for dealing with the util-vserver module, specifically the scholz branch
[build.git] / module-tag.py
index 18d1a3a..7b1146c 100755 (executable)
@@ -75,7 +75,7 @@ class Command:
         result=file(tmp).read()
         os.unlink(tmp)
         if self.options.debug:
-            print '+',self.command,'Done',
+            print 'Done',
         return result
 
 class Svnpath:
@@ -84,8 +84,6 @@ class Svnpath:
         self.options=options
 
     def url_exists (self):
-        if self.options.verbose:
-            print 'Checking url',self.path
         return os.system("svn list %s &> /dev/null"%self.path) == 0
 
     def dir_needs_revert (self):
@@ -98,27 +96,58 @@ class Svnpath:
 
 class Module:
 
+    svn_magic_line="--This line, and those below, will be ignored--"
+    
+    redirectors=[ # ('module_name_varname','name'),
+                  ('module_version_varname','version'),
+                  ('module_taglevel_varname','taglevel'), ]
+
     # where to store user's config
     config_storage="CONFIG"
     # 
-    configKeys=[ ('svnpath',"Enter your toplevel svnpath (e.g. svn+ssh://thierry@svn.planet-lab.org/svn/)"),
-                 ('username',"Enter your firstname and lastname for changelogs"),
-                 ("email","Enter your email address for changelogs") ]
     config={}
 
-    svn_magic_line="--This line, and those below, will be ignored--"
-    
-    redirectors=[ ('module_name_varname','name'),
-                  ('module_version_varname','version'),
-                  ('module_taglevel_varname','taglevel'), ]
+    import commands
+    configKeys=[ ('svnpath',"Enter your toplevel svnpath",
+                  "svn+ssh://%s@svn.planet-lab.org/svn/"%commands.getoutput("id -un")),
+                 ("build", "Enter the name of your build module","build"),
+                 ('username',"Enter your firstname and lastname for changelogs",""),
+                 ("email","Enter your email address for changelogs",""),
+                 ]
+
+    @staticmethod
+    def prompt_config ():
+        for (key,message,default) in Module.configKeys:
+            Module.config[key]=""
+            while not Module.config[key]:
+                Module.config[key]=raw_input("%s [%s] : "%(message,default)).strip() or default
+
+
+    # for parsing module spec name:branch
+    matcher_branch_spec=re.compile("\A(?P<name>[\w-]+):(?P<branch>[\w\.]+)\Z")
+    matcher_rpm_define=re.compile("%(define|global)\s+(\S+)\s+(\S*)\s*")
+
+    def __init__ (self,module_spec,options):
+        # parse module spec
+        attempt=Module.matcher_branch_spec.match(module_spec)
+        if attempt:
+            self.name=attempt.group('name')
+            self.branch=attempt.group('branch')
+        else:
+            self.name=module_spec
+            self.branch=None
 
-    def __init__ (self,name,options):
-        self.name=name
         self.options=options
-        self.moddir="%s/%s/%s"%(os.getenv("HOME"),options.modules,name)
-        self.trunkdir="%s/trunk"%(self.moddir)
-        self.varmatcher=re.compile("%define\s+(\S+)\s+(\S*)\s*")
+        self.moddir="%s/%s"%(options.workdir,self.name)
+
+    def edge_dir (self):
+        if not self.branch:
+            return "%s/trunk"%(self.moddir)
+        else:
+            return "%s/branches/%s"%(self.moddir,self.branch)
 
+    def tags_dir (self):
+        return "%s/tags"%(self.moddir)
 
     def run (self,command):
         return Command(command,self.options).run()
@@ -134,19 +163,33 @@ class Module:
 
