Add version to all LLVM cmake package

Add a version to non-LLVM cmake package so that users needing an exact
version match can use the version parameter to find_package. Also adjust
the find_package(LLVM) to use an exact version match as well.

Reviewed By: arsenm, stellaraccident, mceier

Differential Revision: https://reviews.llvm.org/D138274

3 files changed, 22 insertions, 3 deletions

diff --git a/flang/cmake/modules/CMakeLists.txt b/flang/cmake/modules/CMakeLists.txt
index 31a6c3c83e48..bf50bcaa18d5 100644
--- a/flang/cmake/modules/CMakeLists.txt
+++ b/flang/cmake/modules/CMakeLists.txt
@@ -28,8 +28,8 @@ set(FLANG_CONFIG_INCLUDE_DIRS
   "${FLANG_BINARY_DIR}/include"
   )
 configure_file(
-  ${CMAKE_CURRENT_SOURCE_DIR}/FlangConfig.cmake.in
-  ${flang_cmake_builddir}/FlangConfig.cmake
+  ${CMAKE_CURRENT_SOURCE_DIR}/FlangConfigVersion.cmake.in
+  ${flang_cmake_builddir}/FlangConfigVersion.cmake
   @ONLY)
 set(FLANG_CONFIG_CMAKE_DIR)
 set(FLANG_CONFIG_LLVM_CMAKE_DIR)
@@ -46,6 +46,10 @@ configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/FlangConfig.cmake.in
   ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/FlangConfig.cmake
   @ONLY)
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/FlangConfigVersion.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/FlangConfigVersion.cmake
+  @ONLY)
 
 set(FLANG_CONFIG_CODE)
 set(FLANG_CONFIG_CMAKE_DIR)
@@ -56,6 +60,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
 
   install(FILES
     ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/FlangConfig.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/FlangConfigVersion.cmake
     DESTINATION ${FLANG_INSTALL_PACKAGE_DIR}
     COMPONENT flang-cmake-exports)
 
diff --git a/flang/cmake/modules/FlangConfig.cmake.in b/flang/cmake/modules/FlangConfig.cmake.in
index 7893cb64b936..ac4b77bd8514 100644
--- a/flang/cmake/modules/FlangConfig.cmake.in
+++ b/flang/cmake/modules/FlangConfig.cmake.in
@@ -2,7 +2,8 @@
 
 @FLANG_CONFIG_CODE@
 
-find_package(LLVM REQUIRED CONFIG
+set(LLVM_VERSION @LLVM_VERSION_MAJOR@.@LLVM_VERSION_MINOR@.@LLVM_VERSION_PATCH@)
+find_package(LLVM ${LLVM_VERSION} EXACT REQUIRED CONFIG
              HINTS "@FLANG_CONFIG_LLVM_CMAKE_DIR@")
 
 set(FLANG_EXPORTED_TARGETS "@FLANG_EXPORTS@")
diff --git a/flang/cmake/modules/FlangConfigVersion.cmake.in b/flang/cmake/modules/FlangConfigVersion.cmake.in
new file mode 100644
index 000000000000..e9ac4ed2da78
--- /dev/null
+++ b/flang/cmake/modules/FlangConfigVersion.cmake.in
@@ -0,0 +1,13 @@
+set(PACKAGE_VERSION "@PACKAGE_VERSION@")
+
+# LLVM is API-compatible only with matching major.minor versions
+# and patch versions not less than that requested.
+if("@LLVM_VERSION_MAJOR@.@LLVM_VERSION_MINOR@" VERSION_EQUAL
+    "${PACKAGE_FIND_VERSION_MAJOR}.${PACKAGE_FIND_VERSION_MINOR}"
+   AND NOT "@LLVM_VERSION_PATCH@" VERSION_LESS "${PACKAGE_FIND_VERSION_PATCH}")
+  set(PACKAGE_VERSION_COMPATIBLE 1)
+  if("@LLVM_VERSION_PATCH@" VERSION_EQUAL
+      "${PACKAGE_FIND_VERSION_PATCH}")
+    set(PACKAGE_VERSION_EXACT 1)
+  endif()
+endif()