Make Function::getInstructionCount const

[mtrofin]

Summary

Function::getInstructionCount can be const.

[davidxl]

lgtm

include/llvm/IR/Function.h

static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
                           const Twine &N, Module &M);
 
   // Provide fast operand accessors.
   DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
 
   /// Returns the number of non-debug IR instructions in this function.
   /// This is equivalent to the sum of the sizes of each basic block contained
   /// within this function.
-  unsigned getInstructionCount();
+  unsigned getInstructionCount() const;
 
   /// Returns the FunctionType for me.
   FunctionType *getFunctionType() const {
     return cast<FunctionType>(getValueType());
   }
 
   /// Returns the type of the ret val.
   Type *getReturnType() const { return getFunctionType()->getReturnType(); }

lib/IR/Function.cpp

 //===----------------------------------------------------------------------===//
 // Helper Methods in Function
 //===----------------------------------------------------------------------===//
 
 LLVMContext &Function::getContext() const {
   return getType()->getContext();
 }
 
-unsigned Function::getInstructionCount() {
+unsigned Function::getInstructionCount() const {
   unsigned NumInstrs = 0;
-  for (BasicBlock &BB : BasicBlocks)
+  for (const BasicBlock &BB : BasicBlocks)
     NumInstrs += std::distance(BB.instructionsWithoutDebug().begin(),
                                BB.instructionsWithoutDebug().end());
   return NumInstrs;
 }
 
 Function *Function::Create(FunctionType *Ty, LinkageTypes Linkage,
                            const Twine &N, Module &M) {
   return Create(Ty, Linkage, M.getDataLayout().getProgramAddressSpace(), N, &M);