Parse libxml2 error constants from libxml2-api.xml instead of the HTML sources to avoid having to generate the documentation.

Also avoid actually writing the output files if there are no changes, to avoid useless rebuilds.

1 files changed, 109 insertions, 106 deletions

diff --git a/update-error-constants.py b/update-error-constants.py
index 8a836856..02928400 100644
--- a/update-error-constants.py
+++ b/update-error-constants.py
@@ -2,23 +2,14 @@
 
 from __future__ import print_function, absolute_import
 
-import sys, os, os.path, re, codecs
+import operator
+import os.path
+import sys
+import xml.etree.ElementTree as ET
 
 BUILD_SOURCE_FILE = os.path.join("src", "lxml", "xmlerror.pxi")
 BUILD_DEF_FILE    = os.path.join("src", "lxml", "includes", "xmlerror.pxd")
 
-if len(sys.argv) < 2 or sys.argv[1].lower() in ('-h', '--help'):
-    print("This script generates the constants in file %s" % BUILD_SOURCE_FILE)
-    print("Call as")
-    print(sys.argv[0], "/path/to/libxml2-doc-dir")
-    sys.exit(len(sys.argv) > 1)
-
-HTML_DIR = os.path.join(sys.argv[1], 'html')
-os.stat(HTML_DIR) # raise an error if we can't find it
-
-sys.path.insert(0, 'src')
-from lxml import etree
-
 # map enum name to Python variable name and alignment for constant name
 ENUM_MAP = {
     'xmlErrorLevel'       : ('__ERROR_LEVELS',  'XML_ERR_'),
@@ -42,6 +33,7 @@ COMMENT = """
 
 """ % os.path.basename(sys.argv[0])
 
+
 def split(lines):
     lines = iter(lines)
     pre = []
@@ -50,108 +42,119 @@ def split(lines):
         if line.startswith('#') and "BEGIN: GENERATED CONSTANTS" in line:
             break
     pre.append('')
+    old = []
     for line in lines:
         if line.startswith('#') and "END: GENERATED CONSTANTS" in line:
             break
+        old.append(line.rstrip('\n'))
     post = ['', line]
     post.extend(lines)
     post.append('')
-    return pre, post
+    return pre, old, post
+
 
 def regenerate_file(filename, result):
+    new = COMMENT + '\n'.join(result)
+
     # read .pxi source file
-    f = codecs.open(filename, 'r', encoding="utf-8")
-    pre, post = split(f)
-    f.close()
+    with open(filename, 'r', encoding="utf-8") as f:
+        pre, old, post = split(f)
+
+    if new.strip() == '\n'.join(old).strip():
+        # no changes
+        return False
 
