Added framework as a flattened directory

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/framework/scripts/check_files.py b/framework/scripts/check_files.py
new file mode 100755
index 0000000..d3a61c1
--- /dev/null
+++ b/framework/scripts/check_files.py
@@ -0,0 +1,575 @@
+#!/usr/bin/env python3
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+
+"""
+This script checks the current state of the source code for minor issues,
+including incorrect file permissions, presence of tabs, non-Unix line endings,
+trailing whitespace, and presence of UTF-8 BOM.
+Note: requires python 3, must be run from Mbed TLS root.
+"""
+
+import argparse
+import codecs
+import inspect
+import logging
+import os
+import re
+import subprocess
+import sys
+try:
+    from typing import FrozenSet, Optional, Pattern # pylint: disable=unused-import
+except ImportError:
+    pass
+
+from mbedtls_framework import build_tree
+
+
+class FileIssueTracker:
+    """Base class for file-wide issue tracking.
+
+    To implement a checker that processes a file as a whole, inherit from
+    this class and implement `check_file_for_issue` and define ``heading``.
+
+    ``suffix_exemptions``: files whose name ends with a string in this set
+     will not be checked.
+
+    ``path_exemptions``: files whose path (relative to the root of the source
+    tree) matches this regular expression will not be checked. This can be
+    ``None`` to match no path. Paths are normalized and converted to ``/``
+    separators before matching.
+
+    ``heading``: human-readable description of the issue
+    """
+
+    suffix_exemptions = frozenset() #type: FrozenSet[str]
+    path_exemptions = None #type: Optional[Pattern[str]]
+    # heading must be defined in derived classes.
+    # pylint: disable=no-member
+
+    def __init__(self):
+        self.files_with_issues = {}
+
+    @staticmethod
+    def normalize_path(filepath):
+        """Normalize ``filepath`` with / as the directory separator."""
+        filepath = os.path.normpath(filepath)
+        # On Windows, we may have backslashes to separate directories.
+        # We need slashes to match exemption lists.
+        seps = os.path.sep
+        if os.path.altsep is not None:
+            seps += os.path.altsep
+        return '/'.join(filepath.split(seps))
+
+    def should_check_file(self, filepath):
+        """Whether the given file name should be checked.
+
+        Files whose name ends with a string listed in ``self.suffix_exemptions``
+        or whose path matches ``self.path_exemptions`` will not be checked.
+        """
+        for files_exemption in self.suffix_exemptions:
+            if filepath.endswith(files_exemption):
+                return False
+        if self.path_exemptions and \
+           re.match(self.path_exemptions, self.normalize_path(filepath)):
+            return False
+        return True
+
+    def check_file_for_issue(self, filepath):
+        """Check the specified file for the issue that this class is for.
+
+        Subclasses must implement this method.
+        """
+        raise NotImplementedError
+
+    def record_issue(self, filepath, line_number):
+        """Record that an issue was found at the specified location."""
+        if filepath not in self.files_with_issues.keys():
+            self.files_with_issues[filepath] = []
+        self.files_with_issues[filepath].append(line_number)
+
+    def output_file_issues(self, logger):
+        """Log all the locations where the issue was found."""
+        if self.files_with_issues.values():
+            logger.info(self.heading)
+            for filename, lines in sorted(self.files_with_issues.items()):
+                if lines:
+                    logger.info("{}: {}".format(
+                        filename, ", ".join(str(x) for x in lines)
+                    ))
+                else:
+                    logger.info(filename)
+            logger.info("")
+
+BINARY_FILE_PATH_RE_LIST = [
+    r'docs/.*\.pdf\Z',
+    r'docs/.*\.png\Z',
+    r'tf-psa-crypto/docs/.*\.pdf\Z',
+    r'tf-psa-crypto/docs/.*\.png\Z',
+    r'programs/fuzz/corpuses/[^.]+\Z',
+    r'framework/data_files/[^.]+\Z',
+    r'framework/data_files/.*\.(crt|csr|db|der|key|pubkey)\Z',
+    r'framework/data_files/.*\.req\.[^/]+\Z',
+    r'framework/data_files/.*malformed[^/]+\Z',
+    r'framework/data_files/format_pkcs12\.fmt\Z',
+    r'framework/data_files/.*\.bin\Z',
+]
+BINARY_FILE_PATH_RE = re.compile('|'.join(BINARY_FILE_PATH_RE_LIST))
+
+class LineIssueTracker(FileIssueTracker):
+    """Base class for line-by-line issue tracking.
+
+    To implement a checker that processes files line by line, inherit from
+    this class and implement `line_with_issue`.
