Is there a way to use the compilation database with clang-expand

[razeh]

My list of source files is larger than can be passed on the command line; is there a way to use a LLVM compilation database?

[goldsborough]

It should be possible because the compilation database was really made for this, but when I tried it I ran into some difficulties. Have you tried passing the db to the -p flag? All clang tools have a -p option for a build path containing the db.
If not and you really want it to work with the compilation database, I'd be glad if you can help looking into it. I'm also interested in the lookup times you will experience with more source files than can be passed on the command line.
Let me know.

[razeh]

If you run clang-expand with just -p, clang-expand complains about not enough positional parameters --- and it looks like this is coming from within clang.

How does adding an option that tells clang expand to use all of the entries in the build database for the source files sound?

[goldsborough]

You still have to pass the source file of the code you have to expand, so I think you're just missing that positional location? Try something like:
clang-expand file_containing_expansion.cpp -p path_containing_compile_commands --line <l> --column <c>
Either way, we'll still need something to read the compilation database as you suggest. In clang-expand.cpp, it should be as simple as merging the database compilations with the source list somehow:

  const auto& sources = options.getSourcePathList();
  auto& db = options.getCompilations();

Will look into it.

[razeh]

If you add the positional argument, you do get further:
run /scratch/razeh/src/clang-expand/source/search.cpp:54
source: Escape.C
run /scratch/razeh/src/clang-expand/source/search.cpp:61
run /scratch/razeh/src/clang-expand/source/search.cpp:87
allCompileCommands.size()!
error: no input files
error: unable to handle compilation, expected exactly one compiler job in ''

It is reading in the compilation database --- as you can see by the debug output I've added.