Update xmake.lua

packages/l/libomp/xmake.lua

@@ -15,6 +15,29 @@ package("libomp")
         add_syslinks("pthread", "dl")
     end
 
+    on_load(function (package)
+        if package.has_tool then
+            for _, toolkind in ipairs({"cc", "cxx"}) do
+                local flagname = toolkind == "cxx" and "cxxflags" or "cflags"
+                if package:has_tool(toolkind, "cl") then
+                    package:add(flagname, "/openmp")
+                elseif package:has_tool(toolkind, "clang", "clangxx") then
+                    if package:is_plat("macosx") then
+                        package:add(flagname, "-Xpreprocessor -fopenmp")
+                    else
+                        package:add(flagname, "-fopenmp")
+                    end
+                elseif package:has_tool(toolkind, "gcc", "gxx") then
+                    package:add(flagname, "-fopenmp")
+                elseif package:has_tool(toolkind, "icc", "icpc") then
+                    package:add(flagname, "-qopenmp")
+                elseif package:has_tool(toolkind, "icl") then
+                    package:add(flagname, "-Qopenmp")
+                end
+            end
+        end
+    end)
+
     on_install("macosx", "linux", "cross", function (package)
         local configs = {"-DLIBOMP_INSTALL_ALIASES=OFF"}
         local shared = package:config("shared")