     @staticmethod
     def init_homedir (options):
-        topdir="%s/%s"%(os.getenv("HOME"),options.modules)
+        topdir=options.workdir
         if options.verbose:
             print 'Checking for',topdir
         storage="%s/%s"%(topdir,Module.config_storage)
+        # sanity check. Either the topdir exists AND we have a config/storage
+        # or topdir does not exist and we create it
+        # to avoid people use their own daily svn repo
+        if os.path.isdir(topdir) and not os.path.isfile(storage):
+            print """The directory %s exists and has no CONFIG file
+If this is your regular working directory, please provide another one as the
+module-* commands need a fresh working dir. Make sure that you do not use 
+that for other purposes than tagging"""%topdir
+            sys.exit(1)
         if not os.path.isdir (topdir):
-            # prompt for login or whatever svnpath
             print "Cannot find",topdir,"let's create it"
-            for (key,message) in Module.configKeys:
-                Module.config[key]=raw_input(message+" : ").strip()
+            Module.prompt_config()
+            print "Checking ...",
             Command("svn co -N %s %s"%(Module.config['svnpath'],topdir),options).run_fatal()
+            Command("svn co -N %s/%s %s/%s"%(Module.config['svnpath'],
+                                             Module.config['build'],
+                                             topdir,
+                                             Module.config['build']),options).run_fatal()
+            print "OK"
+            
             # store config
             f=file(storage,"w")
-            for (key,message) in Module.configKeys:
+            for (key,message,default) in Module.configKeys:
                 f.write("%s=%s\n"%(key,Module.config[key]))
             f.close()
             if options.debug:
@@ -159,10 +202,10 @@ class Module:
                 (key,value)=re.compile("^(.+)=(.+)$").match(line).groups()
                 Module.config[key]=value                
             f.close()
-            if options.debug:
-                print 'Using config'
-                for (key,message) in Module.configKeys:
-                    print key,'=',Module.config[key]
+        if options.verbose:
+            print '******** Using config'
+            for (key,message,default) in Module.configKeys:
+                print '\t',key,'=',Module.config[key]
 
     def init_moddir (self):
         if self.options.verbose:
@@ -173,50 +216,72 @@ class Module:
             print 'Cannot find %s - check module name'%self.moddir
             sys.exit(1)
 
-    def init_trunkdir (self):
+    def init_subdir (self,fullpath):
         if self.options.verbose:
-            print 'Checking for',self.trunkdir
-        if not os.path.isdir (self.trunkdir):
-            self.run_fatal("svn up -N %s"%self.trunkdir)
+            print 'Checking for',fullpath
+        if not os.path.isdir (fullpath):
+            self.run_fatal("svn up -N %s"%fullpath)
 
-    def revert_trunkdir (self):
+    def revert_subdir (self,fullpath):
+        if self.options.fast_checks:
+            if self.options.verbose: print 'Skipping revert of %s'%fullpath
+            return
         if self.options.verbose:
-            print 'Checking whether',self.trunkdir,'needs being reverted'
-        if Svnpath(self.trunkdir,self.options).dir_needs_revert():
-            self.run_fatal("svn revert -R %s"%self.trunkdir)
+            print 'Checking whether',fullpath,'needs being reverted'
+        if Svnpath(fullpath,self.options).dir_needs_revert():
+            self.run_fatal("svn revert -R %s"%fullpath)
 
-    def update_trunkdir (self):
+    def update_subdir (self,fullpath):
         if self.options.fast_checks:
+            if self.options.verbose: print 'Skipping update of %s'%fullpath
             return
         if self.options.verbose:
-            print 'Updating',self.trunkdir
-        self.run_fatal("svn update %s"%self.trunkdir)
+            print 'Updating',fullpath
+        self.run_fatal("svn update -N %s"%fullpath)
+
+    def init_edge_dir (self):
+        # if branch, edge_dir is two steps down
+        if self.branch:
+            self.init_subdir("%s/branches"%self.moddir)
+        self.init_subdir(self.edge_dir())
+
+    def revert_edge_dir (self):
+        self.revert_subdir(self.edge_dir())
+
+    def update_edge_dir (self):
+        self.update_subdir(self.edge_dir())
 
