multiple() args should only take 1 value

If multiple() args take more than 1 value, they'll consume positional
arguments not intended to be values. This was causing `--raw-line ""
header.h` to break option parsing.

(Excluding cflags_args, which is for positional arguments after the end
of options marker, `--`.)

Author: jdub

src/lib.rs

@@ -128,7 +128,7 @@ pub fn builder() -> Builder {
 pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::Error>
     where I: Iterator<Item=String>
 {
-    let mmm = App::new("bindgen")
+    let matches = App::new("bindgen")
         .version(env!("CARGO_PKG_VERSION"))
         .about("Generates Rust bindings from C/C++ headers.")
         .usage("bindgen [FLAGS] [OPTIONS] <header> -- <clang-args>...")
@@ -141,13 +141,15 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .help("Mark any enum whose name matches <regex> as a set of bitfield flags instead of an enumeration.")
                 .value_name("regex")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("blacklist-type")
                 .long("blacklist-type")
                 .help("Mark a type as hidden.")
                 .value_name("type")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("builtins")
                 .long("builtins")
                 .help("Output bindings for builtin definitions, e.g. __builtin_va_list."),
@@ -156,6 +158,7 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .help("Use the given prefix before raw types instead of ::std::os::raw.")
                 .value_name("prefix")
                 .takes_value(true),
+            // All positional arguments after the end of options marker, `--`
             Arg::with_name("clang-args")
                 .multiple(true),
             Arg::with_name("dummy-uses")
@@ -172,7 +175,8 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .long("framework-link")
                 .help("Link to framework.")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("ignore-functions")
                 .long("ignore-functions")
                 .help("Do not generate bindings for functions or methods. This is useful when you only care about struct layouts."),
@@ -184,7 +188,8 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .long("link")
                 .help("Link to dynamic library.")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("no-unstable-rust")
                 .long("no-unstable-rust")
                 .help("Do not generate unstable Rust code."),
@@ -193,7 +198,8 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .help("Mark a type as opaque.")
                 .value_name("type")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("output")
                 .short("o")
                 .long("output")
@@ -203,12 +209,14 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .long("raw-line")
                 .help("Add a raw line of Rust code at the beginning of output.")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("static")
                 .long("static-link")
                 .help("Link to static library.")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("use-core")
                 .long("use-core")
                 .help("Use types from Rust core instead of std."),
@@ -220,28 +228,24 @@ pub fn builder_from_flags<I>(args: I) -> Result<(Builder, Box<io::Write>), io::E
                 .help("Whitelist all the free-standing functions matching <regex>. Other non-whitelisted functions will not be generated.")
                 .value_name("regex")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("whitelist-type")
                 .long("whitelist-type")
                 .help("Whitelist the type. Other non-whitelisted types will not be generated.")
                 .value_name("type")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
             Arg::with_name("whitelist-var")
                 .long("whitelist-var")
                 .help("Whitelist all the free-standing variables matching <regex>. Other non-whitelisted variables will not be generated.")
                 .value_name("regex")
                 .takes_value(true)
-                .multiple(true),
+                .multiple(true)
+                .number_of_values(1),
         ]) // .args()
-        .get_matches_from_safe(args);
-
-    match mmm {
-        Ok(ref m) => println!("{:#?}", m),
-        Err(ref e) => println!("{:#?}", e)
-    };
-
-    let matches = mmm.unwrap();
+        .get_matches_from(args);
 
     let mut builder = builder();