Add tests with re2 and compiler feature detection.

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "re2"]
+	path = re2
+	url = https://github.com/google/re2/

Cargo.toml

@@ -5,4 +5,9 @@ edition = "2021"
 build = "src/build.rs"
 
 [build-dependencies]
+cc = "1.0.73"
 cmake = "0.1"
+
+[features]
+std = []
+re2 = ["std"]

README.md

@@ -2,6 +2,8 @@
 
 > Minimal example of using CMake from Rust
 
+This tests compiler feature detection, as well as more complicated examples with thread support when the `re2` feature is enabled.
+
 ## License
 
 Licensed under either of

libsum/CMakeLists.txt

@@ -4,3 +4,5 @@ project(sum)
 add_library(sum sum.c)
 target_include_directories(sum PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 install(TARGETS sum DESTINATION lib)
+
+target_compile_features(sum PUBLIC cxx_std_11)

match.cc

@@ -0,0 +1,9 @@
+#include <re2/re2.h>
+
+extern "C" {
+  bool is_match(const char* pattern, const char* string) {
+    re2::StringPiece regex(pattern);
+    re2::StringPiece input(string);
+    return re2::RE2::FullMatch(input, regex);
+  }
+}

src/bin/hello.rs

@@ -1,5 +1,17 @@
+#[cfg(feature = "re2")]
+use rust_cmake_hello_world::hello_is_match;
 use rust_cmake_hello_world::multiply_add;
 
 pub fn main() {
     println!("multiply_add(2, 3, 4)={:?}", multiply_add(2, 3, 4));
+    #[cfg(feature = "re2")]
+    {
+        let pattern = "Hello.*";
+        let input = "Hello World";
+        let matches = match hello_is_match(pattern, input) {
+            true => "matches",
+            false => "does not match",
+        };
+        println!("{pattern:?} {matches} the input {input:?}");
+    }
 }

src/build.rs

@@ -1,7 +1,30 @@
 use cmake;
 
 fn main() {
+    println!("cargo:rerun-if-changed=src/build.rs");
+
+    build_sum();
+    build_re2();
+}
+
+fn build_sum() {
     let dst = cmake::build("libsum");
     println!("cargo:rustc-link-search=native={}/lib", dst.display());
     println!("cargo:rustc-link-lib=static=sum");
 }
+
+fn build_re2() {
+    if cfg!(feature = "re2") {
+        let dst = cmake::build("re2");
+
+        cc::Build::new()
+            .cpp(true)
+            .file("match.cc")
+            .include(dst.join("include"))
+            .compile("libmatch.a");
+
+        println!("cargo:rerun-if-changed=match.cc");
+        println!("cargo:rustc-link-search=native={}/build", dst.display());
+        println!("cargo:rustc-link-lib=static=re2");
+    }
+}

src/lib.rs

@@ -1,4 +1,10 @@
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(feature = "re2")]
+mod re2;
+
+#[cfg(feature = "re2")]
+pub use self::re2::hello_is_match;
 
 pub fn multiply_add(x: i32, y: i32, z: i32) -> i32 {
     x * unsafe { sum(y, z) }

src/re2.rs

@@ -0,0 +1,14 @@
+#![cfg(feature = "re2")]
+
+use std::ffi::CString;
+use std::os::raw::c_char;
+
+pub fn hello_is_match(pattern: &str, input: &str) -> bool {
+    let pattern = CString::new(pattern).unwrap();
+    let input = CString::new(input).unwrap();
+    unsafe { is_match(pattern.as_ptr(), input.as_ptr()) }
+}
+
+extern "C" {
+    fn is_match(pattern: *const c_char, string: *const c_char) -> bool;
+}