-    def guess_specname (self):
-        attempt="%s/%s.spec"%(self.trunkdir,self.name)
+    def main_specname (self):
+        attempt="%s/%s.spec"%(self.edge_dir(),self.name)
         if os.path.isfile (attempt):
             return attempt
         else:
             try:
-                return glob("%s/*.spec"%self.trunkdir)[0]
+                return glob("%s/*.spec"%self.edge_dir())[0]
             except:
                 print 'Cannot guess specfile for module %s'%self.name
                 sys.exit(1)
 
+    def all_specnames (self):
+        return glob("%s/*.spec"%self.edge_dir())
+
     def parse_spec (self, specfile, varnames):
-        if self.options.debug:
-            print 'parse_spec',specfile,
+        if self.options.verbose:
+            print 'Parsing',specfile,
+            for var in varnames:
+                print "[%s]"%var,
+            print ""
         result={}
         f=open(specfile)
         for line in f.readlines():
-            if self.varmatcher.match(line):
-                (var,value)=self.varmatcher.match(line).groups()
+            attempt=Module.matcher_rpm_define.match(line)
+            if attempt:
+                (define,var,value)=attempt.groups()
                 if var in varnames:
                     result[var]=value
         f.close()
-        if self.options.verbose:
-            print 'found',len(result),'keys'
         if self.options.debug:
+            print 'found',len(result),'keys'
             for (k,v) in result.iteritems():
                 print k,'=',v
         return result
@@ -224,7 +289,7 @@ class Module:
     # stores in self.module_name_varname the rpm variable to be used for the module's name
     # and the list of these names in self.varnames
     def spec_dict (self):
-        specfile=self.guess_specname()
+        specfile=self.main_specname()
         redirector_keys = [ varname for (varname,default) in Module.redirectors]
         redirect_dict = self.parse_spec(specfile,redirector_keys)
         if self.options.debug:
@@ -244,23 +309,24 @@ class Module:
         return result
 
     def patch_spec_var (self, patch_dict):
-        specfile=self.guess_specname()
-        newspecfile=specfile+".new"
-        if self.options.verbose:
-            print 'Patching',specfile,'for',patch_dict.keys()
-        spec=open (specfile)
-        new=open(newspecfile,"w")
-
-        for line in spec.readlines():
-            if self.varmatcher.match(line):
-                (var,value)=self.varmatcher.match(line).groups()
-                if var in patch_dict.keys():
-                    new.write('%%define %s %s\n'%(var,patch_dict[var]))
-                    continue
-            new.write(line)
-        spec.close()
-        new.close()
-        os.rename(newspecfile,specfile)
+        for specfile in self.all_specnames():
+            newspecfile=specfile+".new"
+            if self.options.verbose:
+                print 'Patching',specfile,'for',patch_dict.keys()
+            spec=open (specfile)
+            new=open(newspecfile,"w")
+
+            for line in spec.readlines():
+                attempt=Module.matcher_rpm_define.match(line)
+                if attempt:
+                    (define,var,value)=attempt.groups()
+                    if var in patch_dict.keys():
+                        new.write('%%%s %s %s\n'%(define,var,patch_dict[var]))
+                        continue
+                new.write(line)
+            spec.close()
+            new.close()
+            os.rename(newspecfile,specfile)
 
     def unignored_lines (self, logfile):
         result=[]
@@ -273,66 +339,105 @@ class Module:
         return result
 
