[flang] Link against zlib when LLVM does.

Original-commit: flang-compiler/f18@2260abe4c27a76e374b286df072e303aa9ea1418
Reviewed-on: https://github.com/flang-compiler/f18/pull/1043

diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
index 2b7a823..f293762 100644 (file)
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -49,6 +49,10 @@ message(STATUS "Build Type: ${CMAKE_BUILD_TYPE}" )
 
 find_package(LLVM REQUIRED CONFIG)
 message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION} in ${LLVM_DIR}")
+# If LLVM links to zlib we need the imported targets so we can too.
+if(LLVM_ENABLE_ZLIB)
+  find_package(ZLIB REQUIRED)
+endif()
 
 list(APPEND CMAKE_MODULE_PATH ${LLVM_DIR})