main functionality done, working

Cargo.toml

@@ -6,5 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-clap = { version = "4.4.4", features = ["derive"] }
+clap = { version = "4.4.4", default_features = false, features = ["derive", "help", "usage", "std", "error-context", "suggestions"] }
 regex = "1.9.5"

src/main.rs

@@ -1,13 +1,14 @@
 use std::fs;
-use std::io::Read;
+use std::io::{Read, Write};
 use std::path::Path;
 use regex::Regex;
 use clap::Parser;
 
 #[derive(Debug)]
 struct CFile {
-    path: String,
-    filename: String,
+    file_path: String,
+    obj_path: String,
+    obj_name: String,
     headers: Vec<String>,
 }
 
@@ -17,29 +18,36 @@ struct Args {
     #[arg(short, long)]
     pretty: bool,
 
+    /// Path to makefile
+    #[arg(short, long, default_value = "./Makefile")]
+    makefile: String,
+    
+    /// Directory to place build files
     #[arg(default_value = "./build")]
     build_dir: String,
 }
 
-fn parse_c_file(path: &Path, re: &Regex) -> CFile {
-    let strpath = path.to_str().unwrap();
-    let filename = path.file_stem().unwrap().to_str().unwrap();
-
+fn parse_c_file(path: &Path, obj_dir: &Path, re: &Regex) -> CFile {
     let mut file_handle = fs::File::open(path).unwrap();
     let mut contents = String::new();
     file_handle.read_to_string(&mut contents).unwrap();
 
     let mut headers: Vec<String> = Vec::new();
-    let caps = re.captures_iter(&contents);
-    for (_, [include_file]) in caps.map(|c| c.extract()) {
+    let captures = re.captures_iter(&contents);
+    for (_, [include_file]) in captures.map(|c| c.extract()) {
         headers.push(path.parent().unwrap()
                          .join(Path::new(include_file))
                          .to_str().unwrap()
                          .to_string());
     }
 
-    return CFile { path: strpath.to_string(), filename: filename.to_string(), headers }
-
+    let obj_path = obj_dir.join(Path::new(path.file_name().unwrap()).with_extension("o"));
+    return CFile { 
+        file_path: path.to_str().unwrap().to_string(),
+        obj_path: obj_path.to_str().unwrap().to_string(),
+        obj_name: obj_path.file_name().unwrap().to_str().unwrap().to_string(),
+        headers
+    }
 }
 
 fn recurse_into_dir<F: FnMut(fs::DirEntry)>(path: &Path, file_callback: &mut F) {
@@ -66,14 +74,13 @@ fn recurse_into_dir<F: FnMut(fs::DirEntry)>(path: &Path, file_callback: &mut F)
 }
 
 fn main() {
-    let mut project_files: Vec<CFile> = Vec::new();
-    let includes_regex = Regex::new(r#"#include\s+"(.*?)""#).unwrap();
-
     let args = Args::parse();
     let build_dir = Path::new(&args.build_dir);
     let pretty = args.pretty;
 
+    let mut project_files: Vec<CFile> = Vec::new();
     let obj_dir = build_dir.join("obj");
+    let includes_regex = Regex::new(r#"#include\s+"(.*?)""#).unwrap();
 
     recurse_into_dir(Path::new("./"), &mut |file| {
         let path = file.path();
@@ -83,7 +90,7 @@ fn main() {
                 if v != "c" {
                     return;
                 }
-                project_files.push(parse_c_file(&path, &includes_regex));
+                project_files.push(parse_c_file(&path, &obj_dir, &includes_regex));
             },
             None => {
                 return;
@@ -91,21 +98,103 @@ fn main() {
         }
     });
 
