[PATCH v3 00/10] kbuild: clang-tidy

[PATCH v3 00/10] kbuild: clang-tidy

[Masahiro Yamada]

I improved gen_compile_commands.py,
then rebased Nathan's v7 [1] on top of them.
To save time, I modified the Makefile part.
No change for run-clang-tools.py

"make clang-tidy" should work in-tree build,
out-of-tree build (O=), and external module build (M=).

V3:
Fix minor mistakes pointed out by Nick
Add a new patch (09/10) to remove the warning about
too few .cmd files.

V2:
Keep the previous work-flow.
You can still manually run scripts/gen_compile_commands.json

'make compile_commands.json' or 'make clang-tidy' is handier
for most cases. As Nick noted, there is 3 % loss of the coverage.

If you need the full compilation database that covers all the
compiled C files, please run the script manually.

[1] https://patchwork.kernel.org/patch/11687833/


Masahiro Yamada (9):
  gen_compile_commands: parse only the first line of .*.cmd files
  gen_compile_commands: use choices for --log_levels option
  gen_compile_commands: do not support .cmd files under tools/ directory
  gen_compile_commands: reword the help message of -d option
  gen_compile_commands: make -o option independent of -d option
  gen_compile_commands: move directory walk to a generator function
  gen_compile_commands: support *.o, *.a, modules.order in positional
    argument
  kbuild: wire up the build rule of compile_commands.json to Makefile
  gen_compile_commands: remove the warning about too few .cmd files

Nathan Huckleberry (1):
  Makefile: Add clang-tidy and static analyzer support to makefile

 MAINTAINERS                                 |   1 +
 Makefile                                    |  45 +++-
 scripts/clang-tools/gen_compile_commands.py | 236 ++++++++++++++++++++
 scripts/clang-tools/run-clang-tools.py      |  74 ++++++
 scripts/gen_compile_commands.py             | 151 -------------
 5 files changed, 352 insertions(+), 155 deletions(-)
 create mode 100755 scripts/clang-tools/gen_compile_commands.py
 create mode 100755 scripts/clang-tools/run-clang-tools.py
 delete mode 100755 scripts/gen_compile_commands.py

-- 
2.25.1

[PATCH v3 01/10] gen_compile_commands: parse only the first line of .*.cmd files

[Masahiro Yamada]

After the allmodconfig build, this script takes about 5 sec on my
machine. Most of the run-time is consumed for needless regex matching.

We know the format of .*.cmd file; the first line is the build command.
There is no need to parse the rest.

With this optimization, now it runs 4 times faster.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
---

(no changes since v2)

Changes in v2:
  - Remove the unneeded variable 'line'

 scripts/gen_compile_commands.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index c458696ef3a7..1bcf33a93cb9 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -125,11 +125,8 @@ def main():
             filepath = os.path.join(dirpath, filename)
 
             with open(filepath, 'rt') as f:
-                for line in f:
-                    result = line_matcher.match(line)
-                    if not result:
-                        continue
-
+                result = line_matcher.match(f.readline())
+                if result:
                     try:
                         entry = process_line(directory, dirpath,
                                              result.group(1), result.group(2))
-- 
2.25.1

[PATCH v3 02/10] gen_compile_commands: use choices for --log_levels option

[Masahiro Yamada]

Use 'choices' instead of the own code to check if the given parameter
is valid.

I also simplified the help message because, with 'choices', --help
shows the list of valid parameters:

  --log_level {DEBUG,INFO,WARNING,ERROR,CRITICAL}

I started the help message with a lower case, "the level of log ..."
in order to be consistent with the -h option:

  -h, --help            show this help message and exit

The message "show this help ..." comes from the ArgumentParser library
code, and I do not know how to change it. So, I changed our code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---

(no changes since v2)

Changes in v2:
  - New patch

 scripts/gen_compile_commands.py | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 1bcf33a93cb9..535248cf2d7e 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -45,24 +45,18 @@ def parse_arguments():
                    'compile_commands.json in the search directory)')
     parser.add_argument('-o', '--output', type=str, help=output_help)
 
-    log_level_help = ('The level of log messages to produce (one of ' +
-                      ', '.join(_VALID_LOG_LEVELS) + '; defaults to ' +
+    log_level_help = ('the level of log messages to produce (defaults to ' +
                       _DEFAULT_LOG_LEVEL + ')')
-    parser.add_argument(
-        '--log_level', type=str, default=_DEFAULT_LOG_LEVEL,
-        help=log_level_help)
+    parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
+                        default=_DEFAULT_LOG_LEVEL, help=log_level_help)
 
     args = parser.parse_args()
 
-    log_level = args.log_level
-    if log_level not in _VALID_LOG_LEVELS:
-        raise ValueError('%s is not a valid log level' % log_level)
-
     directory = args.directory or os.getcwd()
     output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)
     directory = os.path.abspath(directory)
 
-    return log_level, directory, output
+    return args.log_level, directory, output
 
 
 def process_line(root_directory, file_directory, command_prefix, relative_path):
-- 
2.25.1

[PATCH v3 03/10] gen_compile_commands: do not support .cmd files under tools/ directory

[Masahiro Yamada]

The tools/ directory uses a different build system, and the format of
.cmd files is different because the tools builds run in a different
work directory.

Supporting two formats compilicates the script.

The only loss by this change is objtool.

Also, rename the confusing variable 'relative_path' because it is
not necessarily a relative path. When the output directory is not
the direct child of the source tree (e.g. O=foo/bar), it is an
absolute path. Rename it to 'file_path'.

os.path.join(root_directory, file_path) works whether the file_path
is relative or not. If file_path is already absolute, it returns it
as-is.

