[Lldb-commits] [clang] [lldb] [llvm] [cmake] Add support for statically linking libxml2 (PR #166867)

[Keith Smiley via lldb-commits]

https://github.com/keith updated https://github.com/llvm/llvm-project/pull/166867

>From c0efc4c4a360bc401b790e6022cf6bd5bfd2f750 Mon Sep 17 00:00:00 2001
From: Keith Smiley <keithbsmiley at gmail.com>
Date: Thu, 4 Dec 2025 16:54:54 +0000
Subject: [PATCH 1/2] redo without external build

---
 clang/cmake/caches/Release.cmake | 1 +
 llvm/CMakeLists.txt              | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/clang/cmake/caches/Release.cmake b/clang/cmake/caches/Release.cmake
index 25f7970119d07..45343c66dfb7f 100644
--- a/clang/cmake/caches/Release.cmake
+++ b/clang/cmake/caches/Release.cmake
@@ -171,6 +171,7 @@ set_final_stage_var(CPACK_GENERATOR "TXZ" STRING)
 set_final_stage_var(CPACK_ARCHIVE_THREADS "0" STRING)
 
 set_final_stage_var(LLVM_USE_STATIC_ZSTD "ON" BOOL)
+set_final_stage_var(LLVM_USE_STATIC_LIBXML2 "ON" BOOL)
 if (LLVM_RELEASE_ENABLE_LTO)
   set_final_stage_var(LLVM_ENABLE_FATLTO "ON" BOOL)
   set_final_stage_var(CPACK_PRE_BUILD_SCRIPTS "${CMAKE_CURRENT_LIST_DIR}/release_cpack_pre_build_strip_lto.cmake" STRING)
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 908580f791f36..7eee65139987f 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -605,6 +605,8 @@ set(LLVM_TARGET_ARCH "host"
 
 set(LLVM_ENABLE_LIBXML2 "ON" CACHE STRING "Use libxml2 if available. Can be ON, OFF, or FORCE_ON")
 
+set(LLVM_USE_STATIC_LIBXML2 "OFF" CACHE BOOL "Use static version of libxml2. Can be ON, or OFF")
+
 option(LLVM_ENABLE_LIBEDIT "Use libedit if available." ON)
 
 option(LLVM_ENABLE_LIBPFM "Use libpfm for performance counters if available." ON)

>From 34f3548a8d3a278f4886801e500b6d8077ad532a Mon Sep 17 00:00:00 2001
From: Keith Smiley <keithbsmiley at gmail.com>
Date: Thu, 4 Dec 2025 17:17:48 +0000
Subject: [PATCH 2/2] re-work

---
 lldb/source/Host/CMakeLists.txt      |  2 +-
 llvm/cmake/modules/FindLibXml2.cmake | 81 ++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 llvm/cmake/modules/FindLibXml2.cmake

