zircon/public/gn/fidl/c.gni

# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("$zx/public/gn/subtarget_aliases.gni")

# This is the $fidl_support module for C bindings.  See fidl_library() for
# details.  This file should not normally be imported by other code.

# This tells fidl_library() to invoke fidl_c_library().
fidl_support_templates = [
  {
    import = "$zx/public/gn/fidl/c.gni"
    target = "fidl_c_library"
    fidlc = "c"
  },
]

# This tells fidl_library() what fidlc outputs fidl_c_library() requires.
fidl_support_fidlc = [
  {
    name = "c"
    files = [
      {
        switch = "--c-header"
        path_prefix = "include/"
        path_suffix = "/c/fidl.h"
      },
      {
        switch = "--c-client"
        path = "client.c"
      },
      {
        switch = "--c-server"
        path = "server.c"
      },
    ]
  },
]

# Provide C bindings for fidl_library().  **Do not use directly!**
#
# This is never used directly, but only indirectly by fidl_library().
# See there for details.
template("fidl_c_library") {
  not_needed([ "target_name" ])
  not_needed(invoker, "*")
  if (current_toolchain != default_toolchain) {
    fidl_target = target_name
    library_target = "$fidl_target.c"

    config("_fidl_c_library.config.$library_target") {
      visibility = [
        ":$library_target.headers",
        ":$library_target.static",
      ]
      include_dirs = [ "${invoker.fidlc_gen_dir}/include" ]
    }

    library(library_target) {
      forward_variables_from(invoker,
                             [
                               "visibility",
                               "testonly",
                             ])

      # Depend on the fidlc generation step and compile what it produces.
      deps = invoker.fidlc_deps
      sources = invoker.fidlc_outputs

      # Users of the bindings library need the generated headers.
      public_configs = [ ":_fidl_c_library.config.$library_target" ]

      # The `.headers` subtarget of a library() only depends on its
      # public_deps.  But all users of the headers need to depend on the
      # generation step too, so put it in public_deps as well.
      public_deps = invoker.fidlc_deps

      # The generated headers of a dependent fidl_library() will #include the
      # generated headers for its dependencies' bindings libraries, so those
      # headers are needed in public_deps.  The generated bindings code may
      # call into its dependencies' bindings code, so the libraries
      # themselves are needed in deps too.
      foreach(dep, invoker.fidl_deps) {
        deps += [ "$dep.c" ]
        public_deps += [ "$dep.c.headers" ]
      }

      # The generated code uses these.
      deps += [
        ":$fidl_target.tables",
        "$zx/system/ulib/fidl",
        "$zx/system/ulib/zircon",
      ]
    }

    # Things normally depend on "fidl/foo:c" rather than "fidl/foo:foo.c".
    subtarget_aliases(target_name) {
      forward_variables_from(invoker,
                             [
                               "visibility",
                               "testonly",
                             ])
      outputs = [
        "c",
        "c.headers",
        "c.static",
      ]
    }
  }
}