     def insert_changelog (self, logfile, oldtag, newtag):
-        specfile=self.guess_specname()
-        newspecfile=specfile+".new"
-        if self.options.verbose:
-            print 'Inserting changelog from %s into %s'%(logfile,specfile)
-        spec=open (specfile)
-        new=open(newspecfile,"w")
-        for line in spec.readlines():
-            new.write(line)
-            if re.compile('%changelog').match(line):
-                dateformat="* %a %b %d %Y"
-                datepart=time.strftime(dateformat)
-                logpart="%s <%s> - %s %s"%(Module.config['username'],
-                                             Module.config['email'],
-                                             oldtag,newtag)
-                new.write(datepart+" "+logpart+"\n")
-                for logline in self.unignored_lines(logfile):
-                    new.write("- " + logline)
-                new.write("\n")
-        spec.close()
-        new.close()
-        os.rename(newspecfile,specfile)
+        for specfile in self.all_specnames():
+            newspecfile=specfile+".new"
+            if self.options.verbose:
+                print 'Inserting changelog from %s into %s'%(logfile,specfile)
+            spec=open (specfile)
+            new=open(newspecfile,"w")
+            for line in spec.readlines():
+                new.write(line)
+                if re.compile('%changelog').match(line):
+                    dateformat="* %a %b %d %Y"
+                    datepart=time.strftime(dateformat)
+                    logpart="%s <%s> - %s %s"%(Module.config['username'],
+                                                 Module.config['email'],
+                                                 oldtag,newtag)
+                    new.write(datepart+" "+logpart+"\n")
+                    for logline in self.unignored_lines(logfile):
+                        new.write("- " + logline)
+                    new.write("\n")
+            spec.close()
+            new.close()
+            os.rename(newspecfile,specfile)
             
     def show_dict (self, spec_dict):
         if self.options.verbose:
             for (k,v) in spec_dict.iteritems():
                 print k,'=',v
 
-    def trunk_url (self):
-        return "%s/%s/trunk"%(Module.config['svnpath'],self.name)
+    def mod_url (self):
+        return "%s/%s"%(Module.config['svnpath'],self.name)
+
+    def edge_url (self):
+        if not self.branch:
+            return "%s/trunk"%(self.mod_url())
+        else:
+            return "%s/branches/%s"%(self.mod_url(),self.branch)
+
     def tag_name (self, spec_dict):
-        return "%s-%s-%s"%(spec_dict[self.module_name_varname],
-                           spec_dict[self.module_version_varname],
-                           spec_dict[self.module_taglevel_varname])
+        try:
+            return "%s-%s-%s"%(#spec_dict[self.module_name_varname],
+                self.name,
+                spec_dict[self.module_version_varname],
+                spec_dict[self.module_taglevel_varname])
+        except KeyError,err:
+            print 'Something is wrong with module %s, cannot determine %s - exiting'%(self.name,err)
+            sys.exit(1)
+
     def tag_url (self, spec_dict):
-        return "%s/%s/tags/%s"%(Module.config['svnpath'],self.name,self.tag_name(spec_dict))
+        return "%s/tags/%s"%(self.mod_url(),self.tag_name(spec_dict))
+
+    def check_svnpath_exists (self, url, message):
+        if self.options.fast_checks:
+            return
+        if self.options.verbose:
+            print 'Checking url (%s) %s'%(url,message),
+        ok=Svnpath(url,self.options).url_exists()
+        if ok:
+            if self.options.verbose: print 'exists - OK'
+        else:
+            if self.options.verbose: print 'KO'
+            print 'Could not find %s URL %s'%(message,url)
+            sys.exit(1)
+    def check_svnpath_not_exists (self, url, message):
+        if self.options.fast_checks:
+            return
+        if self.options.verbose:
+            print 'Checking url (%s) %s'%(url,message),
+        ok=not Svnpath(url,self.options).url_exists()
+        if ok:
+            if self.options.verbose: print 'does not exist - OK'
+        else:
+            if self.options.verbose: print 'KO'
+            print '%s URL %s already exists - exiting'%(message,url)
+            sys.exit(1)
 
