scripts: include function versions in API definition

In order to auto-generate more of the language binding code, it is
desirable to know what libvirt version an API was introduced in.
We can extract this information from the .syms files and expose
it in the API description

eg instead of

  <function name='virNodeNumOfDevices' file='libvirt-nodedev'
            module='libvirt-nodedev'>

we now have

  <function name='virNodeNumOfDevices' file='libvirt-nodedev'
            module='libvirt-nodedev' version='0.5.0'>

This will benefit this proposal:

  https://gitlab.com/libvirt/libvirt-go-module/-/merge_requests/7

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Victor Toso <victortoso@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

scripts/apibuild.py

@@ -2030,8 +2030,9 @@ class CParser:
 
 class docBuilder:
     """A documentation builder"""
-    def __init__(self, name, path='.', directories=['.'], includes=[]):
+    def __init__(self, name, syms, path='.', directories=['.'], includes=[]):
         self.name = name
+        self.syms = syms
         self.path = path
         self.directories = directories
         if name == "libvirt":
@@ -2044,6 +2045,7 @@ class docBuilder:
             self.includes = includes + list(admin_included_files.keys())
         self.modules = {}
         self.headers = {}
+        self.versions = {}
         self.idx = index()
         self.xref = {}
         self.index = {}
@@ -2114,6 +2116,44 @@ class docBuilder:
             self.modules[module] = idx
             self.idx.merge_public(idx)
 
+    def scanVersions(self):
+        prefix = self.name.upper().replace("-", "_") + "_"
+
+        version = None
+        prevversion = None
+        with open(self.syms, "r") as syms:
+            while True:
+                line = syms.readline()
+                if not line:
+                    break
+                line = line.strip()
+                if line.startswith("#"):
+                    continue
+                if line == "":
+                    continue
+
+                if line.startswith(prefix) and line.endswith(" {"):
+                    version = line[len(prefix):-2]
+                elif line == "global:":
+                    continue
+                elif line == "local:":
+                    continue
+                elif line.startswith("}"):
+                    if prevversion is None:
+                        if line != "};":
+                            raise Exception("Unexpected closing version")
+                    else:
+                        if line != ("} %s%s;" % (prefix, prevversion)):
+                            raise Exception("Unexpected end of version '%s': %s'" % (line, "} " + prefix + version))
+
+                    prevversion = version
+                    version = None
+                elif line.endswith(";") and version is not None:
+                    func = line[:-1]
+                    self.versions[func] = version
+                else:
+                    raise Exception("Unexpected line in syms file: %s" % line)
+
     def scan(self):
         for directory in self.directories:
             files = glob.glob(directory + "/*.c")
@@ -2136,6 +2176,7 @@ class docBuilder:
                     self.headers[file] = None
         self.scanHeaders()
         self.scanModules()
+        self.scanVersions()
 
     def modulename_file(self, file):
         module = os.path.basename(file)
@@ -2275,7 +2316,15 @@ class docBuilder:
             print("=>", id)
 
         # NB: this is consumed by a regex in 'getAPIFilenames' in hvsupport.pl
-        output.write("    <%s name='%s' file='%s' module='%s'>\n" % (id.type,
+        if id.type == "function":
+            ver = self.versions[name]
+            if ver is None:
+                raise Exception("Missing version for '%s'" % name)
+            output.write("    <function name='%s' file='%s' module='%s' version='%s'>\n" % (
+                name, self.modulename_file(id.header),
+                self.modulename_file(id.module), self.versions[name]))
+        else:
+            output.write("    <functype name='%s' file='%s' module='%s'>\n" % (
                 name, self.modulename_file(id.header),
                 self.modulename_file(id.module)))
         #
@@ -2406,9 +2455,16 @@ class app:
         print(msg)
 
     def rebuild(self, name, srcdir, builddir):
-        if name not in ["libvirt", "libvirt-qemu", "libvirt-lxc", "libvirt-admin"]:
+        syms = {
+            "libvirt": srcdir + "/../src/libvirt_public.syms",
+            "libvirt-qemu": srcdir + "/../src/libvirt_qemu.syms",
+            "libvirt-lxc": srcdir + "/../src/libvirt_lxc.syms",
+            "libvirt-admin": srcdir + "/../src/admin/libvirt_admin_public.syms",
+        }
+        if name not in syms:
             self.warning("rebuild() failed, unknown module %s" % name)
             return None
+
         builder = None
         if glob.glob(srcdir + "/../src/libvirt.c") != []:
             if not quiet:
@@ -2418,7 +2474,7 @@ class app:
                     srcdir + "/../src/util",
                     srcdir + "/../include/libvirt",
                     builddir + "/../include/libvirt"]
-            builder = docBuilder(name, builddir, dirs, [])
+            builder = docBuilder(name, syms[name], builddir, dirs, [])
         else:
             self.warning("rebuild() failed, unable to guess the module")
             return None