diff --git a/zircon/BUILD.gn b/zircon/BUILD.gn
index c65e65f7f4a30ec488bebd4a40783a53fd4362ac..af4441dcce3e4241a4900742aa544a40e8f1a09a 100644
--- a/zircon/BUILD.gn
+++ b/zircon/BUILD.gn
@@ -484,6 +484,7 @@ build_api_module("legacy_images") {
}
}
+
# This describes all the generated source files in the build.
#
# The intent is that telling Ninja to build all these individual files
@@ -500,6 +501,41 @@ build_api_module("generated_sources") {
data_keys = [ "generated_sources" ]
}
+# This describes pre-generated FIDL bindings that are required by the build.
+#
+# TODO(BLD-441): This will go away when fidlgen is built in this build.
+# See $zx/public/gn/fidl/llcpp.gni, where the metadata is generated.
+#
+# Type: list(scope)
+#
+# name
+# Required: The FIDL library name as it appears in FIDL source (with dots).
+# Type: string
+#
+# label
+# Required: The label of the fidl_library() target.
+# Type: label_no_toolchain
+#
+# json
+# Required: Path to the fidlc --json output.
+# Type: path relative to $root_build_dir
+#
+# target_gen_dir
+# Required: The place in the source tree where generated files go.
+# Type: path relative to $root_build_dir
+#
+# args
+# Required: Argument list for `fidlgen` if run in $root_build_dir.
+# Type: list(string)
+#
+build_api_module("fidl_gen") {
+ testonly = true
+ data_keys = [ "fidl_gen" ]
+ deps = [
+ ":all-cpu",
+ ]
+}
+
# TODO(TC-303): ids.txt is deprecated and will be removed.
if (current_toolchain == default_toolchain) {
action("ids") {
diff --git a/zircon/public/gn/fidl.gni b/zircon/public/gn/fidl.gni
index 029cbc40e06f1b97b86b4a85390f3084b7ec0aa5..78102688e20480518663d2726807742402d6bcb3 100644
--- a/zircon/public/gn/fidl.gni
+++ b/zircon/public/gn/fidl.gni
@@ -86,7 +86,10 @@ import("$zx/public/gn/fidl/fidlc.gni")
# TODO(mcgrathr): Add more language generators. For language support from
# a different petal, add a build argument to contribute to this list via
# default_overrides.
-fidl_support = [ "$zx/public/gn/fidl/c.gni" ]
+fidl_support = [
+ "$zx/public/gn/fidl/c.gni",
+ "$zx/public/gn/fidl/llcpp.gni",
+]
# Each support module defines $fidl_support_fidlc and
# $fidl_support_templates lists in its .gni file.
@@ -333,6 +336,7 @@ template("fidl_library") {
"visibility",
"testonly",
])
+ fidl_sources = invoker.sources
# The bindings-library template can map these to corresponding
# bindings-library targets.
diff --git a/zircon/public/gn/fidl/llcpp.gni b/zircon/public/gn/fidl/llcpp.gni
new file mode 100644
index 0000000000000000000000000000000000000000..93b7546216970d361c3949d4e6f0c4e3e338e107
--- /dev/null
+++ b/zircon/public/gn/fidl/llcpp.gni
@@ -0,0 +1,152 @@
+# Copyright 2019 The Fuchsia Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("$zx/public/gn/subtarget_aliases.gni")
+
+# This is the $fidl_support module for "low-level" C++ bindings.
+# See fidl_library() for details. This file should not normally be
+# imported by other code.
+
+# This tells fidl_library() to invoke fidl_llcpp_library().
+fidl_support_templates = [
+ {
+ import = "$zx/public/gn/fidl/llcpp.gni"
+ target = "fidl_llcpp_library"
+ fidlc = "json"
+ },
+]
+
+# This tells fidl_library() what fidlc outputs fidl_llcpp_library() requires.