     # locate specfile, parse it, check it and show values
+##############################
     def do_version (self):
         self.init_moddir()
-        self.init_trunkdir()
-        self.revert_trunkdir()
-        self.update_trunkdir()
-        print '==============================',self.name
-        #for (key,message) in Module.configKeys:
-        #    print key,':',Module.config[key]
+        self.init_edge_dir()
+        self.revert_edge_dir()
+        self.update_edge_dir()
         spec_dict = self.spec_dict()
-        print 'trunk url',self.trunk_url()
-        print 'latest tag url',self.tag_url(spec_dict)
-        print 'specfile:',self.guess_specname()
         for varname in self.varnames:
             if not spec_dict.has_key(varname):
                 print 'Could not find %%define for %s'%varname
                 return
             else:
                 print varname+":",spec_dict[varname]
+        print 'edge url',self.edge_url()
+        print 'latest tag url',self.tag_url(spec_dict)
+        if self.options.verbose:
+            print 'main specfile:',self.main_specname()
+            print 'specfiles:',self.all_specnames()
 
     init_warning="""WARNING
 The module-init function has the following limitations
 * it does not handle changelogs
 * it does not scan the -tags*.mk files to adopt the new tags"""
+##############################
     def do_init(self):
         if self.options.verbose:
             print Module.init_warning
@@ -340,39 +445,49 @@ The module-init function has the following limitations
                 return
 
         self.init_moddir()
-        self.init_trunkdir()
-        self.revert_trunkdir()
-        self.update_trunkdir()
+        self.init_edge_dir()
+        self.revert_edge_dir()
+        self.update_edge_dir()
         spec_dict = self.spec_dict()
 
-        trunk_url=self.trunk_url()
+        edge_url=self.edge_url()
         tag_name=self.tag_name(spec_dict)
         tag_url=self.tag_url(spec_dict)
         # check the tag does not exist yet
-        if not self.options.fast_checks and Svnpath(tag_url,self.options).url_exists():
-            print 'Module %s already has a tag %s'%(self.name,tag_name)
-            return
+        self.check_svnpath_not_exists(tag_url,"new tag")
 
         if self.options.message:
             svnopt='--message "%s"'%self.options.message
         else:
             svnopt='--editor-cmd=%s'%self.options.editor
         self.run_prompt("Create initial tag",
-                        "svn copy %s %s %s"%(svnopt,trunk_url,tag_url))
+                        "svn copy %s %s %s"%(svnopt,edge_url,tag_url))
 
+##############################
     def do_diff (self):
         self.init_moddir()
-        self.init_trunkdir()
-        self.revert_trunkdir()
-        self.update_trunkdir()
+        self.init_edge_dir()
+        self.revert_edge_dir()
+        self.update_edge_dir()
         spec_dict = self.spec_dict()
         self.show_dict(spec_dict)
 
-        trunk_url=self.trunk_url()
+        edge_url=self.edge_url()
         tag_url=self.tag_url(spec_dict)
-        print 'x'*67,self.name
-        self.run("svn diff %s %s"%(tag_url,trunk_url))
+        self.check_svnpath_exists(edge_url,"edge track")
+        self.check_svnpath_exists(tag_url,"latest tag")
+        diff_output = Command("svn diff %s %s"%(tag_url,edge_url),self.options).output_of()
+        if self.options.list:
+            if diff_output:
+                print self.name
+        else:
+            if not self.options.only or diff_output:
+                print 'x'*40,'module',self.name
+                print 'x'*20,'<',tag_url
+                print 'x'*20,'>',edge_url
+                print diff_output
 
+##############################
     def patch_tags_file (self, tagsfile, oldname, newname):
         newtagsfile=tagsfile+".new"
         if self.options.verbose:
@@ -392,15 +507,15 @@ The module-init function has the following limitations
 
     def do_tag (self):
         self.init_moddir()
-        self.init_trunkdir()
-        self.revert_trunkdir()
-        self.update_trunkdir()
+        self.init_edge_dir()
+        self.revert_edge_dir()
+        self.update_edge_dir()
         # parse specfile
         spec_dict = self.spec_dict()
         self.show_dict(spec_dict)
         
