Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Tom Roeder]

On Tue, Feb 09, 2021 at 12:27:29PM -0700, Nathan Chancellor wrote:
>On Tue, Feb 09, 2021 at 09:56:20PM +0800, Stephen Zhang wrote:
>> Nathan Chancellor <nathan@kernel.org> 于2021年2月9日周二 上午3:54写道：
>>
>> > On Mon, Feb 08, 2021 at 07:28:57PM +0800, Stephen Zhang wrote:
>> > > The default source directory is set equal to build directory which
>> > > specified by "-d".But it is designed to be set to the current working
>> > > directoy by default, as the help messge says.It makes a differece when
>> > > source directory and build directory are in separted directorys.
>> > >
>> > > Signed-off-by: Stephen Zhang <stephenzhangzsd@gmail.com>
>> >
>> > I don't think this patch makes much sense unless I am misunderstanding
>> > the description of the problem. The entire point of this script is to
>> > parse the .cmd files that kbuild generates and those are only present
>> > in the build directory, not the source directory, so we should never be
>> > looking in there, unless args.directory is its default value, which is
>> > the way the script is currently written. Your patch would appear to
>> > either make use do way more searching than necessary (if the build
>> > folder is within the source folder) or miss it altogether (if the build
>> > folder is outside the source folder).
>> >
>> > Cheers,
>> > Nathan
>
>Just as an FYI, your email was HTML, which means it won't hit LKML.
>
>> Specifically,the souce directory is  /vm/linux/tools/perf on my machine,
>> while the build
>> directory is /vm/tmpbuild/tools/perf .In the build directory , Execute the
>> command:
>>
>> /vm/linux/scripts/clang-tools/gen_compile_commands.py --log_level DEBUG -d .
>>
>> The resulting debugging message is:
>>
>>     INFO: Could not add line from /vm/tmpbuild/tools/perf/.perf.o.cmd: File
>> /vm/tmpbuild/tools/perf/perf.c
>>     not found.
>>
>> But actually what we want is ：
>>
>>     add line from /vm/tmpbuild/tools/perf/.perf.o.cmd: File
>> /vm/linux/tools/perf/perf.c.
>>
>> The    " /vm/tmpbuild/tools/perf " of  the "File
>> /vm/tmpbuild/tools/perf/perf.c not found." is passed by  "-d".
>>
>> so it is the "-d" which decides the source prefix.
>>
>> Then we execute:
>>
>>  /vm/linux/scripts/clang-tools/gen_compile_commands.py --log_level DEBUG
>> -d  /vm/linux/tools/perf
>>
>> But in the oringnal code , the default build directory is the same as  the
>> source directory:
>>
>> @@ -64,7 +64,7 @@ def parse_arguments():
>>              os.path.abspath(args.directory),
>>              args.output,
>>              args.ar,
>> -            args.paths if len(args.paths) > 0 else [args.directory])
>> +            args.paths if len(args.paths) > 0 else [os.getcwd()])
>>
>> after changing  it ,we then get the right result.
>
>Okay I think I see what is going on here. Your patch does not actually
>fix the problem from what I can tell though:
>
>$ mkdir -p /tmp/build/perf
>
>$ make -C tools/perf -skj"$(nproc)" O=/tmp/build/perf
>
>$ cd /tmp/build/perf
>
>$ ~/cbl/src/linux/scripts/clang-tools/gen_compile_commands.py --log_level INFO -d .
>...
>INFO: Could not add line from /tmp/build/perf/arch/x86/tests/.bp-modify.o.cmd: File /tmp/build/perf/arch/x86/tests/bp-modify.c not found
>INFO: Could not add line from /tmp/build/perf/arch/x86/tests/.insn-x86.o.cmd: File /tmp/build/perf/arch/x86/tests/insn-x86.c not found
>INFO: Could not add line from /tmp/build/perf/arch/x86/tests/.arch-tests.o.cmd: File /tmp/build/perf/arch/x86/tests/arch-tests.c not found
>INFO: Could not add line from /tmp/build/perf/arch/x86/tests/.intel-pt-pkt-decoder-test.o.cmd: File /tmp/build/perf/arch/x86/tests/intel-pt-pkt-decoder-test.c not found
>...
>
>The script has to know where the source location is in your particular
>use case because the .cmd files do not record it (maybe some future
>improvement?)
>
>This patch appears to generate what I think the compile_commands.json
>should look like for the most part, I am not sure if this is proper or
>works correctly though. CC'ing Tom Roeder who originally wrote this.
>Tom, the initial patch and description of the issue is here:
>https://lore.kernel.org/r/1612783737-3512-1-git-send-email-stephenzhangzsd@gmail.com/