I used os.path.abspath() to normalize file paths. If you run this
script against the kernel built with O=foo option, the file_path
contains '../' patterns. os.path.abspath() fixes up 'foo/bar/../baz'
into 'foo/baz', and produces a cleaner commands_database.json.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---

Changes in v3:
  - Add a comment about why I used os.path.abspath()

Changes in v2:
  - New patch

 scripts/gen_compile_commands.py | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 535248cf2d7e..49fff0b0b385 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -59,23 +59,21 @@ def parse_arguments():
     return args.log_level, directory, output
 
 
-def process_line(root_directory, file_directory, command_prefix, relative_path):
+def process_line(root_directory, command_prefix, file_path):
     """Extracts information from a .cmd line and creates an entry from it.
 
     Args:
         root_directory: The directory that was searched for .cmd files. Usually
             used directly in the "directory" entry in compile_commands.json.
-        file_directory: The path to the directory the .cmd file was found in.
         command_prefix: The extracted command line, up to the last element.
-        relative_path: The .c file from the end of the extracted command.
-            Usually relative to root_directory, but sometimes relative to
-            file_directory and sometimes neither.
+        file_path: The .c file from the end of the extracted command.
+            Usually relative to root_directory, but sometimes absolute.
 
     Returns:
         An entry to append to compile_commands.
 
     Raises:
-        ValueError: Could not find the extracted file based on relative_path and
+        ValueError: Could not find the extracted file based on file_path and
             root_directory or file_directory.
     """
     # The .cmd files are intended to be included directly by Make, so they
@@ -84,20 +82,14 @@ def process_line(root_directory, file_directory, command_prefix, relative_path):
     # by Make, so this code replaces the escaped version with '#'.
     prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
 
-    cur_dir = root_directory
-    expected_path = os.path.join(cur_dir, relative_path)
-    if not os.path.exists(expected_path):
-        # Try using file_directory instead. Some of the tools have a different
-        # style of .cmd file than the kernel.
-        cur_dir = file_directory
-        expected_path = os.path.join(cur_dir, relative_path)
-        if not os.path.exists(expected_path):
-            raise ValueError('File %s not in %s or %s' %
-                             (relative_path, root_directory, file_directory))
+    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
+    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
+    if not os.path.exists(abs_path):
+        raise ValueError('File %s not found' % abs_path)
     return {
-        'directory': cur_dir,
-        'file': relative_path,
-        'command': prefix + relative_path,
+        'directory': root_directory,
+        'file': abs_path,
+        'command': prefix + file_path,
     }
 
 
@@ -122,7 +114,7 @@ def main():
                 result = line_matcher.match(f.readline())
                 if result:
                     try:
-                        entry = process_line(directory, dirpath,
+                        entry = process_line(directory,
                                              result.group(1), result.group(2))
                         compile_commands.append(entry)
                     except ValueError as err:
-- 
2.25.1

[PATCH v3 04/10] gen_compile_commands: reword the help message of -d option

[Masahiro Yamada]

I think the help message of the -d option is somewhat misleading.

  Path to the kernel source directory to search (defaults to the working directory)

The part "kernel source directory" is the source of the confusion.
Some people misunderstand as if this script did not support separate
output directories.

Actually, this script also works for out-of-tree builds. You can
use the -d option to point to the object output directory, not to
the source directory. It should match to the O= option used in the
previous kernel build, and then appears in the "directory" field of
compile_commands.json.

Reword the help message.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---

Changes in v3:
  - Add the missing punctuation to the comment

Changes in v2:
  - New patch

 scripts/gen_compile_commands.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 49fff0b0b385..f37c1dac8db4 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -31,13 +31,13 @@ def parse_arguments():
 
     Returns:
         log_level: A logging level to filter log output.
-        directory: The directory to search for .cmd files.
+        directory: The work directory where the objects were built.
         output: Where to write the compile-commands JSON file.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
 
-    directory_help = ('Path to the kernel source directory to search '
+    directory_help = ('specify the output directory used for the kernel build '
                       '(defaults to the working directory)')
     parser.add_argument('-d', '--directory', type=str, help=directory_help)
 
-- 
2.25.1

[PATCH v3 05/10] gen_compile_commands: make -o option independent of -d option

[Masahiro Yamada]

Change the -o option independent of the -d option, which is I think
clearer behavior. Some people may like to use -d to specify a separate
output directory, but still output the compile_commands.py in the
source directory (unless the source tree is read-only) because it is
the default location Clang Tools search for the compilation database.

Also, move the default parameter to the default= argument of the
.add_argument().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---

(no changes since v2)

Changes in v2:
  - New patch

 scripts/gen_compile_commands.py | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index f37c1dac8db4..71a0630ae188 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -39,11 +39,13 @@ def parse_arguments():
 
     directory_help = ('specify the output directory used for the kernel build '
                       '(defaults to the working directory)')
-    parser.add_argument('-d', '--directory', type=str, help=directory_help)
+    parser.add_argument('-d', '--directory', type=str, default='.',
+                        help=directory_help)
 
-    output_help = ('The location to write compile_commands.json (defaults to '
-                   'compile_commands.json in the search directory)')
-    parser.add_argument('-o', '--output', type=str, help=output_help)
+    output_help = ('path to the output command database (defaults to ' +
+                   _DEFAULT_OUTPUT + ')')
+    parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
+                        help=output_help)
 
     log_level_help = ('the level of log messages to produce (defaults to ' +
                       _DEFAULT_LOG_LEVEL + ')')
@@ -52,11 +54,9 @@ def parse_arguments():
 
     args = parser.parse_args()
 
-    directory = args.directory or os.getcwd()
-    output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)
-    directory = os.path.abspath(directory)
-
-    return args.log_level, directory, output
+    return (args.log_level,
+            os.path.abspath(args.directory),
+            args.output)
 
 
 def process_line(root_directory, command_prefix, file_path):
-- 
2.25.1

[PATCH v3 06/10] gen_compile_commands: move directory walk to a generator function

[Masahiro Yamada]

Currently, this script walks under the specified directory (default to
the current directory), then parses all .cmd files found.

