[CMake] Simplify CMake handling for libxml2

[phosek]

Summary

This matches the changes made to handling of zlib done in 10b1b4a
where we rely on find_package and the imported target rather than
manually appending the library and include paths. The use of
LLVM_LIBXML2_ENABLED has been replaced by LLVM_ENABLE_LIBXML2
thus reducing the number of variables.

[compnerd]

Thank you for renaming the variable while at it - it's far more conventional.

llvm/lib/WindowsManifest/CMakeLists.txt

11

Can you not get away with

if(LLVM_ENABLE_LIBXML2)
  target_link_libraries(LLVMWindowsManifest PRIVATE LibXml2::LibXml2)
endif()

instead?

13

A nice little comment to remind the reader that this is for llvm-config would be appreciated.

lld/test/CMakeLists.txt

 set(LLVM_SOURCE_DIR "${LLVM_MAIN_SRC_DIR}")
 set(LLVM_BINARY_DIR "${LLVM_BINARY_DIR}")
 set(LLVM_BUILD_MODE "%(build_mode)s")
 set(LLVM_TOOLS_DIR "${LLVM_TOOLS_BINARY_DIR}/%(build_config)s")
 set(LLVM_LIBS_DIR "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/%(build_config)s")
 
 llvm_canonicalize_cmake_booleans(
   LLVM_ENABLE_ZLIB
-  LLVM_LIBXML2_ENABLED
+  LLVM_ENABLE_LIBXML2
   )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
   )

lld/test/lit.cfg.py

 # Set a fake constant version so that we get consistent output.
 config.environment['LLD_VERSION'] = 'LLD 1.0'
 config.environment['LLD_IN_TEST'] = '1'
 
 # Indirectly check if the mt.exe Microsoft utility exists by searching for
 # cvtres, which always accompanies it.  Alternatively, check if we can use
 # libxml2 to merge manifests.
 if (lit.util.which('cvtres', config.environment['PATH']) or
-        config.llvm_libxml2_enabled):
+        config.have_libxml2):
     config.available_features.add('manifest_tool')
 
-if config.llvm_libxml2_enabled:
+if config.have_libxml2:
     config.available_features.add('libxml2')
 
 if config.have_dia_sdk:
     config.available_features.add("diasdk")
 
 if config.sizeof_void_p == 8:
     config.available_features.add("llvm-64-bits")
 

lld/test/lit.site.cfg.py.in

 @LIT_SITE_CFG_IN_HEADER@
 
 import lit.util
 
 config.have_dia_sdk = lit.util.pythonize_bool("@LLVM_ENABLE_DIA_SDK@")
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_libs_dir = "@LLVM_LIBS_DIR@"
-config.llvm_libxml2_enabled = @LLVM_LIBXML2_ENABLED@
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.lld_obj_root = "@LLD_BINARY_DIR@"
 config.lld_libs_dir = "@LLVM_LIBRARY_OUTPUT_INTDIR@"
 config.lld_tools_dir = "@LLVM_RUNTIME_OUTPUT_INTDIR@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
 try:
     config.llvm_tools_dir = config.llvm_tools_dir % lit_config.params
     config.llvm_libs_dir = config.llvm_libs_dir % lit_config.params
 except KeyError as e:
     key, = e.args
     lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key,key))
 
 import lit.llvm
 lit.llvm.initialize(lit_config, config)
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LLD_SOURCE_DIR@/test/lit.cfg.py")

llvm/cmake/config-ix.cmake

if(LLVM_ENABLE_ZLIB STREQUAL FORCE_ON)
       find_package(ZLIB REQUIRED)
     else()
       find_package(ZLIB)
     endif()
     set(LLVM_ENABLE_ZLIB "${ZLIB_FOUND}")
   endif()
 
