Optimize liblzma.a build

Cargo.toml

@@ -32,5 +32,10 @@ tokio-core = "0.1.17"
 tokio = ["tokio-io", "futures"]
 static = ["lzma-sys/static"]
 
+fat-lto = ["lzma-sys/fat-lto"]
+thin-lto = ["lzma-sys/thin-lto"]
+
+thin = ["lzma-sys/thin"]
+
 [package.metadata.docs.rs]
 features = ["tokio-io", "futures"]

lzma-sys/Cargo.toml

@@ -26,3 +26,8 @@ pkg-config = "0.3.14"
 
 [features]
 static = []
+
+fat-lto = [] # Enable fat-lto, will override thin-lto if specified
+thin-lto = [] # Enable thin-lto, will fallback to fat-lto if not supported
+
+thin = [] # Enable HAVE_SMALL to optimize for size

lzma-sys/build.rs

@@ -74,6 +74,27 @@ fn main() {
         }
     }
 
+    build
+        .flag_if_supported("-ffunction-sections")
+        .flag_if_supported("-fdata-sections")
+        .flag_if_supported("-fmerge-all-constants");
+
+    if cfg!(feature = "fat-lto") {
+        build.flag_if_supported("-flto");
+    } else if cfg!(feature = "thin-lto") {
+        if build.is_flag_supported("-flto=thin").unwrap_or(false) {
+            build.flag("-flto=thin");
+        } else {
+            build.flag_if_supported("-flto");
+        }
+    }
+
+    if cfg!(feature = "thin") {
+        build.define("HAVE_SMALL", Some("1"));
+
+        build.opt_level_str("z");
+    }
+
     build.compile("liblzma.a");
 }
 

lzma-sys/config.h

@@ -39,6 +39,8 @@
     #define MYTHREAD_POSIX 1
 #endif
 
+#define NDEBUG 1
+
 #if defined(__sun)
     #define HAVE_CLOCK_GETTIME 1
     #define HAVE_DECL_CLOCK_MONOTONIC 1