Add support for env_logger

When RUST_LOG environment variable is set, uses env_logger instead of
our custom logger. This is desirable for debugging purposes.

4 files changed, 85 insertions, 6 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 56836188..2ad39c5f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -8,6 +8,7 @@ dependencies = [
  "clap 2.26.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "clippy 0.0.164 (registry+https://github.com/rust-lang/crates.io-index)",
  "copypasta 0.0.1",
+ "env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "errno 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "font 0.1.0",
@@ -30,6 +31,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "aho-corasick"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "android_glue"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -299,6 +308,15 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "env_logger"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "errno"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -615,6 +633,14 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "memchr"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.30 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "memmap"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -884,6 +910,18 @@ version = "0.1.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "regex"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "aho-corasick 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "regex-syntax"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1094,6 +1132,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "thread_local"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "time"
 version = "0.1.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1133,6 +1180,14 @@ version = "0.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "unreachable"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "user32-sys"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1142,6 +1197,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "utf8-ranges"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "utf8parse"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1157,6 +1217,11 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "vte"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1321,6 +1386,7 @@ dependencies = [
 ]
 
 [metadata]
+"checksum aho-corasick 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "500909c4f87a9e52355b26626d890833e9e1d53ac566db76c36faa984b889699"
 "checksum android_glue 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "000444226fcff248f2bc4c7625be32c63caccfecc2723a2b9f78a7487a49c407"
 "checksum ansi_term 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "23ac7c30002a5accbf7e8987d0632fa6de155b7c3d39d0067317a391e00a2ef6"
 "checksum approx 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08abcc3b4e9339e33a3d0a5ed15d84a687350c05689d825e0f6655eef9e76a94"
@@ -1354,6 +1420,7 @@ dependencies = [
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum dwmapi-sys 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "07c4c7cc7b396419bc0a4d90371d0cee16cb5053b53647d287c0b728000c41fe"
 "checksum either 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "18785c1ba806c258137c937e44ada9ee7e69a37e3c72077542cd2f069d78562a"
+"checksum env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3ddf21e73e016298f5cb37d6ef8e8da8e39f91f9ec8b0df44b7deb16a9f8cd5b"
 "checksum errno 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b2c858c42ac0b88532f48fca88b0ed947cad4f1f64d904bcd6c9f138f7b95d70"
 "checksum euclid 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ba6ab6f0e63a602978f4b8cf8a43f87a1a475ddf32407f087d579a13cf06b114"
 "checksum expat-sys 2.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "c470ccb972f2088549b023db8029ed9da9426f5affbf9b62efff7009ab8ed5b1"
@@ -1391,6 +1458,7 @@ dependencies = [
 "checksum magenta-sys 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "40d014c7011ac470ae28e2f76a02bfea4a8480f73e701353b49ad7a8d75f4699"
 "checksum malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
 "checksum matches 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "100aabe6b8ff4e4a7e32c1c13523379802df0772b82466207ac25b013f193376"
+"checksum memchr 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1dbccc0e46f1ea47b9f17e6d67c5a96bd27030519c519c9c91327e31275a47b4"
 "checksum memmap 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "69253224aa10070855ea8fe9dbe94a03fc2b1d7930bb340c9e586a7513716fea"
 "checksum mio 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a637d1ca14eacae06296a008fa7ad955347e34efcb5891cfd8ba05491a37907e"
 "checksum mio 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)" = "dbd91d3bfbceb13897065e97b2ef177a09a438cb33612b2d371bf568819a9313"
@@ -1420,6 +1488,7 @@ dependencies = [
 "checksum quote 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e920b65c65f10b2ae65c831a81a073a89edd28c7cce89475bff467ab4167a"
 "checksum rand 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)" = "eb250fd207a4729c976794d03db689c9be1d634ab5a1c9da9492a13d8fecbcdf"
 "checksum redox_syscall 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "8dde11f18c108289bef24469638a04dce49da56084f2d50618b226e47eb04509"
+"checksum regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1731164734096285ec2a5ec7fea5248ae2f5485b3feeb0115af4fda2183b2d1b"
 "checksum regex-syntax 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ad890a5eef7953f55427c50575c680c42841653abd2b028b68cd223d157f62db"
 "checksum rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)" = "dcf128d1287d2ea9d80910b5f1120d0b8eede3fbf1abe91c40d39ea7d51e6fda"
 "checksum semver 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a3186ec9e65071a2095434b1f5bb24838d4e8e130f584c790f6033c79943537"
@@ -1447,16 +1516,20 @@ dependencies = [
 "checksum tempfile 2.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "5b92290d7f1ce2d221405d5c78b9c568c9f1debb314aa92a513cd99db709f931"
 "checksum term_size 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2b6b55df3198cc93372e85dd2ed817f0e38ce8cc0f22eb32391bfad9c4bf209"
 "checksum textwrap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f728584ea33b0ad19318e20557cb0a39097751dbb07171419673502f848c7af6"
+"checksum thread_local 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "1697c4b57aeeb7a536b647165a2825faddffb1d3bad386d507709bd51a90bb14"
 "checksum time 0.1.38 (registry+https://github.com/rust-lang/crates.io-index)" = "d5d788d3aa77bc0ef3e9621256885555368b47bd495c13dd2e7413c89f845520"
 "checksum toml 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "a7540f4ffc193e0d3c94121edb19b055670d369f77d5804db11ae053a45b6e7e"
 "checksum unicode-normalization 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "51ccda9ef9efa3f7ef5d91e8f9b83bbe6955f9bf86aec89d5cce2c874625920f"
 "checksum unicode-segmentation 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a8083c594e02b8ae1654ae26f0ade5158b119bd88ad0e8227a5d8fcd72407946"
 "checksum unicode-width 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "bf3a113775714a22dcb774d8ea3655c53a32debae63a063acc00a91cc586245f"
 "checksum unicode-xid 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f860d7d29cf02cb2f3f359fd35991af3d30bac52c57d265a3c461074cb4dc"
+"checksum unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
 "checksum user32-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6717129de5ac253f5642fc78a51d0c7de6f9f53d617fc94e9bae7f6e71cf5504"
+"checksum utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "662fab6525a98beff2921d7f61a39e7d59e0b425ebc7d0d9e66d316e55124122"
 "checksum utf8parse 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a15ea87f3194a3a454c78d79082b4f5e85f6956ddb6cb86bbfbe4892aa3c0323"
 "checksum vcpkg 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9e0a7d8bed3178a8fb112199d466eeca9ed09a14ba8ad67718179b4fd5487d0b"
 "checksum vec_map 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "887b5b631c2ad01628bbbaa7dd4c869f80d3186688f8d0b6f58774fbe324988c"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum vte 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a01634c75db59478405de08d8567c40c578bba80c565217ee709934b551720d8"
 "checksum walkdir 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "c66c0b9792f0a765345452775f3adbd28dde9d33f30d13e5dcc5ae17cf6f3780"
 "checksum wayland-client 0.9.9 (registry+https://github.com/rust-lang/crates.io-index)" = "15aaf730e0720ac3c25259bd8af44eacd509ae03e85a3ca64b0d4f7fe9d8da03"
diff --git a/Cargo.toml b/Cargo.toml
index fb31a1d7..04c02385 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,7 @@ unicode-width = "0.1.4"
 arraydeque = "0.2.3"
 glutin = "0.9.2"
 clippy = { version = "*", optional = true }
-
+env_logger = "0.4"
 
