Add formatting/static analysis (#486)

* Reform source with clang-format.

Rules applied with:
    $ find . -iname *.h -o -iname *.cc | xargs clang-format \
        -style=file -i -fallback-style=google

* Add clang-format and analyze to build.

Based on the excellent work at: https://github.com/ttroy50/cmake-examples

* Clean up CMake stuff on macOS.

* Remove vim/emacs modelines.

* Update copyright dates.

* Build fixes.

* Build fixes.

* Build fixes.

* Build fixes.

* Build fixes.

* Build fixes.

cmake/scripts/clang-format-check-changed.py

@@ -0,0 +1,163 @@
+#!/usr/bin/env python
+
+import argparse
+import os
+import sys
+import subprocess
+
+
+def check_file(filename, excludes, extensions):
+    """
+    Check if a file should be included in our check
+    """
+    name, ext = os.path.splitext(filename)
+
+    if len(ext) > 0 and ext in extensions:
+        if len(excludes) == 0:
+            return True
+
+        for exclude in excludes:
+            if exclude in filename:
+                return False
+
+        return True
+
+    return False
+
+
+def check_directory(directory, excludes, extensions):
+    output = []
+
+    if len(excludes) > 0:
+        for exclude in excludes:
+            if exclude in directory:
+                directory_excluded = False
+                return output
+
+    for root, _, files in os.walk(directory):
+        for file in files:
+            filename = os.path.join(root, file)
+            if check_file(filename, excludes, extensions):
+                print("Will check file [{}]".format(filename))
+                output.append(filename)
+    return output
+
+def get_git_root(git_bin):
+    cmd = [git_bin, "rev-parse", "--show-toplevel"]
+    try:
+        return subprocess.check_output(cmd).strip()
+    except subprocess.CalledProcessError, e:
+        print("Error calling git [{}]".format(e))
+        raise
+
+def clean_git_filename(line):
+    """
+    Takes a line from git status --porcelain and returns the filename
+    """
+    file = None
+    git_status = line[:2]
+    # Not an exhaustive list of git status output but should
+    # be enough for this case
+    # check if this is a delete
+    if 'D' in git_status:
+        return None
+    # ignored file
+    if '!' in git_status:
+        return None
+    # Covers renamed files
+    if '->' in line:
+        file = line[3:].split('->')[-1].strip()
+    else:
+        file = line[3:].strip()
+
+    return file
+
+
+def get_changed_files(git_bin, excludes, file_extensions):
+    """
+    Run git status and return the list of changed files
+    """
+    extensions = file_extensions.split(",")
+    # arguments coming from cmake will be *.xx. We want to remove the *
+    for i, extension in enumerate(extensions):
+        if extension[0] == '*':
+            extensions[i] = extension[1:]
+
+    git_root = get_git_root(git_bin)
+
+    cmd = [git_bin, "status", "--porcelain", "--ignore-submodules"]
+    print("git cmd = {}".format(cmd))
+    output = []
+    returncode = 0
+    try:
+        cmd_output = subprocess.check_output(cmd)
+        for line in cmd_output.split('\n'):
+            if len(line) > 0:
+                file = clean_git_filename(line)
+                if not file:
+                    continue
+                file = os.path.join(git_root, file)
+
+                if file[-1] == "/":
+                    directory_files = check_directory(
+                        file, excludes, file_extensions)
+                    output = output + directory_files
+                else:
+                    if check_file(file, excludes, file_extensions):
+                        print("Will check file [{}]".format(file))
+                        output.append(file)
+
+    except subprocess.CalledProcessError, e:
+        print("Error calling git [{}]".format(e))
+        returncode = e.returncode
+
+    return output, returncode
+
+
+def run_clang_format(clang_format_bin, changed_files):
+    """
+    Run clang format on a list of files 
+    @return 0 if formatted correctly.
+    """
+    if len(changed_files) == 0:
+        return 0
+    cmd = [clang_format_bin, "-style=file",
+           "-output-replacements-xml"] + changed_files
+    print("clang-format cmd = {}".format(cmd))
+    try:
+        cmd_output = subprocess.check_output(cmd)
+        if "replacement offset" in cmd_output:
+            print("ERROR: Changed files don't match format")
+            return 1
+    except subprocess.CalledProcessError, e:
+        print("Error calling clang-format [{}]".format(e))
+        return e.returncode
+
+    return 0
+
+
+def cli():
+    # global params
+    parser = argparse.ArgumentParser(prog='clang-format-check-changed',
+                                     description='Checks if files chagned in git match the .clang-format specification')
+    parser.add_argument("--file-extensions", type=str,
+                        default=".cpp,.h,.cxx,.hxx,.hpp,.cc,.ipp",
+                        help="Comma seperated list of file extensions to check")
+    parser.add_argument('--exclude', action='append', default=[],
+                        help='Will not match the files / directories with these in the name')
+    parser.add_argument('--clang-format-bin', type=str, default="clang-format",
+                        help="The clang format binary")
+    parser.add_argument('--git-bin', type=str, default="git",
+                        help="The git binary")
+    args = parser.parse_args()
+
+    # Run gcovr to get the .gcda files form .gcno
+    changed_files, returncode = get_changed_files(
+        args.git_bin, args.exclude, args.file_extensions)
+    if returncode != 0:
+        return returncode
+
+    return run_clang_format(args.clang_format_bin, changed_files)
+
+if __name__ == '__main__':
+    sys.exit(cli())