[CMake] Unify handling of libxml2 with other libraries

[phosek]

Summary

Use LLVM_ENABLE_LIBXML2 to enable the use of libxml2 and HAVE_LIBXML2
to signal its presence.

[delcypher]

llvm/cmake/config-ix.cmake

167

If LLVM_ENABLE_LIBXML2 is enabled but we don't find libxml2 then we should emit an error.

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

38

Isn't @HAVE_LIBXML2@ going to expand to the string TRUE? That doesn't seem like it would work. First because it's not quoted, second because config.have_libxml2 probably should be a python bool.

[phosek]

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

38

It'll because of llvm_canonicalize_cmake_booleans, see the change above in llvm/test/CMakeLists.txt.

[phosek]

llvm/cmake/config-ix.cmake

167

This is already handled by the check below (when LLVM_ENABLE_LIBXML2 is set to FORCE_ON), we could check it to emit an error even when it's set just to ON but I don't know whether that's going to break any existing users?

llvm/cmake/config-ix.cmake

if(LLVM_ENABLE_TERMINFO)
           break()
         endif()
       endforeach()
     else()
       set(HAVE_TERMINFO 0)
     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)
+        set(HAVE_LIBXML2 TRUE)
         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()
-        set(LIBXML2_LIBS "xml2")
       endif()
     endif()
   endif()
 endif()
 
-if (LLVM_ENABLE_LIBXML2 STREQUAL "FORCE_ON" AND NOT LLVM_LIBXML2_ENABLED)
-  message(FATAL_ERROR "Failed to congifure libxml2")
+if (LLVM_ENABLE_LIBXML2 STREQUAL "FORCE_ON" AND NOT HAVE_LIBXML2)
+  message(FATAL_ERROR "libxml2 enabled but not found.")
 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_TERMINFO @LLVM_ENABLE_TERMINFO@)
 
 set(LLVM_ENABLE_THREADS @LLVM_ENABLE_THREADS@)
 
 set(LLVM_ENABLE_UNWIND_TABLES @LLVM_ENABLE_UNWIND_TABLES@)
 
 set(LLVM_ENABLE_ZLIB @LLVM_ENABLE_ZLIB@)
 
-set(LLVM_LIBXML2_ENABLED @LLVM_LIBXML2_ENABLED@)
+set(LLVM_ENABLE_LIBXML2 @LLVM_ENABLE_LIBXML2@)
 
 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

 #cmakedefine HAVE_PTHREAD_GETNAME_NP ${HAVE_PTHREAD_GETNAME_NP}
 
 /* Define to 1 if you have the `pthread_setname_np' function. */
 #cmakedefine HAVE_PTHREAD_SETNAME_NP ${HAVE_PTHREAD_SETNAME_NP}
 
 /* Define to 1 if you have the `z' library (-lz). */
 #cmakedefine HAVE_LIBZ ${HAVE_LIBZ}
 
+/* Define to 1 if you have the `xml2' library (-lxml2). */
+#cmakedefine HAVE_LIBXML2 ${HAVE_LIBXML2}
+
 /* Define to 1 if you have the <link.h> header file. */
 #cmakedefine HAVE_LINK_H ${HAVE_LINK_H}
 
 /* Define to 1 if you have the `lseek64' function. */
 #cmakedefine HAVE_LSEEK64 ${HAVE_LSEEK64}
 
 /* Define to 1 if you have the <mach/mach.h> header file. */
 #cmakedefine HAVE_MACH_MACH_H ${HAVE_MACH_MACH_H}

 
 /* 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

 set(system_libs)
 if( CMAKE_HOST_UNIX )
-  if( LLVM_LIBXML2_ENABLED )
-    set(system_libs ${system_libs} ${LIBXML2_LIBS})
+  if( HAVE_LIBXML2 )
+    set(system_libs ${system_libs} ${LIBXML2_LIBRARIES})
   endif()
 endif()
 
 add_llvm_library(LLVMWindowsManifest
   WindowsManifestMerger.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/WindowsManifest
   ${Backtrace_INCLUDE_DIRS}
 
   LINK_LIBS ${system_libs}
   )
 
 set_property(TARGET LLVMWindowsManifest PROPERTY LLVM_SYSTEM_LIBS "${system_libs}")

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 HAVE_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 HAVE_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 HAVE_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_LIBXML2
   HAVE_LIBZ
   HAVE_OCAMLOPT
   HAVE_OCAML_OUNIT
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS
   LLVM_INCLUDE_GO_TESTS
   LLVM_LIBXML2_ENABLED

llvm/test/lit.cfg.py

 
 # .debug_frame is not emitted for targeting Windows x64.
 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.have_libxml2:
+    config.available_features.add('libxml2')
+
 if config.enable_threads:
     config.available_features.add('thread_support')
 
-if config.llvm_libxml2_enabled:
-    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 = @HAVE_LIBZ@
 config.have_libxar = @HAVE_LIBXAR@
+config.have_libxml2 = @HAVE_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@
 
 # Support substitution of the tools_dir with user parameters. This is
 # used when we can't determine the tool dir at configuration time.