+    """
+
+    # Exclude binary files.
+    path_exemptions = BINARY_FILE_PATH_RE
+
+    def issue_with_line(self, line, filepath, line_number):
+        """Check the specified line for the issue that this class is for.
+
+        Subclasses must implement this method.
+        """
+        raise NotImplementedError
+
+    def check_file_line(self, filepath, line, line_number):
+        if self.issue_with_line(line, filepath, line_number):
+            self.record_issue(filepath, line_number)
+
+    def check_file_for_issue(self, filepath):
+        """Check the lines of the specified file.
+
+        Subclasses must implement the ``issue_with_line`` method.
+        """
+        with open(filepath, "rb") as f:
+            for i, line in enumerate(iter(f.readline, b"")):
+                self.check_file_line(filepath, line, i + 1)
+
+
+def is_windows_file(filepath):
+    _root, ext = os.path.splitext(filepath)
+    return ext in ('.bat', '.dsp', '.dsw', '.sln', '.vcxproj')
+
+
+class ShebangIssueTracker(FileIssueTracker):
+    """Track files with a bad, missing or extraneous shebang line.
+
+    Executable scripts must start with a valid shebang (#!) line.
+    """
+
+    heading = "Invalid shebang line:"
+
+    # Allow either /bin/sh, /bin/bash, or /usr/bin/env.
+    # Allow at most one argument (this is a Linux limitation).
+    # For sh and bash, the argument if present must be options.
+    # For env, the argument must be the base name of the interpreter.
+    _shebang_re = re.compile(rb'^#! ?(?:/bin/(bash|sh)(?: -[^\n ]*)?'
+                             rb'|/usr/bin/env ([^\n /]+))$')
+    _extensions = {
+        b'bash': 'sh',
+        b'perl': 'pl',
+        b'python3': 'py',
+        b'sh': 'sh',
+    }
+
+    path_exemptions = re.compile(r'framework/scripts/quiet/.*')
+
+    def is_valid_shebang(self, first_line, filepath):
+        m = re.match(self._shebang_re, first_line)
+        if not m:
+            return False
+        interpreter = m.group(1) or m.group(2)
+        if interpreter not in self._extensions:
+            return False
+        if not filepath.endswith('.' + self._extensions[interpreter]):
+            return False
+        return True
+
+    def check_file_for_issue(self, filepath):
+        is_executable = os.access(filepath, os.X_OK)
+        with open(filepath, "rb") as f:
+            first_line = f.readline()
+        if first_line.startswith(b'#!'):
+            if not is_executable:
+                # Shebang on a non-executable file
+                self.files_with_issues[filepath] = None
+            elif not self.is_valid_shebang(first_line, filepath):
+                self.files_with_issues[filepath] = [1]
+        elif is_executable:
+            # Executable without a shebang
+            self.files_with_issues[filepath] = None
+
+
+class EndOfFileNewlineIssueTracker(FileIssueTracker):
+    """Track files that end with an incomplete line
+    (no newline character at the end of the last line)."""
+
+    heading = "Missing newline at end of file:"
+
+    path_exemptions = BINARY_FILE_PATH_RE
+
+    def check_file_for_issue(self, filepath):
+        with open(filepath, "rb") as f:
+            try:
+                f.seek(-1, 2)
+            except OSError:
+                # This script only works on regular files. If we can't seek
+                # 1 before the end, it means that this position is before
+                # the beginning of the file, i.e. that the file is empty.
+                return
+            if f.read(1) != b"\n":
+                self.files_with_issues[filepath] = None
+
+
+class Utf8BomIssueTracker(FileIssueTracker):
+    """Track files that start with a UTF-8 BOM.
+    Files should be ASCII or UTF-8. Valid UTF-8 does not start with a BOM."""
+
+    heading = "UTF-8 BOM present:"
+
+    suffix_exemptions = frozenset([".vcxproj", ".sln"])
+    path_exemptions = BINARY_FILE_PATH_RE
+
+    def check_file_for_issue(self, filepath):
+        with open(filepath, "rb") as f:
+            if f.read().startswith(codecs.BOM_UTF8):
+                self.files_with_issues[filepath] = None
+
+
+class UnicodeIssueTracker(LineIssueTracker):
+    """Track lines with invalid characters or invalid text encoding."""
+
+    heading = "Invalid UTF-8 or forbidden character:"
+
+    # Only allow valid UTF-8, and only other explicitly allowed characters.
