Add underscores to private data members (#898)

This is the last PR I plan to have focused on #720

executable_semantics/syntax/parse_and_lex_context.h

@@ -18,13 +18,13 @@ class ParseAndLexContext {
  public:
   // Creates an instance analyzing the given input file.
   ParseAndLexContext(Nonnull<const std::string*> input_file_name, bool trace)
-      : input_file_name(input_file_name), trace_(trace) {}
+      : input_file_name_(input_file_name), trace_(trace) {}
 
   // Writes a syntax error diagnostic containing message to standard error.
   auto PrintDiagnostic(const std::string& message) -> void;
 
   auto source_loc() -> SourceLocation {
-    return SourceLocation(input_file_name,
+    return SourceLocation(input_file_name_,
                           static_cast<int>(current_token_position.begin.line));
   }
 
@@ -36,7 +36,7 @@ class ParseAndLexContext {
  private:
   // A path to the file processed, relative to the current working directory
   // when *this is called.
-  Nonnull<const std::string*> input_file_name;
+  Nonnull<const std::string*> input_file_name_;
 
   bool trace_;
 };