDebugRecord(
       DenseSet<VarID> &VarIDSet,
       DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
-      StringRef FuncName, bool Before) override;
+      StringRef FuncName, bool Before) override {
+    for (const auto &I : instructions(Func)) {
+      for (DbgRecord &DR : I.getDbgRecordRange()) {
+        if (auto *Dbg = dyn_cast<DbgVariableRecord>(&DR)) {
+          auto *DbgVar = Dbg->getVariable();
+          auto DbgLoc = DR.getDebugLoc();
+          populateVarIDSetAndInlinedMap(DbgVar, DbgLoc, VarIDSet, InlinedAtsMap,
+                                        FuncName, Before);
+        }
+      }
+    }
+  }
 
   template <typename IRUnitT> static const IRUnitT *unwrapIR(Any IR) {
     const IRUnitT **IRPtr = llvm::any_cast<const IRUnitT *>(&IR);

llvm/include/llvm/Passes/StandardInstrumentations.h

@@ -19,13 +19,13 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
+#include "llvm/CodeGen/DroppedVariableStats.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/OptBisect.h"
 #include "llvm/IR/PassTimingInfo.h"
 #include "llvm/IR/ValueHandle.h"
-#include "llvm/Passes/DroppedVariableStats.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/Transforms/IPO/SampleProfileProbe.h"

llvm/lib/CodeGen/CMakeLists.txt

@@ -50,6 +50,7 @@ add_llvm_component_library(LLVMCodeGen
   DeadMachineInstructionElim.cpp
   DetectDeadLanes.cpp
   DFAPacketizer.cpp
+  DroppedVariableStats.cpp
   DwarfEHPrepare.cpp
   EarlyIfConversion.cpp
   EdgeBundles.cpp

llvm/lib/Passes/DroppedVariableStats.cpp renamed to llvm/lib/CodeGen/DroppedVariableStats.cpp

@@ -11,7 +11,7 @@
 ///
 ///===---------------------------------------------------------------------===//
 
-#include "llvm/Passes/DroppedVariableStats.h"
+#include "llvm/CodeGen/DroppedVariableStats.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Module.h"
@@ -162,33 +162,3 @@ void DroppedVariableStatsIR::registerCallbacks(
   PIC.registerAfterPassInvalidatedCallback(
       [this](StringRef P, const PreservedAnalyses &PA) { return cleanup(); });
 }
-
-void DroppedVariableStatsIR::visitEveryInstruction(
-    unsigned &DroppedCount, DenseMap<VarID, DILocation *> &InlinedAtsMap,
-    VarID Var) {
-  const DIScope *DbgValScope = std::get<0>(Var);
-  for (const auto &I : instructions(Func)) {
-    auto *DbgLoc = I.getDebugLoc().get();
-    if (!DbgLoc)
-      continue;
-    if (updateDroppedCount(DbgLoc, DbgLoc->getScope(), DbgValScope,
-                           InlinedAtsMap, Var, DroppedCount))
-      break;
-  }
-}
-
-void DroppedVariableStatsIR::visitEveryDebugRecord(
-    DenseSet<VarID> &VarIDSet,
-    DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
-    StringRef FuncName, bool Before) {
-  for (const auto &I : instructions(Func)) {
-    for (DbgRecord &DR : I.getDbgRecordRange()) {
-      if (auto *Dbg = dyn_cast<DbgVariableRecord>(&DR)) {
-        auto *DbgVar = Dbg->getVariable();
-        auto DbgLoc = DR.getDebugLoc();
-        populateVarIDSetAndInlinedMap(DbgVar, DbgLoc, VarIDSet, InlinedAtsMap,
-                                      FuncName, Before);
-      }
-    }
-  }
-}

llvm/lib/Passes/CMakeLists.txt

@@ -1,6 +1,5 @@
 add_llvm_component_library(LLVMPasses
   CodeGenPassBuilder.cpp
-  DroppedVariableStats.cpp
   OptimizationLevel.cpp
   PassBuilder.cpp
   PassBuilderBindings.cpp

llvm/unittests/CodeGen/CMakeLists.txt

@@ -27,6 +27,7 @@ add_llvm_unittest(CodeGenTests
   CCStateTest.cpp
   DIEHashTest.cpp
   DIETest.cpp
+  DroppedVariableStatsIRTest.cpp
   DwarfStringPoolEntryRefTest.cpp
   InstrRefLDVTest.cpp
   LowLevelTypeTest.cpp

llvm/unittests/IR/DroppedVariableStatsIRTest.cpp renamed to llvm/unittests/CodeGen/DroppedVariableStatsIRTest.cpp

@@ -43,7 +43,6 @@ add_llvm_unittest(IRTests
   ShuffleVectorInstTest.cpp
   StructuralHashTest.cpp
   TimePassesTest.cpp
-  DroppedVariableStatsIRTest.cpp
   TypesTest.cpp
   UseTest.cpp
   UserTest.cpp