3 files changed, 71 insertions, 11 deletions

diff --git a/xmake/actions/build/kinds/object.lua b/xmake/actions/build/kinds/object.lua
index 045045041..2b801aeb0 100644
--- a/xmake/actions/build/kinds/object.lua
+++ b/xmake/actions/build/kinds/object.lua
@@ -27,6 +27,7 @@ import("core.base.option")
 import("core.tool.compiler")
 import("core.tool.extractor")
 import("core.project.config")
+import("core.language.language")
 import("detect.tools.find_ccache")
 
 -- build the object from the *.[o|obj] source file
@@ -101,10 +102,7 @@ function _build_object(target, buildinfo, index, sourcebatch, ccache)
     table.insert(depfiles, sourcefile)
     
     -- add precompiled header to the dependent files
-    local precompiled_header = target:get("precompiled_header")
-    if precompiled_header then
-        table.insert(depfiles, precompiled_header)
-    end
+    table.join2(depfiles, target:pcsourcefile())
 
     -- check the dependent files are modified?
     local modified      = false
@@ -232,7 +230,7 @@ end
 function _build_precompiled_header(target, buildinfo)
 
     -- get the precompiled header
-    local precompiled_header = target:get("precompiled_header")
+    local precompiled_header, precompiled_source = target:pcsourcefile()
     if not precompiled_header then
         return 
     end
@@ -244,7 +242,14 @@ function _build_precompiled_header(target, buildinfo)
     local sourcefile = precompiled_header
     local objectfile = target:pcheaderfile()
     local incdepfile = objectfile .. ".d"
-    local sourcekind = sourcekinds[path.extension(precompiled_header)] or "cc"
+
+    -- init sourcekind
+    local sourcekind = nil
+    if precompiled_source then
+        sourcekind = language.sourcekind_of(precompiled_source)
+    else
+        sourcekind = sourcekinds[path.extension(precompiled_header)] or "cc"
+    end
 
     -- init source batch
     local sourcebatch = {sourcekind = sourcekind, sourcefiles = {sourcefile}, objectfiles = {objectfile}, incdepfiles = {incdepfile}}
diff --git a/xmake/core/project/target.lua b/xmake/core/project/target.lua
index ee033a892..7999ee2de 100644
--- a/xmake/core/project/target.lua
+++ b/xmake/core/project/target.lua
@@ -711,11 +711,41 @@ function target:configheader(outputdir)
     return configheader, outputheader
 end
 
+-- get the precompiled source file (.[h|hpp], .[c|cpp])
+function target:pcsourcefile()
+
+    -- get it from the cache first
+    if self._PCSOURCEFILE then
+        return unpack(self._PCSOURCEFILE)
+    end
+
+    -- get the precompiled header and source file 
+    local headerfile = nil
+    local sourcefile = nil
+    for _, file in ipairs(table.wrap(self:get("precompiled_header"))) do
+        local extension = path.extension(file)
+        if not headerfile and extension:startswith(".h") then
+            headerfile = file
+        else
+            sourcefile = file
+        end
+        if headerfile and sourcefile then
+            break
+        end
+    end
+
+    -- save to cache
+    self._PCSOURCEFILE = {headerfile, sourcefile}
+
+    -- ok?
+    return headerfile, sourcefile
+end
+
 -- get the precompiled header file (xxx.h.pch)
 function target:pcheaderfile()
 
     -- get the precompiled header file in the object directory
-    local precompiled_header = self:get("precompiled_header")
+    local precompiled_header = self:pcsourcefile()
     if precompiled_header then
 
         -- get it from the cache first
diff --git a/xmake/modules/core/tools/gcc.lua b/xmake/modules/core/tools/gcc.lua
index 4f53cc19c..254f3301a 100644
--- a/xmake/modules/core/tools/gcc.lua
+++ b/xmake/modules/core/tools/gcc.lua
@@ -252,10 +252,13 @@ end
 
 -- make the precompiled header flag
 function nf_precompiled_header(self, headerfile, target)
-    if self:name() == "clang" then
-        return "-include " .. headerfile .. " -include-pch " .. target:pcheaderfile()
-    else
-        return "-include " .. headerfile 
+    local extension = path.extension(headerfile)
+    if extension == ".h" or extension == ".hpp" then
+        if self:name() == "clang" then
+            return "-include " .. headerfile .. " -include-pch " .. target:pcheaderfile()
+        else
+            return "-include " .. headerfile 
+        end
     end
 end
 
@@ -280,6 +283,15 @@ function _include_deps(self, sourcefile, flags)
     -- the temporary file
     local tmpfile = os.tmpfile()
 
+    -- uses pchflags for precompiled header
+    if _g._PCHFLAGS then
+        local key = sourcefile .. tostring(flags)
+        local pchflags = _g._PCHFLAGS[key] 
+        if pchflags then
+            flags = pchflags
+        end
+    end
+
     -- generate it
     os.runv(self:program(), table.join("-c", "-E", "-MM", flags or {}, "-o", tmpfile, sourcefile))
 
@@ -304,6 +316,10 @@ end
 -- make the complie arguments list for the precompiled header
 function _compargv1_pch(self, headerfile, objectfile, flags)
 
+    -- init key and cache
+    local key = headerfile .. tostring(flags)
+    _g._PCHFLAGS = _g._PCHFLAGS or {}
+
     -- remove "-include xxx.h" and "-include-pch xxx.pch"
     local pchflags = {}
     local include = false
@@ -316,6 +332,15 @@ function _compargv1_pch(self, headerfile, objectfile, flags)
         end
     end
 
+    -- compile header.h as c++?
+    if self:kind() == "cxx" and headerfile:endswith(".h") then
+        table.insert(pchflags, "-x")
+        table.insert(pchflags, "c++-header")
+    end
+
+    -- save pchflags to cache
+    _g._PCHFLAGS[key] = pchflags
+
     -- make complie arguments list
     return self:program(), table.join("-c", pchflags, "-o", objectfile, headerfile)
 end