cpp

clang-format-tugraz

Provides a .clang-format configuration that satisfies the C++ coding standard of TUGraz.

Usage

With the .clang-format file in the current directory, run the following command to format ../assignment/file.cpp:

clang-format -style=file ../assignment/file.cpp -i

Created with clang-format-configurator

Mostly custom rules with Mozilla style as fallback.

CS inconsistencies:

• Empty lines with spaces: "Exception Basisklasse" example (occurs in almost all examples)

• Random empty line: "Haupt .cpp Datei" example

  try
  
  {
    result = style.calculateSum(10, 20);
  } 
  catch(Sep::InvalidArgumentException& caught_exception)
  {
    //handle exception - silent catch is bad!
  }
  

Things not correctly formatted by clang-format

Indentation of access modifier blocks

//----------------------------------------------------------------------------
// Custom Made Invalid Argument Exception
// class to demonstrate the styleguide
//
class InvalidArgumentException : OwnBaseException
{
  public:
    //--------------------------------------------------------------------------
    // Constructor
    // Constructs the excpeption and outputs the error message.
    //
    InvalidArgumentException(const char* message);
};

will be wrongly formatted as

//----------------------------------------------------------------------------
// Custom Made Invalid Argument Exception
// class to demonstrate the styleguide
//
class InvalidArgumentException : OwnBaseException
{
  public:
  //--------------------------------------------------------------------------
  // Constructor
  // Constructs the excpeption and outputs the error message.
  //
  InvalidArgumentException(const char* message);
};

Notice the missing indentation layer of the public methods.

There is apparently no way to configure clang-format to do this

Things not checked by clang-format

Naming

	Naming convention
Classes, Enums, Structs, Unions and Namespaces	AllWordsCapitalizedWithoutUnderscore
Methods and Functions	firstWordLowerCaseRestCapitalizedWithoutUnderscores
Local variables and parameters	all_lower_case_with_underscores
Class member variables	all_lower_case_with_underscores_and_trailing_underscore_
Constants, Enum elements, Includeguards	ALL_UPPERCASE_WITH_UNDERSCORES

Parameter consistency

Parameter order should be consistent. (Either one is fine.)

int insert(List* list, Element* element); // First parameter is the list, second parameter the element to insert
int remove(Element* element, List* list); // Seems odd that you now first enter the element to remove, doesn't it?

File header

//-----------------------------------------------------------------------------
// <Filename>.cpp
//
// Group: Group <Group Number>, study assistant <Name of Study assistant>
//
// Authors: <Name> <Matriculum Number>
// <Name> <Matriculum Number>
// <Add one row for every additional group member>
//-----------------------------------------------------------------------------
//

Class and function header

//------------------------------------------------------------------------------
// This is an example header comment. Feel free to copypaste and adapt it!
//
// @param human the human to check
// @param number_to_return_if_not_married the number to return if the human
//        is not married. Should be 0 or 1 for example purposes
//
// @return int age of spouse
//
int getAgeOfSpouse(Human* human, int number_to_return_if_not_married)
{
  ...
}

Header comments are only necessary in header files (*.h). Additionally, getter and setter functions can be grouped as shown in this code example.

Group code segments

int MyClass::doSomething()
{
  // Calculate prerequesites
  int some_variable = clacPrerequesite1();
  int some_other_var = calcPrerequesite2();

  // Perform main calculation
  int intermediate_result = numberCrunchPreprocess(some_variable, some_other_var);
  int result = numberCrunchMagicHappensHere(intermediate_result);

  // Finalize and return result
  return prettify(result);
}

Group code segments with empty lines.

Includeguards

#ifndef MY_CLASS_H
#define MY_CLASS_H
class MyClass
{
};
#endif // MY_CLASS_H

Types definitions must be surrounded by includeguards.

Initializer lists

MyClass::MyClass()
{
  counter_ = 0;
}

should be

MyClass::MyClass() : counter_(0)
{
}

Multi-assignment

int a = 0, b = 1, c = 2;

should be

int a = 0;
int b = 0;
int c = 0;

Braces around single-line statements

if (1 == 1)
  print("foo");

should be

if (1 == 1)
{
  print("foo");
}

Additional

• Try not to include header files from within header files.
• Don't include whole namespaces (i.e. don't using namespace std;).
• Use C++ casts instead of C ones.
• Class member variables must not be public.