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, 24 insertions, 1 deletions

diff --git a/clang/cmake/modules/CMakeLists.txt b/clang/cmake/modules/CMakeLists.txt
index 880d51f5aef7..749ef672c34f 100644
--- a/clang/cmake/modules/CMakeLists.txt
+++ b/clang/cmake/modules/CMakeLists.txt
@@ -32,6 +32,10 @@ configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/ClangConfig.cmake.in
   ${clang_cmake_builddir}/ClangConfig.cmake
   @ONLY)
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/ClangConfigVersion.cmake.in
+  ${clang_cmake_builddir}/ClangConfigVersion.cmake
+  @ONLY)
 set(CLANG_CONFIG_CMAKE_DIR)
 set(CLANG_CONFIG_LLVM_CMAKE_DIR)
 
@@ -59,6 +63,10 @@ configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/ClangConfig.cmake.in
   ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/ClangConfig.cmake
   @ONLY)
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/ClangConfigVersion.cmake.in
+  ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/ClangConfigVersion.cmake
+  @ONLY)
 set(CLANG_CONFIG_CODE)
 set(CLANG_CONFIG_CMAKE_DIR)
 
@@ -67,6 +75,7 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
 
   install(FILES
     ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/ClangConfig.cmake
+    ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/ClangConfigVersion.cmake
     ${CMAKE_CURRENT_SOURCE_DIR}/AddClang.cmake
     DESTINATION ${CLANG_INSTALL_PACKAGE_DIR}
     COMPONENT clang-cmake-exports)
diff --git a/clang/cmake/modules/ClangConfig.cmake.in b/clang/cmake/modules/ClangConfig.cmake.in
index 2a254463d6f5..5f67681649c6 100644
--- a/clang/cmake/modules/ClangConfig.cmake.in
+++ b/clang/cmake/modules/ClangConfig.cmake.in
@@ -2,7 +2,8 @@
 
 @CLANG_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 "@CLANG_CONFIG_LLVM_CMAKE_DIR@")
 
 set(CLANG_EXPORTED_TARGETS "@CLANG_EXPORTS@")
diff --git a/clang/cmake/modules/ClangConfigVersion.cmake.in b/clang/cmake/modules/ClangConfigVersion.cmake.in
new file mode 100644
index 000000000000..e9ac4ed2da78
--- /dev/null
+++ b/clang/cmake/modules/ClangConfigVersion.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()