Split it into a separate helper function because the next commit will
add more helpers to pick up .cmd files associated with given file(s).

There is no point to build and return a huge list at once. I used a
generator so it works in the for-loop with less memory.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---

Changes in v3:
  - Add the missing punctuation in the comment

Changes in v2:
  - New patch

 scripts/gen_compile_commands.py | 44 ++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 71a0630ae188..e45f17be8817 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -33,6 +33,7 @@ def parse_arguments():
         log_level: A logging level to filter log output.
         directory: The work directory where the objects were built.
         output: Where to write the compile-commands JSON file.
+        paths: The list of directories to handle to find .cmd files.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
@@ -56,7 +57,28 @@ def parse_arguments():
 
     return (args.log_level,
             os.path.abspath(args.directory),
-            args.output)
+            args.output,
+            [args.directory])
+
+
+def cmdfiles_in_dir(directory):
+    """Generate the iterator of .cmd files found under the directory.
+
+    Walk under the given directory, and yield every .cmd file found.
+
+    Args:
+        directory: The directory to search for .cmd files.
+
+    Yields:
+        The path to a .cmd file.
+    """
+
+    filename_matcher = re.compile(_FILENAME_PATTERN)
+
+    for dirpath, _, filenames in os.walk(directory):
+        for filename in filenames:
+            if filename_matcher.match(filename):
+                yield os.path.join(dirpath, filename)
 
 
 def process_line(root_directory, command_prefix, file_path):
@@ -95,31 +117,29 @@ def process_line(root_directory, command_prefix, file_path):
 
 def main():
     """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output = parse_arguments()
+    log_level, directory, output, paths = parse_arguments()
 
     level = getattr(logging, log_level)
     logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
 
-    filename_matcher = re.compile(_FILENAME_PATTERN)
     line_matcher = re.compile(_LINE_PATTERN)
 
     compile_commands = []
-    for dirpath, _, filenames in os.walk(directory):
-        for filename in filenames:
-            if not filename_matcher.match(filename):
-                continue
-            filepath = os.path.join(dirpath, filename)
 
-            with open(filepath, 'rt') as f:
+    for path in paths:
+        cmdfiles = cmdfiles_in_dir(path)
+
+        for cmdfile in cmdfiles:
+            with open(cmdfile, 'rt') as f:
                 result = line_matcher.match(f.readline())
                 if result:
                     try:
-                        entry = process_line(directory,
-                                             result.group(1), result.group(2))
+                        entry = process_line(directory, result.group(1),
+                                             result.group(2))
                         compile_commands.append(entry)
                     except ValueError as err:
                         logging.info('Could not add line from %s: %s',
-                                     filepath, err)
+                                     cmdfile, err)
 
     with open(output, 'wt') as f:
         json.dump(compile_commands, f, indent=2, sort_keys=True)
-- 
2.25.1

[PATCH v3 07/10] gen_compile_commands: support *.o, *.a, modules.order in positional argument

[Masahiro Yamada]

This script currently searches the specified directory for .cmd files.
One drawback is it may contain stale .cmd files after you rebuild the
kernel several times without 'make clean'.

This commit supports *.o, *.a, and modules.order as positional
parameters. If such files are given, they are parsed to collect
associated .cmd files. I added a generator helper for each of them.

This feature is useful to get the list of active .cmd files from the
last build, and will be used by the next commit to wire up the
compile_commands.json rule to the Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v3:
  - Use 'llvm-ar' instead of 'ar' for the default of -a option
  - Fix the corrupted comment block

Changes in v2:
  - Separate the file parser into generator functions
  - Use 'obj' instead of 'object' because 'object' is a built-in function
  - I think using 'file' is OK because it is not a built-in function in Python3
    (https://docs.python.org/3/library/functions.html)
    Anyway, the variable 'file' is no longer used in this version
  - Keep the previous work-flow to allow to search the given directory

 scripts/gen_compile_commands.py | 100 ++++++++++++++++++++++++++++++--
 1 file changed, 96 insertions(+), 4 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index e45f17be8817..f370375b2f70 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -12,6 +12,7 @@ import json
 import logging
 import os
 import re
+import subprocess
 
 _DEFAULT_OUTPUT = 'compile_commands.json'
 _DEFAULT_LOG_LEVEL = 'WARNING'
@@ -32,8 +33,9 @@ def parse_arguments():
     Returns:
         log_level: A logging level to filter log output.
         directory: The work directory where the objects were built.
+        ar: Command used for parsing .a archives.
         output: Where to write the compile-commands JSON file.
-        paths: The list of directories to handle to find .cmd files.
+        paths: The list of files/directories to handle to find .cmd files.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
@@ -53,12 +55,21 @@ def parse_arguments():
     parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
                         default=_DEFAULT_LOG_LEVEL, help=log_level_help)
 
