gen_compile_commands: handle multiple lines per .mod file

scripts/clang-tools/gen_compile_commands.py incorrectly assumes that each .mod file only contains one line. That assumption was correct when the script was originally created, but commit 9413e7640564 ("kbuild:
split the second line of *.mod into *.usyms") changed the .mod file format so that there is one entry per line, and potentially many lines.

The problem can be reproduced by using Kbuild to generate compile_commands.json, like this:

make CC=clang compile_commands.json

In many cases, the problem might be overlooked because many subsystems only have one line anyway. However, in some subsystems (Nouveau, with 762 entries, is a notable example) it results in skipping most of the subsystem.

Fix this by fully processing each .mod file.

Fixes 9413e7640564 ("kbuild: split the second line of *.mod into *.usyms")

Cc Masahiro Yamada <[email protected]>

Cc Nick Desaulniers <[email protected]>

Signed-off-by John Hubbard <[email protected]>

---

Link to v2:
https://lore.kernel.org/all/[email protected]/

Changes since v2:

* Restored a blank line.

* Rewrote the commit description.

thanks,
John Hubbard

 scripts/clang-tools/gen_compile_commands.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

scripts/clang-tools/gen_compile_commands.py +3 -4

index 1d1bde1fd45e..47da25b3ba7d 100755
@@ -157,10 +157,10 @@ def cmdfiles_for_modorder(modorder):
             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.
+            # Read from *.mod, to get a list of objects that compose the module.
             with open(mod) as m:
-                for obj in m.readline().split():
-                    yield to_cmdfile(obj)
+                for mod_line in m:
+                    yield to_cmdfile(mod_line.rstrip())
 
 
 def process_line(root_directory, command_prefix, file_path):
--

2.36.1

Quoted 17 lines · John Hubbard

scripts/clang-tools/gen_compile_commands.py incorrectly assumes that each .mod file only contains one line. That assumption was correct when the script was originally created, but commit 9413e7640564 ("kbuild:
split the second line of *.mod into *.usyms") changed the .mod file format so that there is one entry per line, and potentially many lines.

The problem can be reproduced by using Kbuild to generate compile_commands.json, like this:

make CC=clang compile_commands.json

In many cases, the problem might be overlooked because many subsystems only have one line anyway. However, in some subsystems (Nouveau, with 762 entries, is a notable example) it results in skipping most of the subsystem.

Quoted 5 lines

Fix this by fully processing each .mod file.

Fixes 9413e7640564 ("kbuild: split the second line of *.mod into *.usyms")

Cc Masahiro Yamada <[email protected]>

Cc Nick Desaulniers <[email protected]>

Thanks for the fix, John!

Reviewed-by Nick Desaulniers <[email protected]>