 [target.'cfg(any(target_os = "linux", target_os = "freebsd", target_os="dragonfly", target_os="openbsd"))'.dependencies]
 x11-dl = "2"
diff --git a/src/lib.rs b/src/lib.rs
index d48ab93b..255215c7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -33,6 +33,7 @@ extern crate arraydeque;
 extern crate cgmath;
 extern crate copypasta;
 extern crate errno;
+extern crate env_logger;
 extern crate fnv;
 extern crate font;
 extern crate glutin;
diff --git a/src/logging.rs b/src/logging.rs
index 6b7a7968..4584b5f6 100644
--- a/src/logging.rs
+++ b/src/logging.rs
@@ -36,7 +36,6 @@ impl<T: Send + io::Write> Logger<T> {
     }
 }
 
-
 impl<T: Send + io::Write> log::Log for Logger<T> {
     fn enabled(&self, metadata: &log::LogMetadata) -> bool {
         metadata.level() <= self.level
@@ -52,8 +51,14 @@ impl<T: Send + io::Write> log::Log for Logger<T> {
 }
 
 pub fn initialize(options: &cli::Options) -> Result<(), log::SetLoggerError> {
-    log::set_logger(|max_log_level| {
-        max_log_level.set(options.log_level);
-        Box::new(Logger::new(io::stdout(), options.log_level))
-    })
+    // Use env_logger if RUST_LOG environment variable is defined. Otherwise,
+    // use the alacritty-only logger.
+    if ::std::env::var("RUST_LOG").is_ok() {
+        ::env_logger::init()
+    } else {
+        log::set_logger(|max_log_level| {
+            max_log_level.set(options.log_level);
+            Box::new(Logger::new(io::stdout(), options.log_level))
+        })
+    }
 }