From a851090dec8600b38d54cd65264e4146ad02b1e0 Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Tue, 27 Aug 2019 20:55:11 +0200
Subject: [PATCH] build: third-party: enable CXX language earlier (#10862)

This is required for `CMAKE_CXX_COMPILER` to be set already, not only
after including third-party/cmake/BuildGperf.cmake.

Closes https://github.com/neovim/neovim/pull/10860.
Ref: 31f879983f
---
 third-party/CMakeLists.txt         | 12 ++++++++++--
 third-party/cmake/BuildGperf.cmake |  1 -
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/third-party/CMakeLists.txt b/third-party/CMakeLists.txt
index 3bfa3fdf39..849b66742e 100644
--- a/third-party/CMakeLists.txt
+++ b/third-party/CMakeLists.txt
@@ -97,11 +97,19 @@ else()
   set(DEPS_C_COMPILER "${CMAKE_C_COMPILER}")
 endif()
 
-set(DEPS_CXX_COMPILER "${CMAKE_CXX_COMPILER}")
+if(USE_BUNDLED_GPERF)
+  enable_language(CXX)
+endif()
+
+if(CMAKE_CXX_COMPILER)
+  set(DEPS_CXX_COMPILER "${CMAKE_CXX_COMPILER}")
+endif()
 
 if(CMAKE_OSX_SYSROOT)
   set(DEPS_C_COMPILER "${DEPS_C_COMPILER} -isysroot${CMAKE_OSX_SYSROOT}")
-  set(DEPS_CXX_COMPILER "${DEPS_CXX_COMPILER} -isysroot${CMAKE_OSX_SYSROOT}")
+  if(DEPS_CXX_COMPILER)
+    set(DEPS_CXX_COMPILER "${DEPS_CXX_COMPILER} -isysroot${CMAKE_OSX_SYSROOT}")
+  endif()
 endif()
 
 # Cross compiling: use these for dependencies built for the
diff --git a/third-party/cmake/BuildGperf.cmake b/third-party/cmake/BuildGperf.cmake
index e922f71ed5..71c3cc1eef 100644
--- a/third-party/cmake/BuildGperf.cmake
+++ b/third-party/cmake/BuildGperf.cmake
@@ -2,7 +2,6 @@
 # cross compiling we still want to build for the HOST system, whenever
 # writing a recipe that is meant for cross-compile, use the HOSTDEPS_* variables
 # instead of DEPS_* - check the main CMakeLists.txt for a list.
-enable_language(CXX)
 
 # BuildGperf(CONFIGURE_COMMAND ... BUILD_COMMAND ... INSTALL_COMMAND ...)
 # Reusable function to build Gperf, wraps ExternalProject_Add.