Thanks! I'll take a look. I'm also CC'ing linux-kbuild, which is the 
subtree that owns the script; I haven't been very involved since I added 
it. My main concern is to make sure that changes don't break the simple 
use case: generating compile_commands.json in an in-tree build without 
any arguments to the script.

>
>$ scripts/clang-tools/gen_compile_commands.py -d /tmp/build/perf -s tools/perf
>
>diff --git a/scripts/clang-tools/gen_compile_commands.py b/scripts/clang-tools/gen_compile_commands.py
>index 8ddb5d099029..ba3b2dcdc3e1 100755
>--- a/scripts/clang-tools/gen_compile_commands.py
>+++ b/scripts/clang-tools/gen_compile_commands.py
>@@ -27,7 +27,8 @@ def parse_arguments():
>
>     Returns:
>         log_level: A logging level to filter log output.
>-        directory: The work directory where the objects were built.
>+        obj_directory: The work directory where the objects were built.
>+        src_directory: The source directory from which the objects were built.
>         ar: Command used for parsing .a archives.
>         output: Where to write the compile-commands JSON file.
>         paths: The list of files/directories to handle to find .cmd files.
>@@ -35,10 +36,15 @@ def parse_arguments():
>     usage = 'Creates a compile_commands.json database from kernel .cmd files'
>     parser = argparse.ArgumentParser(description=usage)
>
>-    directory_help = ('specify the output directory used for the kernel build '
>-                      '(defaults to the working directory)')
>-    parser.add_argument('-d', '--directory', type=str, default='.',
>-                        help=directory_help)
>+    obj_directory_help = ('specify the output directory used for the kernel build '
>+                          '(defaults to the working directory)')
>+    parser.add_argument('-d', '--obj_directory', type=str, default='.',
>+                        help=obj_directory_help)
>+
>+    src_directory_help = ('specify the source directory used for the kernel build '
>+                          '(defaults to the working directory)')
>+    parser.add_argument('-s', '--src_directory', type=str, default='.',
>+                        help=src_directory_help)
>
>     output_help = ('path to the output command database (defaults to ' +
>                    _DEFAULT_OUTPUT + ')')
>@@ -55,16 +61,17 @@ def parse_arguments():
>
>     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')
>+                  'If nothing is specified, the build 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),
>+            os.path.abspath(args.obj_directory),
>+            os.path.abspath(args.src_directory),
>             args.output,
>             args.ar,
>-            args.paths if len(args.paths) > 0 else [args.directory])
>+            args.paths if len(args.paths) > 0 else [args.obj_directory])
>
>
> def cmdfiles_in_dir(directory):
>@@ -154,22 +161,23 @@ def cmdfiles_for_modorder(modorder):
>                     yield to_cmdfile(obj)
>
>
>-def process_line(root_directory, command_prefix, file_path):
>+def process_line(obj_directory, src_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
>+        obj_directory: The directory that was searched for .cmd files. Usually
>             used directly in the "directory" entry in compile_commands.json.
>+        src_directory: The directory that was used to build the object files.
>         command_prefix: The extracted command line, up to the last element.
>         file_path: The .c file from the end of the extracted command.
>-            Usually relative to root_directory, but sometimes absolute.
>+            Usually relative to obj_directory, but sometimes absolute.
>
>     Returns:
>         An entry to append to compile_commands.
>
>     Raises:
>         ValueError: Could not find the extracted file based on file_path and
>-            root_directory or file_directory.
>+            src_directory or file_directory.
>     """
>     # The .cmd files are intended to be included directly by Make, so they
>     # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
>@@ -177,20 +185,23 @@ def process_line(root_directory, command_prefix, file_path):
>     # by Make, so this code replaces the escaped version with '#'.
>     prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
>
>-    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
>-    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
>+    if os.path.isabs(file_path):
>+        abs_path = file_path
>+    else:
>+        # Use os.path.abspath() to normalize the path resolving '.' and '..' .
>+        abs_path = os.path.abspath(os.path.join(src_directory, file_path))
>     if not os.path.exists(abs_path):
>         raise ValueError('File %s not found' % abs_path)
>     return {
>-        'directory': root_directory,
>+        'directory': obj_directory,
>         'file': abs_path,
>-        'command': prefix + file_path,
>+        'command': prefix + abs_path,
>     }
>
>
> def main():
>     """Walks through the directory and finds and parses .cmd files."""
>-    log_level, directory, output, ar, paths = parse_arguments()
>+    log_level, obj_directory, src_directory, output, ar, paths = parse_arguments()
>
>     level = getattr(logging, log_level)
>     logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
>@@ -221,8 +232,8 @@ def main():
>                 result = line_matcher.match(f.readline())
>                 if result:
>                     try:
>-                        entry = process_line(directory, result.group(1),
>-                                             result.group(2))
>+                        entry = process_line(obj_directory, src_directory,
>+                                             result.group(1), result.group(2))
>                         compile_commands.append(entry)
>                     except ValueError as err:
>                         logging.info('Could not add line from %s: %s',

