Mark static_flag and shared_flag as deprecated

They are meaningless since cc-rs only generates static libraries.

Closes rust-lang#1444
Closes rust-lang#594

Author: Builder

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cc"
-version = "1.2.40"
+version = "1.2.41"
 authors = ["Alex Crichton <[email protected]>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/cc-rs"

src/lib.rs

@@ -783,26 +783,28 @@ impl Build {
 
     /// Set the `-shared` flag.
     ///
-    /// When enabled, the compiler will produce a shared object which can
-    /// then be linked with other objects to form an executable.
+    /// This will typically be ignored by the compiler when calling [`Self::compile()`] since it only
+    /// produces static libraries.
     ///
     /// # Example
     ///
     /// ```no_run
+    /// // This will create a library named "liblibfoo.so.a"
     /// cc::Build::new()
     ///     .file("src/foo.c")
     ///     .shared_flag(true)
     ///     .compile("libfoo.so");
     /// ```
+    #[deprecated = "cc only creates static libraries, setting this does nothing"]
     pub fn shared_flag(&mut self, shared_flag: bool) -> &mut Build {
         self.shared_flag = Some(shared_flag);
         self
     }
 
     /// Set the `-static` flag.
     ///
-    /// When enabled on systems that support dynamic linking, this prevents
-    /// linking with the shared libraries.
+    /// This will typically be ignored by the compiler when calling [`Self::compile()`] since it only
+    /// produces static libraries.
     ///
     /// # Example
     ///
@@ -813,6 +815,7 @@ impl Build {
     ///     .static_flag(true)
     ///     .compile("foo");
     /// ```
+    #[deprecated = "cc only creates static libraries, setting this does nothing"]
     pub fn static_flag(&mut self, static_flag: bool) -> &mut Build {
         self.static_flag = Some(static_flag);
         self