+    # We deliberately exclude all characters that aren't a simple non-blank,
+    # non-zero-width glyph, apart from a very small set (tab, ordinary space,
+    # line breaks, "basic" no-break space and soft hyphen). In particular,
+    # non-ASCII control characters, combinig characters, and Unicode state
+    # changes (e.g. right-to-left text) are forbidden.
+    # Note that we do allow some characters with a risk of visual confusion,
+    # for example '-' (U+002D HYPHEN-MINUS) vs '­' (U+00AD SOFT HYPHEN) vs
+    # '‐' (U+2010 HYPHEN), or 'A' (U+0041 LATIN CAPITAL LETTER A) vs
+    # 'Α' (U+0391 GREEK CAPITAL LETTER ALPHA).
+    GOOD_CHARACTERS = ''.join([
+        '\t\n\r -~', # ASCII (tabs and line endings are checked separately)
+        '\u00A0-\u00FF', # Latin-1 Supplement (for NO-BREAK SPACE and punctuation)
+        '\u2010-\u2027\u2030-\u205E', # General Punctuation (printable)
+        '\u2070\u2071\u2074-\u208E\u2090-\u209C', # Superscripts and Subscripts
+        '\u2190-\u21FF', # Arrows
+        '\u2200-\u22FF', # Mathematical Symbols
+        '\u2500-\u257F' # Box Drawings characters used in markdown trees
+    ])
+    # Allow any of the characters and ranges above, and anything classified
+    # as a word constituent.
+    GOOD_CHARACTERS_RE = re.compile(r'[\w{}]+\Z'.format(GOOD_CHARACTERS))
+
+    def issue_with_line(self, line, _filepath, line_number):
+        try:
+            text = line.decode('utf-8')
+        except UnicodeDecodeError:
+            return True
+        if line_number == 1 and text.startswith('\uFEFF'):
+            # Strip BOM (U+FEFF ZERO WIDTH NO-BREAK SPACE) at the beginning.
+            # Which files are allowed to have a BOM is handled in
+            # Utf8BomIssueTracker.
+            text = text[1:]
+        return not self.GOOD_CHARACTERS_RE.match(text)
+
+class UnixLineEndingIssueTracker(LineIssueTracker):
+    """Track files with non-Unix line endings (i.e. files with CR)."""
+
+    heading = "Non-Unix line endings:"
+
+    def should_check_file(self, filepath):
+        if not super().should_check_file(filepath):
+            return False
+        return not is_windows_file(filepath)
+
+    def issue_with_line(self, line, _filepath, _line_number):
+        return b"\r" in line
+
+
+class WindowsLineEndingIssueTracker(LineIssueTracker):
+    """Track files with non-Windows line endings (i.e. CR or LF not in CRLF)."""
+
+    heading = "Non-Windows line endings:"
+
+    def should_check_file(self, filepath):
+        if not super().should_check_file(filepath):
+            return False
+        return is_windows_file(filepath)
+
+    def issue_with_line(self, line, _filepath, _line_number):
+        return not line.endswith(b"\r\n") or b"\r" in line[:-2]
+
+
+class TrailingWhitespaceIssueTracker(LineIssueTracker):
+    """Track lines with trailing whitespace."""
+
+    heading = "Trailing whitespace:"
+    suffix_exemptions = frozenset([".dsp", ".md"])
+
+    def issue_with_line(self, line, _filepath, _line_number):
+        return line.rstrip(b"\r\n") != line.rstrip()
+
+
+class TabIssueTracker(LineIssueTracker):
+    """Track lines with tabs."""
+
+    heading = "Tabs present:"
+    suffix_exemptions = frozenset([
+        ".make",
+        ".pem", # some openssl dumps have tabs
+        ".sln",
+        "/.gitmodules",
+        "/Makefile",
+        "/Makefile.inc",
+        "/generate_visualc_files.pl",
+    ])
+
+    def issue_with_line(self, line, _filepath, _line_number):
+        return b"\t" in line
+
+
+class MergeArtifactIssueTracker(LineIssueTracker):
+    """Track lines with merge artifacts.
+    These are leftovers from a ``git merge`` that wasn't fully edited."""
+
+    heading = "Merge artifact:"
+
+    def issue_with_line(self, line, _filepath, _line_number):
+        # Detect leftover git conflict markers.
