Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/tools/opt/Debugify.cpp

@@ -0,0 +1,212 @@
+//===- Debugify.cpp - Attach synthetic debug info to everything -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file This pass attaches synthetic debug info to everything. It can be used
+/// to create targeted tests for debug info preservation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO.h"
+
+using namespace llvm;
+
+namespace {
+
+bool applyDebugifyMetadata(Module &M) {
+  // Skip modules with debug info.
+  if (M.getNamedMetadata("llvm.dbg.cu")) {
+    errs() << "Debugify: Skipping module with debug info\n";
+    return false;
+  }
+
+  DIBuilder DIB(M);
+  LLVMContext &Ctx = M.getContext();
+
+  // Get a DIType which corresponds to Ty.
+  DenseMap<uint64_t, DIType *> TypeCache;
+  auto getCachedDIType = [&](Type *Ty) -> DIType * {
+    uint64_t Size = M.getDataLayout().getTypeAllocSizeInBits(Ty);
+    DIType *&DTy = TypeCache[Size];
+    if (!DTy) {
+      std::string Name = "ty" + utostr(Size);
+      DTy = DIB.createBasicType(Name, Size, dwarf::DW_ATE_unsigned);
+    }
+    return DTy;
+  };
+
+  unsigned NextLine = 1;
+  unsigned NextVar = 1;
+  auto File = DIB.createFile(M.getName(), "/");
+  auto CU =
+      DIB.createCompileUnit(dwarf::DW_LANG_C, DIB.createFile(M.getName(), "/"),
+                            "debugify", /*isOptimized=*/true, "", 0);
+
+  // Visit each instruction.
+  for (Function &F : M) {
+    if (F.isDeclaration())
+      continue;
+
+    auto SPType = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+    bool IsLocalToUnit = F.hasPrivateLinkage() || F.hasInternalLinkage();
+    auto SP =
+        DIB.createFunction(CU, F.getName(), F.getName(), File, NextLine, SPType,
+                           IsLocalToUnit, F.hasExactDefinition(), NextLine,
+                           DINode::FlagZero, /*isOptimized=*/true);
+    F.setSubprogram(SP);
+    for (BasicBlock &BB : F) {
+      // Attach debug locations.
+      for (Instruction &I : BB)
+        I.setDebugLoc(DILocation::get(Ctx, NextLine++, 1, SP));
+
+      // Attach debug values.
+      for (Instruction &I : BB) {
+        // Skip void-valued instructions.
+        if (I.getType()->isVoidTy())
+          continue;
+
+        // Skip the terminator instruction and any just-inserted intrinsics.
+        if (isa<TerminatorInst>(&I) || isa<DbgValueInst>(&I))
+          break;
+
+        std::string Name = utostr(NextVar++);
+        const DILocation *Loc = I.getDebugLoc().get();
+        auto LocalVar = DIB.createAutoVariable(SP, Name, File, Loc->getLine(),
+                                               getCachedDIType(I.getType()),
+                                               /*AlwaysPreserve=*/true);
+        DIB.insertDbgValueIntrinsic(&I, LocalVar, DIB.createExpression(), Loc,
+                                    BB.getTerminator());
+      }
+    }
+    DIB.finalizeSubprogram(SP);
+  }
+  DIB.finalize();
+
+  // Track the number of distinct lines and variables.
+  NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.debugify");
+  auto *IntTy = Type::getInt32Ty(Ctx);
+  auto addDebugifyOperand = [&](unsigned N) {
+    NMD->addOperand(MDNode::get(
+        Ctx, ValueAsMetadata::getConstant(ConstantInt::get(IntTy, N))));
+  };
+  addDebugifyOperand(NextLine - 1); // Original number of lines.
+  addDebugifyOperand(NextVar - 1);  // Original number of variables.
+  return true;
+}
+
+void checkDebugifyMetadata(Module &M) {
+  // Skip modules without debugify metadata.
+  NamedMDNode *NMD = M.getNamedMetadata("llvm.debugify");
+  if (!NMD)
+    return;
+
+  auto getDebugifyOperand = [&](unsigned Idx) -> unsigned {
+    return mdconst::extract<ConstantInt>(NMD->getOperand(Idx)->getOperand(0))
+        ->getZExtValue();
+  };
+  unsigned OriginalNumLines = getDebugifyOperand(0);
+  unsigned OriginalNumVars = getDebugifyOperand(1);
+  bool HasErrors = false;
+
+  // Find missing lines.
+  BitVector MissingLines{OriginalNumLines, true};
+  for (Function &F : M) {
+    for (Instruction &I : instructions(F)) {
+      if (isa<DbgValueInst>(&I))
+        continue;
+
+      auto DL = I.getDebugLoc();
+      if (DL) {
+        MissingLines.reset(DL.getLine() - 1);
+        continue;
+      }
+
+      outs() << "ERROR: Instruction with empty DebugLoc -- ";
+      I.print(outs());
+      outs() << "\n";
+      HasErrors = true;
+    }
+  }
+  for (unsigned Idx : MissingLines.set_bits())
+    outs() << "WARNING: Missing line " << Idx + 1 << "\n";
+
+  // Find missing variables.
+  BitVector MissingVars{OriginalNumVars, true};
+  for (Function &F : M) {
+    for (Instruction &I : instructions(F)) {
+      auto *DVI = dyn_cast<DbgValueInst>(&I);
+      if (!DVI)
+        continue;
+
+      unsigned Var = ~0U;
+      (void)to_integer(DVI->getVariable()->getName(), Var, 10);
+      assert(Var <= OriginalNumVars && "Unexpected name for DILocalVariable");
+      MissingVars.reset(Var - 1);
+    }
+  }
+  for (unsigned Idx : MissingVars.set_bits())
+    outs() << "ERROR: Missing variable " << Idx + 1 << "\n";
+  HasErrors |= MissingVars.count() > 0;
+
+  outs() << "CheckDebugify: " << (HasErrors ? "FAIL" : "PASS") << "\n";
+}
+
+/// Attach synthetic debug info to everything.
+struct DebugifyPass : public ModulePass {
+  bool runOnModule(Module &M) override { return applyDebugifyMetadata(M); }
+
+  DebugifyPass() : ModulePass(ID) {}
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+
+  static char ID; // Pass identification.
+};
+
+/// Check debug info inserted by -debugify for completeness.
+struct CheckDebugifyPass : public ModulePass {
+  bool runOnModule(Module &M) override {
+    checkDebugifyMetadata(M);
+    return false;
+  }
+
+  CheckDebugifyPass() : ModulePass(ID) {}
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+
+  static char ID; // Pass identification.
+};
+
+} // end anonymous namespace
+
+char DebugifyPass::ID = 0;
+static RegisterPass<DebugifyPass> X("debugify",
+                                    "Attach debug info to everything");
+
+char CheckDebugifyPass::ID = 0;
+static RegisterPass<CheckDebugifyPass> Y("check-debugify",
+                                         "Check debug info from -debugify");