   find_library(ICONV_LIBRARY_PATH NAMES iconv libiconv libiconv-2 c)
-  set(LLVM_LIBXML2_ENABLED 0)
-  set(LIBXML2_FOUND 0)
   if((LLVM_ENABLE_LIBXML2) AND ((CMAKE_SYSTEM_NAME MATCHES "Linux") AND (ICONV_LIBRARY_PATH) OR APPLE))
-    find_package(LibXml2)
-    if (LIBXML2_FOUND)
-      set(LLVM_LIBXML2_ENABLED 1)
-      if ((CMAKE_OSX_SYSROOT) AND (EXISTS ${CMAKE_OSX_SYSROOT}/${LIBXML2_INCLUDE_DIR}))
-        include_directories(${CMAKE_OSX_SYSROOT}/${LIBXML2_INCLUDE_DIR})
-      else()
-        include_directories(${LIBXML2_INCLUDE_DIR})
-      endif()
+    if(LLVM_ENABLE_LIBXML2 STREQUAL FORCE_ON)
+      find_package(LibXml2 REQUIRED)
+      find_package(LibXml2)
     endif()
+    set(LLVM_ENABLE_LIBXML2 "${LIBXML2_FOUND}")
   endif()
 else()
   set(LLVM_ENABLE_ZLIB FALSE)
-endif()
-
-if (LLVM_ENABLE_LIBXML2 STREQUAL "FORCE_ON" AND NOT LLVM_LIBXML2_ENABLED)
-  message(FATAL_ERROR "Failed to congifure libxml2")
+  set(LLVM_ENABLE_LIBXML2 FALSE)
 endif()
 
 check_library_exists(xar xar_open "" HAVE_LIBXAR)
 if(HAVE_LIBXAR)
   set(XAR_LIB xar)
 endif()
 
 # function checks

llvm/cmake/modules/LLVMConfig.cmake.in

 
 set(LLVM_ENABLE_UNWIND_TABLES @LLVM_ENABLE_UNWIND_TABLES@)
 
 set(LLVM_ENABLE_ZLIB @LLVM_ENABLE_ZLIB@)
 if(LLVM_ENABLE_ZLIB)
   find_package(ZLIB)
 endif()
 
-set(LLVM_LIBXML2_ENABLED @LLVM_LIBXML2_ENABLED@)
+set(LLVM_ENABLE_LIBXML2 @LLVM_ENABLE_LIBXML2@)
+if(LLVM_ENABLE_LIBXML2)
+  find_package(LibXml2)
+endif()
 
 set(LLVM_WITH_Z3 @LLVM_WITH_Z3@)
 
 set(LLVM_ENABLE_DIA_SDK @LLVM_ENABLE_DIA_SDK@)
 
 set(LLVM_NATIVE_ARCH @LLVM_NATIVE_ARCH@)
 
 set(LLVM_ENABLE_PIC @LLVM_ENABLE_PIC@)

llvm/include/llvm/Config/config.h.cmake

 
 /* LLVM version information */
 #cmakedefine LLVM_VERSION_INFO "${LLVM_VERSION_INFO}"
 
 /* Whether tools show host and target info when invoked with --version */
 #cmakedefine01 LLVM_VERSION_PRINTER_SHOW_HOST_TARGET_INFO
 
 /* Define if libxml2 is supported on this platform. */
-#cmakedefine LLVM_LIBXML2_ENABLED ${LLVM_LIBXML2_ENABLED}
+#cmakedefine LLVM_ENABLE_LIBXML2 ${LLVM_ENABLE_LIBXML2}
 
 /* Define to the extension used for shared libraries, say, ".so". */
 #cmakedefine LTDL_SHLIB_EXT "${LTDL_SHLIB_EXT}"
 
 /* Define to the address where bug reports for this package should be sent. */
 #cmakedefine PACKAGE_BUGREPORT "${PACKAGE_BUGREPORT}"
 