+        if line.startswith(b'<<<<<<< ') or line.startswith(b'>>>>>>> '):
+            return True
+        if line.startswith(b'||||||| '): # from merge.conflictStyle=diff3
+            return True
+        if line.rstrip(b'\r\n') == b'=======' and \
+           not _filepath.endswith('.md'):
+            return True
+        return False
+
+
+def this_location():
+    frame = inspect.currentframe()
+    assert frame is not None
+    info = inspect.getframeinfo(frame)
+    return os.path.basename(info.filename), info.lineno
+THIS_FILE_BASE_NAME, LINE_NUMBER_BEFORE_LICENSE_ISSUE_TRACKER = this_location()
+
+class LicenseIssueTracker(LineIssueTracker):
+    """Check copyright statements and license indications.
+
+    This class only checks that statements are correct if present. It does
+    not enforce the presence of statements in each file.
+    """
+
+    heading = "License issue:"
+
+    LICENSE_EXEMPTION_RE_LIST = []
+
+    # Exempt third-party drivers which may be under a different license
+    if build_tree.looks_like_tf_psa_crypto_root(os.getcwd()):
+        LICENSE_EXEMPTION_RE_LIST.append(r'drivers/(?=(everest)/.*)')
+    elif build_tree.is_mbedtls_3_6():
+        LICENSE_EXEMPTION_RE_LIST.append(r'3rdparty/(?!(p256-m)/.*)')
+
+    LICENSE_EXEMPTION_RE_LIST += [
+        # Documentation explaining the license may have accidental
+        # false positives.
+        r'(ChangeLog|LICENSE|framework\/LICENSE|[-0-9A-Z_a-z]+\.md)\Z',
+        # Files imported from TF-M, and not used except in test builds,
+        # may be under a different license.
+        r'configs/ext/crypto_config_profile_medium\.h\Z',
+        r'configs/ext/tfm_mbedcrypto_config_profile_medium\.h\Z',
+        r'configs/ext/README\.md\Z',
+        # Third-party file.
+        r'dco\.txt\Z',
+        r'framework\/dco\.txt\Z',
+    ]
+    path_exemptions = re.compile('|'.join(BINARY_FILE_PATH_RE_LIST +
+                                          LICENSE_EXEMPTION_RE_LIST))
+
+    COPYRIGHT_HOLDER = rb'The Mbed TLS Contributors'
+    # Catch "Copyright foo", "Copyright (C) foo", "Copyright © foo", etc.
+    COPYRIGHT_RE = re.compile(rb'.*\bcopyright\s+((?:\w|\s|[()]|[^ -~])*\w)', re.I)
+
+    SPDX_HEADER_KEY = b'SPDX-License-Identifier'
+    LICENSE_IDENTIFIER = b'Apache-2.0 OR GPL-2.0-or-later'
+    SPDX_RE = re.compile(br'.*?(' +
+                         re.escape(SPDX_HEADER_KEY) +
+                         br')(:\s*(.*?)\W*\Z|.*)', re.I)
+
+    LICENSE_MENTION_RE = re.compile(rb'.*(?:' + rb'|'.join([
+        rb'Apache License',
+        rb'General Public License',
+    ]) + rb')', re.I)
+
+    def __init__(self):
+        super().__init__()
+        # Record what problem was caused. We can't easily report it due to
+        # the structure of the script. To be fixed after
+        # https://github.com/Mbed-TLS/mbedtls/pull/2506
+        self.problem = None
+
+    def issue_with_line(self, line, filepath, line_number):
+        #pylint: disable=too-many-return-statements
+
+        # Use endswith() rather than the more correct os.path.basename()
+        # because experimentally, it makes a significant difference to
+        # the running time.
+        if filepath.endswith(THIS_FILE_BASE_NAME) and \
+           line_number > LINE_NUMBER_BEFORE_LICENSE_ISSUE_TRACKER:
+            # Avoid false positives from the code in this class.
+            # Also skip the rest of this file, which is highly unlikely to
+            # contain any problematic statements since we put those near the
+            # top of files.
+            return False
+
+        m = self.COPYRIGHT_RE.match(line)
+        if m and m.group(1) != self.COPYRIGHT_HOLDER:
+            self.problem = 'Invalid copyright line'
+            return True
+
+        m = self.SPDX_RE.match(line)
+        if m:
+            if m.group(1) != self.SPDX_HEADER_KEY:
+                self.problem = 'Misspelled ' + self.SPDX_HEADER_KEY.decode()
+                return True
+            if not m.group(3):
+                self.problem = 'Improperly formatted SPDX license identifier'
+                return True
+            if m.group(3) != self.LICENSE_IDENTIFIER:
+                self.problem = 'Wrong SPDX license identifier'
+                return True
+
+        m = self.LICENSE_MENTION_RE.match(line)
+        if m:
+            self.problem = 'Suspicious license mention'
+            return True
+
+        return False
+
+
+class ErrorAddIssueTracker(LineIssueTracker):
+    """Signal direct additions of error codes.
