fix: use CFLAGS from Makefile

Author: ensh63

nginx-sys/build/main.rs

@@ -192,7 +192,8 @@ impl NginxSource {
 /// Generates Rust bindings for NGINX
 fn generate_binding(nginx: &NginxSource) {
     let autoconf_makefile_path = nginx.build_dir.join("Makefile");
-    let includes: Vec<_> = parse_includes_from_makefile(&autoconf_makefile_path)
+    let (includes, defines) = parse_makefile(&autoconf_makefile_path);
+    let includes: Vec<_> = includes
         .into_iter()
         .map(|path| {
             if path.is_absolute() {
@@ -207,7 +208,7 @@ fn generate_binding(nginx: &NginxSource) {
         .map(|path| format!("-I{}", path.to_string_lossy()))
         .collect();
 
-    print_cargo_metadata(nginx, &includes).expect("cargo dependency metadata");
+    print_cargo_metadata(nginx, &includes, &defines).expect("cargo dependency metadata");
 
     // bindgen targets the latest known stable by default
     let rust_target: bindgen::RustTarget = env::var("CARGO_PKG_RUST_VERSION")
@@ -243,20 +244,27 @@ fn generate_binding(nginx: &NginxSource) {
 /// Reads through the makefile generated by autoconf and finds all of the includes
 /// used to compile nginx. This is used to generate the correct bindings for the
 /// nginx source code.
-fn parse_includes_from_makefile(nginx_autoconf_makefile_path: &PathBuf) -> Vec<PathBuf> {
-    fn extract_include_part(line: &str) -> &str {
-        line.strip_suffix('\\').map_or(line, |s| s.trim())
-    }
-    /// Extracts the include path from a line of the autoconf generated makefile.
-    fn extract_after_i_flag(line: &str) -> Option<&str> {
-        let mut parts = line.split("-I ");
-        match parts.next() {
-            Some(_) => parts.next().map(extract_include_part),
-            None => None,
+pub fn parse_makefile(
+    nginx_autoconf_makefile_path: &PathBuf,
+) -> (Vec<PathBuf>, Vec<(String, Option<String>)>) {
+    fn add_includes(includes: &mut Vec<String>, line: &str) {
+        let mut words = line.split_ascii_whitespace();
+        while let Some(word) = words.next() {
+            if word == "-I" {
+                if let Some(inc) = words.next() {
+                    includes.push(inc.to_string());
+                }
+            } else if let Some(inc) = word.strip_prefix("-I") {
+                includes.push(inc.to_string());
+            }
         }
     }
 
     let mut includes = vec![];
+    let mut cflags_includes = vec![];
+
+    let mut defines = vec![];
+
     let makefile_contents = match read_to_string(nginx_autoconf_makefile_path) {
         Ok(path) => path,
         Err(e) => {
@@ -268,35 +276,47 @@ fn parse_includes_from_makefile(nginx_autoconf_makefile_path: &PathBuf) -> Vec<P
         }
     };
 
-    let mut includes_lines = false;
-    for line in makefile_contents.lines() {
-        if !includes_lines {
-            if let Some(stripped) = line.strip_prefix("ALL_INCS") {
-                includes_lines = true;
-                if let Some(part) = extract_after_i_flag(stripped) {
-                    includes.push(part);
-                }
-                continue;
-            }
+    let lines = makefile_contents.lines();
+    let mut line: String = "".to_string();
+    for l in lines {
+        if let Some(part) = l.strip_suffix("\\") {
+            line += part;
+            continue;
         }
 
-        if includes_lines {
-            if let Some(part) = extract_after_i_flag(line) {
-                includes.push(part);
-            } else {
-                break;
+        line += l;
+
+        if let Some(tail) = line.strip_prefix("ALL_INCS") {
+            add_includes(&mut includes, tail);
+        } else if let Some(tail) = line.strip_prefix("CFLAGS") {
+            add_includes(&mut cflags_includes, tail);
+
+            let words = line.split_ascii_whitespace();
+            for word in words {
+                if let Some(def) = word.strip_prefix("-D") {
+                    if let Some((name, value)) = def.split_once("=") {
+                        defines.push((name.to_string(), Some(value.to_string())));
+                    } else {
+                        defines.push((def.to_string(), None));
+                    }
+                }
             }
         }
+
+        line.clear();
     }
 
-    includes.into_iter().map(PathBuf::from).collect()
+    includes.append(&mut cflags_includes);
+
+    (includes.into_iter().map(PathBuf::from).collect(), defines)
 }
 
 /// Collect info about the nginx configuration and expose it to the dependents via
 /// `DEP_NGINX_...` variables.
 pub fn print_cargo_metadata<T: AsRef<Path>>(
     nginx: &NginxSource,
     includes: &[T],
+    defines: &[(String, Option<String>)],
 ) -> Result<(), Box<dyn StdError>> {
     // Unquote and merge C string constants
     let unquote_re = regex::Regex::new(r#""(.*?[^\\])"\s*"#).unwrap();
@@ -311,7 +331,7 @@ pub fn print_cargo_metadata<T: AsRef<Path>>(
     let mut ngx_features: Vec<String> = vec![];
     let mut ngx_os = String::new();
 
-    let expanded = expand_definitions(includes)?;
+    let expanded = expand_definitions(includes, defines)?;
     for line in String::from_utf8(expanded)?.lines() {
         let Some((name, value)) = line
             .trim()
@@ -372,7 +392,10 @@ pub fn print_cargo_metadata<T: AsRef<Path>>(
     Ok(())
 }
 
-fn expand_definitions<T: AsRef<Path>>(includes: &[T]) -> Result<Vec<u8>, Box<dyn StdError>> {
+fn expand_definitions<T: AsRef<Path>>(
+    includes: &[T],
+    defines: &[(String, Option<String>)],
+) -> Result<Vec<u8>, Box<dyn StdError>> {
     let path = PathBuf::from(env::var("OUT_DIR")?).join("expand.c");
     let mut writer = std::io::BufWriter::new(File::create(&path)?);
 
@@ -418,8 +441,13 @@ RUST_CONF_{flag}=NGX_{flag}
     writer.flush()?;
     drop(writer);
 
-    Ok(cc::Build::new()
-        .includes(includes)
-        .file(path)
-        .try_expand()?)
+    let mut builder = cc::Build::new();
+
+    builder.includes(includes).file(path);
+
+    for def in defines {
+        builder.define(&def.0, def.1.as_deref());
+    }
+
+    Ok(builder.try_expand()?)
 }