 /* Define to the full name of this package. */

llvm/lib/WindowsManifest/CMakeLists.txt

+if(LLVM_ENABLE_LIBXML2)
+  set(imported_libs LibXml2::LibXml2)
+endif()
+
 add_llvm_component_library(LLVMWindowsManifest
   WindowsManifestMerger.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/WindowsManifest
-  ${Backtrace_INCLUDE_DIRS})
-
-if(LIBXML2_LIBRARIES)
-  target_link_libraries(LLVMWindowsManifest PUBLIC ${LIBXML2_LIBRARIES})
+  ${Backtrace_INCLUDE_DIRS}
+  LINK_LIBS ${imported_libs})
 
-  get_filename_component(xml2_library ${LIBXML2_LIBRARIES} NAME)
-  if (CMAKE_STATIC_LIBRARY_PREFIX AND
-      xml2_library MATCHES "^${CMAKE_STATIC_LIBRARY_PREFIX}.*${CMAKE_STATIC_LIBRARY_SUFFIX}$")
-    string(REGEX REPLACE "^${CMAKE_STATIC_LIBRARY_PREFIX}" "" xml2_library ${xml2_library})
-    string(REGEX REPLACE "${CMAKE_STATIC_LIBRARY_SUFFIX}$" "" xml2_library ${xml2_library})
-  elseif (CMAKE_SHARED_LIBRARY_PREFIX AND
-          xml2_library MATCHES "^${CMAKE_SHARED_LIBRARY_PREFIX}.*${CMAKE_SHARED_LIBRARY_SUFFIX}$")
-    string(REGEX REPLACE "^${CMAKE_SHARED_LIBRARY_PREFIX}" "" xml2_library ${xml2_library})
-    string(REGEX REPLACE "${CMAKE_SHARED_LIBRARY_SUFFIX}$" "" xml2_library ${xml2_library})
+if(LLVM_ENABLE_LIBXML2)
+  string(TOUPPER ${CMAKE_BUILD_TYPE} build_type)
+  get_property(libxml2_library TARGET LibXml2::LibXml2 PROPERTY LOCATION_${build_type})
+  if(NOT libxml2_library)
+    get_property(libxml2_library TARGET LibXml2::LibXml2 PROPERTY LOCATION)
+  endif()
+  get_filename_component(libxml2_library ${libxml2_library} NAME)
+  if(CMAKE_STATIC_LIBRARY_PREFIX AND CMAKE_STATIC_LIBRARY_SUFFIX AND
+     libxml2_library MATCHES "^${CMAKE_STATIC_LIBRARY_PREFIX}.*${CMAKE_STATIC_LIBRARY_SUFFIX}$")
+    string(REGEX REPLACE "^${CMAKE_STATIC_LIBRARY_PREFIX}" "" libxml2_library ${libxml2_library})
+    string(REGEX REPLACE "${CMAKE_STATIC_LIBRARY_SUFFIX}$" "" libxml2_library ${libxml2_library})
+  endif()
+  if(CMAKE_SHARED_LIBRARY_PREFIX AND CMAKE_SHARED_LIBRARY_SUFFIX AND
+     libxml2_library MATCHES "^${CMAKE_SHARED_LIBRARY_PREFIX}.*${CMAKE_SHARED_LIBRARY_SUFFIX}$")
+    string(REGEX REPLACE "^${CMAKE_SHARED_LIBRARY_PREFIX}" "" libxml2_library ${libxml2_library})
+    string(REGEX REPLACE "${CMAKE_SHARED_LIBRARY_SUFFIX}$" "" libxml2_library ${libxml2_library})
   endif()
-  set_property(TARGET LLVMWindowsManifest PROPERTY
-    LLVM_SYSTEM_LIBS ${xml2_library})
+  set_property(TARGET LLVMWindowsManifest PROPERTY LLVM_SYSTEM_LIBS ${libxml2_library})
 endif()

llvm/lib/WindowsManifest/WindowsManifestMerger.cpp

 //===---------------------------------------------------------------------===//
 
 #include "llvm/WindowsManifest/WindowsManifestMerger.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/MemoryBuffer.h"
 
