From 9b77138b71e04bb127ec1fb3ae280bca33c59ae1 Mon Sep 17 00:00:00 2001
From: RomantsovS <romancov123@gmail.com>
Date: Mon, 23 Dec 2024 14:39:13 -0800
Subject: [PATCH] examples/cpp/route_guide add missing command line parsing
 (#37857)

The gRPC basic turorial says to call the following command to run the server `./route_guide_server --db_path=path/to/route_guide_db.json`

But the server and client do not parse command line arguments and they always use default value `route_guide_db.json`. Thus the example only works if we run it from `examples/cpp/route_guide` dir. Otherwise we get the following error: `helper.cc:49] Failed to open route_guide_db.json
Aborted (core dumped)`

Add
`absl::ParseCommandLine(argc, argv);`
to both server and client `main` similar to `route_guide_callback_server.cc`

Closes #37857

PiperOrigin-RevId: 709154601
---
 examples/cpp/route_guide/BUILD                 | 2 ++
 examples/cpp/route_guide/Makefile              | 4 ++--
 examples/cpp/route_guide/route_guide_client.cc | 2 ++
 examples/cpp/route_guide/route_guide_server.cc | 2 ++
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/examples/cpp/route_guide/BUILD b/examples/cpp/route_guide/BUILD
index 2ea012ca2ee62..9a19d895a8c92 100644
--- a/examples/cpp/route_guide/BUILD
+++ b/examples/cpp/route_guide/BUILD
@@ -39,6 +39,7 @@ cc_binary(
         ":route_guide_helper",
         "//:grpc++",
         "//examples/protos:route_guide",
+        "@com_google_absl//absl/flags:parse",
     ],
 )
 
@@ -53,6 +54,7 @@ cc_binary(
         ":route_guide_helper",
         "//:grpc++",
         "//examples/protos:route_guide",
+        "@com_google_absl//absl/flags:parse",
     ],
 )
 
diff --git a/examples/cpp/route_guide/Makefile b/examples/cpp/route_guide/Makefile
index ae254230f68d6..0b4940dd4c329 100644
--- a/examples/cpp/route_guide/Makefile
+++ b/examples/cpp/route_guide/Makefile
@@ -25,7 +25,7 @@ PROTOBUF_UTF8_RANGE_LINK_LIBS = -lutf8_validity
 HOST_SYSTEM = $(shell uname | cut -f 1 -d_)
 SYSTEM ?= $(HOST_SYSTEM)
 CXX = g++
-CPPFLAGS += `pkg-config --cflags protobuf grpc`
+CPPFLAGS += `pkg-config --cflags protobuf grpc absl_flags absl_flags_parse`
 CXXFLAGS += -std=c++17
 ifeq ($(SYSTEM),Darwin)
 LDFLAGS += -L/usr/local/lib `pkg-config --libs --static protobuf grpc++ $(PROTOBUF_ABSL_DEPS)`\
@@ -35,7 +35,7 @@ LDFLAGS += -L/usr/local/lib `pkg-config --libs --static protobuf grpc++ $(PROTOB
            -lgrpc++_reflection\
            -ldl
 else
-LDFLAGS += -L/usr/local/lib `pkg-config --libs --static protobuf grpc++ $(PROTOBUF_ABSL_DEPS)`\
+LDFLAGS += -L/usr/local/lib `pkg-config --libs --static protobuf grpc++ absl_flags absl_flags_parse $(PROTOBUF_ABSL_DEPS)`\
            $(PROTOBUF_UTF8_RANGE_LINK_LIBS) \
            -pthread\
            -Wl,--no-as-needed -lgrpc++_reflection -Wl,--as-needed\
diff --git a/examples/cpp/route_guide/route_guide_client.cc b/examples/cpp/route_guide/route_guide_client.cc
index 73983f458d934..af9f2fdda3069 100644
--- a/examples/cpp/route_guide/route_guide_client.cc
+++ b/examples/cpp/route_guide/route_guide_client.cc
@@ -29,6 +29,7 @@
 #include <string>
 #include <thread>
 
+#include "absl/flags/parse.h"
 #include "helper.h"
 #ifdef BAZEL_BUILD
 #include "examples/protos/route_guide.grpc.pb.h"
@@ -216,6 +217,7 @@ class RouteGuideClient {
 };
 
 int main(int argc, char** argv) {
+  absl::ParseCommandLine(argc, argv);
   // Expect only arg: --db_path=path/to/route_guide_db.json.
   std::string db = routeguide::GetDbFileContent(argc, argv);
   RouteGuideClient guide(
diff --git a/examples/cpp/route_guide/route_guide_server.cc b/examples/cpp/route_guide/route_guide_server.cc
index 7a6a1c8ecaa13..b037ca0815aa9 100644
--- a/examples/cpp/route_guide/route_guide_server.cc
+++ b/examples/cpp/route_guide/route_guide_server.cc
@@ -29,6 +29,7 @@
 #include <memory>
 #include <string>
 
+#include "absl/flags/parse.h"
 #include "helper.h"
 #ifdef BAZEL_BUILD
 #include "examples/protos/route_guide.grpc.pb.h"
@@ -182,6 +183,7 @@ void RunServer(const std::string& db_path) {
 }
 
 int main(int argc, char** argv) {
+  absl::ParseCommandLine(argc, argv);
   // Expect only arg: --db_path=path/to/route_guide_db.json.
   std::string db = routeguide::GetDbFileContent(argc, argv);
   RunServer(db);