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Stephen Zhang]

Nathan Chancellor <nathan@kernel.org> 于2021年2月11日周四 上午2:24写道：
>
> On Wed, Feb 10, 2021 at 08:15:27PM +0800, Stephen Zhang wrote:
> > Nathan Chancellor <nathan@kernel.org> 于2021年2月10日周三 上午3:27写道：
> >
> > > Just as an FYI, your email was HTML, which means it won't hit LKML.
> >
> >
> > Thanks for pointing that out. The existence of a GFW makes it difficult for
> > me to connect
> > to the mail server.  so I use git client to send patches only and reply to
> > emails with
> > gmail  web client.
>
> You can configure your Gmail web client to send text responses by
> default by clicking on the three dot menu in the compose window then
> chose the "plain text mode" option.
>

Thanks, this has always been a problem for me.

> The build directory needs to be involved because that is where the .cmd
> files will be but the source directory needs to be known because the
> source files in the .cmd files are relative to the source directory, not
> the build directory. This happens to work in most situations like I
> point out above but not always.
>
> I think that my patch is most likely the way to go unless others feel
> differently. It would be nice if you could give it a go.
>
> Cheers,
> Nathan

Do you mean  my patch's failure  in some cases  is because the build
directoty isn't involved after using "-d" to specify the source directory?

Actually, the build directory has already been involved by the "path"
argument. See:

def main():
    for path in paths:
         ....
        if os.path.isdir(path):
            cmdfiles = cmdfiles_in_dir(path)
        .....

where the value of paths  is passed by  the "path" argument. Do I miss
something?

