From 4f198f16ddeda471b4d3c654285bf5c8a3e27944 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Mon, 21 Jan 2019 10:20:07 +0800
Subject: [PATCH] Add -log-file=stderr and make it default

---
 src/log.cc  |  1 +
 src/main.cc | 10 ++++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/log.cc b/src/log.cc
index a10a4a7d..3e2b5592 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -72,6 +72,7 @@ Message::~Message() {
   std::lock_guard<std::mutex> lock(mtx);
   stream_ << '\n';
   fputs(stream_.str().c_str(), file);
+  fflush(file);
   if (verbosity_ == Verbosity_FATAL)
     abort();
 }
diff --git a/src/main.cc b/src/main.cc
index 95cd0363..a4df3b8a 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -59,7 +59,7 @@ opt<std::string> opt_index("index",
 list<std::string> opt_init("init", desc("extra initialization options in JSON"),
                            cat(C));
 opt<std::string> opt_log_file("log-file", desc("log"), value_desc("filename"),
-                              cat(C));
+                              init("stderr"), cat(C));
 opt<std::string> opt_log_file_append("log-file-append", desc("log"),
                                      value_desc("filename"), cat(C));
 
@@ -96,9 +96,11 @@ int main(int argc, char **argv) {
   bool language_server = true;
 
   if (opt_log_file.size() || opt_log_file_append.size()) {
-    ccls::log::file = opt_log_file.size()
-                          ? fopen(opt_log_file.c_str(), "wb")
-                          : fopen(opt_log_file_append.c_str(), "ab");
+    if (opt_log_file.size())
+      ccls::log::file =
+          opt_log_file == "stderr" ? stderr : fopen(opt_log_file.c_str(), "wb");
+    else
+      ccls::log::file = fopen(opt_log_file_append.c_str(), "ab");
     if (!ccls::log::file) {
       fprintf(
           stderr, "failed to open %s\n",