diff --git a/lldb/source/Host/CMakeLists.txt b/lldb/source/Host/CMakeLists.txt
index 3184d3a1ead0d..e3a5840564ac1 100644
--- a/lldb/source/Host/CMakeLists.txt
+++ b/lldb/source/Host/CMakeLists.txt
@@ -154,7 +154,7 @@ if (CMAKE_SYSTEM_NAME MATCHES "NetBSD")
   list(APPEND EXTRA_LIBS kvm)
 endif()
 if (LLDB_ENABLE_LIBXML2)
-  list(APPEND EXTRA_LIBS LibXml2::LibXml2)
+  list(APPEND EXTRA_LIBS LibXml2::LibXml2Shared)
 endif()
 if (HAVE_LIBDL)
   list(APPEND EXTRA_LIBS ${CMAKE_DL_LIBS})
diff --git a/llvm/cmake/modules/FindLibXml2.cmake b/llvm/cmake/modules/FindLibXml2.cmake
new file mode 100644
index 0000000000000..2dc5aa2594eac
--- /dev/null
+++ b/llvm/cmake/modules/FindLibXml2.cmake
@@ -0,0 +1,81 @@
+# Based on https://gitlab.kitware.com/cmake/cmake/-/blob/3986f4b79ea6bf247eefad7ddb883cd6f65ac5c1/Modules/FindLibXml2.cmake
+# With support for using a static libxml2 library
+
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig QUIET)
+if(PkgConfig_FOUND)
+  pkg_check_modules(PC_LIBXML QUIET libxml-2.0)
+endif()
+
+find_path(LIBXML2_INCLUDE_DIR NAMES libxml/xpath.h
+  HINTS
+  ${PC_LIBXML_INCLUDEDIR}
+  ${PC_LIBXML_INCLUDE_DIRS}
+  PATH_SUFFIXES libxml2
+)
+
+if(DEFINED LIBXML2_LIBRARIES AND NOT DEFINED LIBXML2_LIBRARY)
+  set(LIBXML2_LIBRARY ${LIBXML2_LIBRARIES})
+endif()
+
+find_library(LIBXML2_SHARED_LIBRARY NAMES xml2 libxml2 libxml2_a
+  HINTS
+  ${PC_LIBXML_LIBDIR}
+  ${PC_LIBXML_LIBRARY_DIRS}
+)
+
+if(LLVM_USE_STATIC_LIBXML2)
+  set(_original_suffixes ${CMAKE_FIND_LIBRARY_SUFFIXES})
+  if(UNIX)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES .a)
+  elseif(WIN32)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES .lib .a)
+  endif()
+
+  find_library(LIBXML2_STATIC_LIBRARY NAMES xml2 libxml2 libxml2_a
+    HINTS
+    ${PC_LIBXML_LIBDIR}
+    ${PC_LIBXML_LIBRARY_DIRS}
+  )
+
+  if(LIBXML2_STATIC_LIBRARY STREQUAL "LIBXML2_STATIC_LIBRARY-NOTFOUND")
+    message(FATAL_ERROR "Static libxml2 requested (LLVM_USE_STATIC_LIBXML2=ON) but not found")
+  endif()
+
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ${_original_suffixes})
+  set(LIBXML2_LIBRARY ${LIBXML2_STATIC_LIBRARY})
+else()
+  set(LIBXML2_LIBRARY ${LIBXML2_SHARED_LIBRARY})
+endif()
+
+set(LIBXML2_LIBRARIES ${LIBXML2_LIBRARY})
+set(LIBXML2_INCLUDE_DIRS ${LIBXML2_INCLUDE_DIR})
+
+unset(LIBXML2_DEFINITIONS)
+foreach(libxml2_pc_lib_dir IN LISTS PC_LIBXML_LIBDIR PC_LIBXML_LIBRARY_DIRS)
+  if (LIBXML2_LIBRARY MATCHES "^${libxml2_pc_lib_dir}")
+    list(APPEND LIBXML2_INCLUDE_DIRS ${PC_LIBXML_INCLUDE_DIRS})
+    set(LIBXML2_DEFINITIONS ${PC_LIBXML_CFLAGS_OTHER})
+    break()
+  endif()
+endforeach()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(LibXml2
+                                  REQUIRED_VARS LIBXML2_LIBRARY LIBXML2_INCLUDE_DIR
+                                  VERSION_VAR LibXml2_VERSION)
+
+mark_as_advanced(LIBXML2_INCLUDE_DIR LIBXML2_LIBRARY)
+
+if(LibXml2_FOUND AND NOT TARGET LibXml2::LibXml2)
+  add_library(LibXml2::LibXml2 UNKNOWN IMPORTED)
+  set_target_properties(LibXml2::LibXml2 PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${LIBXML2_INCLUDE_DIRS}")
+  set_target_properties(LibXml2::LibXml2 PROPERTIES INTERFACE_COMPILE_OPTIONS "${LIBXML2_DEFINITIONS}")
+  set_property(TARGET LibXml2::LibXml2 APPEND PROPERTY IMPORTED_LOCATION "${LIBXML2_LIBRARY}")
+
+  add_library(LibXml2::LibXml2Shared UNKNOWN IMPORTED)
+  set_target_properties(LibXml2::LibXml2Shared PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${LIBXML2_INCLUDE_DIRS}")
+  set_target_properties(LibXml2::LibXml2Shared PROPERTIES INTERFACE_COMPILE_OPTIONS "${LIBXML2_DEFINITIONS}")
+  set_property(TARGET LibXml2::LibXml2Shared APPEND PROPERTY IMPORTED_LOCATION "${LIBXML2_SHARED_LIBRARY}")
+endif()