Cheers,
Stephen

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Masahiro Yamada]

On Thu, Feb 11, 2021 at 10:48 PM Stephen Zhang
<stephenzhangzsd@gmail.com> wrote:
>
> Nathan Chancellor <nathan@kernel.org> 于2021年2月11日周四 上午2:24写道：
> >
> > On Wed, Feb 10, 2021 at 08:15:27PM +0800, Stephen Zhang wrote:
> > > Nathan Chancellor <nathan@kernel.org> 于2021年2月10日周三 上午3:27写道：
> > >
> > > > Just as an FYI, your email was HTML, which means it won't hit LKML.
> > >
> > >
> > > Thanks for pointing that out. The existence of a GFW makes it difficult for
> > > me to connect
> > > to the mail server.  so I use git client to send patches only and reply to
> > > emails with
> > > gmail  web client.
> >
> > You can configure your Gmail web client to send text responses by
> > default by clicking on the three dot menu in the compose window then
> > chose the "plain text mode" option.
> >
>
> Thanks, this has always been a problem for me.
>
> > The build directory needs to be involved because that is where the .cmd
> > files will be but the source directory needs to be known because the
> > source files in the .cmd files are relative to the source directory, not
> > the build directory. This happens to work in most situations like I
> > point out above but not always.
> >
> > I think that my patch is most likely the way to go unless others feel
> > differently. It would be nice if you could give it a go.
> >
> > Cheers,
> > Nathan
>
> Do you mean  my patch's failure  in some cases  is because the build
> directoty isn't involved after using "-d" to specify the source directory?
>
> Actually, the build directory has already been involved by the "path"
> argument. See:
>
> def main():
>     for path in paths:
>          ....
>         if os.path.isdir(path):
>             cmdfiles = cmdfiles_in_dir(path)
>         .....
>
> where the value of paths  is passed by  the "path" argument. Do I miss
> something?
>
> Cheers,
> Stephen
>
> --
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Please stop.


Commit 6ca4c6d25949117dc5b4845612e290b6d89e70a8
removed the tools/ support.


There exist two build systems in the Linux source tree.
Kbuild covers the entire tree except tools/.
The tools/ directory adopts a different build system.

It is a pity that the tools/ directory
went in a wrong direction, and people
try to fix problems in a wrong layer.


You are not the first person to send to
tweak obj/source trees of this script.

You can not do this correctly
without terribly messing up the code.

Please do not try to support tools/.



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Stephen Zhang]

Masahiro Yamada <masahiroy@kernel.org> 于2021年2月11日周四 下午10:16写道：
> Please stop.
>
>
> Commit 6ca4c6d25949117dc5b4845612e290b6d89e70a8
> removed the tools/ support.
>
>
> There exist two build systems in the Linux source tree.
> Kbuild covers the entire tree except tools/.
> The tools/ directory adopts a different build system.
>
> It is a pity that the tools/ directory
> went in a wrong direction, and people
> try to fix problems in a wrong layer.
>
>
> You are not the first person to send to
> tweak obj/source trees of this script.
>
> You can not do this correctly
> without terribly messing up the code.
>
> Please do not try to support tools/.
>
>
>
> --
> Best Regards
> Masahiro Yamada

Thanks for the suggestion.But what we try to support is scripts/
instead of tools/. 'tools/' here is to help explaining the problem.
Or am I just misunderstanding your words?

--
Best Regards
Stephen Zhang

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Masahiro Yamada]

On Fri, Feb 12, 2021 at 8:20 PM Stephen Zhang <stephenzhangzsd@gmail.com> wrote:
>
> Masahiro Yamada <masahiroy@kernel.org> 于2021年2月11日周四 下午10:16写道：
> > Please stop.
> >
> >
> > Commit 6ca4c6d25949117dc5b4845612e290b6d89e70a8
> > removed the tools/ support.
> >
> >
> > There exist two build systems in the Linux source tree.
> > Kbuild covers the entire tree except tools/.
> > The tools/ directory adopts a different build system.
> >
> > It is a pity that the tools/ directory
> > went in a wrong direction, and people
> > try to fix problems in a wrong layer.
> >
> >
> > You are not the first person to send to
> > tweak obj/source trees of this script.
> >
> > You can not do this correctly
> > without terribly messing up the code.
> >
> > Please do not try to support tools/.
> >
> >
> >
> > --
> > Best Regards
> > Masahiro Yamada
>
> Thanks for the suggestion.But what we try to support is scripts/
> instead of tools/. 'tools/' here is to help explaining the problem.
> Or am I just misunderstanding your words?



