compile commands functionality added

src/config.rs

@@ -6,6 +6,7 @@ use toml::{Table, Value};
 pub struct Config {
     pub build_dir: String,
     pub compile_commands: bool,
+    pub compile_commands_target: String,
 }
 
 impl Config {
@@ -13,6 +14,7 @@ impl Config {
         Config {
             build_dir: String::from("build"),
             compile_commands: false,
+            compile_commands_target: String::from(""),
         }
     }
     pub fn set(&mut self, table: &Table) {
@@ -27,12 +29,19 @@ impl Config {
                 }
                 "compile_commands" => {
                     if let Value::Boolean(b) = table.get(k).unwrap() {
-                        eprintln!("warn: config.compile_commands has no functionality (yet)");
+                        //eprintln!("warn: config.compile_commands has no functionality (yet)");
                         self.compile_commands = *b;
                     } else {
                         panic!("fatal: {k} invalid type, must be a boolean.");
                     }
                 }
+                "compile_commands_target" => {
+                    if let Value::String(s) = table.get(k).unwrap() {
+                        self.compile_commands_target = s.to_owned();
+                    } else {
+                        panic!("fatal: {k} invalid type, must be a string.");
+                    }
+                }
                 _ => panic!("fatal: unrecognized key {k}."),
             }
         }

src/main.rs

@@ -1,6 +1,9 @@
 use clap::Parser;
 use core::panic;
-use std::fs::{read, write};
+use std::{
+    fs::{read, write},
+    path::Path,
+};
 use toml::{Table, Value};
 
 mod target;
@@ -16,19 +19,23 @@ struct Args {
 
     #[arg(short, long, default_value = "build.ninja")]
     output_file: String,
+
+    #[arg(long)]
+    write_compile_commands: Option<String>,
 }
 
-fn gen_ninja_code(config: &Target) -> String {
+fn gen_ninja_code(target: &Target) -> String {
     let mut ret = String::from("\n");
 
-    let name = &config.name;
+    // necessary because you cannot access struct members in a format string :(
-    let outfile = &config.outfile;
+    let name = &target.name;
-    let compiler = &config.compiler;
+    let outfile = &target.outfile;
-    let compiler_flags = &config.compiler_flags.join(" ");
+    let compiler = &target.compiler;
-    let linker = &config.linker;
+    let compiler_flags = &target.compiler_flags.join(" ");
-    let linker_flags = config.linker_flags.join(" ");
+    let linker = &target.linker;
-    let linker_libs = config.linker_libs.join(" ");
+    let linker_flags = &target.linker_flags.join(" ");
-    let sources = &config.sources;
+    let linker_libs = &target.linker_libs.join(" ");
+    let sources = &target.sources;
 
     ret.push_str(&format!(
         "\
@@ -65,7 +72,7 @@ build $builddir/{name}/dep: mkdir
     ret.push_str(&format!(
         " || $builddir/{name}/obj $builddir/{name}/dep\nbuild {name}: phony $builddir/{name}/{outfile}\n"
     ));
-    if config.is_default {
+    if target.is_default {
         ret.push_str(&format!("\ndefault {name}\n"));
     }
     ret.push_str(&format!("# END TARGET {name}\n"));
@@ -73,6 +80,41 @@ build $builddir/{name}/dep: mkdir
     ret
 }
 
+fn gen_compile_commands(target: &Target, build_dir: &str) -> String {
+    let mut ret = String::from("[\n");
+
+    let name = &target.name;
+    let compiler = &target.compiler;
+    let compiler_flags = &target.compiler_flags.join(" ");
+
+    let pwd = Path::new(".");
+    let pwd = pwd
+        .canonicalize()
+        .expect("cwd is non canonical (something is very wrong)");
+    let pwd = pwd.to_str().unwrap();
+
+    for (i, s) in target.sources.iter().enumerate() {
+        let new_file = s.replace("/", "-");
+        let obj_name = format!("{build_dir}/{name}/obj/{new_file}.o");
+
+        ret.push_str(&format!(
+            "  {{
+    \"directory\": \"{pwd}\",
+    \"command\": \"{compiler} {compiler_flags} -o {obj_name} -c {s}\",
+    \"file\": \"{s}\"
+  }}"
+        ));
+        if i != target.sources.len() - 1 {
+            ret.push(',');
+        }
+        ret.push('\n');
+    }
+
+    ret.push_str("]\n");
+
+    ret
+}
+
 fn main() {
     let args = Args::parse();
     let output_file = &args.output_file;
@@ -84,23 +126,61 @@ fn main() {
     let parsed_config = toml::from_str::<Table>(&config_file_string)
         .unwrap_or_else(|e| panic!("fatal: could not parse config file: {e}"));
 
