Revert clap from arg parsing during setup (rust-lang#3078)

`--help` and `--version` commands were being overriden by clap, so we
are going back to the simple parsing with the added logic for
`use-local-toolchain`.

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 and MIT licenses.

Author: jaisnan

Cargo.lock

@@ -33,15 +33,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "ansi_term"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
-dependencies = [
- "winapi",
-]
-
 [[package]]
 name = "anstream"
 version = "0.6.13"
@@ -96,17 +87,6 @@ version = "1.0.80"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5ad32ce52e4161730f7098c077cd2ed6229b5804ccf99e5366be1ab72a98b4e1"
 
-[[package]]
-name = "atty"
-version = "0.2.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
-dependencies = [
- "hermit-abi",
- "libc",
- "winapi",
-]
-
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -145,7 +125,7 @@ version = "0.48.0"
 dependencies = [
  "anyhow",
  "cargo_metadata",
- "clap 4.5.2",
+ "clap",
  "which",
 ]
 
@@ -187,21 +167,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "clap"
-version = "2.34.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0610544180c38b88101fecf2dd634b174a62eef6946f84dfc6a7127512b381c"
-dependencies = [
- "ansi_term",
- "atty",
- "bitflags 1.3.2",
- "strsim 0.8.0",
- "textwrap",
- "unicode-width",
- "vec_map",
-]
-
 [[package]]
 name = "clap"
 version = "4.5.2"
@@ -221,7 +186,7 @@ dependencies = [
  "anstream",
  "anstyle",
  "clap_lex",
- "strsim 0.11.0",
+ "strsim",
 ]
 
 [[package]]
@@ -427,15 +392,6 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
-[[package]]
-name = "hermit-abi"
-version = "0.1.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
-dependencies = [
- "libc",
-]
-
 [[package]]
 name = "home"
 version = "0.5.9"
@@ -481,7 +437,7 @@ dependencies = [
 name = "kani-compiler"
 version = "0.48.0"
 dependencies = [
- "clap 4.5.2",
+ "clap",
  "cprover_bindings",
  "home",
  "itertools",
@@ -504,7 +460,7 @@ version = "0.48.0"
 dependencies = [
  "anyhow",
  "cargo_metadata",
- "clap 4.5.2",
+ "clap",
  "comfy-table",
  "console",
  "glob",
@@ -531,7 +487,6 @@ name = "kani-verifier"
 version = "0.48.0"
 dependencies = [
  "anyhow",
- "clap 2.34.0",
  "home",
  "os_info",
 ]
@@ -550,7 +505,7 @@ dependencies = [
 name = "kani_metadata"
 version = "0.48.0"
 dependencies = [
- "clap 4.5.2",
+ "clap",
  "cprover_bindings",
  "serde",
  "strum 0.26.2",
@@ -1095,12 +1050,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "strsim"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
-
 [[package]]
 name = "strsim"
 version = "0.11.0"
@@ -1178,15 +1127,6 @@ dependencies = [
  "windows-sys",
 ]
 
-[[package]]
-name = "textwrap"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
-dependencies = [
- "unicode-width",
-]
-
 [[package]]
 name = "thiserror"
 version = "1.0.57"
@@ -1365,12 +1305,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830b7e5d4d90034032940e4ace0d9a9a057e7a45cd94e6c007832e39edb82f6d"
 
-[[package]]
-name = "vec_map"
-version = "0.8.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
-
 [[package]]
 name = "version_check"
 version = "0.9.4"

Cargo.toml

@@ -19,7 +19,6 @@ include = ["/src", "/build.rs", "/rust-toolchain.toml", "/LICENSE-*", "/README.m
 [dependencies]
 anyhow = "1"
 home = "0.5"
-clap = "2.33.3"
 os_info = { version = "3", default-features = false }
 
 [[bin]]

src/lib.rs

@@ -16,7 +16,6 @@ mod cmd;
 mod os_hacks;
 mod setup;
 
-use clap::{App, Arg, SubCommand};
 use std::ffi::OsString;
 use std::os::unix::prelude::CommandExt;
 use std::path::{Path, PathBuf};
@@ -60,50 +59,54 @@ enum ArgsResult {
 