You took 'tools/perf' as an example,
so I just thought you were trying to fix the tools/.



I can get scripts/ entries without any problem.

If you do O= build, you can pass that directory
to the -d option of gen_compile_commands.py

  -d DIRECTORY, --directory DIRECTORY
                        specify the output directory used for the
kernel build (defaults to the working
                        directory)


This is the steps I tested.


masahiro@oscar:~/ref/linux$ make O=build  defconfig all -j24
  [ snip ]
masahiro@oscar:~/ref/linux$
./scripts/clang-tools/gen_compile_commands.py  -d build
masahiro@oscar:~/ref/linux$ grep '"file":' compile_commands.json |
grep scripts/ | head -n5
    "file": "/home/masahiro/ref/linux/scripts/mod/empty.c"
    "file": "/home/masahiro/ref/linux/scripts/mod/sumversion.c"
    "file": "/home/masahiro/ref/linux/scripts/mod/file2alias.c"
    "file": "/home/masahiro/ref/linux/scripts/mod/modpost.c"
    "file": "/home/masahiro/ref/linux/build/scripts/kconfig/parser.tab.c"








-- 
Best Regards
Masahiro Yamada

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Stephen Zhang]

Masahiro Yamada <masahiroy@kernel.org> 于2021年2月13日周六 下午8:46写道：
> This is the steps I tested.
>
>
> masahiro@oscar:~/ref/linux$ make O=build  defconfig all -j24
>   [ snip ]
> masahiro@oscar:~/ref/linux$
> ./scripts/clang-tools/gen_compile_commands.py  -d build
> masahiro@oscar:~/ref/linux$ grep '"file":' compile_commands.json |
> grep scripts/ | head -n5
>     "file": "/home/masahiro/ref/linux/scripts/mod/empty.c"
>     "file": "/home/masahiro/ref/linux/scripts/mod/sumversion.c"
>     "file": "/home/masahiro/ref/linux/scripts/mod/file2alias.c"
>     "file": "/home/masahiro/ref/linux/scripts/mod/modpost.c"
>     "file": "/home/masahiro/ref/linux/build/scripts/kconfig/parser.tab.c"
>
> --
> Best Regards
> Masahiro Yamada

Thanks. Nathan had a detailed description about  this:

> $ make O=build
>
> will work with '-d .' because the .cmd files are in '.' and the source
> files will be placed relative to '.', which is correct. Your command
> does not work for two reasons:
>
> 1. You are using a build directory that is not a subpath of the source
> directory. In other words, this script would not work for
>
> $ make O=/tmp/build
>
> because '-d /tmp/build' needs to be used to find the .cmd files but then
> the relative path of the source files is messed up, as you point out.

This may help you reproduce the problem. So you shoud try:

>masahiro@oscar:~/ref/linux$ make O=/tmp/build  defconfig all -j24

where the build directory  is not a subpath of the source directory.

--
Best Regards
Stephen Zhang

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Masahiro Yamada]