+    ar_help = 'command used for parsing .a archives'
+    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
+
+    paths_help = ('directories to search or files to parse '
+                  '(files should be *.o, *.a, or modules.order). '
+                  'If nothing is specified, the current directory is searched')
+    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
+
     args = parser.parse_args()
 
     return (args.log_level,
             os.path.abspath(args.directory),
             args.output,
-            [args.directory])
+            args.ar,
+            args.paths if len(args.paths) > 0 else [args.directory])
 
 
 def cmdfiles_in_dir(directory):
@@ -81,6 +92,73 @@ def cmdfiles_in_dir(directory):
                 yield os.path.join(dirpath, filename)
 
 
+def to_cmdfile(path):
+    """Return the path of .cmd file used for the given build artifact
+
+    Args:
+        Path: file path
+
+    Returns:
+        The path to .cmd file
+    """
+    dir, base = os.path.split(path)
+    return os.path.join(dir, '.' + base + '.cmd')
+
+
+def cmdfiles_for_o(obj):
+    """Generate the iterator of .cmd files associated with the object
+
+    Yield the .cmd file used to build the given object
+
+    Args:
+        obj: The object path
+
+    Yields:
+        The path to .cmd file
+    """
+    yield to_cmdfile(obj)
+
+
+def cmdfiles_for_a(archive, ar):
+    """Generate the iterator of .cmd files associated with the archive.
+
+    Parse the given archive, and yield every .cmd file used to build it.
+
+    Args:
+        archive: The archive to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
+        yield to_cmdfile(obj)
+
+
+def cmdfiles_for_modorder(modorder):
+    """Generate the iterator of .cmd files associated with the modules.order.
+
+    Parse the given modules.order, and yield every .cmd file used to build the
+    contained modules.
+
+    Args:
+        modorder: The modules.order file to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    with open(modorder) as f:
+        for line in f:
+            ko = line.rstrip()
+            base, ext = os.path.splitext(ko)
+            if ext != '.ko':
+                sys.exit('{}: module path must end with .ko'.format(ko))
+            mod = base + '.mod'
+	    # The first line of *.mod lists the objects that compose the module.
+            with open(mod) as m:
+                for obj in m.readline().split():
+                    yield to_cmdfile(obj)
+
+
 def process_line(root_directory, command_prefix, file_path):
     """Extracts information from a .cmd line and creates an entry from it.
 
@@ -117,7 +195,7 @@ def process_line(root_directory, command_prefix, file_path):
 
 def main():
     """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output, paths = parse_arguments()
+    log_level, directory, output, ar, paths = parse_arguments()
 
     level = getattr(logging, log_level)
     logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
@@ -127,7 +205,21 @@ def main():
     compile_commands = []
 
     for path in paths:
-        cmdfiles = cmdfiles_in_dir(path)
+        # If 'path' is a directory, handle all .cmd files under it.
+        # Otherwise, handle .cmd files associated with the file.
+        # Most of built-in objects are linked via archives (built-in.a or lib.a)
+        # but some objects are linked to vmlinux directly.
+        # Modules are listed in modules.order.
+        if os.path.isdir(path):
+            cmdfiles = cmdfiles_in_dir(path)
+        elif path.endswith('.o'):
+            cmdfiles = cmdfiles_for_o(path)
+        elif path.endswith('.a'):
+            cmdfiles = cmdfiles_for_a(path, ar)
+        elif path.endswith('modules.order'):
+            cmdfiles = cmdfiles_for_modorder(path)
+        else:
+            sys.exit('{}: unknown file type'.format(path))
 
         for cmdfile in cmdfiles:
             with open(cmdfile, 'rt') as f:
-- 
2.25.1

[PATCH v3 08/10] kbuild: wire up the build rule of compile_commands.json to Makefile

[Masahiro Yamada]

Currently, you need to manually run scripts/gen_compile_commands.py
to create compile_commands.json. It parses all the .*.cmd files found
under the specified directory.

If you rebuild the kernel over again without 'make clean',
.*.cmd files from older builds will create stale entries in
compile_commands.json.

This commit wires up the compile_commands.json rule to Makefile, and
makes it parse only the .*.cmd files involved in the current build.

Pass $(KBUILD_VMLINUX_OBJS), $(KBUILD_VMLINUX_LIBS), and modules.order
to the script. The objects or archives linked to vmlinux are listed in
$(KBUILD_VMLINUX_OBJS) or $(KBUILD_VMLINUX_LIBS). All the modules are
listed in modules.order.

You can create compile_commands.json from Make:

  $ make -j$(nproc) CC=clang compile_commands.json

You can also build vmlinux, modules, and compile_commands.json all
together in a single command:

  $ make -j$(nproc) CC=clang all compile_commands.json

It works for M= builds as well. In this case, compile_commands.json
is created in the top directory of the external module.

This is convenient, but it has a drawback; the coverage of the
compile_commands.json is reduced because only the objects linked to
vmlinux or modules are handled. For example, the following C files are
not included in the compile_commands.json:

 - Decompressor source files (arch/*/boot/)
 - VDSO source files
 - C files used to generate intermediates (e.g. kernel/bounds.c)
 - Standalone host programs

I think it is fine for most developers because our main interest is
the kernel-space code.

If you want to cover all the compiled C files, please build the kernel,
then run the script manually as you did before:

  $ make clean    # if you want to remove stale .cmd files [optional]
  $ make -j$(nproc) CC=clang
  $ scripts/gen_compile_commands.py

Here is a note for out-of-tree builds. 'make compile_commands.json'
works with O= option, but please notice compile_commands.json is
created in the object tree instead of the source tree.

Some people may want to have compile_commands.json in the source tree
because Clang Tools searches for it through all parent paths of the
first input source file.