+fidl_support_fidlc = [
+ {
+ name = "json"
+ files = [
+ {
+ switch = "--json"
+ path = "fidl.json"
+ },
+ ]
+ },
+]
+
+# Provide LLCPP 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_llcpp_library") {
+ fidl_target = target_name
+ library_target = "$fidl_target.llcpp"
+ not_needed(invoker, "*")
+ if (current_toolchain != default_toolchain) {
+ # TODO(BLD-441): For now the bindings have to be generated and
+ # checked into the source tree. So this is just a normal vanilla
+ # C++ library, except that its sources live in the gen/llcpp/
+ # subdirectory of the fidl_library() target's source directory and
+ # the public headers live in gen/llcpp/include/. The Fuchsia GN
+ # build has code in //TBD to regenerate these files and check that
+ # the copies in the source tree are up to date.
+
+ config("_fidl_llcpp_library.config.$library_target") {
+ visibility = [
+ ":$library_target.headers",
+ ":$library_target.static",
+ ]
+ include_dirs = [ "gen/llcpp/include" ]
+ }
+
+ library(library_target) {
+ forward_variables_from(invoker,
+ [
+ "visibility",
+ "testonly",
+ ])
+
+ sources = [
+ "gen/llcpp/fidl.cc",
+ ]
+
+ configs += [ "$zx/public/gn/config:visibility_hidden" ]
+
+ # Users of the bindings library need the generated headers.
+ public_configs = [ ":_fidl_llcpp_library.config.$library_target" ]
+
+ deps = []
+ public_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 += [ "$dep.llcpp" ]
+ public_deps += [ "$dep.llcpp.headers" ]
+ }
+
+ # The generated code uses these.
+ public_deps += [ "$zx/system/ulib/fidl:fidl-llcpp.headers" ]
+ deps += [ "$zx/system/ulib/fidl:fidl-llcpp" ]
+
+ # TODO(BLD-441): Get the metadata below into the dependency graph.
+ # Putting the metadata here directly would duplicate the information
+ # across different toolchains that build the library. So instead,
+ # use a dummy group() in $default_toolchain as a single node to hold
+ # the metadata.
+ deps += [ ":${fidl_target}.llcpp($default_toolchain)" ]
+ }
+
+ # Things normally depend on "fidl/foo:llcpp" rather than
+ # "fidl/foo:foo.llcpp".
+ subtarget_aliases(target_name) {
+ forward_variables_from(invoker,
+ [
+ "visibility",
+ "testonly",
+ ])
+ outputs = [
+ "llcpp",
+ "llcpp.headers",
+ "llcpp.static",
+ ]
+ }
+ } else {
+ # TODO(BLD-441): This exists only for the deps above. This generates
+ # metadata for the build_api_module("fidl_gen") at top-level that
+ # informs the //tool/fidlgen_llcpp_zircon scripts what generated sources
+ # need to be updated.
+ # This will go away when the bindings generation is done directly here.
+ fidlc_outputs = invoker.fidlc_outputs
+ assert(fidlc_outputs == [ fidlc_outputs[0] ])
+ group(library_target) {
+ metadata = {
+ fidl_gen = [
+ {
+ label = get_label_info(":$target_name", "label_no_toolchain")
+ fidl_sources = rebase_path(invoker.fidl_sources, root_build_dir)
+ name = invoker.fidl_name
+ target_gen_dir = rebase_path("gen/llcpp", root_build_dir)
+ json = rebase_path(fidlc_outputs[0], root_build_dir)
+
+ # TODO(BLD-442): Could generate an individual response file
+ # here that could be used very simply to drive running fidlgen.
+ # Alternatively, give fidlgen as "JSON response file" feature:
+ # `fidlgen -json-args foo.json` reads a dictionary from the
+ # file. Then we could write that JSON fragment right here in
+ # place of this args list.
+ args = [
+ "-json",
+ json,
+ "-include-base",
+ "$target_gen_dir/include",
+ "-header",
+ "$target_gen_dir/include/${invoker.fidl_path}/llcpp/fidl.h",
+ "-source",
+ "$target_gen_dir/fidl.cc",
+ ]
+ },
+ ]
+ }
+ }
+ }
+}