Use #pragma once instead of preprocessor guards (#93)

Other tasks achieved by this commit:
- Fix hooks for shebang and Py3 compatibility.
- Reformat some header files to comply with code style.

Author: robertodr

.githooks/license_maintainer.py

@@ -23,39 +23,39 @@
 
 from datetime import date
 import glob
-import mmap
 import os
 import re
 import shutil
 import tempfile
 
+
 def add_header(filepath, header, YEAR, AUTHORS):
     """
     Add or update header in source file
     """
     tmpdir = tempfile.gettempdir()
     tmpfil = os.path.join(tmpdir, os.path.basename(filepath) + '.bak')
     shutil.copy2(filepath, tmpfil)
-    with open(tmpfil, 'r+b') as tmp:
+    with open(tmpfil, 'r') as tmp:
         inpt = tmp.readlines()
         output = []
 
         # Check if header is already present
         present = re.compile('PCMSolver, an API for the Polarizable Continuum Model')
-        if filter(present.search, inpt):
+        if list(filter(present.search, inpt)):
             # Check if year and authors in current file are up to date
             toupdate = re.compile(r'{0} (?!{1} {2}).*\n'.format('Copyright \(C\)', YEAR, AUTHORS))
-            if filter(toupdate.search, inpt):
-                print('Updating header in {}'.format(filepath))
+            if list(filter(toupdate.search, inpt)):
+                print(('Updating header in {}'.format(filepath)))
                 # Check to preserve '#!' at the top of the file
                 if len(inpt) > 0 and inpt[0].startswith('#!'):
                     output.append(inpt[0] + '\n')
                     inpt = inpt[1:]
                 regex = re.compile(r'Copyright \(C\).*\n')
                 repl  = r'Copyright (C) ' + YEAR + ' ' + AUTHORS + '\n'
-                output.extend(map(lambda x: re.sub(regex, repl, x), inpt))
+                output.extend([re.sub(regex, repl, x) for x in inpt])
         else:
-            print('Adding header in {}'.format(filepath))
+            print(('Adding header in {}'.format(filepath)))
             # Check to preserve '#!' at the top of the file
             if len(inpt) > 0 and inpt[0].startswith('#!'):
                 output.append(inpt[0] + '\n')
@@ -68,8 +68,8 @@ def add_header(filepath, header, YEAR, AUTHORS):
             try:
                 f = open(filepath, 'w')
                 f.writelines(output)
-            except IOError, err:
-                print('Something went wrong trying to add header to {}: {}'.format(filepath, err))
+            except IOError as err:
+                print(('Something went wrong trying to add header to {}: {}'.format(filepath, err)))
             finally:
                 f.close()
         os.remove(tmpfil)
@@ -79,12 +79,12 @@ def prepare_header(stub, YEAR, AUTHORS):
     """
     Update year and author information in license header template
     """
-    with open(stub, 'r+b') as l:
+    with open(stub, 'r') as l:
         header = l.read()
         # Insert correct YEAR and AUTHORS in stub
         rep = {'YEAR' : YEAR, 'AUTHORS' : AUTHORS}
-        rep = dict((re.escape(k), v) for k, v in rep.iteritems())
-        pattern = re.compile("|".join(rep.keys()))
+        rep = dict((re.escape(k), v) for k, v in rep.items())
+        pattern = re.compile("|".join(list(rep.keys())))
         header = pattern.sub(lambda m: rep[re.escape(m.group(0))], header)
     return header
 
