libbindgen: Make logging optional

Note that the log crate isn't completely banished, as other is required
by other dependencies.

2 files changed, 37 insertions, 1 deletions

diff --git a/libbindgen/src/lib.rs b/libbindgen/src/lib.rs
index e4923b77..84c69310 100644
--- a/libbindgen/src/lib.rs
+++ b/libbindgen/src/lib.rs
@@ -29,9 +29,15 @@ extern crate clang_sys;
 extern crate libc;
 extern crate regex;
 #[macro_use]
+extern crate lazy_static;
+
+#[cfg(feature = "logging")]
+#[macro_use]
 extern crate log;
+
+#[cfg(not(feature = "logging"))]
 #[macro_use]
-extern crate lazy_static;
+mod log_stubs;
 
 // A macro to declare an internal module for which we *must* provide
 // documentation for. If we are building with the "_docs" feature, then the
diff --git a/libbindgen/src/log_stubs.rs b/libbindgen/src/log_stubs.rs
new file mode 100644
index 00000000..4262e120
--- /dev/null
+++ b/libbindgen/src/log_stubs.rs
@@ -0,0 +1,30 @@
+macro_rules! log {
+    (target: $target:expr, $lvl:expr, $($arg)+) => {
+        let _ = $target;
+        let _ = log!($lvl, $($arg)+);
+    };
+    ($lvl:expr, $($arg:tt)+) => {
+        let _ = $lvl;
+        let _ = format_args!($($arg)+);
+    };
+}
+macro_rules! error {
+    (target: $target:expr, $($arg:tt)*) => { log!($target, $($arg)*); };
+    ($($arg:tt)*) => { log!("", $($arg)*); };
+}
+macro_rules! warn {
+    (target: $target:expr, $($arg:tt)*) => { log!($target, $($arg)*); };
+    ($($arg:tt)*) => { log!("", $($arg)*); };
+}
+macro_rules! info {
+    (target: $target:expr, $($arg:tt)*) => { log!($target, $($arg)*); };
+    ($($arg:tt)*) => { log!("", $($arg)*); };
+}
+macro_rules! debug {
+    (target: $target:expr, $($arg:tt)*) => { log!($target, $($arg)*); };
+    ($($arg:tt)*) => { log!("", $($arg)*); };
+}
+macro_rules! trace {
+    (target: $target:expr, $($arg:tt)*) => { log!($target, $($arg)*); };
+    ($($arg:tt)*) => { log!("", $($arg)*); };
+}