15.4.72  src/app/make7/make-compiler/backend-per-platform.pkg

## backend-per-platform.pkg
## (C) 1999 Lucent Technologies, Bell Laboratories
## Author: Matthias Blume (blume@kurims.kyoto-u.ac.jp)

# Compiled by:
#     src/app/make7/Make7.make6




# On-demand loading, caching and invocation
# of platform-specific compilers.
#
#
# In directory
#
#     src/lib/core/make-compiler
#
# we define cross/compilers for a number of platforms:
#
#     ppc-macos.make6
#     ppc-unix.make6
#     sparc-unix.make6
#     x86-unix.make6
#     x86-win32.make6
#
# Rather than have all of these in memory at all times
# in the compile servers, we load them one at a time in
# response to specific requests from
#
#     src/app/make7/main/compile-server.pkg



package backend_per_platform {

    stipulate
        loaded_platforms =  REF string_set::empty;              # Remember which target compilers we already have in memory.
    herein                                                              # string_set    is from   src/app/make7/util/stringset.pkg
        # This function is invoked (only) from
        #     src/app/make7/main/compile-server.pkg
        #
        fun invoke
                make                                            # This is the standard 'make' entrypoint into src/app/make7/main/make7-g.pkg
                platform                                        # 'platform' string is architecture+OS, e.g. "x86-linux" 
                backend_request                                 # See Backend_Request comments in  src/app/make7/make-compiler/backend-index.pkg
            =
            {   platform_specific_backend_makefile
                    =
                    cat ["$ROOT/src/lib/core/make-compiler/", platform, ".make6"];     #  eg. x86-unix -> $ROOT/src/lib/core/make-compiler/x86-unix.make6 
            

                if   (not (string_set::member (*loaded_platforms, platform_specific_backend_makefile)))
                     
                     if   (make  platform_specific_backend_makefile)
                         
                          loaded_platforms
                              :=
                              string_set::add  (*loaded_platforms,  platform_specific_backend_makefile);
                     else
                          raise exception FAIL (cat ["dynamic linkage of ", platform, " platform-specific backend '", platform_specific_backend_makefile, "' failed"]);
                     fi;
                fi;



                # The desired platform-specific backend is now
                # in memory, and as part of the process of loading it,
                #
                #   src/app/make7/make-compiler/make-compiler-g.pkg
                #
                # will have registered a compile function for it,
                # which we now invoke:
                #
                backend_index::invoke                                   # backend_index         is from   src/app/make7/make-compiler/backend-index.pkg
                    platform                                            # 'platform' string is architecture+OS, e.g. "x86-linux" 
                    backend_request;                                    # See Backend_Request comments in  src/app/make7/make-compiler/backend-index.pkg
            };
    end;
};