Drop the cmake build time dependency by building libh3 with the cc crate

.github/workflows/ci.yml

@@ -14,7 +14,10 @@ on:
 
 jobs:
   lint:
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, windows-latest, macos-latest ]
+    runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout
         uses: actions/checkout@v1
@@ -27,7 +30,8 @@ jobs:
       - name: Install GDAL
         run: |
           sudo apt-get update
-          sudo apt-get install cmake libgdal-dev
+          sudo apt-get install libgdal-dev
+        if: matrix.os == 'ubuntu-latest'
 
       - name: Install latest stable
         uses: actions-rs/toolchain@v1
@@ -46,13 +50,24 @@ jobs:
         with:
           command: clippy
           args: --all-targets --all-features
+        if: matrix.os == 'ubuntu-latest'
 
       - name: Test with cargo
         uses: actions-rs/cargo@v1.0.1
         with:
           command: test
           toolchain: stable
           args: --workspace --all-features --all-targets
+        if: matrix.os == 'ubuntu-latest'
+
+      - name: Test with cargo
+        uses: actions-rs/cargo@v1.0.1
+        with:
+          command: test
+          toolchain: stable
+          # no gdal available
+          args: --workspace --exclude "h3ron-ndarray"
+        if: matrix.os != 'ubuntu-latest'
 
 #
 #  rust-publish:

h3ron-h3-sys/CHANGES.md

@@ -12,6 +12,8 @@ python extension.
 
 ## h3ron-h3-sys Unreleased
 
+* Drop the `cmake` build time dependency by building `libh3` with the `cc` crate.
+
 ## h3ron-h3-sys 0.14.0 - 2022-08-23
 
 * Upgrade to h3 v4.0.0

h3ron-h3-sys/Cargo.toml

@@ -11,14 +11,19 @@ readme = "README.md"
 homepage = "https://github.com/nmandery/h3ron"
 repository = "https://github.com/nmandery/h3ron"
 exclude = [
-    "libh3/docs",
+    "libh3/cmake",
+    "libh3/CMakeLists.txt",
+    "libh3/CMakeTests.cmake",
     "libh3/dev-docs",
-    "libh3/website",
-    "libh3/src/apps",
-    "libh3/tests",
+    "libh3/docs",
     "libh3/examples",
     "libh3/.git",
     "libh3/.github",
+    "libh3/KML",
+    "libh3/scripts",
+    "libh3/src/apps",
+    "libh3/tests",
+    "libh3/website",
 ]
 
 [package.metadata.docs.rs]
@@ -32,5 +37,6 @@ optional = true
 
 [build-dependencies]
 bindgen = "^0.60"
-cmake = "^0.1"
 regex = "^1.5.5"
+cc = "1"
+glob = "0.3"

h3ron-h3-sys/README.md

@@ -8,4 +8,4 @@ bindgen-generated [rust](https://rust-lang.org) bindings for [H3](https://uber.g
 
 These bindings are basically just the autogenerated bindings emitted by [bindgen](https://github.com/rust-lang/rust-bindgen). The bindings
 compile using the included (referenced via a git submodule) H3 source code. H3 will be statically linked into the binary, so there is
-no need to install a system-wide libh3. For the build `cmake` is required.
+no need to install a system-wide libh3.

h3ron-h3-sys/build.rs

@@ -1,47 +1,75 @@
 extern crate bindgen;
-extern crate cmake;
 extern crate regex;
 
-use cmake::Config;
+use glob::glob;
 use regex::Regex;
 use std::env;
-use std::fs;
+use std::fs::{create_dir_all, read_to_string, OpenOptions};
+use std::io::Write;
 use std::path::PathBuf;
 
+fn h3_version() -> (String, String, String) {
+    let version_contents = read_to_string("libh3/VERSION").unwrap();
+    let cap = Regex::new("^(?P<mj>[0-9]+)\\.(?P<mn>[0-9]+)\\.(?P<pt>[0-9]+)")
+        .unwrap()
+        .captures(&version_contents)
+        .expect("version number not found");
+    (
+        cap["mj"].to_string(),
+        cap["mn"].to_string(),
+        cap["pt"].to_string(),
+    )
+}
+
+fn configure_header() -> (PathBuf, PathBuf) {
+    let mut include_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    include_dir.push("include");
+    create_dir_all(&include_dir).unwrap();
+
+    let (version_major, version_minor, version_patch) = h3_version();
+    let header_contents = read_to_string("libh3/src/h3lib/include/h3api.h.in")
+        .unwrap()
+        .replace("@H3_VERSION_MAJOR@", &version_major)
+        .replace("@H3_VERSION_MINOR@", &version_minor)
+        .replace("@H3_VERSION_PATCH@", &version_patch);
+    let mut h3api_header = include_dir.clone();
+    h3api_header.push("h3api.h");
+    write!(
+        OpenOptions::new()
+            .create(true)
+            .truncate(true)
+            .write(true)
+            .open(&h3api_header)
+            .unwrap(),
+        "{}",
+        header_contents
+    )
+    .unwrap();
+
+    (include_dir, h3api_header)
+}
+
 fn main() {
     println!("cargo:rerun-if-changed=libh3");
+    let (configured_includes, h3api_header) = configure_header();
 
-    // build h3ron as a static library
-    let dst_path = Config::new("libh3")
-        .define("BUILD_BENCHMARKS", "OFF")
-        .define("BUILD_FILTERS", "OFF")
-        .define("BUILD_GENERATORS", "OFF")
-        .define("BUILD_TESTING", "OFF")
-        .define("BUILD_FUZZERS", "OFF")
-        .define("ENABLE_COVERAGE", "OFF")
-        .define("ENABLE_DOCS", "OFF")
-        .define("ENABLE_FORMAT", "OFF")
-        .define("ENABLE_LINTING", "OFF")
-        .build();
-
-    // link to the static library we just build
-    println!("cargo:rustc-link-lib=static=h3");
-    println!(
-        "cargo:rustc-link-search=native={}",
-        dst_path.join("lib").display()
-    );
+    cc::Build::new()
+        .include("libh3/src/h3lib/include")
+        .include(configured_includes)
+        .files(glob("libh3/src/h3lib/lib/*.c").unwrap().map(|p| p.unwrap()))
+        .compile("h3");
 
-    let header_path = dst_path.join("include/h3/h3api.h");
     let mut builder = bindgen::Builder::default().header(
-        dst_path
-            .join("include/h3/h3api.h")
-            .into_os_string()
+        h3api_header
+            .as_path()
+            .as_os_str()
+            .to_owned()
             .into_string()
             .expect("Path could not be converted to string"),
     );
 
     // read the contents of the header to extract functions and types
-    let header_contents = fs::read_to_string(header_path).expect("Unable to read h3 header");
+    let header_contents = read_to_string(h3api_header).expect("Unable to read h3 header");
     for cap in Regex::new(r"H3_EXPORT\(\s*(?P<func>[a-zA-Z0-9_]+)\s*\)")
         .unwrap()
         .captures_iter(&header_contents)