However, you cannot do this for O= builds. Kbuild should never generate
any build artifact in the source tree when O= is given because the
source tree might be read-only. Any write attempt to the source tree
is monitored and the violation may be reported. See the commit log of
8ef14c2c41d9.

So, the only possible way is to create compile_commands.json in the
object tree, then specify '-p <build-path>' when you use clang-check,
clang-tidy, etc.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
---

(no changes since v1)

 Makefile | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 9cac6fde3479..65ed336a6de1 100644
--- a/Makefile
+++ b/Makefile
@@ -635,7 +635,7 @@ endif
 # in addition to whatever we do anyway.
 # Just "make" or "make all" shall build modules as well
 
-ifneq ($(filter all modules nsdeps,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps %compile_commands.json,$(MAKECMDGOALS)),)
   KBUILD_MODULES := 1
 endif
 
@@ -1464,7 +1464,8 @@ endif # CONFIG_MODULES
 
 # Directories & files removed with 'make clean'
 CLEAN_FILES += include/ksym vmlinux.symvers \
-	       modules.builtin modules.builtin.modinfo modules.nsdeps
+	       modules.builtin modules.builtin.modinfo modules.nsdeps \
+	       compile_commands.json
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \
@@ -1698,9 +1699,12 @@ KBUILD_MODULES := 1
 
 build-dirs := $(KBUILD_EXTMOD)
 PHONY += modules
-modules: descend
+modules: $(MODORDER)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
+$(MODORDER): descend
+	@:
+
 PHONY += modules_install
 modules_install: _emodinst_ _emodinst_post
 
@@ -1714,8 +1718,12 @@ PHONY += _emodinst_post
 _emodinst_post: _emodinst_
 	$(call cmd,depmod)
 
+compile_commands.json: $(extmod-prefix)compile_commands.json
+PHONY += compile_commands.json
+
 clean-dirs := $(KBUILD_EXTMOD)
-clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps
+clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
+	$(KBUILD_EXTMOD)/compile_commands.json
 
 PHONY += help
 help:
@@ -1828,6 +1836,19 @@ nsdeps: export KBUILD_NSDEPS=1
 nsdeps: modules
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
 
+# Clang Tooling
+# ---------------------------------------------------------------------------
+
+quiet_cmd_gen_compile_commands = GEN     $@
+      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
+
+$(extmod-prefix)compile_commands.json: scripts/gen_compile_commands.py \
+	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
+	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
+	$(call if_changed,gen_compile_commands)
+
+targets += $(extmod-prefix)compile_commands.json
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
-- 
2.25.1

[PATCH v3 09/10] gen_compile_commands: remove the warning about too few .cmd files

[Masahiro Yamada]

This warning was useful when users previously needed to manually
build the kernel and run this script.

Now you can simply do 'make compile_commands.json', which updates
all the necessary build artifacts and automatically creates the
compilation database. There is no more worry for a mistake like
"Oh, I forgot to build the kernel".

Now, this warning is rather annoying.

You can create compile_commands.json for an external module:

  $ make M=/path/to/your/external/module compile_commands.json

Then, this warning is displayed since there are usually less than
300 files in a single module.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v3:
  - New patch

 scripts/gen_compile_commands.py | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index f370375b2f70..1de745577e6d 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -21,11 +21,6 @@ _FILENAME_PATTERN = r'^\..*\.cmd$'
 _LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
 _VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
 
-# A kernel build generally has over 2000 entries in its compile_commands.json
-# database. If this code finds 300 or fewer, then warn the user that they might
-# not have all the .cmd files, and they might need to compile the kernel.
-_LOW_COUNT_THRESHOLD = 300
-
 
 def parse_arguments():
     """Sets up and parses command-line arguments.
@@ -236,11 +231,6 @@ def main():
     with open(output, 'wt') as f:
         json.dump(compile_commands, f, indent=2, sort_keys=True)
 
-    count = len(compile_commands)
-    if count < _LOW_COUNT_THRESHOLD:
-        logging.warning(
-            'Found %s entries. Have you compiled the kernel?', count)
-
 
 if __name__ == '__main__':
     main()
-- 
2.25.1

[PATCH v3 10/10] Makefile: Add clang-tidy and static analyzer support to makefile

[Masahiro Yamada]

From: Nathan Huckleberry <nhuck@google.com>

This patch adds clang-tidy and the clang static-analyzer as make
targets. The goal of this patch is to make static analysis tools
usable and extendable by any developer or researcher who is familiar
with basic c++.

The current static analysis tools require intimate knowledge of the
internal workings of the static analysis. Clang-tidy and the clang
static analyzers expose an easy to use api and allow users unfamiliar
with clang to write new checks with relative ease.

===Clang-tidy===

Clang-tidy is an easily extendable 'linter' that runs on the AST.
Clang-tidy checks are easy to write and understand. A check consists of
two parts, a matcher and a checker. The matcher is created using a
domain specific language that acts on the AST
(https://clang.llvm.org/docs/LibASTMatchersReference.html).  When AST
nodes are found by the matcher a callback is made to the checker. The
checker can then execute additional checks and issue warnings.

Here is an example clang-tidy check to report functions that have calls
to local_irq_disable without calls to local_irq_enable and vice-versa.
Functions flagged with __attribute((annotation("ignore_irq_balancing")))
are ignored for analysis. (https://reviews.llvm.org/D65828)

===Clang static analyzer===

The clang static analyzer is a more powerful static analysis tool that
uses symbolic execution to find bugs. Currently there is a check that
looks for potential security bugs from invalid uses of kmalloc and
kfree. There are several more general purpose checks that are useful for
the kernel.

