[clang][bytecode] Accept current PC argument in Function::dump() (#170449)

This is useful since we can highlight the opcode that OpPC points to.

Author: tbaederr

clang/lib/AST/ByteCode/Disasm.cpp

@@ -138,9 +138,16 @@ static size_t getNumDisplayWidth(size_t N) {
   return L;
 }
 
-LLVM_DUMP_METHOD void Function::dump() const { dump(llvm::errs()); }
+LLVM_DUMP_METHOD void Function::dump(CodePtr PC) const {
+  dump(llvm::errs(), PC);
+}
 
-LLVM_DUMP_METHOD void Function::dump(llvm::raw_ostream &OS) const {
+LLVM_DUMP_METHOD void Function::dump(llvm::raw_ostream &OS,
+                                     CodePtr OpPC) const {
+  if (OpPC) {
+    assert(OpPC >= getCodeBegin());
+    assert(OpPC <= getCodeEnd());
+  }
   {
     ColorScope SC(OS, true, {llvm::raw_ostream::BRIGHT_GREEN, true});
     OS << getName() << " " << (const void *)this << "\n";
@@ -154,6 +161,7 @@ LLVM_DUMP_METHOD void Function::dump(llvm::raw_ostream &OS) const {
     size_t Addr;
     std::string Op;
     bool IsJump;
+    bool CurrentOp = false;
     llvm::SmallVector<std::string> Args;
   };
 
@@ -171,6 +179,7 @@ LLVM_DUMP_METHOD void Function::dump(llvm::raw_ostream &OS) const {
     auto Op = PC.read<Opcode>();
     Text.Addr = Addr;
     Text.IsJump = isJumpOpcode(Op);
+    Text.CurrentOp = (PC == OpPC);
     switch (Op) {
 #define GET_DISASM
 #include "Opcodes.inc"
@@ -198,9 +207,15 @@ LLVM_DUMP_METHOD void Function::dump(llvm::raw_ostream &OS) const {
   Text.reserve(Code.size());
   size_t LongestLine = 0;
   // Print code to a string, one at a time.
-  for (auto C : Code) {
+  for (const auto &C : Code) {
     std::string Line;
     llvm::raw_string_ostream LS(Line);
+    if (OpPC) {
+      if (C.CurrentOp)
+        LS << " * ";
+      else
+        LS << "   ";
+    }
     LS << C.Addr;
     LS.indent(LongestAddr - getNumDisplayWidth(C.Addr) + 4);
     LS << C.Op;

clang/lib/AST/ByteCode/Function.h

@@ -312,8 +312,8 @@ class Function final {
 
 public:
   /// Dumps the disassembled bytecode to \c llvm::errs().
-  void dump() const;
-  void dump(llvm::raw_ostream &OS) const;
+  void dump(CodePtr PC = {}) const;
+  void dump(llvm::raw_ostream &OS, CodePtr PC = {}) const;
 };
 
 } // namespace interp

clang/lib/AST/ByteCode/Source.h

@@ -51,6 +51,7 @@ class CodePtr final {
   explicit operator bool() const { return Ptr; }
   bool operator<=(const CodePtr &RHS) const { return Ptr <= RHS.Ptr; }
   bool operator>=(const CodePtr &RHS) const { return Ptr >= RHS.Ptr; }
+  bool operator==(const CodePtr RHS) const { return Ptr == RHS.Ptr; }
 
   /// Reads data and advances the pointer.
   template <typename T> std::enable_if_t<!std::is_pointer<T>::value, T> read() {