 #include <map>
 
-#if LLVM_LIBXML2_ENABLED
+#if LLVM_ENABLE_LIBXML2
 #include <libxml/xmlreader.h>
 #endif
 
 #define TO_XML_CHAR(X) reinterpret_cast<const unsigned char *>(X)
 #define FROM_XML_CHAR(X) reinterpret_cast<const char *>(X)
 
 using namespace llvm;
 using namespace windows_manifest;
 
 char WindowsManifestError::ID = 0;
 
 WindowsManifestError::WindowsManifestError(const Twine &Msg) : Msg(Msg.str()) {}
 
 void WindowsManifestError::log(raw_ostream &OS) const { OS << Msg; }
 
 class WindowsManifestMerger::WindowsManifestMergerImpl {
 public:
   ~WindowsManifestMergerImpl();
   Error merge(const MemoryBuffer &Manifest);
   std::unique_ptr<MemoryBuffer> getMergedManifest();
 
 private:
   static void errorCallback(void *Ctx, const char *Format, ...);
   Error getParseError();
-#if LLVM_LIBXML2_ENABLED
+#if LLVM_ENABLE_LIBXML2
   xmlDocPtr CombinedDoc = nullptr;
   std::vector<xmlDocPtr> MergedDocs;
 
   bool Merged = false;
   struct XmlDeleter {
     void operator()(xmlChar *Ptr) { xmlFree(Ptr); }
     void operator()(xmlDoc *Ptr) { xmlFreeDoc(Ptr); }
   };
   int BufferSize = 0;
   std::unique_ptr<xmlChar, XmlDeleter> Buffer;
 #endif
   bool ParseErrorOccurred = false;
 };
 
-#if LLVM_LIBXML2_ENABLED
+#if LLVM_ENABLE_LIBXML2
 
 static constexpr std::pair<StringLiteral, StringLiteral> MtNsHrefsPrefixes[] = {
     {"urn:schemas-microsoft-com:asm.v1", "ms_asmv1"},
     {"urn:schemas-microsoft-com:asm.v2", "ms_asmv2"},
     {"urn:schemas-microsoft-com:asm.v3", "ms_asmv3"},
     {"http://schemas.microsoft.com/SMI/2005/WindowsSettings",
      "ms_windowsSettings"},
     {"urn:schemas-microsoft-com:compatibility.v1", "ms_compatibilityv1"}};

llvm/test/CMakeLists.txt

 llvm_canonicalize_cmake_booleans(
   BUILD_SHARED_LIBS
   HAVE_LIBXAR
   HAVE_OCAMLOPT
   HAVE_OCAML_OUNIT
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS
   LLVM_ENABLE_ZLIB
+  LLVM_ENABLE_LIBXML2
   LLVM_INCLUDE_GO_TESTS
-  LLVM_LIBXML2_ENABLED
   LLVM_LINK_LLVM_DYLIB
   LLVM_TOOL_LTO_BUILD
   LLVM_USE_INTEL_JITEVENTS
   LLVM_BUILD_EXAMPLES
   LLVM_ENABLE_PLUGINS
   LLVM_BYE_LINK_INTO_TOOLS
   LLVM_HAVE_TF_AOT
   LLVM_HAVE_TF_API

llvm/test/lit.cfg.py

if not re.match(r'^x86_64.*-(windows-gnu|windows-msvc)', config.target_triple):
     config.available_features.add('debug_frame')
 
 if config.have_libxar:
     config.available_features.add('xar')
 
 if config.enable_threads:
     config.available_features.add('thread_support')
 