The clang static analyzer is well documented and designed to be
extensible.
(https://clang-analyzer.llvm.org/checker_dev_manual.html)
(https://github.com/haoNoQ/clang-analyzer-guide/releases/download/v0.1/clang-analyzer-guide-v0.1.pdf)

The main draw of the clang tools is how accessible they are. The clang
documentation is very nice and these tools are built specifically to be
easily extendable by any developer. They provide an accessible method of
bug-finding and research to people who are not overly familiar with the
kernel codebase.

Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

(no changes since v1)

 MAINTAINERS                                   |  1 +
 Makefile                                      | 20 ++++-
 .../{ => clang-tools}/gen_compile_commands.py |  0
 scripts/clang-tools/run-clang-tools.py        | 74 +++++++++++++++++++
 4 files changed, 93 insertions(+), 2 deletions(-)
 rename scripts/{ => clang-tools}/gen_compile_commands.py (100%)
 create mode 100755 scripts/clang-tools/run-clang-tools.py

diff --git a/MAINTAINERS b/MAINTAINERS
index deaafb617361..19b916dbc796 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4247,6 +4247,7 @@ W:	https://clangbuiltlinux.github.io/
 B:	https://github.com/ClangBuiltLinux/linux/issues
 C:	irc://chat.freenode.net/clangbuiltlinux
 F:	Documentation/kbuild/llvm.rst
+F:	scripts/clang-tools/
 K:	\b(?i:clang|llvm)\b
 
 CLEANCACHE API
diff --git a/Makefile b/Makefile
index 65ed336a6de1..9ece191d8d51 100644
--- a/Makefile
+++ b/Makefile
@@ -635,7 +635,7 @@ endif
 # in addition to whatever we do anyway.
 # Just "make" or "make all" shall build modules as well
 
-ifneq ($(filter all modules nsdeps %compile_commands.json,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
   KBUILD_MODULES := 1
 endif
 
@@ -1577,6 +1577,8 @@ help:
 	@echo  '  export_report   - List the usages of all exported symbols'
 	@echo  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
+	@echo  '  clang-analyzer  - Check with clang static analyzer'
+	@echo  '  clang-tidy      - Check with clang-tidy'
 	@echo  ''
 	@echo  'Tools:'
 	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
@@ -1842,13 +1844,27 @@ nsdeps: modules
 quiet_cmd_gen_compile_commands = GEN     $@
       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
 
-$(extmod-prefix)compile_commands.json: scripts/gen_compile_commands.py \
+$(extmod-prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
 	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
 	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
 	$(call if_changed,gen_compile_commands)
 
 targets += $(extmod-prefix)compile_commands.json
 
+PHONY += clang-tidy clang-analyzer
+
+ifdef CONFIG_CC_IS_CLANG
+quiet_cmd_clang_tools = CHECK   $<
+      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
+
+clang-tidy clang-analyzer: $(extmod-prefix)compile_commands.json
+	$(call cmd,clang_tools)
+else
+clang-tidy clang-analyzer:
+	@echo "$@ requires CC=clang" >&2
+	@false
+endif
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
diff --git a/scripts/gen_compile_commands.py b/scripts/clang-tools/gen_compile_commands.py
similarity index 100%
rename from scripts/gen_compile_commands.py
rename to scripts/clang-tools/gen_compile_commands.py
diff --git a/scripts/clang-tools/run-clang-tools.py b/scripts/clang-tools/run-clang-tools.py
new file mode 100755
index 000000000000..fa7655c7cec0
--- /dev/null
+++ b/scripts/clang-tools/run-clang-tools.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2020
+#
+# Author: Nathan Huckleberry <nhuck@google.com>
+#
+"""A helper routine run clang-tidy and the clang static-analyzer on
+compile_commands.json.
+"""
+
+import argparse
+import json
+import multiprocessing
+import os
+import subprocess
+import sys
+
+
+def parse_arguments():
+    """Set up and parses command-line arguments.
+    Returns:
+        args: Dict of parsed args
+        Has keys: [path, type]
+    """
+    usage = """Run clang-tidy or the clang static-analyzer on a
+        compilation database."""
+    parser = argparse.ArgumentParser(description=usage)
+
+    type_help = "Type of analysis to be performed"
+    parser.add_argument("type",
+                        choices=["clang-tidy", "clang-analyzer"],
+                        help=type_help)
+    path_help = "Path to the compilation database to parse"
+    parser.add_argument("path", type=str, help=path_help)
+
+    return parser.parse_args()
+
+
+def init(l, a):
+    global lock
+    global args
+    lock = l
+    args = a
+
+
+def run_analysis(entry):
+    # Disable all checks, then re-enable the ones we want
+    checks = "-checks=-*,"
+    if args.type == "clang-tidy":
+        checks += "linuxkernel-*"
+    else:
+        checks += "clang-analyzer-*"
+    p = subprocess.run(["clang-tidy", "-p", args.path, checks, entry["file"]],
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.STDOUT,
+                       cwd=entry["directory"])
+    with lock:
+        sys.stderr.buffer.write(p.stdout)
+
+
+def main():
+    args = parse_arguments()
+
+    lock = multiprocessing.Lock()
+    pool = multiprocessing.Pool(initializer=init, initargs=(lock, args))
+    # Read JSON data into the datastore variable
+    with open(args.path, "r") as f:
+        datastore = json.load(f)
+        pool.map(run_analysis, datastore)
+
+
+if __name__ == "__main__":
+    main()
-- 
2.25.1

