Add a dump method to MachineFunctionProperties for better error messages

[dschuff]

Summary

This makes check failures much easier to understand.
Make it empty (but leave it in the class) for NDEBUG builds.

[dschuff]

• Also print the properties when printing the MF

[qcolombet]

include/llvm/CodeGen/MachineFunction.h

146

Short story, rename dump -> print.

The convention is to have dump to be available only in debug build, but more importantly to have it to print on dbgs().
What we want here is a print method.

lib/CodeGen/MachineFunction.cpp

396

print calls print, not dump.

[dschuff]

• Also print the properties when printing the MF
• Rename dump->print

include/llvm/CodeGen/MachineFunction.h

MachineFunctionProperties &clear(const MachineFunctionProperties &MFP) {
     return *this;
   }
   // Returns true if all properties set in V (i.e. required by a pass) are set
   // in this.
   bool verifyRequiredProperties(const MachineFunctionProperties &V) const {
     return !V.Properties.test(Properties);
   }
 
+  void dump(raw_ostream &ROS) const;
+
 private:
   BitVector Properties =
       BitVector(static_cast<unsigned>(Property::LastProperty));
 };
 
 class MachineFunction {
   const Function *Fn;
   const TargetMachine &Target;

lib/CodeGen/MachineFunction.cpp

 
 static cl::opt<unsigned>
     AlignAllFunctions("align-all-functions",
                       cl::desc("Force the alignment of all functions."),
                       cl::init(0), cl::Hidden);
 
 void MachineFunctionInitializer::anchor() {}
 
+void MachineFunctionProperties::dump(raw_ostream &ROS) const {
+  // Leave this function even in NDEBUG as an out-of-line anchor.
+#ifndef NDEBUG
+  if (!Properties.any()) {
+    ROS << "(empty)";
+    return;
+  }
+  for (BitVector::size_type i = 0; i < Properties.size(); ++i) {
+    if (Properties[i]) {
+      switch(static_cast<Property>(i)) {
+        case Property::AllVRegsAllocated:
+          ROS << "AllVRegsAllocated ";
+          break;
+        default:
+          // TODO: Implement IsSSA/TracksLiveness when we make them properties.
+          llvm_unreachable("Unexpected value for property enum");
+      }
+    }
+  }
+#endif
+}
+
 //===----------------------------------------------------------------------===//
 // MachineFunction implementation
 //===----------------------------------------------------------------------===//
 
 // Out-of-line virtual method.
 MachineFunctionInfo::~MachineFunctionInfo() {}
 
 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {

 StringRef MachineFunction::getName() const {
   assert(getFunction() && "No function!");
   return getFunction()->getName();
 }
 
 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
   OS << "# Machine code for function " << getName() << ": ";
   if (RegInfo) {
     OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
     if (!RegInfo->tracksLiveness())
       OS << ", not tracking liveness";
   }
   OS << '\n';
 
   // Print Frame Information
   FrameInfo->print(*this, OS);
 

lib/CodeGen/MachineFunctionPass.cpp

bool MachineFunctionPass::runOnFunction(Function &F) {
   // Do not codegen any 'available_externally' functions at all, they have
   // definitions outside the translation unit.
   if (F.hasAvailableExternallyLinkage())
     return false;
 
   MachineFunction &MF = getAnalysis<MachineFunctionAnalysis>().getMF();
   MachineFunctionProperties &MFProps = MF.getProperties();
 
-  assert(MFProps.verifyRequiredProperties(RequiredProperties) &&
-         "Properties required by the pass are not met by the function");
+#ifndef NDEBUG
+  if (!MFProps.verifyRequiredProperties(RequiredProperties)) {
+    errs() << "MachineFunctionProperties required by " << getPassName()
+           << " pass are not met by function " << F.getName() << ".\n"
+           << "Required properties: ";
+    RequiredProperties.dump(errs());
+    errs() << "\nCurrent properties: ";
+    MFProps.dump(errs());
+    errs() << "\n";
+    llvm_unreachable("MachineFunctionProperties check failed");
+  }
+#endif
 
   bool RV = runOnMachineFunction(MF);
 
   MFProps.set(SetProperties);
   MFProps.clear(ClearedProperties);
   return RV;
 }