Add a Builder::header_contents method to allow passing source code as a string to a Builder

Currently the Builder API requires input as header files on disk. This allows
passing C source directly to clang using the existing UnsavedFile struct.

Author: luser

src/clang.rs

@@ -1409,7 +1409,9 @@ impl Drop for Diagnostic {
 /// A file which has not been saved to disk.
 pub struct UnsavedFile {
     x: CXUnsavedFile,
-    name: CString,
+    /// The name of the unsaved file. Kept here to avoid leaving dangling pointers in
+    /// `CXUnsavedFile`.
+    pub name: CString,
     contents: CString,
 }
 
@@ -1431,6 +1433,15 @@ impl UnsavedFile {
     }
 }
 
+impl fmt::Debug for UnsavedFile {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt,
+               "UnsavedFile(name: {:?}, contents: {:?})",
+               self.name,
+               self.contents)
+    }
+}
+
 /// Convert a cursor kind into a static string.
 pub fn kind_to_str(x: CXCursorKind) -> String {
     unsafe { cxstring_into_string(clang_getCursorKindSpelling(x)) }

src/ir/context.rs

@@ -182,7 +182,7 @@ impl<'ctx> BindgenContext<'ctx> {
             clang::TranslationUnit::parse(&index,
                                           "",
                                           &options.clang_args,
-                                          &[],
+                                          &options.input_unsaved_files,
                                           parse_options)
                 .expect("TranslationUnit::parse failed");
 

src/lib.rs

@@ -175,6 +175,14 @@ impl Builder {
         self
     }
 
+    /// Add `contents` as an input C/C++ header named `name`.
+    ///
+    /// The file `name` will be added to the clang arguments.
+    pub fn header_contents(mut self, name: &str, contents: &str) -> Builder {
+        self.options.input_unsaved_files.push(clang::UnsavedFile::new(name, contents));
+        self
+    }
+
     /// Set the output graphviz file.
     pub fn emit_ir_graphviz<T: Into<String>>(mut self, path: T) -> Builder {
         let path = path.into();
@@ -573,6 +581,9 @@ pub struct BindgenOptions {
     /// The input header file.
     pub input_header: Option<String>,
 
+    /// Unsaved files for input.
+    pub input_unsaved_files: Vec<clang::UnsavedFile>,
+
     /// Generate a dummy C/C++ file that includes the header and has dummy uses
     /// of all types defined therein. See the `uses` module for more.
     pub dummy_uses: Option<String>,
@@ -662,6 +673,7 @@ impl Default for BindgenOptions {
             raw_lines: vec![],
             clang_args: vec![],
             input_header: None,
+            input_unsaved_files: vec![],
             dummy_uses: None,
             parse_callbacks: None,
             codegen_config: CodegenConfig::all(),
@@ -754,6 +766,10 @@ impl<'ctx> Bindings<'ctx> {
             options.clang_args.push(h.clone())
         }
 
+        for f in options.input_unsaved_files.iter() {
+            options.clang_args.push(f.name.to_str().unwrap().to_owned())
+        }
+
         let mut context = BindgenContext::new(options);
         try!(parse(&mut context));
 

tests/tests.rs

@@ -3,7 +3,7 @@ extern crate diff;
 extern crate bindgen;
 extern crate shlex;
 
-use bindgen::Builder;
+use bindgen::{Builder, builder};
 use std::fs;
 use std::io::{BufRead, BufReader, Error, ErrorKind, Read, Write};
 use std::path::PathBuf;
@@ -144,3 +144,19 @@ macro_rules! test_header {
 
 // This file is generated by build.rs
 include!(concat!(env!("OUT_DIR"), "/tests.rs"));
+
+#[test]
+fn test_header_contents() {
+    let bindings = builder()
+        .header_contents("test.h", "int foo(const char* a);")
+        .no_unstable_rust()
+        .generate()
+        .unwrap()
+        .to_string();
+    assert_eq!(bindings, "/* automatically generated by rust-bindgen */
+
+extern \"C\" {
+    pub fn foo(a: *const ::std::os::raw::c_schar) -> ::std::os::raw::c_int;
+}
+");
+}