Re: [PATCH v3 07/10] gen_compile_commands: support *.o, *.a, modules.order in positional argument

[Nick Desaulniers]

On Sat, Aug 22, 2020 at 7:56 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> This script currently searches the specified directory for .cmd files.
> One drawback is it may contain stale .cmd files after you rebuild the
> kernel several times without 'make clean'.
>
> This commit supports *.o, *.a, and modules.order as positional
> parameters. If such files are given, they are parsed to collect
> associated .cmd files. I added a generator helper for each of them.
>
> This feature is useful to get the list of active .cmd files from the
> last build, and will be used by the next commit to wire up the
> compile_commands.json rule to the Makefile.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>
> Changes in v3:
>   - Use 'llvm-ar' instead of 'ar' for the default of -a option
>   - Fix the corrupted comment block
>
> Changes in v2:
>   - Separate the file parser into generator functions
>   - Use 'obj' instead of 'object' because 'object' is a built-in function
>   - I think using 'file' is OK because it is not a built-in function in Python3
>     (https://docs.python.org/3/library/functions.html)
>     Anyway, the variable 'file' is no longer used in this version
>   - Keep the previous work-flow to allow to search the given directory
>
>  scripts/gen_compile_commands.py | 100 ++++++++++++++++++++++++++++++--
>  1 file changed, 96 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
> index e45f17be8817..f370375b2f70 100755
> --- a/scripts/gen_compile_commands.py
> +++ b/scripts/gen_compile_commands.py
> @@ -12,6 +12,7 @@ import json
>  import logging
>  import os
>  import re
> +import subprocess
>
>  _DEFAULT_OUTPUT = 'compile_commands.json'
>  _DEFAULT_LOG_LEVEL = 'WARNING'
> @@ -32,8 +33,9 @@ def parse_arguments():
>      Returns:
>          log_level: A logging level to filter log output.
>          directory: The work directory where the objects were built.
> +        ar: Command used for parsing .a archives.
>          output: Where to write the compile-commands JSON file.
> -        paths: The list of directories to handle to find .cmd files.
> +        paths: The list of files/directories to handle to find .cmd files.
>      """
>      usage = 'Creates a compile_commands.json database from kernel .cmd files'
>      parser = argparse.ArgumentParser(description=usage)
> @@ -53,12 +55,21 @@ def parse_arguments():
>      parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
>                          default=_DEFAULT_LOG_LEVEL, help=log_level_help)
>
> +    ar_help = 'command used for parsing .a archives'
> +    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
> +
> +    paths_help = ('directories to search or files to parse '
> +                  '(files should be *.o, *.a, or modules.order). '
> +                  'If nothing is specified, the current directory is searched')
> +    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
> +
>      args = parser.parse_args()
>
>      return (args.log_level,
>              os.path.abspath(args.directory),
>              args.output,
> -            [args.directory])
> +            args.ar,
> +            args.paths if len(args.paths) > 0 else [args.directory])
>
>
>  def cmdfiles_in_dir(directory):
> @@ -81,6 +92,73 @@ def cmdfiles_in_dir(directory):
>                  yield os.path.join(dirpath, filename)
>
>
> +def to_cmdfile(path):
> +    """Return the path of .cmd file used for the given build artifact
> +
> +    Args:
> +        Path: file path
> +
> +    Returns:
> +        The path to .cmd file
> +    """
> +    dir, base = os.path.split(path)
> +    return os.path.join(dir, '.' + base + '.cmd')
> +
> +
> +def cmdfiles_for_o(obj):
> +    """Generate the iterator of .cmd files associated with the object
> +
> +    Yield the .cmd file used to build the given object
> +
> +    Args:
> +        obj: The object path
> +
> +    Yields:
> +        The path to .cmd file
> +    """
> +    yield to_cmdfile(obj)
> +
> +
> +def cmdfiles_for_a(archive, ar):
> +    """Generate the iterator of .cmd files associated with the archive.
> +
> +    Parse the given archive, and yield every .cmd file used to build it.
> +
> +    Args:
> +        archive: The archive to parse
> +
> +    Yields:
> +        The path to every .cmd file found
> +    """
> +    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
> +        yield to_cmdfile(obj)
> +
> +
> +def cmdfiles_for_modorder(modorder):
> +    """Generate the iterator of .cmd files associated with the modules.order.
> +
> +    Parse the given modules.order, and yield every .cmd file used to build the
> +    contained modules.
> +
> +    Args:
> +        modorder: The modules.order file to parse
> +
> +    Yields:
> +        The path to every .cmd file found
> +    """
> +    with open(modorder) as f:
> +        for line in f:
> +            ko = line.rstrip()
> +            base, ext = os.path.splitext(ko)
> +            if ext != '.ko':
> +                sys.exit('{}: module path must end with .ko'.format(ko))
> +            mod = base + '.mod'
> +           # The first line of *.mod lists the objects that compose the module.
> +            with open(mod) as m:
> +                for obj in m.readline().split():
> +                    yield to_cmdfile(obj)
> +
> +
>  def process_line(root_directory, command_prefix, file_path):
>      """Extracts information from a .cmd line and creates an entry from it.
>
> @@ -117,7 +195,7 @@ def process_line(root_directory, command_prefix, file_path):
>
>  def main():
>      """Walks through the directory and finds and parses .cmd files."""
> -    log_level, directory, output, paths = parse_arguments()
> +    log_level, directory, output, ar, paths = parse_arguments()
>
>      level = getattr(logging, log_level)
>      logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
> @@ -127,7 +205,21 @@ def main():
>      compile_commands = []
>
>      for path in paths:
> -        cmdfiles = cmdfiles_in_dir(path)
> +        # If 'path' is a directory, handle all .cmd files under it.
> +        # Otherwise, handle .cmd files associated with the file.
> +        # Most of built-in objects are linked via archives (built-in.a or lib.a)
> +        # but some objects are linked to vmlinux directly.
> +        # Modules are listed in modules.order.
> +        if os.path.isdir(path):
> +            cmdfiles = cmdfiles_in_dir(path)
> +        elif path.endswith('.o'):
> +            cmdfiles = cmdfiles_for_o(path)
> +        elif path.endswith('.a'):
> +            cmdfiles = cmdfiles_for_a(path, ar)
> +        elif path.endswith('modules.order'):
> +            cmdfiles = cmdfiles_for_modorder(path)
> +        else:
> +            sys.exit('{}: unknown file type'.format(path))
>
>          for cmdfile in cmdfiles:
>              with open(cmdfile, 'rt') as f:
> --
> 2.25.1
>