         # side effects
-        trunk_url=self.trunk_url()
+        edge_url=self.edge_url()
         old_tag_name = self.tag_name(spec_dict)
         old_tag_url=self.tag_url(spec_dict)
         if (self.options.new_version):
@@ -415,16 +530,12 @@ The module-init function has the following limitations
         # sanity check
         new_tag_name = self.tag_name(spec_dict)
         new_tag_url=self.tag_url(spec_dict)
-        for url in [ trunk_url, old_tag_url ] :
-            if not self.options.fast_checks and not Svnpath(url,self.options).url_exists():
-                print 'Could not find svn URL %s'%url
-                sys.exit(1)
-        if not self.options.fast_checks and Svnpath(new_tag_url,self.options).url_exists():
-            print 'New tag\'s svn URL %s already exists ! '%url
-            sys.exit(1)
+        self.check_svnpath_exists (edge_url,"edge track")
+        self.check_svnpath_exists (old_tag_url,"previous tag")
+        self.check_svnpath_not_exists (new_tag_url,"new tag")
 
         # checking for diffs
-        diff_output=Command("svn diff %s %s"%(old_tag_url,trunk_url),
+        diff_output=Command("svn diff %s %s"%(old_tag_url,edge_url),
                             self.options).output_of()
         if len(diff_output) == 0:
             if not prompt ("No difference in trunk for module %s, want to tag anyway"%self.name,False):
@@ -438,11 +549,11 @@ The module-init function has the following limitations
         # so we can provide useful information, such as version numbers and diff
         # in the same file
         changelog="/tmp/%s-%d.txt"%(self.name,os.getpid())
-        file(changelog,"w").write("""Tagging module %s  -- from %s to %s
+        file(changelog,"w").write("""Tagging module %s - %s
 
 %s
 Please write a changelog for this new tag in the section above
-"""%(self.name,old_tag_name,new_tag_name,Module.svn_magic_line))
+"""%(self.name,new_tag_name,Module.svn_magic_line))
 
         if not self.options.verbose or prompt('Want to see diffs while writing changelog',True):
             file(changelog,"a").write('DIFF=========\n' + diff_output)
@@ -457,66 +568,176 @@ Please write a changelog for this new tag in the section above
             self.insert_changelog (changelog,old_tag_name,new_tag_name)
 
         ## update build
-        build = Module(self.options.build,self.options)
+        try:
+            buildname=Module.config['build']
+        except:
+            buildname="build"
+        build = Module(buildname,self.options)
         build.init_moddir()
-        build.init_trunkdir()
-        build.revert_trunkdir()
-        build.update_trunkdir()
+        build.init_edge_dir()
+        build.revert_edge_dir()
+        build.update_edge_dir()
         
-        for tagsfile in glob(build.trunkdir+"/*-tags*.mk"):
+        for tagsfile in glob(build.edge_dir()+"/*-tags*.mk"):
             if prompt("Want to adopt new tag in %s"%tagsfile):
                 self.patch_tags_file(tagsfile,old_tag_name,new_tag_name)
 
         paths=""
-        paths += self.trunkdir + " "
-        paths += build.trunkdir + " "
+        paths += self.edge_dir() + " "
+        paths += build.edge_dir() + " "
         self.run_prompt("Check","svn diff " + paths)
         self.run_prompt("Commit","svn commit --file %s %s"%(changelog,paths))
-        self.run_prompt("Create tag","svn copy --file %s %s %s"%(changelog,trunk_url,new_tag_url))
+        self.run_prompt("Create tag","svn copy --file %s %s %s"%(changelog,edge_url,new_tag_url))
 
         if self.options.debug:
             print 'Preserving',changelog
         else:
             os.unlink(changelog)
             
