Merge #154: cmake: Port changes from PR28981

b8fd285 fixup! cmake: Add external signer support (Hennadii Stepanov)

Pull request description:

  This PR ports changes from bitcoin#28981.

ACKs for top commit:
  laanwj:
    Code review ACK b8fd285

Tree-SHA512: 338f0c8b4c94e2c706658c6b2f1306de8b6d9836dcebcefe7b81cd79d5dabf471b03afc597047a42351fda72b6c9ec2828b02c177f03df0011d3b801addda1bf

CMakeLists.txt

@@ -101,11 +101,8 @@ tristate_option(WITH_USDT
   "if sys/sdt.h is found."
   AUTO
 )
-tristate_option(WITH_EXTERNAL_SIGNER
-  "Enable external signer support."
-  "if Boost.Process is found."
-  AUTO
-)
+cmake_dependent_option(WITH_EXTERNAL_SIGNER "Enable external signer support." ON "NOT WIN32" OFF)
+set(ENABLE_EXTERNAL_SIGNER ${WITH_EXTERNAL_SIGNER})
 tristate_option(WITH_QRENCODE "Enable QR code support." "if libqrencode is found." AUTO)
 
 option(MULTIPROCESS "Build multiprocess bitcoin-node, bitcoin-wallet, and bitcoin-gui executables in addition to monolithic bitcoind and bitcoin-qt executables. Requires libmultiprocess library. Experimental." OFF)

cmake/module/AddBoostIfNeeded.cmake

@@ -55,54 +55,4 @@ function(add_boost_if_needed)
     endif()
   endif()
 
-  if(WITH_EXTERNAL_SIGNER)
-    include(CheckCXXSourceCompiles)
-    set(CMAKE_REQUIRED_INCLUDES ${Boost_INCLUDE_DIR})
-    # Boost 1.78 requires the following workaround.
-    # See: https://github.com/boostorg/process/issues/235
-    set(CMAKE_REQUIRED_FLAGS "-Wno-error=narrowing")
-    # Boost 1.73 requires the following workaround on systems with
-    # libc<2.34 only, as newer libc has integrated the functionality
-    # of the libpthread library.
-    set(CMAKE_REQUIRED_LIBRARIES Threads::Threads)
-    check_cxx_source_compiles("
-      #define BOOST_PROCESS_USE_STD_FS
-      #include <boost/process.hpp>
-      #include <string>
-
-      int main()
-      {
-        namespace bp = boost::process;
-        bp::opstream stdin_stream;
-        bp::ipstream stdout_stream;
-        bp::child c(\"dummy\", bp::std_out > stdout_stream, bp::std_err > stdout_stream, bp::std_in < stdin_stream);
-        stdin_stream << std::string{\"test\"} << std::endl;
-        if (c.running()) c.terminate();
-        c.wait();
-        c.exit_code();
-      }
-      " HAVE_BOOST_PROCESS
-    )
-    if(HAVE_BOOST_PROCESS)
-      if(WIN32)
-        # Boost Process for Windows uses Boost ASIO. Boost ASIO performs
-        # pre-main init of Windows networking libraries, which we do not
-        # want.
-        set(WITH_EXTERNAL_SIGNER OFF PARENT_SCOPE)
-        set(ENABLE_EXTERNAL_SIGNER OFF PARENT_SCOPE)
-      else()
-        set(WITH_EXTERNAL_SIGNER ON PARENT_SCOPE)
-        set(ENABLE_EXTERNAL_SIGNER ON PARENT_SCOPE)
-        target_compile_definitions(Boost::headers INTERFACE
-          BOOST_PROCESS_USE_STD_FS
-        )
-      endif()
-    elseif(WITH_EXTERNAL_SIGNER STREQUAL "AUTO")
-      set(WITH_EXTERNAL_SIGNER OFF PARENT_SCOPE)
-      set(ENABLE_EXTERNAL_SIGNER OFF PARENT_SCOPE)
-    else()
-      message(FATAL_ERROR "External signing is not supported for this Boost version.")
-    endif()
-  endif()
-
 endfunction()