3 files changed, 13 insertions, 4 deletions
diff --git a/xmake/rules/c++/modules/modules_support/clang.lua b/xmake/rules/c++/modules/modules_support/clang.lua
index e67bacef1..160c08b25 100644
--- a/xmake/rules/c++/modules/modules_support/clang.lua
+++ b/xmake/rules/c++/modules/modules_support/clang.lua
@@ -150,7 +150,12 @@ function generate_dependencies(target, sourcebatch, opt)
 
             -- no support of p1689 atm
             local jsonfile = path.translate(path.join(outputdir, path.filename(sourcefile) .. ".json"))
-            common.fallback_generate_dependencies(target, jsonfile, sourcefile)
+            common.fallback_generate_dependencies(target, jsonfile, sourcefile, function(file)
+                local compinst = target:compiler("cxx")
+                local ifile = path.translate(path.join(outputdir, path.filename(file) .. ".i"))
+                os.vrunv(compinst:program(), {"-E", "-x", "c++", file,  "-o", ifile})
+                return io.readfile(ifile)
+            end)
             changed = true
 
             local dependinfo = io.readfile(jsonfile)
diff --git a/xmake/rules/c++/modules/modules_support/common.lua b/xmake/rules/c++/modules/modules_support/common.lua
index 593913887..e91712ffd 100644
--- a/xmake/rules/c++/modules/modules_support/common.lua
+++ b/xmake/rules/c++/modules/modules_support/common.lua
@@ -376,7 +376,7 @@ end
     }
   ]
 }]]
-function fallback_generate_dependencies(target, jsonfile, sourcefile)
+function fallback_generate_dependencies(target, jsonfile, sourcefile, preprocess_file)
     local output = {version = 0, revision = 0, rules = {}}
     local rule = {outputs = {jsonfile}}
     rule["primary-output"] = target:objectfile(sourcefile)
@@ -385,7 +385,7 @@ function fallback_generate_dependencies(target, jsonfile, sourcefile)
     local module_name_private
     local module_deps = {}
     local module_deps_set = hashset.new()
-    local sourcecode = io.readfile(sourcefile)
+    local sourcecode = preprocess_file(sourcefile)
     sourcecode = sourcecode:gsub("//.-\n", "\n")
     sourcecode = sourcecode:gsub("/%*.-%*/", "")
     for _, line in ipairs(sourcecode:split("\n", {plain = true})) do
diff --git a/xmake/rules/c++/modules/modules_support/gcc.lua b/xmake/rules/c++/modules/modules_support/gcc.lua
index 20a8437aa..1d26a543e 100644
--- a/xmake/rules/c++/modules/modules_support/gcc.lua
+++ b/xmake/rules/c++/modules/modules_support/gcc.lua
@@ -145,7 +145,11 @@ function generate_dependencies(target, sourcebatch, opt)
                 local args = {sourcefile, "-MD", "-MT", jsonfile, "-MF", dfile, depfileflag .. jsonfile, trtbdflag, depoutputfile .. target:objectfile(sourcefile), "-o", ifile}
                 os.vrunv(compinst:program(), table.join(compinst:compflags({target = target}), common_args, args), {envs = vcvars})
             else
-                common.fallback_generate_dependencies(target, jsonfile, sourcefile)
+                common.fallback_generate_dependencies(target, jsonfile, sourcefile, function(file)
+                    local ifile = path.translate(path.join(outputdir, path.filename(file) .. ".i"))
+                    os.vrunv(compinst:program(), {"-E", "-x", "c++", file,  "-o", ifile})
+                    return io.readfile(ifile)
+                end)
             end
             changed = true