Scaffolding for generation of intrinsics files.

This CL sets up the basis for the intrinsic file generation. All of
the GN and CMake pieces are setup, but they aren't hooked into the
main build yet. That will be a followup which just enables the
generation in order to allow easy reverting.

Change-Id: Iccac59377076ed6ac66eeaf0be965be2f49bc738
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/107981
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>

src/tint/BUILD.gn

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import("//build_overrides/build.gni")
-
 import("../../tint_overrides_with_defaults.gni")
 
 if (tint_build_unittests) {
@@ -848,6 +847,140 @@ libtint_source_set("libtint_glsl_writer_src") {
   public_deps = [ ":libtint_core_src" ]
 }
 
+# Template to help invoke code generator for tint template files.
+#
+# Variables:
+#   input: The prefix for the template to generate, does not include the .tmpl extension
+template("tint_intrinsic_generator") {
+  _sources = [
+    "${invoker.input}.tmpl",
+    "${tint_root_dir}/src/tint/intrinsics.def",
+  ]
+
+  _outputs = [ "${target_gen_dir}/${invoker.input}" ]
+
+  _script = "${tint_root_dir}/generator/tint_gen_template.py"
+  _args = [
+    "--output",
+    rebase_path(root_gen_dir),
+    "--template",
+    "src/tint/" + invoker.input + ".tmpl",
+  ]
+
+  action("${target_name}") {
+    script = _script
+    outputs = _outputs
+    sources = _sources
+    args = _args
+  }
+}
+
+# Template to help invoke code generator for tint template files for source files. By default this
+# will generate a `h` and `cc` build rule for the provided `input`
+#
+# Variables:
+#   input: The prefix for the template, minus the file extension and .tmpl
+#
+#   bench: set true to generate a bench template
+#
+#   test: set true to generate a test template
+template("tint_intrinsic_src_generator") {
+  tint_intrinsic_generator("${target_name}_h") {
+    input = "${invoker.input}.h"
+  }
+  tint_intrinsic_generator("${target_name}_cc") {
+    input = "${invoker.input}.cc"
+  }
+
+  if (defined(invoker.bench) && invoker.bench) {
+    tint_intrinsic_generator("${target_name}_bench") {
+      input = "${invoker.input}_bench.cc"
+    }
+  }
+  if (defined(invoker.test) && invoker.test) {
+    tint_intrinsic_generator("${target_name}_test") {
+      input = "${invoker.input}_test.cc"
+    }
+  }
+
+  source_set(target_name) {
+    deps = [
+      ":${target_name}_cc",
+      ":${target_name}_h",
+    ]
+
+    if (defined(invoker.bench) && invoker.bench) {
+      deps += [ ":${target_name}_bench" ]
+    }
+    if (defined(invoker.test) && invoker.test) {
+      deps += [ ":${target_name}_test" ]
+    }
+  }
+}
+
+tint_intrinsic_generator("tint_intrinsics_inl") {
+  input = "resolver/intrinsic_table.inl"
+}
+
+tint_intrinsic_src_generator("tint_init_conv_intrinsic") {
+  input = "resolver/init_conv_intrinsic"
+}
+
+tint_intrinsic_src_generator("tint_sem_builtin_type") {
+  input = "sem/builtin_type"
+}
+
+tint_intrinsic_src_generator("tint_sem_parameter_usage") {
+  input = "sem/parameter_usage"
+}
+
+tint_intrinsic_src_generator("tint_ast_extension") {
+  input = "ast/extension"
+  bench = true
+  test = true
+}
+
+tint_intrinsic_src_generator("tint_ast_access") {
+  input = "ast/access"
+}
+
+tint_intrinsic_src_generator("tint_ast_builtin_value") {
+  input = "ast/builtin_value"
+  bench = true
+  test = true
+}
+
+tint_intrinsic_src_generator("tint_ast_texel_format") {
+  input = "ast/texel_format"
+  bench = true
+  test = true
+}
+
+tint_intrinsic_src_generator("tint_ast_address_space") {
+  input = "ast/address_space"
+  bench = true
+  test = true
+}
+
+tint_intrinsic_src_generator("tint_ast_interpolate_attribute") {
+  input = "ast/interpolate_attribute"
+}
+
+libtint_source_set("tint_gen_deps") {
+  deps = [
+    ":tint_ast_access",
+    ":tint_ast_address_space",
+    ":tint_ast_builtin_value",
+    ":tint_ast_extension",
+    ":tint_ast_interpolate_attribute",
+    ":tint_ast_texel_format",
+    ":tint_init_conv_intrinsic",
+    ":tint_intrinsics_inl",
+    ":tint_sem_builtin_type",
+    ":tint_sem_parameter_usage",
+  ]
+}
+
 source_set("libtint") {
   public_deps = [ ":libtint_core_src" ]