handle python_subpackage_only, fixes ghopenSUSE/python-rpm-macros#73

README.md

@@ -47,6 +47,10 @@ particular flavor, and autogenerate subpackages for all the other flavors.
 Alternately, it is to take package `python-modname` and generate subpackages for all flavors,
 leaving the top-level package empty.
 
+Additionally it is possible for non-Python packages which define a subpackage
+`%package -n python-modname` and corresponding `%description -n python-modname` etc., 
+to autogenerate all desired flavor subpackages `<flavor>-modname`.
+
 ### Build Set
 
 The default build set is listed in the __`%pythons`__ macro. Every entry in `%pythons` generates a
@@ -107,6 +111,10 @@ expansion of `$python_` inside the `%python_expand` macro.
 * __`%python_subpackages`__ expands to the autogenerated subpackages. This should go at the end of the
 main headers section.
 
+* __`%python_subpackage_only`__. Undefined by default. If you want to generate `<flavor>-modname`
+subpackages for a non-python main package, make sure to `%define python_subpackage_only 1` before
+`%python_subpackages` and use `-n %{python_flavor}-modname` for section headers.
+
 * __`%python_enable_dependency_generator`__ expands to a define to enable automatic requires generation
 of Python module dependencies using egg-info/dist-info metadata. This should go above the
 `%python_subpackages` macro, preferably closer to the top of the spec. Intended usage:
@@ -204,7 +212,6 @@ is still required.
 appropriate environmental variables very similar to `%pytest` and `%pytest_arch`.
 
 
-
 #### Alternative-related, general:
 
 * __`%prepare_alternative [-t <targetfile> ] <name>`__  replaces `<targetfile>` with a symlink to
@@ -243,6 +250,7 @@ the first one applies for `uninstall_alternative`.
 
   Each of these has a flavor-specific spelling: `%python2_alternative` etc.
 
+
 #### Flavor-specific macros  
 
 In addition, the following flavor-specific macros are known and supported by the configuration:
@@ -279,8 +287,11 @@ well as `py3` variants, are recognized for Fedora compatibility.
   `<flavor>-modname`.
 
 * __`%files %{python_files foo}`__ expands the `%files` section for all generated flavor subpackages
-  of `<flavor>-modname-foo`
-
+  of `<flavor>-modname-foo`.
+
+For subpackages of non-python packages with `%python_subpackage_only`and
+ `%package -n %{python_flavor}-modname`, also use `%files %{python_files modname}`.
+
 Always use the flavor-agnostic macro versions `%python_*` inside `%python_files` marked `%files` sections.
 
 See also the Filelists section of the 

macros.lua

@@ -52,6 +52,12 @@ function _python_scan_spec()
         flavor = spec_name_prefix
     end
 
+    subpackage_only = rpm.expand("0%{?python_subpackage_only}") ~= "0"
+    if subpackage_only then
+        is_called_python = false
+        modname = ""
+    end
+
     -- find the spec file
     specpath = rpm.expand("%_specfile")
 
@@ -280,7 +286,7 @@ function python_subpackages()
         "pre", "post", "preun", "postun", "pretrans", "posttrans"}
 
     -- before we start, print Provides: python2-modname
-    if is_called_python and old_python2 then
+    if is_called_python and old_python2 and not subpackage_only then
         print(rpm.expand("Provides: python2-" .. modname .. " = %{?epoch:%{epoch}:}%{version}-%{release}\n"))
     end
 
@@ -306,9 +312,15 @@ function python_subpackages()
 
             rpm.define("python_flavor " .. python)
 
-            local section_function = process_package_line
-            print(section_headline("package", current_flavor, nil))
-            print_obsoletes(modname)
+            local section_function
+
+            if subpackage_only then
+                section_function = ignore_line
+            else
+                section_function = process_package_line
+                print(section_headline("package", current_flavor, nil))
+                print_obsoletes(modname)
+            end
 
             while true do
                 -- collect lines until braces match. it's what rpm does, kind of.
@@ -330,8 +342,27 @@ function python_subpackages()
 
                 if KNOWN_SECTIONS[newsection] then
                     -- enter new section
-                    if param and param:startswith("-n") then
-                        -- ignore named section
+                    local submodname
+                    local subparam
+                    local ignore_section = false
+                    if subpackage_only then
+                        ignore_section = true
+                        if param then
+                            if newsection == "files" then
+                                submodname, subparam = param:match("%%{python_files%s+(%S+)%s*(.*)}")
+                            else
+                                submodname, subparam = param:match("^%-n%s+%%{python_flavor}%-(%S+)%s*(.*)$")
+                            end
+                            if submodname then
+                                modname = submodname
+                                param = subparam
+                                ignore_section = false
+                            end
+                        end
+                    elseif (param and param:startswith("-n")) then
+                        ignore_section = true
+                    end
+                    if ignore_section then
                         section_function = ignore_line
                     elseif newsection == "package" then
                         print(section_headline("package", current_flavor, param))
@@ -426,6 +457,11 @@ function python_files()
     local param = ""
     if tonumber(nparams) > 0 then param = rpm.expand("%1") end
 
+    if subpackage_only then
+        modname = param
+        param = ""
+    end
+
     print("-n " .. package_name(flavor, modname, param))
 
     if not _python_subpackages_emitted then