// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.//! This module wraps libdeno::deno_set_v8_flagsuse crate::libdeno::deno_set_v8_flags;use libc::c_char;use libc::c_int;use std::ffi::CStr;use std::ffi::CString;use std::vec::Vec;
/// Pass the command line arguments to v8./// Returns a vector of command line arguments that V8 did not understand.pub fn v8_set_flags(args: Vec<String>) -> Vec<String> { // deno_set_v8_flags(int* argc, char** argv) mutates argc and argv to remove // flags that v8 understands.
// Make a new array, that can be modified by V8::SetFlagsFromCommandLine(), // containing mutable raw pointers to the individual command line args. let mut raw_argv = args .iter() .map(|arg| CString::new(arg.as_str()).unwrap().into_bytes_with_nul()) .collect::<Vec<_>>(); let mut c_argv = raw_argv .iter_mut() .map(|arg| arg.as_mut_ptr() as *mut c_char) .collect::<Vec<_>>();
// Store the length of the c_argv array in a local variable. We'll pass // a pointer to this local variable to deno_set_v8_flags(), which then // updates its value. let mut c_argv_len = c_argv.len() as c_int; // Let v8 parse the arguments it recognizes and remove them from c_argv. unsafe { deno_set_v8_flags(&mut c_argv_len, c_argv.as_mut_ptr()) }; // If c_argv_len was updated we have to change the length of c_argv to match. c_argv.truncate(c_argv_len as usize); // Copy the modified arguments list into a proper rust vec and return it. c_argv .iter() .map(|ptr| unsafe { let cstr = CStr::from_ptr(*ptr as *const c_char); let slice = cstr.to_str().unwrap(); slice.to_string() }) .collect()}