@@ -94,26 +94,26 @@ def file_license(attributes):
     Obtain dictionary { file : license } from .gitattributes
     """
     file_license = {}
-    with open(attributes, 'r+b') as f:
+    with open(attributes, 'r') as f:
         # Read in .gitattributes
-        tmp_mm = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
+        tmp = f.read()
         # Removing all comment lines and other attributes
-        pattern = re.compile("|".join([r'(?m)^\#.*\n?', r'^((?!licensefile).)*$']))
-        gitattributes = re.sub(pattern, '', tmp_mm).split()
+        pattern = re.compile(r'(?m)^\#.*\n?|^((?!licensefile).)*$')
+        gitattributes = re.sub(pattern, '', tmp).split()
         # Obtain list of files
         fil = [x for x in gitattributes if not 'licensefile' in x]
         # Remove licensefile= from strings
         lic = [re.sub(r'licensefile\=', '', x) for x in gitattributes if 'licensefile' in x]
         # Create list of blacklisted files
-        blacklist = [fname for key, value in dict(zip(fil, lic)).items()
+        blacklist = [fname for key, value in list(dict(list(zip(fil, lic))).items())
                        if value == '!licensefile'
                        for fname in glob.glob(key)]
         # Now create a dictionary with the files to be considered for
         # license header manipulation
-        file_license = { key : value
-                  for k, value in dict(zip(fil, lic)).items()
-                  for key in glob.glob(k)
-                  if key not in blacklist}
+        file_license = {key: value
+                        for k, value in list(dict(list(zip(fil, lic))).items())
+                        for key in glob.glob(k)
+                        if key not in blacklist}
     return file_license
 
 
@@ -129,7 +129,7 @@ def license_maintainer():
 
     headerize = file_license(os.path.join(project_root_dir, '.gitattributes'))
 
-    for fname, license in headerize.items():
+    for fname, license in list(headerize.items()):
         # Prepare header
         header = prepare_header(os.path.join(project_root_dir, license), YEAR, AUTHORS)
         add_header(fname, header, YEAR, AUTHORS)

.githooks/pre-commit-clang-format

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # git pre-commit hook that runs an clang-format stylecheck.
 # Features:

.githooks/pre-commit-license-maintainer

@@ -1,3 +1,3 @@
-#!/bin/bash
+#!/bin/sh
 
 python .githooks/license_maintainer.py

CHANGELOG.md

@@ -13,6 +13,12 @@
   of the ASC.
 - Restored compilation for g++ < v5.1.
 
+### Changed
+
+- Use [`#pragma once`](https://en.wikipedia.org/wiki/Pragma_once) instead of
+  `#ifndef, #define, #endif` to guard against multiple inclusion of header
+  files.
+
 ## [Version 1.1.10] - 2017-03-27
 
 ### Changed

api/PCMInput.h

@@ -21,8 +21,7 @@
  * PCMSolver API, see: <http://pcmsolver.readthedocs.io/>
  */
 
-#ifndef PCMINPUT_H
-#define PCMINPUT_H
+#pragma once
 
 // To cope with the fact that C doesn't have bool as primitive type
 #ifndef pcmsolver_bool_t_DEFINED
@@ -78,5 +77,3 @@ typedef struct PCMInput {
   /// Type of Green's function requested outside the cavity.
   char outside_type[22];
 } PCMInput;
-
-#endif // PCMINPUT_H

api/pcmsolver.h

@@ -21,10 +21,10 @@
  * PCMSolver API, see: <http://pcmsolver.readthedocs.io/>
  */
 
-#ifndef PCMSOLVER_H_INCLUDED
-#define PCMSOLVER_H_INCLUDED
+#pragma once
 
 #include <stddef.h>
+
 #include "PCMInput.h"
 #include "PCMSolverExport.h"
 
@@ -271,5 +271,3 @@ PCMSolver_API void pcmsolver_write_timings(pcmsolver_context_t * context);
 #ifdef __cplusplus
 }
 #endif
-
-#endif /* PCMSOLVER_H_INCLUDED */

doc/programmers/coding-standards.rst

@@ -31,8 +31,7 @@ Follow these guidelines to decide whether to include or forward declare:
 
 .. code-block:: cpp
 
-    #ifndef MYCLASS_HPP
-    #define MYCLASS_HPP
+    #pragma once
 
     //==============================
     // Forward declared dependencies
@@ -57,8 +56,6 @@ Follow these guidelines to decide whether to include or forward declare:
                                   //    don't do anything about MyFriend
     };
 
-    #endif // MYCLASS_HPP
-
 
 Proper overloading of `operator<<`
 ----------------------------------

include/Citation.hpp

@@ -21,8 +21,7 @@
  * PCMSolver API, see: <http://pcmsolver.readthedocs.io/>
  */
 
