Made headeronly targets appears as phony targets (so it doesn't ask for a linker it doesn't requires)

Author: PierreEVEN

xmake/plugins/project/make/makefile.lua

@@ -334,7 +334,7 @@ function _add_toolchains(makefile, outputdir)
 
     -- add toolchains from targets
     for targetname, target in pairs(project.targets()) do
-        if not target:is_phony() then
+        if not _phony_or_headeronly(target) then
             local program = _get_program_from_target(target, target:linker():kind())
             if program then
                 makefile:print("%s_%s=%s", targetname, target:linker():kind():upper(), program)
@@ -353,10 +353,14 @@ function _add_toolchains(makefile, outputdir)
     makefile:print("")
 end
 
+function _phony_or_headeronly(target) 
+    return target:is_phony() or target:is_headeronly()
+end
+
 -- add flags
 function _add_flags(makefile, targetflags, outputdir)
     for targetname, target in pairs(project.targets()) do
-        if not target:is_phony() then
+        if not _phony_or_headeronly(target) then
             for _, sourcebatch in pairs(target:sourcebatches()) do
                 local sourcekind = sourcebatch.sourcekind
                 if sourcekind then
@@ -512,7 +516,7 @@ function _add_build_target(makefile, target, targetflags, outputdir)
     local precmds_label = _add_build_custom_commands_before(makefile, target, outputdir)
 
     -- is phony target?
-    if target:is_phony() then
+    if _phony_or_headeronly(target) then
         return _add_build_phony(makefile, target)
     end
 
@@ -539,7 +543,7 @@ function _add_build_target(makefile, target, targetflags, outputdir)
     -- make dependence for the dependent targets
     for _, depname in ipairs(target:get("deps")) do
         local dep = project.target(depname, {namespace = target:namespace()})
-        makefile:write(" " .. (dep:is_phony() and depname or _get_relative_unix_path(dep:targetfile(), outputdir)))
+        makefile:write(" " .. (_phony_or_headeronly(dep) and depname or _get_relative_unix_path(dep:targetfile(), outputdir)))
     end
 
     -- make dependence for objects
@@ -650,7 +654,7 @@ function _add_clean_target(makefile, target, outputdir)
         makefile:write(" clean_" .. dep)
     end
     makefile:print("")
-    if not target:is_phony() then
+    if not _phony_or_headeronly(target) then
         _add_remove_files(makefile, target:targetfile(), outputdir)
         _add_remove_files(makefile, target:symbolfile(), outputdir)
         _add_remove_files(makefile, target:objectfiles(), outputdir)