Draft: Simplify DFX behavior

src/dfx/Cargo.toml

@@ -49,6 +49,7 @@ tokio = "0.1"
 url = "2.1.0"
 wabt = "0.9.2"
 wasmparser = "0.45.0"
+structopt = "0.3.8"
 
 [dev-dependencies]
 env_logger = "0.6"

src/dfx/src/config/cache.rs

@@ -1,12 +1,11 @@
 use crate::config::dfx_version;
 use crate::lib::error::DfxError::CacheError;
-use crate::lib::error::{CacheErrorKind, DfxError, DfxResult};
+use crate::lib::error::{CacheErrorKind, DfxResult};
 use crate::util;
 use indicatif::{ProgressBar, ProgressDrawTarget};
 use semver::Version;
 use std::os::unix::fs::PermissionsExt;
 use std::path::PathBuf;
-use std::process::ExitStatus;
 
 // POSIX permissions for files in the cache.
 const EXEC_READ_USER_ONLY_PERMISSION: u32 = 0o500;
@@ -188,18 +187,3 @@ pub fn list_versions() -> DfxResult<Vec<Version>> {
 
     Ok(result)
 }
-
-pub fn call_cached_dfx(v: &Version) -> DfxResult<ExitStatus> {
-    let v = format!("{}", v);
-    let command_path = get_binary_path_from_version(&v, "dfx")?;
-    if command_path == std::env::current_exe()? {
-        return Err(DfxError::Unknown(
-            format_args!("Invalid cache for version {}.", v).to_string(),
-        ));
-    }
-
-    std::process::Command::new(command_path)
-        .args(std::env::args().skip(1))
-        .status()
-        .map_err(DfxError::from)
-}

src/dfx/src/main.rs

@@ -1,5 +1,5 @@
 use crate::commands::CliCommand;
-use crate::config::{dfx_version, dfx_version_str};
+use crate::config::{dfx_version_str};
 use crate::lib::environment::{Environment, EnvironmentImpl};
 use crate::lib::error::*;
 use clap::{App, AppSettings};
@@ -49,20 +49,7 @@ fn exec(env: &impl Environment, args: &clap::ArgMatches<'_>, cli: &App<'_, '_>)
 fn main() {
     let result = match EnvironmentImpl::new() {
         Ok(env) => {
-            // If we're not using the right version, forward the call to the cache dfx.
-            if dfx_version() != env.get_version() {
-                match crate::config::cache::call_cached_dfx(env.get_version()) {
-                    Ok(status) => std::process::exit(status.code().unwrap_or(0)),
-                    Err(e) => {
-                        eprintln!("Error when trying to forward to project dfx:\n{:?}", e);
-                        eprintln!("Installed executable: {}", dfx_version());
-                        std::process::exit(1)
-                    }
-                };
-            }
-
             let matches = cli(&env).get_matches();
-
             exec(&env, &matches, &(cli(&env)))
         }
         Err(e) => Err(e),