Add flag to inject additional #include lines

cmd/src/main.rs

@@ -33,6 +33,10 @@ struct Opt {
     /// Emit header with declarations only
     #[structopt(long)]
     header: bool,
+
+    /// Any additional headers to #include
+    #[structopt(short, long)]
+    include: Vec<String>,
 }
 
 fn write(content: impl AsRef<[u8]>) {
@@ -42,9 +46,13 @@ fn write(content: impl AsRef<[u8]>) {
 fn main() {
     let opt = Opt::from_args();
 
+    let gen = gen::Opt {
+        include: opt.include,
+    };
+
     match (opt.input, opt.header) {
-        (Some(input), true) => write(gen::do_generate_header(&input)),
-        (Some(input), false) => write(gen::do_generate_bridge(&input)),
+        (Some(input), true) => write(gen::do_generate_header(&input, gen)),
+        (Some(input), false) => write(gen::do_generate_bridge(&input, gen)),
         (None, true) => write(include::HEADER),
         (None, false) => unreachable!(), // enforced by required_unless
     }

gen/include.rs

@@ -49,6 +49,12 @@ impl Includes {
     }
 }
 
+impl Extend<String> for Includes {
+    fn extend<I: IntoIterator<Item = String>>(&mut self, iter: I) {
+        self.custom.extend(iter);
+    }
+}
+
 impl Display for Includes {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         for include in &self.custom {

gen/mod.rs

@@ -36,17 +36,23 @@ struct Input {
     module: Vec<Item>,
 }
 
-pub(super) fn do_generate_bridge(path: &Path) -> OutFile {
+#[derive(Default)]
+pub(super) struct Opt {
+    /// Any additional headers to #include
+    pub include: Vec<String>,
+}
+
+pub(super) fn do_generate_bridge(path: &Path, opt: Opt) -> OutFile {
     let header = false;
-    generate(path, header)
+    generate(path, opt, header)
 }
 
-pub(super) fn do_generate_header(path: &Path) -> OutFile {
+pub(super) fn do_generate_header(path: &Path, opt: Opt) -> OutFile {
     let header = true;
-    generate(path, header)
+    generate(path, opt, header)
 }
 
-fn generate(path: &Path, header: bool) -> OutFile {
+fn generate(path: &Path, opt: Opt, header: bool) -> OutFile {
     let source = match fs::read_to_string(path) {
         Ok(source) => source,
         Err(err) => format_err(path, "", Error::Io(err)),
@@ -57,7 +63,7 @@ fn generate(path: &Path, header: bool) -> OutFile {
         let apis = syntax::parse_items(bridge.module)?;
         let types = Types::collect(&apis)?;
         check::typecheck(&apis, &types)?;
-        let out = write::gen(bridge.namespace, &apis, &types, header);
+        let out = write::gen(bridge.namespace, &apis, &types, opt, header);
         Ok(out)
     })() {
         Ok(out) => out,

gen/write.rs

@@ -1,10 +1,16 @@
-use crate::gen::include;
 use crate::gen::out::OutFile;
+use crate::gen::{include, Opt};
 use crate::syntax::atom::Atom::{self, *};
 use crate::syntax::{Api, ExternFn, Struct, Type, Types, Var};
 use proc_macro2::Ident;
 
-pub(super) fn gen(namespace: Vec<String>, apis: &[Api], types: &Types, header: bool) -> OutFile {
+pub(super) fn gen(
+    namespace: Vec<String>,
+    apis: &[Api],
+    types: &Types,
+    opt: Opt,
+    header: bool,
+) -> OutFile {
     let mut out_file = OutFile::new(namespace.clone(), header);
     let out = &mut out_file;
 
@@ -12,6 +18,7 @@ pub(super) fn gen(namespace: Vec<String>, apis: &[Api], types: &Types, header: b
         writeln!(out, "#pragma once");
     }
 
+    out.include.extend(opt.include);
     for api in apis {
         if let Api::Include(include) = api {
             out.include.insert(include.value());

src/lib.rs

@@ -383,6 +383,7 @@ pub mod private {
 }
 
 use crate::error::Result;
+use crate::gen::Opt;
 use anyhow::anyhow;
 use std::fs;
 use std::io::{self, Write};
@@ -465,13 +466,13 @@ impl Build {
 }
 
 fn try_generate_bridge(rust_source_file: &Path) -> Result<cc::Build> {
-    let header = gen::do_generate_header(rust_source_file);
+    let header = gen::do_generate_header(rust_source_file, Opt::default());
     let header_path = paths::out_with_extension(rust_source_file, ".h")?;
     fs::create_dir_all(header_path.parent().unwrap())?;
     fs::write(&header_path, header)?;
     paths::symlink_header(&header_path, rust_source_file);
 
-    let bridge = gen::do_generate_bridge(rust_source_file);
+    let bridge = gen::do_generate_bridge(rust_source_file, Opt::default());
     let bridge_path = paths::out_with_extension(rust_source_file, ".cc")?;
     fs::write(&bridge_path, bridge)?;
     let mut build = paths::cc_build();