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Hack the MagickWand bindings

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Using rust-bindgen to generate the bindings for the MagickWand library is
extremely difficult with the new versions of rust-bindgen. The old versions
of the generated bindings will be used for now, and nothing will be
generated at build time.

cargo test passes
This commit is contained in:
Nathan Fiedler 2017-04-06 19:58:58 -07:00
parent f4843c246c
commit b22e97c908
4 changed files with 8169 additions and 91 deletions
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3
Cargo.toml
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@ -12,3 +12,6 @@ build = "build.rs"
[dependencies]
libc = ">=0.2"
# [build-dependencies]
# bindgen = "0.22.1"

0
bindings.rs → bindings_freebsd.rs
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8097
bindings_macos.rs Normal file
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File diff suppressed because it is too large Load diff

160
build.rs
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@ -13,104 +13,71 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// extern crate bindgen;
use std::env;
use std::fs::{copy, File};
use std::io::prelude::*;
use std::path::{Path, PathBuf};
use std::process::Command;
use std::process::{Command, Stdio};
// use bindgen::Builder;
static HEADER: &'static str = "#include <wand/MagickWand.h>\n";
static LIBPATH: &'static str = "/Library/Developer/CommandLineTools/usr/lib";
// static HEADER: &'static str = "#include <wand/MagickWand.h>\n";
// static LIBPATH: &'static str = "/Library/Developer/CommandLineTools/usr/lib";
fn run_bindgen(out_dir: String, bindings_path_str: &str) {
// Install rust-bindgen so we can generate the bindings. While the
// bindgen crate is nice, it does not appear to support setting
// environment variables like DYLD_LIBRARY_PATH.
let home_dir = env::home_dir().expect("home directory");
let mut cargo_bin = PathBuf::from(home_dir);
cargo_bin.push(".cargo");
cargo_bin.push("bin");
cargo_bin.push("bindgen");
println!("BINDGEN_PATH={:?}", cargo_bin);
if !cargo_bin.exists() {
Command::new("cargo")
.arg("install")
.arg("bindgen")
.status().expect("cargo install bindgen");
}
// fn run_bindgen(out_dir: &PathBuf, bindings_path_str: &PathBuf) {
// // Get the compiler flags for the MagickWand library.
// let mw_cflags_output = Command::new("pkg-config")
// .arg("--cflags")
// .arg("MagickWand")
// .output().expect("pkg-config --cflags MagickWand");
// let mw_cflags = std::str::from_utf8(&mw_cflags_output.stdout).unwrap().trim();
// println!("CFLAGS={:?}", mw_cflags);
// Get the compiler flags for the MagickWand library.
let mw_cflags_output = Command::new("pkg-config")
.arg("--cflags")
.arg("MagickWand")
.output().expect("pkg-config --cflags MagickWand");
let mw_cflags = std::str::from_utf8(&mw_cflags_output.stdout).unwrap().trim();
let mw_cflags_arr: Vec<&str> = mw_cflags.split_whitespace().collect();
println!("CFLAGS={:?}", mw_cflags_arr);
// // Extract the library name for use with the --link option below.
// // This just happens to be the first argument from the output of
// // pkg-config when given the --libs-only-l option. We lop off the
// // leading "-l" since we only need the name (e.g. "MagickWand-6").
// let mw_ldflags_output = Command::new("pkg-config")
// .arg("--libs-only-l")
// .arg("MagickWand")
// .output().expect("pkg-config --libs-only-l MagickWand");
// let mw_ldflags = std::str::from_utf8(&mw_ldflags_output.stdout).unwrap().trim();
// println!("LDFLAGS={:?}", mw_ldflags);
// let mw_ldflags_arr: Vec<&str> = mw_ldflags.split_whitespace().collect();
// let link_arg = &mw_ldflags_arr[0][2..];
// Extract the library name for use with the --link option below.
// This just happens to be the first argument from the output of
// pkg-config when given the --libs-only-l option. We lop off the
// leading "-l" since we only need the name (e.g. "MagickWand-6").
let mw_ldflags_output = Command::new("pkg-config")
.arg("--libs-only-l")
.arg("MagickWand")
.output().expect("pkg-config --libs-only-l MagickWand");
let mw_ldflags = std::str::from_utf8(&mw_ldflags_output.stdout).unwrap().trim();
let mw_ldflags_arr: Vec<&str> = mw_ldflags.split_whitespace().collect();
let link_arg = &mw_ldflags_arr[0][2..];
// let gen_h_path = out_dir.join("gen.h");
// // Create the header file that rust-bindgen needs as input.
// let mut gen_h = File::create(&gen_h_path).expect("could not create file");
// gen_h.write_all(HEADER.as_bytes()).expect("could not write header file");
