fix zlib and openssl package mode

CMakeLists.txt

@@ -123,10 +123,8 @@ if("${gRPC_ZLIB_PROVIDER}" STREQUAL "module")
     set(gRPC_INSTALL FALSE)
   endif()
 elseif("${gRPC_ZLIB_PROVIDER}" STREQUAL "package")
-  find_package(ZLIB)
-  if(TARGET ZLIB::ZLIB)
-    set(_gRPC_ZLIB_LIBRARIES ZLIB::ZLIB)
-  endif()
+  find_package(ZLIB REQUIRED)
+  set(_gRPC_ZLIB_LIBRARIES ${ZLIB_LIBRARIES})
   set(_gRPC_FIND_ZLIB "if(NOT ZLIB_FOUND)\n  find_package(ZLIB)\nendif()")
 endif()
 
@@ -145,7 +143,7 @@ if("${gRPC_CARES_PROVIDER}" STREQUAL "module")
     set(gRPC_INSTALL FALSE)
   endif()
 elseif("${gRPC_CARES_PROVIDER}" STREQUAL "package")
-  find_package(c-ares CONFIG)
+  find_package(c-ares REQUIRED CONFIG)
   if(TARGET c-ares::cares)
     set(_gRPC_CARES_LIBRARIES c-ares::cares)
   endif()
@@ -189,7 +187,7 @@ if("${gRPC_PROTOBUF_PROVIDER}" STREQUAL "module")
     set(gRPC_INSTALL FALSE)
   endif()
 elseif("${gRPC_PROTOBUF_PROVIDER}" STREQUAL "package")
-  find_package(Protobuf ${gRPC_PROTOBUF_PACKAGE_TYPE})
+  find_package(Protobuf REQUIRED ${gRPC_PROTOBUF_PACKAGE_TYPE})
   if(Protobuf_FOUND OR PROTOBUF_FOUND)
     if(TARGET protobuf::${_gRPC_PROTOBUF_LIBRARY_NAME})
       set(_gRPC_PROTOBUF_LIBRARIES protobuf::${_gRPC_PROTOBUF_LIBRARY_NAME})
@@ -234,11 +232,9 @@ if("${gRPC_SSL_PROVIDER}" STREQUAL "module")
     set(gRPC_INSTALL FALSE)
   endif()
 elseif("${gRPC_SSL_PROVIDER}" STREQUAL "package")
-  find_package(OpenSSL)
-  if(TARGET OpenSSL::SSL)
-    set(_gRPC_SSL_LIBRARIES OpenSSL::SSL)
-  endif()
-  set(_gRPC_FIND_SSL "if(NOT OpenSSL_FOUND)\n  find_package(OpenSSL)\nendif()")
+  find_package(OpenSSL REQUIRED)
+  set(_gRPC_SSL_LIBRARIES ${OPENSSL_LIBRARIES})
+  set(_gRPC_FIND_SSL "if(NOT OPENSSL_FOUND)\n  find_package(OpenSSL)\nendif()")
 endif()
 
 if("${gRPC_GFLAGS_PROVIDER}" STREQUAL "module")

templates/CMakeLists.txt.template

@@ -168,10 +168,8 @@
       set(gRPC_INSTALL FALSE)
     endif()
   elseif("<%text>${gRPC_ZLIB_PROVIDER}</%text>" STREQUAL "package")
-    find_package(ZLIB)
-    if(TARGET ZLIB::ZLIB)
-      set(_gRPC_ZLIB_LIBRARIES ZLIB::ZLIB)
-    endif()
+    find_package(ZLIB REQUIRED)
+    set(_gRPC_ZLIB_LIBRARIES <%text>${ZLIB_LIBRARIES}</%text>)
     set(_gRPC_FIND_ZLIB "if(NOT ZLIB_FOUND)\n  find_package(ZLIB)\nendif()")
   endif()
 
@@ -190,7 +188,7 @@
       set(gRPC_INSTALL FALSE)
     endif()
   elseif("<%text>${gRPC_CARES_PROVIDER}</%text>" STREQUAL "package")
-    find_package(c-ares CONFIG)
+    find_package(c-ares REQUIRED CONFIG)
     if(TARGET c-ares::cares)
       set(_gRPC_CARES_LIBRARIES c-ares::cares)
     endif()
@@ -234,7 +232,7 @@
       set(gRPC_INSTALL FALSE)
     endif()
   elseif("<%text>${gRPC_PROTOBUF_PROVIDER}</%text>" STREQUAL "package")
-    find_package(Protobuf <%text>${gRPC_PROTOBUF_PACKAGE_TYPE}</%text>)
+    find_package(Protobuf REQUIRED <%text>${gRPC_PROTOBUF_PACKAGE_TYPE}</%text>)
     if(Protobuf_FOUND OR PROTOBUF_FOUND)
       if(TARGET protobuf::<%text>${_gRPC_PROTOBUF_LIBRARY_NAME}</%text>)
         set(_gRPC_PROTOBUF_LIBRARIES protobuf::<%text>${_gRPC_PROTOBUF_LIBRARY_NAME}</%text>)
@@ -279,11 +277,9 @@
       set(gRPC_INSTALL FALSE)
     endif()
   elseif("<%text>${gRPC_SSL_PROVIDER}</%text>" STREQUAL "package")
-    find_package(OpenSSL)
-    if(TARGET OpenSSL::SSL)
-      set(_gRPC_SSL_LIBRARIES OpenSSL::SSL)
-    endif()
-    set(_gRPC_FIND_SSL "if(NOT OpenSSL_FOUND)\n  find_package(OpenSSL)\nendif()")
+    find_package(OpenSSL REQUIRED)
+    set(_gRPC_SSL_LIBRARIES <%text>${OPENSSL_LIBRARIES}</%text>)
+    set(_gRPC_FIND_SSL "if(NOT OPENSSL_FOUND)\n  find_package(OpenSSL)\nendif()")
   endif()
 
   if("<%text>${gRPC_GFLAGS_PROVIDER}</%text>" STREQUAL "module")