-if config.llvm_libxml2_enabled:
+if config.have_libxml2:
     config.available_features.add('libxml2')
 
 if config.have_opt_viewer_modules:
     config.available_features.add('have_opt_viewer_modules')

llvm/test/lit.site.cfg.py.in

 config.host_cc = "@HOST_CC@"
 config.host_cxx = "@HOST_CXX@"
 # Note: ldflags can contain double-quoted paths, so must use single quotes here.
 config.host_ldflags = '@HOST_LDFLAGS@'
 config.llvm_use_intel_jitevents = @LLVM_USE_INTEL_JITEVENTS@
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.have_libxar = @HAVE_LIBXAR@
+config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.have_dia_sdk = @LLVM_ENABLE_DIA_SDK@
 config.enable_ffi = @LLVM_ENABLE_FFI@
 config.build_examples = @LLVM_BUILD_EXAMPLES@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
-config.llvm_libxml2_enabled = @LLVM_LIBXML2_ENABLED@
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
 config.libcxx_used = @LLVM_LIBCXX_USED@
 config.has_plugins = @LLVM_ENABLE_PLUGINS@
 config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
 config.have_tf_aot = @LLVM_HAVE_TF_AOT@
 config.have_tf_api = @LLVM_HAVE_TF_API@

llvm/utils/gn/secondary/lld/test/BUILD.gn

write_lit_cfg("lit_site_cfg") {
   extra_values = []
   if (llvm_enable_dia_sdk) {
     extra_values += [ "LLVM_ENABLE_DIA_SDK=1" ]
   } else {
     extra_values += [ "LLVM_ENABLE_DIA_SDK=0" ]  # Must be 0.
   }
 
   if (llvm_enable_libxml2) {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=1" ]
+    extra_values += [ "LLVM_ENABLE_LIBXML2=1" ]
   } else {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=0" ]  # Must be 0.
+    extra_values += [ "LLVM_ENABLE_LIBXML2=0" ]  # Must be 0.
   }
 
   if (llvm_enable_zlib) {
     extra_values += [ "LLVM_ENABLE_ZLIB=1" ]
   } else {
     extra_values += [ "LLVM_ENABLE_ZLIB=0" ]  # Must be 0.
   }
 

llvm/utils/gn/secondary/llvm/include/llvm/Config/BUILD.gn

write_cmake_config("config") {
 
   if (llvm_enable_zlib) {
     values += [ "LLVM_ENABLE_ZLIB=1" ]
   } else {
     values += [ "LLVM_ENABLE_ZLIB=" ]
   }
 
   if (llvm_enable_libxml2) {
-    values += [ "LLVM_LIBXML2_ENABLED=1" ]
+    values += [ "LLVM_ENABLE_LIBXML2=1" ]
   } else {
-    values += [ "LLVM_LIBXML2_ENABLED=" ]
+    values += [ "LLVM_ENABLE_LIBXML2=" ]
   }
 }
 
 write_cmake_config("llvm-config") {
   input = "llvm-config.h.cmake"
   output = "$target_gen_dir/llvm-config.h"
   values = [
     "LLVM_ENABLE_DUMP=",

llvm/utils/gn/secondary/llvm/test/BUILD.gn

write_lit_config("lit_site_cfg") {
 
   if (llvm_enable_dia_sdk) {
     extra_values += [ "LLVM_ENABLE_DIA_SDK=1" ]
   } else {
     extra_values += [ "LLVM_ENABLE_DIA_SDK=0" ]  # Must be 0.
   }
 
   if (llvm_enable_libxml2) {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=1" ]
+    extra_values += [ "LLVM_ENABLE_LIBXML2=1" ]
   } else {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=0" ]  # Must be 0.
+    extra_values += [ "LLVM_ENABLE_LIBXML2=0" ]  # Must be 0.
   }
 
   if (llvm_enable_threads) {
     extra_values += [ "LLVM_ENABLE_THREADS=1" ]
   } else {
     extra_values += [ "LLVM_ENABLE_THREADS=0" ]  # Must be 0.
   }