From 8690833dd7d8448e27f11addf03ec4f296963ee1 Mon Sep 17 00:00:00 2001
From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Date: Mon, 15 Mar 2021 13:44:51 -0700
Subject: [PATCH] Use local rules for flex/bison
Use local flex and bison rules for the packet parser instead of
depending on the rules in common-mk. Right now, the packet parser is
using a re-entrant parser which can't be used with C++ codegen for flex.
Common-mk maintainers would like the flex code to use C++ codegen since
it is compiling the file as C++.
Bug: 176847216
Tag: #floss
Test: atest --host bluetooth_test_gd
Change-Id: I731adcff7c966543300d2cdf1f87ef2a69b8a211
---
system/gd/packet/parser/BUILD.gn | 4 +-
system/gd/packet/parser/bison.gni | 75 +++++++++++++++++++++++++++++++
system/gd/packet/parser/flex.gni | 70 +++++++++++++++++++++++++++++
3 files changed, 147 insertions(+), 2 deletions(-)
create mode 100644 system/gd/packet/parser/bison.gni
create mode 100644 system/gd/packet/parser/flex.gni
diff --git a/system/gd/packet/parser/BUILD.gn b/system/gd/packet/parser/BUILD.gn
index 9889672cc83..dd4f3b09710 100644
--- a/system/gd/packet/parser/BUILD.gn
+++ b/system/gd/packet/parser/BUILD.gn
@@ -14,8 +14,8 @@
# limitations under the License.
#
-import("//common-mk/bison.gni")
-import("//common-mk/flex.gni")
+import("flex.gni")
+import("bison.gni")
config("pktgen_configs") {
include_dirs = [ "//bt/gd/packet/parser" ]
diff --git a/system/gd/packet/parser/bison.gni b/system/gd/packet/parser/bison.gni
new file mode 100644
index 00000000000..b52541b32f3
--- /dev/null
+++ b/system/gd/packet/parser/bison.gni
@@ -0,0 +1,75 @@
+#
+# Copyright 2021 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Bison is a parser generator which reads a specification of a context-free
+# language and generates a parser which decides whether the input conforms to
+# the grammar specified.
+
+# Generate header and source files using Bison.
+#
+# Note: We generate C++ output for Bison. We also set --language to C++
+# (equivalent to %language c++) which forces Bison to generate a C++ parser.
+#
+# Parameters:
+# sources: Grammar files used to generate the parsers.
+template("bison_source") {
+ action_name = "${target_name}_gen"
+ action_foreach(action_name) {
+ forward_variables_from(invoker, [ "sources" ])
+ assert(defined(sources), "sources must be set")
+ foreach(s, sources) {
+ assert(get_path_info(s, "extension") == "yy",
+ "Expecting Bison extension yy: ${s}")
+ }
+
+ script = "//common-mk/file_generator_wrapper.py"
+ outprefix = "${target_gen_dir}/{{source_name_part}}"
+ args = [
+ "bison",
+ "--language=c++",
+ "--defines=${outprefix}.h",
+ "-o",
+ "${outprefix}.cc",
+ "{{source}}",
+ ]
+ outputs = [
+ "${outprefix}.h",
+ "${outprefix}.cc",
+ ]
+ }
+
+ all_dependent_config_name = "_${target_name}_all_dependent_config"
+ config(all_dependent_config_name) {
+ include_dirs = [ "${target_gen_dir}" ]
+ }
+
+ source_set(target_name) {
+ sources = get_target_outputs(":${action_name}")
+ all_dependent_configs = [ ":${all_dependent_config_name}" ]
+ deps = [ ":${action_name}" ]
+
+ if (defined(invoker.configs)) {
+ configs += invoker.configs
+ }
+
+ # Silence some warnings. The autogenerated code includes parts that have
+ # fallthroughs and unreachable code. This may silence legitimate issues in
+ # user written code in the grammar files as well. User beware!
+ cflags_cc = [
+ "-Wno-implicit-fallthrough",
+ "-Wno-unreachable-code",
+ ]
+ }
+}
diff --git a/system/gd/packet/parser/flex.gni b/system/gd/packet/parser/flex.gni
new file mode 100644
index 00000000000..1fcba233d4e
--- /dev/null
+++ b/system/gd/packet/parser/flex.gni
@@ -0,0 +1,70 @@
+#
+# Copyright 2021 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Flex (fast lexical analyzer generator) is used for parsing languages. It is
+# commonly used with a parser generator (like Bison).
+
+# Generate source files using Flex.
+#
+# Note: We generate .cc files for Flex. However, you must set %option c++ if you
+# want to generate a C++ scanner class. We don't use --c++ in case you have
+# %option reentrant set, which is mutually exclusive with %option c++.
+#
+# Parameters:
+# sources: Files used to generate the lexers.
+template("flex_source") {
+ action_name = "${target_name}_gen"
+ action_foreach(action_name) {
+ forward_variables_from(invoker, [ "sources" ])
+ assert(defined(sources), "sources must be set")
+ foreach(s, sources) {
+ assert(get_path_info(s, "extension") == "ll",
+ "Expecting Flex extension ll: ${s}")
+ }
+
+ script = "//common-mk/file_generator_wrapper.py"
+ outformat = "${target_gen_dir}/{{source_name_part}}.cc"
+ args = [
+ "flex",
+ "-o",
+ outformat,
+ "{{source}}",
+ ]
+ outputs = [ outformat ]
+ }
+
+ all_dependent_config_name = "_${target_name}_all_dependent_config"
+ config(all_dependent_config_name) {
+ include_dirs = [ "${target_gen_dir}" ]
+ }
+
+ source_set(target_name) {
+ sources = get_target_outputs(":${action_name}")
+ all_dependent_configs = [ ":${all_dependent_config_name}" ]
+ deps = [ ":${action_name}" ]
+
+ if (defined(invoker.configs)) {
+ configs += invoker.configs
+ }
+
+ # Silence some warnings. The autogenerated code includes parts that have
+ # fallthroughs and unreachable code. This may silence legitimate issues in
+ # user written code in the lexer as well. User beware!
+ cflags_cc = [
+ "-Wno-implicit-fallthrough",
+ "-Wno-unreachable-code",
+ ]
+ }
+}
--
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