     # write .pxi source file
-    f = codecs.open(filename, 'w', encoding="utf-8")
-    f.write(''.join(pre))
-    f.write(COMMENT)
-    f.write('\n'.join(result))
-    f.write(''.join(post))
-    f.close()
-
-collect_text = etree.XPath("string()")
-find_enums = etree.XPath(
-    "//html:pre[@class = 'programlisting' and contains(text(), 'Enum')]",
-    namespaces = {'html' : 'http://www.w3.org/1999/xhtml'})
-
-def parse_enums(html_dir, html_filename, enum_dict):
-    PARSE_ENUM_NAME  = re.compile(r'\s*enum\s+(\w+)\s*{', re.I).match
-    PARSE_ENUM_VALUE = re.compile(r'\s*=\s+([0-9]+)\s*(?::\s*(.*))?').match
-    tree = etree.parse(os.path.join(html_dir, html_filename))
-    enums = find_enums(tree)
-    for enum in enums:
-        enum_name = PARSE_ENUM_NAME(collect_text(enum))
-        if not enum_name:
-            continue
-        enum_name = enum_name.group(1)
-        if enum_name not in ENUM_MAP:
+    with open(filename, 'w', encoding="utf-8") as f:
+        f.write(''.join(pre))
+        f.write(new)
+        f.write(''.join(post))
+
+    return True
+
+
+def parse_enums(doc_dir, api_filename, enum_dict):
+    tree = ET.parse(os.path.join(doc_dir, api_filename))
+    for enum in tree.iterfind('symbols/enum'):
+        enum_type = enum.get('type')
+        if enum_type not in ENUM_MAP:
             continue
-        print("Found enum", enum_name)
-        entries = []
-        for child in enum:
-            name = child.text
-            match = PARSE_ENUM_VALUE(child.tail)
-            if not match:
-                print("Ignoring enum %s (failed to parse field '%s')" % (
-                        enum_name, name))
-                break
-            value, descr = match.groups()
-            entries.append((name, int(value), descr))
-        else:
-            enum_dict[enum_name] = entries
-    return enum_dict
-
-enum_dict = {}
-parse_enums(HTML_DIR, 'libxml-xmlerror.html',   enum_dict)
-#parse_enums(HTML_DIR, 'libxml-xpath.html',      enum_dict)
-#parse_enums(HTML_DIR, 'libxml-xmlschemas.html', enum_dict)
-parse_enums(HTML_DIR, 'libxml-relaxng.html',    enum_dict)
-
-# regenerate source files
-pxi_result = []
-append_pxi = pxi_result.append
-pxd_result = []
-append_pxd = pxd_result.append
-
-append_pxd('cdef extern from "libxml/xmlerror.h":')
-
-ctypedef_indent = ' '*4
-constant_indent = ctypedef_indent*2
-
-for enum_name in ENUM_ORDER:
-    constants = enum_dict[enum_name]
-    pxi_name, prefix = ENUM_MAP[enum_name]
-
-    append_pxd(ctypedef_indent + 'ctypedef enum %s:' % enum_name)
-    append_pxi('cdef object %s = """\\' % pxi_name)
-
-    prefix_len = len(prefix)
-    length = 2  # each string ends with '\n\0'
-    for name, val, descr in constants:
-        if descr and descr != str(val):
-            line = '%-50s = %7d # %s' % (name, val, descr)
-        else:
-            line = '%-50s = %7d' % (name, val)
-        append_pxd(constant_indent + line)
-
-        if name[:prefix_len] == prefix and len(name) > prefix_len:
-            name = name[prefix_len:]
-        line = '%s=%d' % (name, val)
-        append_pxi(line)
-        length += len(line) + 2  # + '\n\0'
-
-    append_pxd('')
-    append_pxi('"""')
-    append_pxi('')
-
-# write source files
-print("Updating file %s" % BUILD_SOURCE_FILE)
-regenerate_file(BUILD_SOURCE_FILE, pxi_result)
-
-print("Updating file %s" % BUILD_DEF_FILE)
-regenerate_file(BUILD_DEF_FILE,    pxd_result)
-
-print("Done")
+        entries = enum_dict.get(enum_type)
+        if not entries:
+            print("Found enum", enum_type)
+            entries = enum_dict[enum_type] = []
+        entries.append((
+            enum.get('name'),
+            int(enum.get('value')),
+            enum.get('info', '').strip(),
+        ))
+
+
+def main(doc_dir):
+    enum_dict = {}
+    parse_enums(doc_dir, 'libxml2-api.xml',   enum_dict)
+    #parse_enums(doc_dir, 'libxml-xmlerror.html',   enum_dict)
+    #parse_enums(doc_dir, 'libxml-xpath.html',      enum_dict)
+    #parse_enums(doc_dir, 'libxml-xmlschemas.html', enum_dict)
+    #parse_enums(doc_dir, 'libxml-relaxng.html',    enum_dict)
+
+    # regenerate source files
+    pxi_result = []
+    append_pxi = pxi_result.append
+    pxd_result = []
+    append_pxd = pxd_result.append
+
+    append_pxd('cdef extern from "libxml/xmlerror.h":')
+
+    ctypedef_indent = ' '*4
+    constant_indent = ctypedef_indent*2
+
+    for enum_name in ENUM_ORDER:
+        constants = enum_dict[enum_name]
+        constants.sort(key=operator.itemgetter(1))
+        pxi_name, prefix = ENUM_MAP[enum_name]
+
+        append_pxd(ctypedef_indent + 'ctypedef enum %s:' % enum_name)
+        append_pxi('cdef object %s = """\\' % pxi_name)
+
+        prefix_len = len(prefix)
+        length = 2  # each string ends with '\n\0'
+        for name, val, descr in constants:
+            if descr and descr != str(val):
+                line = '%-50s = %7d # %s' % (name, val, descr)
+            else:
+                line = '%-50s = %7d' % (name, val)
+            append_pxd(constant_indent + line)
+
+            if name[:prefix_len] == prefix and len(name) > prefix_len:
+                name = name[prefix_len:]
+            line = '%s=%d' % (name, val)
+            append_pxi(line)
+            length += len(line) + 2  # + '\n\0'
+
+        append_pxd('')
+        append_pxi('"""')
+        append_pxi('')
+
+    # write source files
+    print("Updating file %s" % BUILD_SOURCE_FILE)
+    updated = regenerate_file(BUILD_SOURCE_FILE, pxi_result)
+    if not updated:
+        print("No changes.")
+
+    print("Updating file %s" % BUILD_DEF_FILE)
+    updated = regenerate_file(BUILD_DEF_FILE,    pxd_result)
+    if not updated:
+        print("No changes.")
+
+    print("Done")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2 or sys.argv[1].lower() in ('-h', '--help'):
+        print("This script generates the constants in file %s" % BUILD_SOURCE_FILE)
+        print("Call as")
+        print(sys.argv[0], "/path/to/libxml2-doc-dir")
+        sys.exit(len(sys.argv) > 1)
+
+    main(sys.argv[1])