clang-scan-deps commandline misses target flags on command line

[redstar]

Xmake Version

v2.9.7+dev.b029e65ed

Operating System Version and Architecture

Ubuntu 24.10 x86_64

Describe Bug

The Include directories added to the target inside a rule are not added to the flags of clang-scan-deps, resulting in a compile error.

It seems that the added options depend on the first file/target scanned. If target src2 is removed from xmake.lua then the option is added as expected, and the source compiles fine.

Expected Behavior

Running xmake config --toolchain=clang -v, the include directory added in the rule should be added to the command line of clang-scan-deps, too. It works this way for normal C++ compilation units, but not for C++20 modules. The idea here is to have a private include file only used in the module body (e.g. a database file / generated code).

Project Configuration

set_languages("c++20")

add_rules("mode.debug", "mode.release")

rule("include")
    before_config(function (target)
        print("include.before_config")
        target:add("includedirs", "$(projectdir)/src1/include")
    end)

target("src1")
    set_kind("static")
    add_rules("include")
    add_files("src1/*.cppm", {public = true})

target("src2")
    set_kind("binary")
    add_deps("src1")
    add_files("src2/*.cpp")

Additional Information and Error Logs

// src1/bar.cppm
module;

export module bar;

#include "foo.h"

export int bar() {
  return foo();
}

// src1/include/foo.h
int foo(); 

// src2/main.cpp
import bar;

int main() {
  return foo();
}

Configuration output:

xmake config --toolchain=clang -v
include.before_config
configure
{
    buildir = build
    ccache = true
    ndk_stdcxx = true
    host = linux
    arch = x86_64
    kind = static
    plat = linux
    toolchain = clang
    mode = release
}

xmake build -v
include.before_config
[  0%]: <src2> generating.module.deps src1/bar.cppm
/usr/bin/clang-scan-deps --format=p1689 -- /usr/bin/clang -x c++ -c src1/bar.cppm -o build/.objs/src2/linux/x86_64/release/src1/bar.cppm.o -Qunused-arguments -m64 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -std=c++20 -DNDEBUG
error: Error while scanning dependencies for src1/bar.cppm:
src1/bar.cppm:5:10: fatal error: 'foo.h' file not found

warning: std and std.compat modules not found! maybe try to add --sdk=<PATH/TO/LLVM> or install libc++

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Title: clang-scan-deps commandline misses target flags on command line

[waruqi]

please provide full project as zip

[waruqi]

add_files("src1/*.cppm", {public = true})

if you mark public = true, src1/cppm files will be compiled in target src2. so clang-scan-deps can only get flags/includedirs from target/src2 instead of src1.

you can remove public = true, it will work.

target("src1")
    set_kind("static")
    add_rules("include")
    add_files("src1/*.cppm")

xmake/xmake/rules/c++/modules/xmake.lua

Lines 81 to 86 in 897c5ab

	if target:orderdeps() then
	local deps_sourcefiles = dependency_scanner.get_targetdeps_modules(target)
	if deps_sourcefiles then
	table.join2(sourcebatch.sourcefiles, deps_sourcefiles)
	end
	end

xmake/xmake/rules/c++/modules/modules_support/clang/dependency_scanner.lua

Line 34 in 897c5ab

local flags = compinst:compflags({sourcefile = sourcefile, target = target}) or {}

src2 {
  sourcefiles = {
    "src2/main.cpp",
    "src1/bar.cppm".  <---------------------------
  },
  rulename = "c++.build.modules.builder",
  objectfiles = {
    "build/.objs/src2/macosx/x86_64/release/src2/main.cpp.o"
  },
  dependfiles = {
    "build/.deps/src2/macosx/x86_64/release/src2/main.cpp.o.d"
  },
  sourcekind = "cxx"
}

@Arthapz When compiling these files, I think clang-scan-deps should use the flags from the original target dependency.