Disable various unused libxml features: catalogs, DocBook, legacy APIs, etc.

third_party/libxml/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Define an "os_include" variable that points at the OS-specific generated
 # headers.  These were generated by running the configure script offline.
 if (is_linux || is_android || is_nacl) {
   os_include = "linux"
 } else if (is_mac || is_ios) {
   os_include = "mac"
@@ skipping 60 matching lines @@
 
 static_library("libxml") {
   output_name = "libxml2"
   sources = [
     "chromium/libxml_utils.cc",
     "chromium/libxml_utils.h",
     "linux/config.h",
     "linux/include/libxml/xmlversion.h",
     "mac/config.h",
     "mac/include/libxml/xmlversion.h",
-    "src/DOCBparser.c",
+    #"src/DOCBparser.c",
     "src/HTMLparser.c",
     "src/HTMLtree.c",
-    "src/SAX.c",
+    #"src/SAX.c",
     "src/SAX2.c",
     "src/buf.c",
     "src/buf.h",
-    "src/c14n.c",
-    "src/catalog.c",
+    #"src/c14n.c",
+    #"src/catalog.c",
     "src/chvalid.c",
-    "src/debugXML.c",
+    #"src/debugXML.c",
     "src/dict.c",
     "src/elfgcchack.h",
     "src/enc.h",
     "src/encoding.c",
     "src/entities.c",
     "src/error.c",
     "src/globals.c",
     "src/hash.c",
     "src/include/libxml/DOCBparser.h",
     "src/include/libxml/HTMLparser.h",
@@ skipping 36 matching lines @@
     "src/include/libxml/xmlschemas.h",
     "src/include/libxml/xmlschemastypes.h",
     "src/include/libxml/xmlstring.h",
     "src/include/libxml/xmlunicode.h",
     "src/include/libxml/xmlwriter.h",
     "src/include/libxml/xpath.h",
     "src/include/libxml/xpathInternals.h",
     "src/include/libxml/xpointer.h",
     "src/include/win32config.h",
     "src/include/wsockcompat.h",
-    "src/legacy.c",
+    #"src/legacy.c",
     "src/libxml.h",
     "src/list.c",
     "src/parser.c",
     "src/parserInternals.c",
     "src/pattern.c",
-    "src/relaxng.c",
+    #"src/relaxng.c",
     "src/save.h",
-    "src/schematron.c",
+    #"src/schematron.c",
     "src/threads.c",
     "src/timsort.h",
     "src/tree.c",
     "src/triodef.h",
     "src/trionan.h",
-
     #"src/trio.c",
     #"src/trio.h",
     #"src/triodef.h",
     #"src/trionan.c",
     #"src/trionan.h",
     #"src/triop.h",
     #"src/triostr.c",
     #"src/triostr.h",
     "src/uri.c",
     "src/valid.c",
-    "src/xinclude.c",
-    "src/xlink.c",
+    #"src/xinclude.c",
+    #"src/xlink.c",
     "src/xmlIO.c",
     "src/xmlmemory.c",
-    "src/xmlmodule.c",
+    #"src/xmlmodule.c",
     "src/xmlreader.c",
-    "src/xmlregexp.c",
+    #"src/xmlregexp.c",
     "src/xmlsave.c",
-    "src/xmlschemas.c",
-    "src/xmlschemastypes.c",
+    #"src/xmlschemas.c",
+    #"src/xmlschemastypes.c",
     "src/xmlstring.c",
     "src/xmlunicode.c",
     "src/xmlwriter.c",
     "src/xpath.c",
-    "src/xpointer.c",
-
+    #"src/xpointer.c",
     #"src/xzlib.c",
     "src/xzlib.h",
     "win32/config.h",
     "win32/include/libxml/xmlversion.h",
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [
     "//build/config/compiler:no_chromium_code",
 
@@ skipping 12 matching lines @@
   if (is_mac || is_ios || is_android) {
     # http://www.xmlsoft.org/threads.html says that this is required when using
     # libxml from several threads, which can possibly happen in chrome. On
     # linux, this is picked up by transitivity from pkg-config output from
     # build/linux/system.gyp.
     defines = [ "_REENTRANT" ]
   }
 
   include_dirs = [ "$os_include" ]
 }