+    if !Path::new(&args.makefile).exists() {
+        fs::File::create(&args.makefile).unwrap();
+    }
+
+    let mut makefile_handle = fs::OpenOptions::new()
+        .read(true)
+        .open(args.makefile.clone()).unwrap();
+    let mut makefile = String::new();
+    makefile_handle.read_to_string(&mut makefile).unwrap();
+
+    let start_key = "#=mgen_start=#";
+    let end_key = "#=mgen_end=#";
+
+    let mut build_rules = String::new();
+
+    build_rules.push_str(&start_key);
+
+    build_rules.push_str("\n");
+
+    let target_path = build_dir.join(Path::new("$(TARGET)"));
+    let target_path = target_path.to_str().unwrap();
+
+    build_rules.push_str(&format!("{}: ", target_path));
     for file in project_files.iter() {
-        let mut build_rule: String = "#=mgen_rule=#\n".to_owned();
+        build_rules.push_str(&format!(" {}", file.obj_path));
+    }
+    build_rules.push_str("\n");
 
-        let objname = file.filename.to_owned() + ".o";
-        let objpath = obj_dir.join(&objname);
-        let objpath = objpath.to_str().unwrap();
+    if pretty {
+        build_rules.push_str(&format!("\t@printf ':: Linking %s ... ' $(TARGET)\n"));
+    }
 
-        build_rule.push_str(&format!("{}: {}", objpath, file.path));
+    build_rules.push_str(&format!("\t{}$(CC) $(LDFLAGS) -o {} ", 
+                                 if pretty {"@"} else {""}, target_path));
+    for file in project_files.iter() {
+        build_rules.push_str(&format!(" {}", file.obj_path));
+    }
+    build_rules.push_str(" $(LDLIBS)\n");
+
+    if pretty {
+        build_rules.push_str(&format!("\t@printf 'done\\n'\n"));
+    }
+
+    for file in project_files.iter() {
+        let mut build_rule = String::new();
+
+        build_rule.push_str("\n");
+        
+        build_rule.push_str(&format!("{}: {}", file.obj_path, file.file_path));
         for header in file.headers.iter() {
             build_rule.push_str(&format!(" {}", header));
         }
+        build_rule.push_str("\n");
 
-        build_rule.push_str(&format!("\n\t$(CC) $(CFLAGS) -o {} -c {}\n",  objpath, file.path ));
+        if pretty {
+            build_rule.push_str(&format!("\t@printf ':: Building {} ... '\n", 
+                                         file.obj_name));
+        }
 
-        println!("'{}'", build_rule);
+        build_rule.push_str(&format!("\t{}$(CC) $(CFLAGS) -o {} -c {}\n", 
+                                     if pretty {"@"} else {""}, 
+                                     file.obj_path, file.file_path ));
+
+        if pretty {
+            build_rule.push_str(&format!("\t@printf 'done\\n'\n"));
+        }
+
+
+        build_rules.push_str(&build_rule);
     }
 
+    build_rules.push_str(&end_key);
+
+    if let Some(start) = makefile.find(start_key) {
+        if let Some(end) = makefile.find(end_key) {
+            let mut makefile_handle = fs::OpenOptions::new()
+                .write(true)
+                .truncate(true)
+                .open(&args.makefile).unwrap();
+            makefile.replace_range(start..(end+end_key.len()), &build_rules);
+            makefile_handle.write(makefile.as_bytes()).unwrap();
+            makefile_handle.flush().unwrap();
+        } else {
+            panic!("Makefile corrupted. Missing `#=mgen_end=#`, but `#=mgen_start=#` is present. Cannot perform replacement")
+        }
+    } else {
+        if let Some(_) = makefile.find(end_key) {
+            panic!("Makefile corrupted. Missing `#=mgen_start=#`, but `#=mgen_end=#` is present. Cannot perform replacement")
+        } else {
+            let mut makefile_handle = fs::OpenOptions::new()
+                .write(true)
+                .truncate(true)
+                .open(&args.makefile).unwrap();
+            makefile.push_str("\n");
+            makefile.push_str(&build_rules);
+            makefile_handle.write(makefile.as_bytes()).unwrap();
+            makefile_handle.flush().unwrap();
+        }
+    }
 }