-usage="""Usage: %prog options module1 [ .. modulen ]
+##############################
+    def do_branch (self):
+
+        print 'module-branch is experimental - exiting'
+        sys.exit(1)
+
+        if self.branch:
+            print 'Cannot create a branch from another branch - exiting'
+            sys.exit(1)
+        self.init_moddir()
+        
+        # xxx - tmp
+        import readline
+        answer = raw_input ("enter tag name [trunk]").strip()
+        if answer == "" or answer == "trunk":
+            ref="/trunk"
+            from_trunk=True
+        else:
+            ref="/tags/%s-%s"%(self.name,answer)
+            from_trunk=False
+
+        ref_url = "%s/%s"%(self.mod_url(),ref)
+        self.check_svnpath_exists (ref_url,"branch creation point")
+        print "Using starting point %s"%ref_url
+        
+        spec=self.main_specname()
+        if not from_trunk:
+            self.init_subdir(self.tags_dir())
+            workdir="%s/%s"%(self.moddir,ref)
+        else:
+            workdir=self.edge_dir()
+
+        self.init_subdir(workdir)
+        self.revert_subdir(workdir)
+        self.update_subdir(workdir)
+
+        print 'got spec',spec
+        if not os.path.isfile(spec):
+            print 'cannot find spec'
+        
+        # read version & taglevel from the origin specfile
+        print 'parsing',spec
+        origin=self.spec_dict()
+        self.show_dict(origin)
+
+        default_branch=self.options.new_version
+        if not default_branch:
+#            try:
+                match=re.compile("\A(?P<main>.*[\.-_])(?P<subid>[0-9]+)\Z").match(origin['version'])
+                new_subid=int(match.group('subid'))+1
+                default_branch="%s%d"%(match.group('main'),new_subid)
+#            except:
+#                default_branch="not found"
+        new_branch_name=raw_input("Enter branch name [%s] "%default_branch) or default_branch
+        
+        new_branch_url="%s/branches/%s"%(self.mod_url(),new_branch_name)
+        self.check_svnpath_not_exists(new_branch_url,"new branch")
+        print new_branch_name
+        
+
+##############################
+usage="""Usage: %prog options module_desc [ .. module_desc ]
 Purpose:
   manage subversion tags and specfile
-  requires the specfile to define name, version and taglevel
-  OR alternatively redirection variables like module_version_varname
-Available functions:
-  module-diff : show difference between trunk and latest tag
-  module-tag  : increment taglevel in specfile, insert changelog in specfile,
-                create new tag and and adopt it in build/*-tags*.mk
-  module-init : create initial tag
-  module-version : only check specfile and print out details"""
+  requires the specfile to define *version* and *taglevel*
+  OR alternatively 
+  redirection variables module_version_varname / module_taglevel_varname
+Trunk:
+  by default, the trunk of modules is taken into account
+  in this case, just mention the module name as <module_desc>
+Branches:
+  if you wish to work on a branch rather than on the trunk, 
+  you can use the following syntax for <module_desc>
+  Mom:2.1
+      works on Mom/branches/2.1 
+"""
+# unsupported yet
+#"""
+#  branch:Mom
+#      the branch_id is deduced from the current *version* in the trunk's specfile
+#      e.g. if Mom/trunk/Mom.spec specifies %define version 2.3, then this script
+#      would use Mom/branches/2.2
+#      if if stated %define version 3.0, then the script fails
+#"""
+
+functions={ 
+    'diff' : "show difference between trunk and latest tag",
+    'tag'  : """increment taglevel in specfile, insert changelog in specfile,
+                create new tag and and adopt it in build/*-tags*.mk""",
+    'init' : "create initial tag",
+    'version' : "only check specfile and print out details",
+    'branch' : """create a branch for this module. 
+                either from trunk, or from a tag""",
+}
 
 def main():
+
+    mode=None
+    for function in functions.keys():
+        if sys.argv[0].find(function) >= 0:
+            mode = function
+            break
+    if not mode:
+        print "Unsupported command",sys.argv[0]
+        sys.exit(1)
+
+    global usage
+    usage += "module-%s.py : %s"%(mode,functions[mode])
     all_modules=os.path.dirname(sys.argv[0])+"/modules.list"
 
