summaryrefslogtreecommitdiff
path: root/llvm/lib/Transforms/Utils/Debugify.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/Transforms/Utils/Debugify.cpp')
-rw-r--r--llvm/lib/Transforms/Utils/Debugify.cpp135
1 files changed, 110 insertions, 25 deletions
diff --git a/llvm/lib/Transforms/Utils/Debugify.cpp b/llvm/lib/Transforms/Utils/Debugify.cpp
index b7b4bfa3734d0..8f98d81a3d797 100644
--- a/llvm/lib/Transforms/Utils/Debugify.cpp
+++ b/llvm/lib/Transforms/Utils/Debugify.cpp
@@ -30,6 +30,17 @@ namespace {
cl::opt<bool> Quiet("debugify-quiet",
cl::desc("Suppress verbose debugify output"));
+enum class Level {
+ Locations,
+ LocationsAndVariables
+};
+cl::opt<Level> DebugifyLevel(
+ "debugify-level", cl::desc("Kind of debug info to add"),
+ cl::values(clEnumValN(Level::Locations, "locations", "Locations only"),
+ clEnumValN(Level::LocationsAndVariables, "location+variables",
+ "Locations and Variables")),
+ cl::init(Level::LocationsAndVariables));
+
raw_ostream &dbg() { return Quiet ? nulls() : errs(); }
uint64_t getAllocSizeInBits(Module &M, Type *Ty) {
@@ -51,10 +62,11 @@ Instruction *findTerminatingInstruction(BasicBlock &BB) {
return I;
return BB.getTerminator();
}
+} // end anonymous namespace
-bool applyDebugifyMetadata(Module &M,
- iterator_range<Module::iterator> Functions,
- StringRef Banner) {
+bool llvm::applyDebugifyMetadata(
+ Module &M, iterator_range<Module::iterator> Functions, StringRef Banner,
+ std::function<bool(DIBuilder &DIB, Function &F)> ApplyToMF) {
// Skip modules with debug info.
if (M.getNamedMetadata("llvm.dbg.cu")) {
dbg() << Banner << "Skipping module with debug info\n";
@@ -63,6 +75,7 @@ bool applyDebugifyMetadata(Module &M,
DIBuilder DIB(M);
LLVMContext &Ctx = M.getContext();
+ auto *Int32Ty = Type::getInt32Ty(Ctx);
// Get a DIType which corresponds to Ty.
DenseMap<uint64_t, DIType *> TypeCache;
@@ -87,6 +100,7 @@ bool applyDebugifyMetadata(Module &M,
if (isFunctionSkipped(F))
continue;
+ bool InsertedDbgVal = false;
auto SPType = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
DISubprogram::DISPFlags SPFlags =
DISubprogram::SPFlagDefinition | DISubprogram::SPFlagOptimized;
@@ -95,11 +109,31 @@ bool applyDebugifyMetadata(Module &M,
auto SP = DIB.createFunction(CU, F.getName(), F.getName(), File, NextLine,
SPType, NextLine, DINode::FlagZero, SPFlags);
F.setSubprogram(SP);
+
+ // Helper that inserts a dbg.value before \p InsertBefore, copying the
+ // location (and possibly the type, if it's non-void) from \p TemplateInst.
+ auto insertDbgVal = [&](Instruction &TemplateInst,
+ Instruction *InsertBefore) {
+ std::string Name = utostr(NextVar++);
+ Value *V = &TemplateInst;
+ if (TemplateInst.getType()->isVoidTy())
+ V = ConstantInt::get(Int32Ty, 0);
+ const DILocation *Loc = TemplateInst.getDebugLoc().get();
+ auto LocalVar = DIB.createAutoVariable(SP, Name, File, Loc->getLine(),
+ getCachedDIType(V->getType()),
+ /*AlwaysPreserve=*/true);
+ DIB.insertDbgValueIntrinsic(V, LocalVar, DIB.createExpression(), Loc,
+ InsertBefore);
+ };
+
for (BasicBlock &BB : F) {
// Attach debug locations.
for (Instruction &I : BB)
I.setDebugLoc(DILocation::get(Ctx, NextLine++, 1, SP));
+ if (DebugifyLevel < Level::LocationsAndVariables)
+ continue;
+
// Inserting debug values into EH pads can break IR invariants.
if (BB.isEHPad())
continue;
@@ -126,25 +160,30 @@ bool applyDebugifyMetadata(Module &M,
if (!isa<PHINode>(I) && !I->isEHPad())
InsertBefore = I->getNextNode();
- 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,
- InsertBefore);
+ insertDbgVal(*I, InsertBefore);
+ InsertedDbgVal = true;
}
}
+ // Make sure we emit at least one dbg.value, otherwise MachineDebugify may
+ // not have anything to work with as it goes about inserting DBG_VALUEs.
+ // (It's common for MIR tests to be written containing skeletal IR with
+ // empty functions -- we're still interested in debugifying the MIR within
+ // those tests, and this helps with that.)
+ if (DebugifyLevel == Level::LocationsAndVariables && !InsertedDbgVal) {
+ auto *Term = findTerminatingInstruction(F.getEntryBlock());
+ insertDbgVal(*Term, Term);
+ }
+ if (ApplyToMF)
+ ApplyToMF(DIB, F);
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))));
+ Ctx, ValueAsMetadata::getConstant(ConstantInt::get(Int32Ty, N))));
};
addDebugifyOperand(NextLine - 1); // Original number of lines.
addDebugifyOperand(NextVar - 1); // Original number of variables.