 /// Parse `args` and decide what to do.
 fn parse_args(args: Vec<OsString>) -> ArgsResult {
-    let matches = App::new("kani")
-        .subcommand(
-            SubCommand::with_name("setup")
-                .arg(Arg::with_name("use-local-bundle").long("use-local-bundle").takes_value(true))
-                .arg(
-                    Arg::with_name("use-local-toolchain")
-                        .long("use-local-toolchain")
-                        .takes_value(true),
-                ),
-        )
-        .subcommand(
-            SubCommand::with_name("kani").subcommand(
-                SubCommand::with_name("setup")
-                    .arg(
-                        Arg::with_name("use-local-bundle")
-                            .long("use-local-bundle")
-                            .takes_value(true),
-                    )
-                    .arg(
-                        Arg::with_name("use-local-toolchain")
-                            .long("use-local-toolchain")
-                            .takes_value(true),
-                    ),
-            ),
-        )
-        .get_matches_from(args);
-
-    // Default is the behaviour for Kani when cargo-kani/ cargo kani runs on its own and sees that there is no setup done yet
-    // Explicit is when the user uses the sub-command cargo-kani setup explicitly
-    if let Some(matches) = matches.subcommand_matches("setup") {
-        let use_local_toolchain = matches.value_of_os("use-local-toolchain").map(OsString::from);
-        let use_local_bundle = matches.value_of_os("use-local-bundle").map(OsString::from);
-        ArgsResult::ExplicitSetup { use_local_bundle, use_local_toolchain }
-    } else if let Some(matches) = matches.subcommand_matches("kani") {
-        if let Some(matches) = matches.subcommand_matches("setup") {
-            let use_local_toolchain =
-                matches.value_of_os("use-local-toolchain").map(OsString::from);
-            let use_local_bundle = matches.value_of_os("use-local-bundle").map(OsString::from);
-            ArgsResult::ExplicitSetup { use_local_bundle, use_local_toolchain }
-        } else {
-            ArgsResult::Default
+    // In an effort to keep our dependencies minimal, we do the bare minimum argument parsing manually.
+    // `args_ez` makes it easy to do crude arg parsing with match.
+    let args_ez: Vec<Option<&str>> = args.iter().map(|x| x.to_str()).collect();
+    // "cargo kani setup" comes in as "cargo-kani kani setup"
+    // "cargo-kani setup" comes in as "cargo-kani setup"
+    match &args_ez[..] {
+        &[_, Some("setup"), Some("--use-local-bundle"), _, Some("--use-local-toolchain"), _] => {
+            ArgsResult::ExplicitSetup {
+                use_local_bundle: Some(args[3].clone()),
+                use_local_toolchain: Some(args[5].clone()),
+            }
+        }
+        &[
+            _,
+            Some("kani"),
+            Some("setup"),
+            Some("--use-local-bundle"),
+            _,
+            Some("--use-local-toolchain"),
+            _,
+        ] => ArgsResult::ExplicitSetup {
+            use_local_bundle: Some(args[4].clone()),
+            use_local_toolchain: Some(args[6].clone()),
+        },
+        &[_, Some("setup"), Some("--use-local-bundle"), _] => ArgsResult::ExplicitSetup {
+            use_local_bundle: Some(args[3].clone()),
+            use_local_toolchain: None,
+        },
+        &[_, Some("kani"), Some("setup"), Some("--use-local-bundle"), _] => {
+            ArgsResult::ExplicitSetup {
+                use_local_bundle: Some(args[4].clone()),
+                use_local_toolchain: None,
+            }
+        }
+        &[_, Some("setup"), Some("--use-local-toolchain"), _] => ArgsResult::ExplicitSetup {
+            use_local_bundle: None,
+            use_local_toolchain: Some(args[3].clone()),
+        },
+        &[_, Some("kani"), Some("setup"), Some("--use-local-toolchain"), _] => {
+            ArgsResult::ExplicitSetup {
+                use_local_bundle: None,
+                use_local_toolchain: Some(args[4].clone()),
+            }
+        }
+        &[_, Some("setup")] | &[_, Some("kani"), Some("setup")] => {
+            ArgsResult::ExplicitSetup { use_local_bundle: None, use_local_toolchain: None }
         }
-    } else {
-        ArgsResult::Default
+        _ => ArgsResult::Default,
     }
 }