     parser=OptionParser(usage=usage,version=subversion_id)
-    parser.add_option("-s","--set-version",action="store",dest="new_version",default=None,
-                      help="When tagging, set new version and reset taglevel to 0")
     parser.add_option("-a","--all",action="store_true",dest="all_modules",default=False,
-                      help="Runs all modules as found in %s"%all_modules)
+                      help="run on all modules as found in %s"%all_modules)
     parser.add_option("-f","--fast-checks",action="store_true",dest="fast_checks",default=False,
-                      help="Skips safety checks, such as svn updates -- use with care")
-    parser.add_option("-c","--no-changelog", action="store_false", dest="changelog", default=True,
-                      help="Does not update changelog section in specfile when tagging")
-    parser.add_option("-e","--editor", action="store", dest="editor", default="emacs",
-                      help="Specify editor")
-    parser.add_option("-m","--message", action="store", dest="message", default=None,
-                      help="Specify log message")
-    parser.add_option("-M","--modules", action="store", dest="modules", default="modules",
-                      help="Name for topdir - defaults to modules")
-    parser.add_option("-B","--build", action="store", dest="build", default="build",
-                      help="Set module name for build, defaults to build")
-    parser.add_option("-v","--verbose", action="store_true", dest="verbose", default=False, 
-                      help="Run in verbose mode")
+                      help="skip safety checks, such as svn updates -- use with care")
+    if mode == "tag" or mode == 'branch':
+        parser.add_option("-s","--set-version",action="store",dest="new_version",default=None,
+                          help="set new version and reset taglevel to 0")
+    if mode == "tag" :
+        parser.add_option("-c","--no-changelog", action="store_false", dest="changelog", default=True,
+                          help="do not update changelog section in specfile when tagging")
+    if mode == "tag" or mode == "init" :
+        parser.add_option("-e","--editor", action="store", dest="editor", default="emacs",
+                          help="specify editor")
+    if mode == "init" :
+        parser.add_option("-m","--message", action="store", dest="message", default=None,
+                          help="specify log message")
+    if mode == "diff" :
+        parser.add_option("-o","--only", action="store_true", dest="only", default=False,
+                          help="report diff only for modules that exhibit differences")
+    if mode == "diff" :
+        parser.add_option("-l","--list", action="store_true", dest="list", default=False,
+                          help="just list modules that exhibit differences")
+    parser.add_option("-w","--workdir", action="store", dest="workdir", 
+                      default="%s/%s"%(os.getenv("HOME"),"modules"),
+                      help="""name for dedicated working dir - defaults to ~/modules
+** THIS MUST NOT ** be your usual working directory""")
+    parser.add_option("-v","--verbose", action="store_true", dest="verbose", default=True, 
+                      help="run in verbose mode")
+    parser.add_option("-q","--quiet", action="store_false", dest="verbose", 
+                      help="run in quiet (non-verbose) mode")
     parser.add_option("-d","--debug", action="store_true", dest="debug", default=False, 
-                      help="Debug mode - mostly more verbose")
+                      help="debug mode - mostly more verbose")
     (options, args) = parser.parse_args()
-    if options.debug: options.verbose=True
 
     if len(args) == 0:
         if options.all_modules:
@@ -527,18 +748,10 @@ def main():
     Module.init_homedir(options)
     for modname in args:
         module=Module(modname,options)
-        if sys.argv[0].find("diff") >= 0:
-            module.do_diff()
-        elif sys.argv[0].find("tag") >= 0:
-            module.do_tag()
-        elif sys.argv[0].find("init") >= 0:
-            module.do_init()
-        elif sys.argv[0].find("version") >= 0:
-            module.do_version()
-        else:
-            print "Unsupported command",sys.argv[0]
-            parser.print_help()
-            sys.exit(1)
+        print '==============================',module.name
+        # call the method called do_<mode>
+        method=Module.__dict__["do_%s"%mode]
+        method(module)
 
 # basically, we exit if anything goes wrong
 if __name__ == "__main__" :