From 9598611e3565094008137c027ccbac69c5f6d020 Mon Sep 17 00:00:00 2001
From: Xavier Del Campo <90845888+midokura-xavi92@users.noreply.github.com>
Date: Fri, 20 Dec 2024 06:05:50 +0100
Subject: [PATCH] CMakeLists.txt: Do not require C++ (#3956)

By default, the project() CMake command defaults to C and C++. [1]
Therefore, CMake might perform tests for both C and C++ compilers as
part of the configuration phase.

However, this has the consequence of the configuration phase to fail if
the system does not have a C++ toolchain installed, even if C++ is not
really used by the top-level project under the default settings.

Some configurations might still require a C++ toolchain, so
enable_language is selectively called under such circumstances.

[1]: https://cmake.org/cmake/help/latest/command/project.html
---
 CMakeLists.txt                                     | 2 +-
 core/iwasm/compilation/iwasm_compl.cmake           | 1 +
 core/iwasm/fast-jit/iwasm_fast_jit.cmake           | 1 +
 core/iwasm/libraries/wasi-nn/cmake/wasi_nn.cmake   | 1 +
 core/shared/platform/windows/shared_platform.cmake | 1 +
 5 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e5a1bf1c50..2bd82fc83a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ if(ESP_PLATFORM)
   return()
 endif()
 
-project (iwasm)
+project (iwasm LANGUAGES C)
 
 set(CMAKE_CXX_STANDARD 17)
 
diff --git a/core/iwasm/compilation/iwasm_compl.cmake b/core/iwasm/compilation/iwasm_compl.cmake
index 4ec4603049..77925d62d8 100644
--- a/core/iwasm/compilation/iwasm_compl.cmake
+++ b/core/iwasm/compilation/iwasm_compl.cmake
@@ -1,6 +1,7 @@
 set (IWASM_COMPL_DIR ${CMAKE_CURRENT_LIST_DIR})
 
 include_directories(${IWASM_COMPL_DIR})
+enable_language(CXX)
 
 if (WAMR_BUILD_DEBUG_AOT EQUAL 1)
     file (GLOB_RECURSE source_all
diff --git a/core/iwasm/fast-jit/iwasm_fast_jit.cmake b/core/iwasm/fast-jit/iwasm_fast_jit.cmake
index cd880a34b2..c5012bd36c 100644
--- a/core/iwasm/fast-jit/iwasm_fast_jit.cmake
+++ b/core/iwasm/fast-jit/iwasm_fast_jit.cmake
@@ -9,6 +9,7 @@ if (WAMR_BUILD_FAST_JIT_DUMP EQUAL 1)
 endif ()
 
 include_directories (${IWASM_FAST_JIT_DIR})
+enable_language(CXX)
 
 if (WAMR_BUILD_TARGET STREQUAL "X86_64" OR WAMR_BUILD_TARGET STREQUAL "AMD_64")
     include(FetchContent)
diff --git a/core/iwasm/libraries/wasi-nn/cmake/wasi_nn.cmake b/core/iwasm/libraries/wasi-nn/cmake/wasi_nn.cmake
index a903f0af1f..c6deab6fca 100644
--- a/core/iwasm/libraries/wasi-nn/cmake/wasi_nn.cmake
+++ b/core/iwasm/libraries/wasi-nn/cmake/wasi_nn.cmake
@@ -22,6 +22,7 @@ add_compile_definitions(
 # - tflite
 if(WAMR_BUILD_WASI_NN_TFLITE EQUAL 1)
   find_package(tensorflow_lite REQUIRED)
+  enable_language(CXX)
 
   add_library(
     wasi_nn_tflite
diff --git a/core/shared/platform/windows/shared_platform.cmake b/core/shared/platform/windows/shared_platform.cmake
index c2d74463fb..7a3331eff1 100644
--- a/core/shared/platform/windows/shared_platform.cmake
+++ b/core/shared/platform/windows/shared_platform.cmake
@@ -6,6 +6,7 @@ set (PLATFORM_SHARED_DIR ${CMAKE_CURRENT_LIST_DIR})
 add_definitions(-DBH_PLATFORM_WINDOWS)
 add_definitions(-DHAVE_STRUCT_TIMESPEC)
 add_definitions(-D_WINSOCK_DEPRECATED_NO_WARNINGS)
+enable_language(CXX)
 
 include_directories(${PLATFORM_SHARED_DIR})
 include_directories(${PLATFORM_SHARED_DIR}/../include)