Got initial unsafe bindings working. See comments.

- This now builds the bindings (still with cbindgen in build.rs,
  will change that in a bit) and links to them successfully. Everything
  currently points to the master branch at Gekkio/imgui-rs, because
  there has not been a release yet with the PR merged that exposes
  the defines in the sys crate.

- I have now included a little demo crate that calls into the unsafe
  generated bindings as a proof of concept. Next there will need to
  be safe and more Rust-y bindings written around this, just like
  imgui-rs has them.

implot-sys/Cargo.toml

@@ -7,6 +7,7 @@ description = "Raw FFI bindings to implot"
 license = "MIT/Apache-2.0"
 categories = ["gui", "external-ffi-bindings"]
 build = "build.rs"
+links = "implot"
 
 [dependencies]
 imgui-sys = { git = "https://github.com/Gekkio/imgui-rs/", branch = "master" }

implot-sys/build.rs

@@ -5,7 +5,7 @@
 // for now, but expected to diverge from that over time.
 use std::{env, fs, io, path::Path};
 
-//use bindgen; // Not used anymore, TODO(4bb4) remove
+use bindgen;
 
 const CPP_FILES: [&str; 2] = [
     "third-party/cimplot/cimplot.cpp",
@@ -45,8 +45,8 @@ fn main() -> io::Result<()> {
     let cimgui_include_path =
         env::var_os("DEP_IMGUI_THIRD_PARTY").expect("DEP_IMGUI_THIRD_PARTY not defined");
     let imgui_include_path = Path::new(&cimgui_include_path).join("imgui");
-    build.include(cimgui_include_path);
-    build.include(imgui_include_path);
+    build.include(&cimgui_include_path);
+    build.include(&imgui_include_path);
 
     // Taken from the imgui-sys build as well
     build.flag_if_supported("-Wno-return-type-c-linkage");
@@ -58,21 +58,20 @@ fn main() -> io::Result<()> {
     build.compile("cimplot");
 
     // --- Create bindgen bindings
-    // TODO(4bb4) move this out to separate shell script (see #1)
-    // The actual generate() errors out right now with parsing errors,
-    // will probably need to whiltelist things, fix preprocessor definitions,
-    // bindgen settings or some combination thereof.
-    //let _bindings = bindgen::Builder::default()
-    //.header(imgui_third_party.into_string().unwrap() + "/cimgui.h")
-    //.header("wrapper.h")
-    //.parse_callbacks(Box::new(bindgen::CargoCallbacks));
-    //.generate()
-    //.expect("Unable to generate bindings");
+    // TODO(4bb4) move this out to separate shell script (see #1) so users don't have
+    // to have clang installed to build this crate.
+    let bindings = bindgen::Builder::default()
+        .header(&(cimgui_include_path.into_string().unwrap() + "/cimgui.h"))
+        .header("third-party/cimplot/cimplot.h")
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+        .clang_arg("-DCIMGUI_DEFINE_ENUMS_AND_STRUCTS=1")
+        .generate()
+        .expect("Unable to generate bindings");
 
-    //let out_path = std::path::PathBuf::from(env::var("OUT_DIR").unwrap());
-    //bindings
-    //.write_to_file(out_path.join("bindings.rs"))
-    //.expect("Couldn't write bindings!");
+    let out_path = std::path::PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
 
     Ok(())
 }

implot-sys/src/lib.rs

@@ -1,3 +1,7 @@
-fn _does_nothing() {
-    println!("This does nothing yet");
-}
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+
+// TODO(4bb4) change this to include the bindings we hand-generate
+// once that is happening
+include!(concat!(env!("OUT_DIR"), "/bindings.rs"));