@@ -159,6 +198,54 @@ bool applyDebugifyMetadata(Module &M,
return true;
}
+bool llvm::stripDebugifyMetadata(Module &M) {
+ bool Changed = false;
+
+ // Remove the llvm.debugify module-level named metadata.
+ NamedMDNode *DebugifyMD = M.getNamedMetadata("llvm.debugify");
+ if (DebugifyMD) {
+ M.eraseNamedMetadata(DebugifyMD);
+ Changed = true;
+ }
+
+ // Strip out all debug intrinsics and supporting metadata (subprograms, types,
+ // variables, etc).
+ Changed |= StripDebugInfo(M);
+
+ // Strip out the dead dbg.value prototype.
+ Function *DbgValF = M.getFunction("llvm.dbg.value");
+ if (DbgValF) {
+ assert(DbgValF->isDeclaration() && DbgValF->use_empty() &&
+ "Not all debug info stripped?");
+ DbgValF->eraseFromParent();
+ Changed = true;
+ }
+
+ // Strip out the module-level Debug Info Version metadata.
+ // FIXME: There must be an easier way to remove an operand from a NamedMDNode.
+ NamedMDNode *NMD = M.getModuleFlagsMetadata();
+ if (!NMD)
+ return Changed;
+ SmallVector<MDNode *, 4> Flags;
+ for (MDNode *Flag : NMD->operands())
+ Flags.push_back(Flag);
+ NMD->clearOperands();
+ for (MDNode *Flag : Flags) {
+ MDString *Key = dyn_cast_or_null<MDString>(Flag->getOperand(1));
+ if (Key->getString() == "Debug Info Version") {
+ Changed = true;
+ continue;
+ }
+ NMD->addOperand(Flag);
+ }
+ // If we left it empty we might as well remove it.
+ if (NMD->getNumOperands() == 0)
+ NMD->eraseFromParent();
+
+ return Changed;
+}
+
+namespace {
/// Return true if a mis-sized diagnostic is issued for \p DVI.
bool diagnoseMisSizedDbgValue(Module &M, DbgValueInst *DVI) {
// The size of a dbg.value's value operand should match the size of the
@@ -206,7 +293,7 @@ bool checkDebugifyMetadata(Module &M,
// Skip modules without debugify metadata.
NamedMDNode *NMD = M.getNamedMetadata("llvm.debugify");
if (!NMD) {
- dbg() << Banner << "Skipping module without debugify metadata\n";
+ dbg() << Banner << ": Skipping module without debugify metadata\n";
return false;
}
@@ -233,7 +320,7 @@ bool checkDebugifyMetadata(Module &M,
// Find missing lines.
for (Instruction &I : instructions(F)) {
- if (isa<DbgValueInst>(&I))
+ if (isa<DbgValueInst>(&I) || isa<PHINode>(&I))
continue;
auto DL = I.getDebugLoc();
@@ -243,11 +330,10 @@ bool checkDebugifyMetadata(Module &M,
}
if (!DL) {
- dbg() << "ERROR: Instruction with empty DebugLoc in function ";
+ dbg() << "WARNING: Instruction with empty DebugLoc in function ";
dbg() << F.getName() << " --";
I.print(dbg());
dbg() << "\n";
- HasErrors = true;
}
}
@@ -287,12 +373,9 @@ bool checkDebugifyMetadata(Module &M,
dbg() << " [" << NameOfWrappedPass << "]";
dbg() << ": " << (HasErrors ? "FAIL" : "PASS") << '\n';
- // Strip the Debugify Metadata if required.
- if (Strip) {
- StripDebugInfo(M);
- M.eraseNamedMetadata(NMD);
- return true;
- }
+ // Strip debugify metadata if required.
+ if (Strip)
+ return stripDebugifyMetadata(M);
return false;
}
@@ -301,7 +384,8 @@ bool checkDebugifyMetadata(Module &M,
/// legacy module pass manager.
struct DebugifyModulePass : public ModulePass {
bool runOnModule(Module &M) override {
- return applyDebugifyMetadata(M, M.functions(), "ModuleDebugify: ");
+ return applyDebugifyMetadata(M, M.functions(),
+ "ModuleDebugify: ", /*ApplyToMF*/ nullptr);
}
DebugifyModulePass() : ModulePass(ID) {}
@@ -320,7 +404,7 @@ struct DebugifyFunctionPass : public FunctionPass {
Module &M = *F.getParent();
auto FuncIt = F.getIterator();
return applyDebugifyMetadata(M, make_range(FuncIt, std::next(FuncIt)),
- "FunctionDebugify: ");
+ "FunctionDebugify: ", /*ApplyToMF*/ nullptr);
}
DebugifyFunctionPass() : FunctionPass(ID) {}
@@ -395,7 +479,8 @@ FunctionPass *createDebugifyFunctionPass() {
}
PreservedAnalyses NewPMDebugifyPass::run(Module &M, ModuleAnalysisManager &) {
- applyDebugifyMetadata(M, M.functions(), "ModuleDebugify: ");
+ applyDebugifyMetadata(M, M.functions(),
+ "ModuleDebugify: ", /*ApplyToMF*/ nullptr);
return PreservedAnalyses::all();
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-06 05:32:23 +0000