support c2rust <path/to/*.c>

c2rust-transpile/src/lib.rs

@@ -13,7 +13,7 @@ pub mod translator;
 pub mod with_stmts;
 
 use std::collections::HashSet;
-use std::fs::{self, File};
+use std::fs::{self, read_dir, File};
 use std::io;
 use std::io::prelude::*;
 use std::path::{Path, PathBuf};
@@ -227,9 +227,44 @@ fn get_module_name(
 
 /// Main entry point to transpiler. Called from CLI tools with the result of
 /// clap::App::get_matches().
-pub fn transpile(tcfg: TranspilerConfig, cc_db: &Path, extra_clang_args: &[&str]) {
+pub fn transpile(tcfg: TranspilerConfig, source_or_cc_db: &Path, extra_clang_args: &[&str]) {
     diagnostics::init(tcfg.enabled_warnings.clone(), tcfg.log_level);
 
+    let temp_json_path = "compile_commands.json";
+    let build_dir = get_build_dir(&tcfg, source_or_cc_db);
+
+    let cc_db = if source_or_cc_db.to_string_lossy().ends_with(".c") {
+        let mut temp_json: Vec<String> = Vec::new();
+        for entry in read_dir(build_dir.clone()).expect("Failed to read directory") {
+            if let Ok(entry) = entry {
+                let path = entry.path();
+                if path.extension() == Some(std::ffi::OsStr::new("c")) {
+                    let command = format!(
+                        r#"{{
+                            "directory": "{}",
+                            "command": "clang {}",
+                            "file": "{}"
+                        }}"#,
+                        build_dir.to_str().unwrap(),
+                        path.to_str().unwrap(),
+                        path.to_str().unwrap()
+                    );
+
+                    temp_json.push(command);
+                }
+            }
+        }
+
+        let temp_json_content = format!("[{}]", temp_json.join(","));
+        fs::File::create(temp_json_path)
+            .and_then(|mut f| f.write_all(temp_json_content.as_bytes()))
+            .expect("Failed to create temp json");
+
+        Path::new(temp_json_path)
+    } else {
+        source_or_cc_db
+    };
+
     let lcmds = get_compile_commands(cc_db, &tcfg.filter).unwrap_or_else(|_| {
         panic!(
             "Could not parse compile commands from {}",
@@ -246,7 +281,7 @@ pub fn transpile(tcfg: TranspilerConfig, cc_db: &Path, extra_clang_args: &[&str]
     let mut workspace_members = vec![];
     let mut num_transpiled_files = 0;
     let mut transpiled_modules = Vec::new();
-    let build_dir = get_build_dir(&tcfg, cc_db);
+
     for lcmd in &lcmds {
         let cmds = &lcmd.cmd_inputs;
         let lcmd_name = lcmd
@@ -367,6 +402,10 @@ pub fn transpile(tcfg: TranspilerConfig, cc_db: &Path, extra_clang_args: &[&str]
     }
 
     tcfg.check_if_all_binaries_used(&transpiled_modules);
+
+    if source_or_cc_db.to_string_lossy().ends_with(".c") {
+        let _ = fs::remove_file(temp_json_path);
+    }
 }
 
 /// Ensure that clang can locate the system headers on macOS 10.14+.

c2rust/src/bin/c2rust-transpile.rs

@@ -226,11 +226,11 @@ fn main() {
         tcfg.emit_modules = true
     };
 
-    let cc_json_path = Path::new(&args.compile_commands);
-    let cc_json_path = cc_json_path.canonicalize().unwrap_or_else(|_| {
+    let source_or_cc_db = Path::new(&args.compile_commands);
+    let source_or_cc_db = source_or_cc_db.canonicalize().unwrap_or_else(|_| {
         panic!(
-            "Could not find compile_commands.json file at path: {}",
-            cc_json_path.display()
+            "Could not find compile_commands.json or source files at path: {}",
+            source_or_cc_db.display()
         )
     });
 
@@ -240,5 +240,5 @@ fn main() {
         .map(AsRef::as_ref)
         .collect::<Vec<_>>();
 
-    c2rust_transpile::transpile(tcfg, &cc_json_path, &extra_args);
+    c2rust_transpile::transpile(tcfg, &source_or_cc_db, &extra_args);
 }