+    // get config
     let mut config = Config::get_default();
-
-    let mut targets: Vec<Target> = Vec::new();
-    targets.push(Target::new(&parsed_config, "main", None));
     for k in parsed_config.keys() {
         if let Value::Table(t) = parsed_config.get(k).unwrap() {
             if k == "config" {
                 config.set(&t);
-            } else {
+                break;
-                targets.push(Target::new(&t, k, Some(&targets[0])));
+            }
+        }
+    }
+    //----
+
+    // parse the main target first
+    let mut targets: Vec<Target> = Vec::new();
+    let main_target = Target::new(&parsed_config, "main", None);
+    targets.push(main_target.clone());
+    let mut target_for_comp_cmds = main_target;
+    let mut target_for_comp_cmds_changed = false;
+
+    // parse other targets
+    for k in parsed_config.keys() {
+        if let Value::Table(t) = parsed_config.get(k).unwrap() {
+            if k == "config" {
+                continue; // ignore config
+            }
+            let target = Target::new(&t, k, Some(&targets[0]));
+            targets.push(target);
+            if let Some(_) = args.write_compile_commands {
+                if *k == config.compile_commands_target {
+                    target_for_comp_cmds = targets[targets.len() - 1].clone();
+                    target_for_comp_cmds_changed = true;
+                }
             }
         }
     }
 
-    let build_dir = config.build_dir;
+    if let Some(file) = args.write_compile_commands {
-    let _compile_commands = config.compile_commands;
+        if config.compile_commands_target == "" {
+            eprintln!(
+                "ngen: warn: no compile_commands target found, using 'main' target by default."
+            );
+        } else if !target_for_comp_cmds_changed && config.compile_commands_target != "main" {
+            let c = &config.compile_commands_target;
+            eprintln!(
+                "ngen: warn: compile_commands target {c} not found, using 'main' target instead."
+            );
+        }
+        write(
+            file,
+            &gen_compile_commands(&target_for_comp_cmds, &config.build_dir),
+        )
+        .expect("fatal: could not write {file}");
+    }
 
+    let build_dir = &config.build_dir;
     let mut ninjafile = format!(
         "\
 # Generated by ngen. Do not modify by hand.
@@ -111,7 +191,7 @@ rule mkdir
   command = mkdir -p $out
   description = Creating directory $out
 
-rule regen
+rule regen_ninjafile
   command = ngen -c $in -o $out
   generator = 1
   description = Regenerating $out
@@ -119,14 +199,31 @@ rule regen
 ",
     );
 
+    if config.compile_commands {
         ninjafile.push_str(&format!(
-        "build {output_file}: regen {config_file_name}\n  pool = console\n"
+            "\
+rule regen_compile_commands
+  command = ngen -c $in --write-compile-commands $out
+  description = Regenerating $out
+
+build $builddir: mkdir
+
+build $builddir/compile_commands.json: regen_compile_commands {config_file_name} | $builddir
+  pool = console
+
+build {output_file}: regen_ninjafile {config_file_name} || $builddir/compile_commands.json
+  pool = console
+"
         ));
+    } else {
+        ninjafile.push_str(&format!(
+            "build {output_file}: regen_ninjafile {config_file_name}\n  pool = console\n"
+        ));
+    }
 
     for t in targets {
         ninjafile.push_str(&gen_ninja_code(&t));
     }
 
-    write(output_file, ninjafile)
+    write(output_file, ninjafile).expect("fatal: could not write ninja file");
-        .unwrap_or_else(|e| panic!("fatal: could not write ninja file: {e}"));
 }