Provide LLVMConfig in both build and install tree

Create separate package configuration files "LLVMConfig.cmake" for the
LLVM build and install trees so that each can have information specific
to its tree.  Configure each with the corresponding include, lib, and
cmake directories.  Include the "LLVM-Config" API modules directly from
the configured cmake modules directory.

In the install tree, compute the installation prefix relative to the
file location.  In the build tree, provide information specific to the
build tree for use by tools like Clang that can build externally against
the LLVM build tree.  Prefix such values in "LLVM_BUILD_" and comment
them as such.

Contributed by Brad King.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201048 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 45 insertions, 8 deletions

diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
index 169418c6b9..4992be0e2f 100644
--- a/cmake/modules/CMakeLists.txt
+++ b/cmake/modules/CMakeLists.txt
@@ -1,6 +1,5 @@
 set(LLVM_INSTALL_PACKAGE_DIR share/llvm/cmake)
 set(llvm_cmake_builddir "${LLVM_BINARY_DIR}/${LLVM_INSTALL_PACKAGE_DIR}")
-set(LLVM_INSTALL_PREFIX ${CMAKE_INSTALL_PREFIX})
 
 get_property(llvm_libs GLOBAL PROPERTY LLVM_LIBS)
 
@@ -10,6 +9,24 @@ foreach(lib ${llvm_libs})
     "${all_llvm_lib_deps}\nset_property(GLOBAL PROPERTY LLVMBUILD_LIB_DEPS_${lib} ${llvm_lib_deps})")
 endforeach(lib)
 
+# Generate LLVMConfig.cmake for the build tree.
+set(LLVM_CONFIG_CODE "
+# LLVM_BUILD_* values available only from LLVM build tree.
+set(LLVM_BUILD_BINARY_DIR \"${LLVM_BINARY_DIR}\")
+set(LLVM_BUILD_ENABLE_ASSERTIONS \"${LLVM_ENABLE_ASSERTIONS}\")
+set(LLVM_BUILD_LIBRARY_DIR \"${LLVM_LIBRARY_DIR}\")
+set(LLVM_BUILD_MAIN_INCLUDE_DIR \"${LLVM_MAIN_INCLUDE_DIR}\")
+set(LLVM_BUILD_MAIN_SRC_DIR \"${LLVM_MAIN_SRC_DIR}\")
+set(LLVM_BUILD_TOOLS_BINARY_DIR \"${LLVM_TOOLS_BINARY_DIR}\")
+")
+set(LLVM_CONFIG_INCLUDE_DIRS
+  "${LLVM_MAIN_INCLUDE_DIR}"
+  "${LLVM_INCLUDE_DIR}"
+  )
+set(LLVM_CONFIG_LIBRARY_DIRS
+  "${LLVM_LIBRARY_DIR}"
+  )
+set(LLVM_CONFIG_CMAKE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 configure_file(
   LLVMConfig.cmake.in
   ${llvm_cmake_builddir}/LLVMConfig.cmake
@@ -25,6 +42,26 @@ file(COPY .
   PATTERN CMakeFiles EXCLUDE
   )
 
+# Generate LLVMConfig.cmake for the install tree.
+set(LLVM_CONFIG_CODE "
+# Compute the installation prefix from this LLVMConfig.cmake file location.
+get_filename_component(LLVM_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" PATH)")
+# Construct the proper number of get_filename_component(... PATH)
+# calls to compute the installation prefix.
+string(REGEX REPLACE "/" ";" _count "${LLVM_INSTALL_PACKAGE_DIR}")
+foreach(p ${_count})
+  set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+endforeach(p)
+set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
+set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib")
+set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")
+configure_file(
+  LLVMConfig.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/LLVMConfig.cmake
+  @ONLY)
+
+# Generate LLVMConfigVersion.cmake for build and install tree.
 configure_file(
   LLVMConfigVersion.cmake.in
   ${llvm_cmake_builddir}/LLVMConfigVersion.cmake
@@ -32,7 +69,7 @@ configure_file(
 
 if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
   install(FILES
-    ${llvm_cmake_builddir}/LLVMConfig.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/LLVMConfig.cmake
     ${llvm_cmake_builddir}/LLVMConfigVersion.cmake
     LLVM-Config.cmake
     DESTINATION ${LLVM_INSTALL_PACKAGE_DIR})
diff --git a/cmake/modules/LLVMConfig.cmake.in b/cmake/modules/LLVMConfig.cmake.in
index 224a26352d..4687838a1e 100644
--- a/cmake/modules/LLVMConfig.cmake.in
+++ b/cmake/modules/LLVMConfig.cmake.in
@@ -1,5 +1,7 @@
 # This file provides information and services to the final user.
 
+@LLVM_CONFIG_CODE@
+
 set(LLVM_VERSION_MAJOR @LLVM_VERSION_MAJOR@)
 set(LLVM_VERSION_MINOR @LLVM_VERSION_MINOR@)
 set(LLVM_PACKAGE_VERSION @PACKAGE_VERSION@)
@@ -36,11 +38,9 @@ set(HAVE_LIBZ @HAVE_LIBZ@)
 set(LLVM_ON_UNIX @LLVM_ON_UNIX@)
 set(LLVM_ON_WIN32 @LLVM_ON_WIN32@)
 
-set(LLVM_INSTALL_PREFIX "@LLVM_INSTALL_PREFIX@")
-set(LLVM_INCLUDE_DIRS ${LLVM_INSTALL_PREFIX}/include)
-set(LLVM_LIBRARY_DIRS ${LLVM_INSTALL_PREFIX}/lib)
+set(LLVM_INCLUDE_DIRS "@LLVM_CONFIG_INCLUDE_DIRS@")
+set(LLVM_LIBRARY_DIRS "@LLVM_CONFIG_LIBRARY_DIRS@")
 set(LLVM_DEFINITIONS "-D__STDC_LIMIT_MACROS" "-D__STDC_CONSTANT_MACROS")
+set(LLVM_CMAKE_DIR "@LLVM_CONFIG_CMAKE_DIR@")
 
-get_filename_component(_SELF_DIR ${CMAKE_CURRENT_LIST_FILE} PATH)
-include(${_SELF_DIR}/LLVM-Config.cmake)
-unset(_SELF_DIR)
+include(${LLVM_CMAKE_DIR}/LLVM-Config.cmake)