On Sun, Feb 14, 2021 at 8:49 PM Stephen Zhang <stephenzhangzsd@gmail.com> wrote:
>
> Masahiro Yamada <masahiroy@kernel.org> 于2021年2月13日周六 下午8:46写道：
> > This is the steps I tested.
> >
> >
> > masahiro@oscar:~/ref/linux$ make O=build  defconfig all -j24
> >   [ snip ]
> > masahiro@oscar:~/ref/linux$
> > ./scripts/clang-tools/gen_compile_commands.py  -d build
> > masahiro@oscar:~/ref/linux$ grep '"file":' compile_commands.json |
> > grep scripts/ | head -n5
> >     "file": "/home/masahiro/ref/linux/scripts/mod/empty.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/sumversion.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/file2alias.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/modpost.c"
> >     "file": "/home/masahiro/ref/linux/build/scripts/kconfig/parser.tab.c"
> >
> > --
> > Best Regards
> > Masahiro Yamada
>
> Thanks. Nathan had a detailed description about  this:
>
> > $ make O=build
> >
> > will work with '-d .' because the .cmd files are in '.' and the source
> > files will be placed relative to '.', which is correct. Your command
> > does not work for two reasons:
> >
> > 1. You are using a build directory that is not a subpath of the source
> > directory. In other words, this script would not work for
> >
> > $ make O=/tmp/build
> >
> > because '-d /tmp/build' needs to be used to find the .cmd files but then
> > the relative path of the source files is messed up, as you point out.
>
> This may help you reproduce the problem. So you shoud try:
>
> >masahiro@oscar:~/ref/linux$ make O=/tmp/build  defconfig all -j24
>
> where the build directory  is not a subpath of the source directory.



So, what is the problem?




-- 
Best Regards
Masahiro Yamada

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Stephen Zhang]

Masahiro Yamada <masahiroy@kernel.org> 于2021年2月15日周一 上午1:10写道：
>
> So, what is the problem?
>
>
>
>
> --
> Best Regards
> Masahiro Yamada

Okay，it seems that I misunderstood what you said before.

--
Best Regards
Stephen Zhang

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Nathan Chancellor]

On Sun, Feb 14, 2021 at 07:49:22PM +0800, Stephen Zhang wrote:
> Masahiro Yamada <masahiroy@kernel.org> 于2021年2月13日周六 下午8:46写道：
> > This is the steps I tested.
> >
> >
> > masahiro@oscar:~/ref/linux$ make O=build  defconfig all -j24
> >   [ snip ]
> > masahiro@oscar:~/ref/linux$
> > ./scripts/clang-tools/gen_compile_commands.py  -d build
> > masahiro@oscar:~/ref/linux$ grep '"file":' compile_commands.json |
> > grep scripts/ | head -n5
> >     "file": "/home/masahiro/ref/linux/scripts/mod/empty.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/sumversion.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/file2alias.c"
> >     "file": "/home/masahiro/ref/linux/scripts/mod/modpost.c"
> >     "file": "/home/masahiro/ref/linux/build/scripts/kconfig/parser.tab.c"
> >
> > --
> > Best Regards
> > Masahiro Yamada
> 
> Thanks. Nathan had a detailed description about  this:
> 
> > $ make O=build
> >
> > will work with '-d .' because the .cmd files are in '.' and the source
> > files will be placed relative to '.', which is correct. Your command
> > does not work for two reasons:
> >
> > 1. You are using a build directory that is not a subpath of the source
> > directory. In other words, this script would not work for
> >
> > $ make O=/tmp/build
> >
> > because '-d /tmp/build' needs to be used to find the .cmd files but then
> > the relative path of the source files is messed up, as you point out.
> 
> This may help you reproduce the problem. So you shoud try:
> 
> >masahiro@oscar:~/ref/linux$ make O=/tmp/build  defconfig all -j24
> 
> where the build directory  is not a subpath of the source directory.
> 

This will actually work for the regular build system as it uses the full
path to the files when O= is outside of the source tree. My comment
applies only to the tools/ build system, which Masahiro has explicitly
said he does not want this script to support.

Cheers,
Nathan

Re: [PATCH v1] clang_tools:gen_compile_commands: Change the default source directory

[Stephen Zhang]

Nathan Chancellor <nathan@kernel.org> 于2021年2月15日周一 上午7:28写道：
>
> This will actually work for the regular build system as it uses the full
> path to the files when O= is outside of the source tree. My comment
> applies only to the tools/ build system, which Masahiro has explicitly
> said he does not want this script to support.
>
> Cheers,
> Nathan

Thanks for the clarification. I start to get what you mean.

Cheers,
Stephen