-#ifndef CITATION_HPP
-#define CITATION_HPP
+#pragma once
 
 #include <algorithm>
 #include <sstream>
@@ -45,7 +44,8 @@ inline std::string citation_message() {
   std::string version(TOSTRING(PROJECT_VERSION));
   rest << "\n" << std::endl;
   rest << " * PCMSolver, an API for the Polarizable Continuum Model electrostatic "
-          "problem. Version " << version << std::endl;
+          "problem. Version "
+       << version << std::endl;
   rest << "   Main authors: R. Di Remigio, L. Frediani, K. Mozgawa" << std::endl;
   rest << "    With contributions from:" << std::endl;
   rest << "     R. Bast            (CMake framework)" << std::endl;
@@ -54,9 +54,11 @@ inline std::string citation_message() {
        << std::endl;
   rest << "   Theory: - J. Tomasi, B. Mennucci and R. Cammi:" << std::endl;
   rest << "            \"Quantum Mechanical Continuum Solvation Models\", Chem. "
-          "Rev., 105 (2005) 2999" << std::endl;
+          "Rev., 105 (2005) 2999"
+       << std::endl;
   rest << "   PCMSolver is distributed under the terms of the GNU Lesser General "
-          "Public License." << std::endl;
+          "Public License."
+       << std::endl;
   return rest.str();
 }
 
@@ -67,5 +69,3 @@ inline std::string version_info() {
   retval << " * Git last commit author : " << GIT_COMMIT_AUTHOR << std::endl;
   return retval.str();
 }
-
-#endif // CITATION_HPP

include/Cxx11Workarounds.hpp

@@ -21,8 +21,7 @@
  * PCMSolver API, see: <http://pcmsolver.readthedocs.io/>
  */
 
-#ifndef CXX11WORKAROUNDS_HPP
-#define CXX11WORKAROUNDS_HPP
+#pragma once
 
 /*! \file Cxx11Workarounds.hpp
  *  \brief Provide hacks and workarounds for C++11
@@ -73,8 +72,8 @@ using std::to_string;
 } /* end namespace pcm */
 #else /* HAS_CXX11*/
 /* Smart pointers workarounds */
-#include <boost/shared_ptr.hpp>
 #include <boost/make_shared.hpp>
+#include <boost/shared_ptr.hpp>
 namespace pcm {
 using boost::shared_ptr;
 using boost::make_shared;
@@ -105,8 +104,8 @@ namespace pcm {
 using boost::array;
 } /* end namespace pcm */
 /* std::to_string workarounds */
-#include <string>
 #include <boost/lexical_cast.hpp>
+#include <string>
 namespace pcm {
 template <typename Source> std::string to_string(const Source & arg) {
   return boost::lexical_cast<std::string>(arg);
@@ -153,5 +152,3 @@ template <typename Source> std::string to_string(const Source & arg) {
 #else /* HAS_CXX11_NORETURN */
 #define __noreturn
 #endif /* HAS_CXX11_NORETURN */
-
-#endif /* CXX11WORKAROUNDS_HPP */

include/ErrorHandling.hpp

@@ -21,8 +21,7 @@
  * PCMSolver API, see: <http://pcmsolver.readthedocs.io/>
  */
 
-#ifndef ERRORHANDLING_HPP
-#define ERRORHANDLING_HPP
+#pragma once
 
 #include <cassert>
 #include <cstdio>
@@ -76,7 +75,8 @@
     std::ostringstream _err;                                                        \
     _err << "PCMSolver fatal error.\n"                                              \
          << " In function " << __func__ << " at line " << __LINE__ << " of file "   \
-         << __FILE__ << "\n" << message << std::endl;                               \
+         << __FILE__ << "\n"                                                        \
+         << message << std::endl;                                                   \
     std::fprintf(stderr, "%s\n", _err.str().c_str());                               \
     std::exit(EXIT_FAILURE);                                                        \
   }
@@ -91,5 +91,3 @@
 #include <boost/static_assert.hpp>
 #define PCMSOLVER_STATIC_ASSERT(arg, msg) BOOST_STATIC_ASSERT_MSG(arg, msg)
 #endif /* HAS_CXX11_STATIC_ASSERT */
-
-#endif /* ERRORHANDLING_HPP */