let gen_h_path = out_dir.clone() + "/gen.h";
// Create the header file that rust-bindgen needs as input.
let mut gen_h = File::create(&gen_h_path).expect("could not create file");
gen_h.write_all(HEADER.as_bytes()).expect("could not write header file");
// // TODO: is this still needed for MacOS?
// // cmd.env("DYLD_LIBRARY_PATH", LIBPATH);
// // TODO: need to fix the Rust enums (i.e. no more "--no-rust-enums" option)
// // TODO: is this still needed for MacOS?
// // // Work around issue #361 in rust-bindgen for the time being.
// // cmd.arg("-U__BLOCKS__");
// let bindings = Builder::default()
// .emit_builtins()
// .no_unstable_rust()
// .ctypes_prefix("libc")
// .header(gen_h_path.to_str().unwrap())
// .clang_arg(mw_cflags)
// .link(link_arg)
// .generate()
// .expect("Unable to generate bindings");
// bindings
// .write_to_file(bindings_path_str)
// .expect("could not write bindings");
// Combine all of that in the invocation of rust-bindgen.
let mut cmd = &mut Command::new(cargo_bin);
if cfg!(target_os = "macos") {
// Mac requires that the xcode tools are installed so that
// rustc can find the clang.dylib file. See also issue
// https://github.com/crabtw/rust-bindgen/issues/89
let lib_path = Path::new(LIBPATH);
if !lib_path.exists() {
panic!("missing {}, run xcode-select --install", LIBPATH);
}
cmd.env("DYLD_LIBRARY_PATH", LIBPATH);
}
let mut output_arg = String::from("--output");
output_arg.push('=');
output_arg.push_str(&bindings_path_str);
cmd.arg("--builtins")
// For the time being, avoid switching to proper Rust enums, as
// that would change quite a bit of the existing code. We can
// change that at a later time, and then remove this option.
.arg("--no-rust-enums")
// There are a few places where our code is still using `libc::`
// types, rather than the new default `std::os::raw` types. We
// can switch at a later time and then remove this option.
.arg("--ctypes-prefix=libc")
// Inform bindgen of the library to which we are linking,
// otherwise it may compile but the tests will fail to link
// properly. The -L and -l arguments provided by pkg-config
// apparently go unused with (newer versions of?) clang.
.arg(format!("--link={}", link_arg))
.arg(output_arg)
.arg(&gen_h_path)
.arg("--");
if cfg!(target_os = "macos") {
// Work around issue #361 in rust-bindgen for the time being.
cmd.arg("-U__BLOCKS__");
}
cmd.args(&mw_cflags_arr[..]);
println!("BINDING_GENERATION={:?}", cmd);
cmd.status().expect("rust-bindgen invocation");
std::fs::remove_file(&gen_h_path).expect("could not remove header file");
}
// std::fs::remove_file(&gen_h_path).expect("could not remove header file");
// }
fn assert_mw_version() {
// This build script depeneds heavily on the pkg-config utility.
if !Command::new("which")
.stdout(Stdio::null())
.arg("pkg-config")
.status().unwrap().success() {
panic!("Cannot find pkg-config, see the README");
@ -151,18 +118,29 @@ fn main() {
// If the MagickWand bindings are missing, generate them using
// rust-bindgen.
//
let out_dir = ::std::env::var("OUT_DIR").unwrap();
let bindings_path_str = out_dir.clone() + "/bindings.rs";
let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
let bindings_path_str = out_dir.join("bindings.rs");
if !Path::new(&bindings_path_str).exists() {
// Either generate the bindings.rs or copy an already generated
// version for FreeBSD. See rust-bindgen issue #385 for details. We
// also need to hack the library path to `cargo test` can find the
// MagickWand libraries.
//
// TODO: binding generation is broken
//
// Using rust-bindgen has become much too difficult for generating
// MagickWand bindings. There are numerous problems, not the least
// of which is I cannot get it to find the MagickWand headers.
//
if cfg!(target_os = "freebsd") {
copy("bindings.rs", &bindings_path_str).expect("cp bindings.rs to out_dir");
copy("bindings_freebsd.rs", &bindings_path_str).expect("cp bindings.rs to out_dir");
// We need to hack the library path to `cargo test` can find
// the MagickWand libraries.
println!("cargo:rustc-link-search=native=/usr/local/lib");
} else if cfg!(target_os = "macos") {
copy("bindings_macos.rs", &bindings_path_str).expect("cp bindings.rs to out_dir");
// We need to hack the library path to `cargo test` can find
// the MagickWand libraries.
println!("cargo:rustc-link-search=native=/usr/local/lib");
} else {
run_bindgen(out_dir, &bindings_path_str);
// run_bindgen(&out_dir, &bindings_path_str);
panic!("Sorry, no bindings for you.");
}
// Work around the include! issue in rustc (as described in the
// rust-bindgen README file) by wrapping the generated code in a