Merge remote-tracking branch 'upstream/master'

Author: jehiggs

.travis.yml

@@ -6,7 +6,7 @@ rust:
 matrix:
   include:
     # Minimum version supported
-    - rust: 1.6.0
+    - rust: 1.9.0
       install:
       script: cargo build
 

README.md

@@ -36,7 +36,8 @@ extern crate gcc;
 
 fn main() {
     gcc::Config::new()
-        .files(["foo.c", "bar.c"])
+        .file("foo.c")
+        .file("bar.c")
         .compile("foo");
 }
 ```

appveyor.yml

@@ -1,4 +1,24 @@
 environment:
+
+  # At the time this was added AppVeyor was having troubles with checking
+  # revocation of SSL certificates of sites like static.rust-lang.org and what
+  # we think is crates.io. The libcurl HTTP client by default checks for
+  # revocation on Windows and according to a mailing list [1] this can be
+  # disabled.
+  #
+  # The `CARGO_HTTP_CHECK_REVOKE` env var here tells cargo to disable SSL
+  # revocation checking on Windows in libcurl. Note, though, that rustup, which
+  # we're using to download Rust here, also uses libcurl as the default backend.
+  # Unlike Cargo, however, rustup doesn't have a mechanism to disable revocation
+  # checking. To get rustup working we set `RUSTUP_USE_HYPER` which forces it to
+  # use the Hyper instead of libcurl backend. Both Hyper and libcurl use
+  # schannel on Windows but it appears that Hyper configures it slightly
+  # differently such that revocation checking isn't turned on by default.
+  #
+  # [1]: https://curl.haxx.se/mail/lib-2016-03/0202.html
+  RUSTUP_USE_HYPER: 1
+  CARGO_HTTP_CHECK_REVOKE: false
+
   matrix:
   - TARGET: x86_64-pc-windows-msvc
     ARCH: amd64

gcc-test/build.rs

@@ -11,6 +11,8 @@ fn main() {
 
     gcc::Config::new()
         .file("src/foo.c")
+        .flag_if_supported("-Wall")
+        .flag_if_supported("-Wfoo-bar-this-flag-does-not-exist")
         .define("FOO", None)
         .define("BAR", Some("1"))
         .compile("libfoo.a");

src/lib.rs

@@ -86,6 +86,7 @@ pub struct Config {
     static_crt: Option<bool>,
     shared_flag: Option<bool>,
     static_flag: Option<bool>,
+    check_file_created: bool,
 }
 
 /// Configuration used to represent an invocation of a C compiler.
@@ -200,6 +201,7 @@ impl Config {
             cargo_metadata: true,
             pic: None,
             static_crt: None,
+            check_file_created: false,
         }
     }
 
@@ -260,6 +262,51 @@ impl Config {
         self
     }
 
+    fn is_flag_supported(&mut self, flag: &str) -> io::Result<bool> {
+        let out_dir = self.get_out_dir();
+        let src = out_dir.join("flag_check.c");
+        if !self.check_file_created {
+            try!(write!(try!(fs::File::create(&src)), "int main(void) {{ return 0; }}"));
+            self.check_file_created = true;
+        }
+
+        let obj = out_dir.join("flag_check");
+        let target = self.get_target();
+        let mut cfg = Config::new();
+        cfg.flag(flag)
+           .target(&target)
+           .opt_level(0)
+           .host(&target)
+           .debug(false)
+           .cpp(self.cpp);
+        let compiler = cfg.get_compiler();
+        let mut cmd = compiler.to_command();
+        command_add_output_file(&mut cmd, &obj, target.contains("msvc"), false);
+        cmd.arg(&src);
+
+        let output = try!(cmd.output());
+        Ok(output.stderr.is_empty())
+    }
+
+    /// Add an arbitrary flag to the invocation of the compiler if it supports it
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// gcc::Config::new()
+    ///             .file("src/foo.c")
+    ///             .flag_if_supported("-Wlogical-op") // only supported by GCC
+    ///             .flag_if_supported("-Wunreachable-code") // only supported by clang
+    ///             .compile("foo");
+    /// ```
+    pub fn flag_if_supported(&mut self, flag: &str) -> &mut Config {
+        if self.is_flag_supported(flag).unwrap_or(false) {
+            self.flag(flag)
+        } else {
+            self
+        }
+    }
+
     /// Set the `-shared` flag.
     ///
     /// When enabled, the compiler will produce a shared object which can
@@ -499,10 +546,18 @@ impl Config {
     /// the `output` may start with `lib` and end with `.a`.  The Rust compilier will create
     /// the assembly with the lib prefix and .a extension.  MSVC will create a file without prefix,
     /// ending with `.lib`.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `output` is not formatted correctly or if one of the underlying
+    /// compiler commands fails. It can also panic if it fails reading file names
+    /// or creating directories.
     pub fn compile(&self, output: &str) {
-        let name_start = if output.starts_with("lib") { 3 } else { 0 };
-        let name_end = if output.ends_with(".a") { output.len() - 2 } else { output.len() };
-        let lib_name = &output[name_start..name_end];
+        let lib_name = if output.starts_with("lib") && output.ends_with(".a") {
+                &output[3..output.len() - 2]
+            } else {
+                &output
+            };
         let dst = self.get_out_dir();
 
         let mut objects = Vec::new();
@@ -591,15 +646,7 @@ impl Config {
                  .to_string_lossy()
                  .into_owned())
         };
-        if msvc && is_asm {
-            cmd.arg("/Fo").arg(dst);
-        } else if msvc {
-            let mut s = OsString::from("/Fo");
-            s.push(&dst);
-            cmd.arg(s);
-        } else {
-            cmd.arg("-o").arg(&dst);
-        }
+        command_add_output_file(&mut cmd, dst, msvc, is_asm);
         cmd.arg(if msvc { "/c" } else { "-c" });
         cmd.arg(file);
 
@@ -611,7 +658,8 @@ impl Config {
     /// This is only relevant for C and C++ files.
     ///
     /// # Panics
-    /// Panics if more than one file is present in the config.
+    /// Panics if more than one file is present in the config, or if compiler
+    /// path has an invalid file name.
     ///
     /// # Example
     /// ```no_run
@@ -1346,3 +1394,16 @@ fn fail(s: &str) -> ! {
     println!("\n\n{}\n\n", s);
     panic!()
 }
+
+
+fn command_add_output_file(cmd: &mut Command, dst: &Path, msvc: bool, is_asm: bool) {
+    if msvc && is_asm {
+        cmd.arg("/Fo").arg(dst);
+    } else if msvc {
+        let mut s = OsString::from("/Fo");
+        s.push(&dst);
+        cmd.arg(s);
+    } else {
+        cmd.arg("-o").arg(&dst);
+    }
+}

tests/test.rs

@@ -183,6 +183,20 @@ fn gnu_shared() {
         .must_not_have("-static");
 }
 
+#[test]
+fn gnu_flag_if_supported() {
+    let test = Test::gnu();
+    test.gcc()
+        .file("foo.c")
+        .flag_if_supported("-Wall")
+        .flag_if_supported("-Wflag-does-not-exist")
+        .compile("libfoo.a");
+
+    test.cmd(0)
+        .must_have("-Wall")
+        .must_not_have("-Wflag-does-not-exist");
+}
+
 #[test]
 fn gnu_static() {
     let test = Test::gnu();