-- 
Thanks,
~Nick Desaulniers

Re: [PATCH v3 09/10] gen_compile_commands: remove the warning about too few .cmd files

[Nick Desaulniers]

On Sat, Aug 22, 2020 at 7:56 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> This warning was useful when users previously needed to manually
> build the kernel and run this script.
>
> Now you can simply do 'make compile_commands.json', which updates
> all the necessary build artifacts and automatically creates the
> compilation database. There is no more worry for a mistake like
> "Oh, I forgot to build the kernel".
>
> Now, this warning is rather annoying.
>
> You can create compile_commands.json for an external module:
>
>   $ make M=/path/to/your/external/module compile_commands.json
>
> Then, this warning is displayed since there are usually less than
> 300 files in a single module.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>
> Changes in v3:
>   - New patch
>
>  scripts/gen_compile_commands.py | 10 ----------
>  1 file changed, 10 deletions(-)
>
> diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
> index f370375b2f70..1de745577e6d 100755
> --- a/scripts/gen_compile_commands.py
> +++ b/scripts/gen_compile_commands.py
> @@ -21,11 +21,6 @@ _FILENAME_PATTERN = r'^\..*\.cmd$'
>  _LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
>  _VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
>
> -# A kernel build generally has over 2000 entries in its compile_commands.json
> -# database. If this code finds 300 or fewer, then warn the user that they might
> -# not have all the .cmd files, and they might need to compile the kernel.
> -_LOW_COUNT_THRESHOLD = 300
> -
>
>  def parse_arguments():
>      """Sets up and parses command-line arguments.
> @@ -236,11 +231,6 @@ def main():
>      with open(output, 'wt') as f:
>          json.dump(compile_commands, f, indent=2, sort_keys=True)
>
> -    count = len(compile_commands)
> -    if count < _LOW_COUNT_THRESHOLD:
> -        logging.warning(
> -            'Found %s entries. Have you compiled the kernel?', count)
> -
>
>  if __name__ == '__main__':
>      main()
> --
> 2.25.1
>


-- 
Thanks,
~Nick Desaulniers

Re: [PATCH v3 00/10] kbuild: clang-tidy

[Masahiro Yamada]

On Sat, Aug 22, 2020 at 11:56 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> I improved gen_compile_commands.py,
> then rebased Nathan's v7 [1] on top of them.
> To save time, I modified the Makefile part.
> No change for run-clang-tools.py
>
> "make clang-tidy" should work in-tree build,
> out-of-tree build (O=), and external module build (M=).
>
> V3:
> Fix minor mistakes pointed out by Nick
> Add a new patch (09/10) to remove the warning about
> too few .cmd files.
>
> V2:
> Keep the previous work-flow.
> You can still manually run scripts/gen_compile_commands.json
>
> 'make compile_commands.json' or 'make clang-tidy' is handier
> for most cases. As Nick noted, there is 3 % loss of the coverage.
>
> If you need the full compilation database that covers all the
> compiled C files, please run the script manually.
>
> [1] https://patchwork.kernel.org/patch/11687833/
>
>
> Masahiro Yamada (9):
>   gen_compile_commands: parse only the first line of .*.cmd files
>   gen_compile_commands: use choices for --log_levels option
>   gen_compile_commands: do not support .cmd files under tools/ directory
>   gen_compile_commands: reword the help message of -d option
>   gen_compile_commands: make -o option independent of -d option
>   gen_compile_commands: move directory walk to a generator function
>   gen_compile_commands: support *.o, *.a, modules.order in positional
>     argument
>   kbuild: wire up the build rule of compile_commands.json to Makefile
>   gen_compile_commands: remove the warning about too few .cmd files
>
> Nathan Huckleberry (1):
>   Makefile: Add clang-tidy and static analyzer support to makefile



All applied to linux-kbuild.







>  MAINTAINERS                                 |   1 +
>  Makefile                                    |  45 +++-
>  scripts/clang-tools/gen_compile_commands.py | 236 ++++++++++++++++++++
>  scripts/clang-tools/run-clang-tools.py      |  74 ++++++
>  scripts/gen_compile_commands.py             | 151 -------------
>  5 files changed, 352 insertions(+), 155 deletions(-)
>  create mode 100755 scripts/clang-tools/gen_compile_commands.py
>  create mode 100755 scripts/clang-tools/run-clang-tools.py
>  delete mode 100755 scripts/gen_compile_commands.py
>
> --
> 2.25.1
>
> --
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-- 
Best Regards
Masahiro Yamada