unxpected -I in compile_command.json

[garfieldkwong]

Xmake Version

v2.7.2+202210241457

Operating System Version and Architecture

Ubuntu 22.04

Describe Bug

xmake use the flag -isystem for the package include path. But when generating the compile_command.json, it is -I

/usr/bin/clang-15 -c -Qunused-arguments -m64 -g -Wall -Wextra -Werror -O0 -std=c++2b -isystem <boost-path>/include -o build/.objs/y/linux/x86_64/debug/src/main.cpp.o src/main.cpp

compile_command.json:

{
  "directory": "<home-path>",
  "arguments": ["/usr/bin/clang-15", "-c", "-Qunused-arguments", "-m64", "-g", "-Wall", "-Wextra", "-Werror", "-O0", "-std=c++2b", "-I", "<boost-path>/include", "-o", "build/.objs/y/linux/x86_64/debug/src/main.cpp.o", "src/main.cpp"],
  "file": "src/main.cpp"
},

Expected Behavior

should generate the following in compile_command.json

{
  "directory": "<home-path>",
  "arguments": ["/usr/bin/clang-15", "-c", "-Qunused-arguments", "-m64", "-g", "-Wall", "-Wextra", "-Werror", "-O0", "-std=c++2b", "-isystem", "<boost-path>/include", "-o", "build/.objs/y/linux/x86_64/debug/src/main.cpp.o", "src/main.cpp"],
  "file": "src/main.cpp"
},

Project Configuration

No response

Additional Information and Error Logs

No response

[waruqi]

I remember previous feedback from users that cpptools or clangd did not yet support parsing headers from -isystem, so xmake uses -I to provide better compatibility.

Also, "-I", "/xx" are valid arguments and the LSP should support it. If they don't support it, you should go to clangd or cpptools and give feedback on the problem.

[garfieldkwong]

I remember previous feedback from users that cpptools or clangd did not yet support parsing headers from -isystem, so xmake uses -I to provide better compatibility.

Also, "-I", "/xx" are valid arguments and the LSP should support it. If they don't support it, you should go to clangd or cpptools and give feedback on the problem.

So could we have an argument to adjust it?

[garfieldkwong]

And according to https://clangd.llvm.org/guides/system-headers#search-directories-mentioned-with-compile-flags, clangd does support "-isystem"

and by my testings, when I replace all "-I" with "-isystem" in compile_commands.json, both clangd and clang-tidy respect the "-isystem" in compile_commands.json

[waruqi]

Not only clangd, but also many LSPs, cpptools/ccls ... There is no guarantee that all LSPs will support -isystem, but -I is certainly the most compatible.

[garfieldkwong]

So could we have an argument to adjust it? Since -isystem will ignore the warning and tidy error but -I will still have it.

[waruqi]

no arguments now.

[waruqi]

I added a --lsp=clangd argument to improve it for clangd.

xmake project -k compile_commands --lsp=clangd