+
+    Adding a low-level error code with a high-level error code is deprecated
+    and should use MBEDTLS_ERROR_ADD.
+    """
+
+    heading = "Direct addition of error codes"
+
+    _ERR_PLUS_RE = re.compile(br'MBEDTLS_ERR_\w+ *\+|'
+                              br'\+ *MBEDTLS_ERR_')
+    _EXCLUDE_RE = re.compile(br' *case ')
+
+    def issue_with_line(self, line, filepath, line_number):
+        if self._ERR_PLUS_RE.search(line) and not self._EXCLUDE_RE.match(line):
+            return True
+        return False
+
+
+class IntegrityChecker:
+    """Sanity-check files under the current directory."""
+
+    def __init__(self, log_file):
+        """Instantiate the sanity checker.
+        Check files under the current directory.
+        Write a report of issues to log_file."""
+        if not build_tree.looks_like_root(os.getcwd()):
+            raise Exception("This script must be run from Mbed TLS or TF-PSA-Crypto root")
+        self.logger = None
+        self.setup_logger(log_file)
+        self.issues_to_check = [
+            ShebangIssueTracker(),
+            EndOfFileNewlineIssueTracker(),
+            Utf8BomIssueTracker(),
+            UnicodeIssueTracker(),
+            UnixLineEndingIssueTracker(),
+            WindowsLineEndingIssueTracker(),
+            TrailingWhitespaceIssueTracker(),
+            TabIssueTracker(),
+            MergeArtifactIssueTracker(),
+            LicenseIssueTracker(),
+        ]
+
+        if not build_tree.is_mbedtls_3_6():
+            self.issues_to_check.append(ErrorAddIssueTracker())
+
+    def setup_logger(self, log_file, level=logging.INFO):
+        """Log to log_file if provided, or to stderr if None."""
+        self.logger = logging.getLogger()
+        self.logger.setLevel(level)
+        if log_file:
+            handler = logging.FileHandler(log_file)
+            self.logger.addHandler(handler)
+        else:
+            console = logging.StreamHandler()
+            self.logger.addHandler(console)
+
+    @staticmethod
+    def collect_files():
+        """Return the list of files to check.
+
+        These are the regular files commited into Git.
+        """
+        bytes_output = subprocess.check_output(['git', '-C', 'framework',
+                                                'ls-files', '-z'])
+        bytes_framework_filepaths = bytes_output.split(b'\0')[:-1]
+        bytes_framework_filepaths = ["framework/".encode() + filepath
+                                     for filepath in bytes_framework_filepaths]
+
+        bytes_output = subprocess.check_output(['git', 'ls-files', '-z'])
+        bytes_filepaths = bytes_output.split(b'\0')[:-1] + \
+                          bytes_framework_filepaths
+        ascii_filepaths = map(lambda fp: fp.decode('ascii'), bytes_filepaths)
+
+        # Filter out directories. Normally Git doesn't list directories
+        # (it only knows about the files inside them), but there is
+        # at least one case where 'git ls-files' includes a directory:
+        # submodules. Just skip submodules (and any other directories).
+        ascii_filepaths = [fp for fp in ascii_filepaths
+                           if os.path.isfile(fp)]
+        # Prepend './' to files in the top-level directory so that
+        # something like `'/Makefile' in fp` matches in the top-level
+        # directory as well as in subdirectories.
+        return [fp if os.path.dirname(fp) else os.path.join(os.curdir, fp)
+                for fp in ascii_filepaths]
+
+    def check_files(self):
+        """Check all files for all issues."""
+        for issue_to_check in self.issues_to_check:
+            for filepath in self.collect_files():
+                if issue_to_check.should_check_file(filepath):
+                    issue_to_check.check_file_for_issue(filepath)
+
+    def output_issues(self):
+        """Log the issues found and their locations.
+
+        Return 1 if there were issues, 0 otherwise.
+        """
+        integrity_return_code = 0
+        for issue_to_check in self.issues_to_check:
+            if issue_to_check.files_with_issues:
+                integrity_return_code = 1
+            issue_to_check.output_file_issues(self.logger)
+        return integrity_return_code
+
+
+def run_main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "-l", "--log_file", type=str, help="path to optional output log",
+    )
+    check_args = parser.parse_args()
+    integrity_check = IntegrityChecker(check_args.log_file)
+    integrity_check.check_files()
+    return_code = integrity_check.output_issues()
+    sys.exit(return_code)
+
+
+if __name__ == "__main__":
+    run_main()