ipc: Upgrade clap

  - Upgrade clap from clap 3 to clap 4.

  - Use the opportunity to change to clap's derive-style API.

6 files changed, 284 insertions, 124 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 298ce7f1..5850e759 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -84,12 +84,55 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
 
 [[package]]
+name = "anstream"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ca84f3628370c59db74ee214b3263d58f9aadd9b4fe7e711fd87dc452b7f163"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is-terminal",
+ "utf8parse",
+]
+
+[[package]]
 name = "anstyle"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "15c4c2c83f81532e5845a733998b6971faca23490340a418e9b72a3ec9de12ea"
 
 [[package]]
+name = "anstyle-parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "938874ff5980b03a87c5524b3ae5b59cf99b1d6bc836848df7bc5ada9643c333"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca11d4be1bab0c8bc8734a9aa7bf4ee8316d462a08c6ac5052f888fef5b494b"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c677ab05e09154296dd37acecd46420c17b9713e8366facafa8fc0885167cf4c"
+dependencies = [
+ "anstyle",
+ "windows-sys",
+]
+
+[[package]]
 name = "anyhow"
 version = "1.0.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -116,17 +159,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "atty"
-version = "0.2.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
-dependencies = [
- "hermit-abi 0.1.19",
- "libc",
- "winapi",
-]
-
-[[package]]
 name = "autocfg"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -457,26 +489,13 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "3.2.25"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ea181bf566f71cb9a5d17a59e1871af638180a18fb0035c92ae62b705207123"
-dependencies = [
- "atty",
- "bitflags 1.3.2",
- "clap_lex 0.2.4",
- "indexmap 1.9.3",
- "strsim",
- "termcolor",
- "textwrap",
-]
-
-[[package]]
-name = "clap"
 version = "4.3.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fb690e81c7840c0d7aade59f242ea3b41b9bc27bcd5997890e7702ae4b32e487"
 dependencies = [
  "clap_builder",
+ "clap_derive",
+ "once_cell",
 ]
 
 [[package]]
@@ -485,17 +504,23 @@ version = "4.3.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5ed2e96bc16d8d740f6f48d663eddf4b8a0983e79210fd55479b7bcd0a69860e"
 dependencies = [
+ "anstream",
  "anstyle",
- "clap_lex 0.5.0",
+ "clap_lex",
+ "strsim",
+ "terminal_size",
 ]
 
 [[package]]
-name = "clap_lex"
-version = "0.2.4"
+name = "clap_derive"
+version = "4.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2850f2f5a82cbf437dd5af4d49848fbdfc27c157c3d010345776f952765261c5"
+checksum = "54a9bb5758fc5dfe728d1019941681eccaf0cf8a4189b692a0ee2f2ecf90a050"
 dependencies = [
- "os_str_bytes",
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.38",
 ]
 
 [[package]]
@@ -516,6 +541,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "colorchoice"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
+
+[[package]]
 name = "const-oid"
 version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -564,7 +595,7 @@ dependencies = [
  "anes",
  "cast",
  "ciborium",
- "clap 4.3.24",
+ "clap",
  "criterion-plot",
  "is-terminal",
  "itertools",
@@ -1245,15 +1276,6 @@ 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 = "hermit-abi"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d77f7ec81a6d05a3abb01ab6eb7590f6083d08449fe5a1c8b1e620283546ccb7"
@@ -1442,6 +1464,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "io-lifetimes"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eae7b9aee968036d54dce06cebaefd919e4472e753296daccd6d344e3e2df0c2"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "windows-sys",
+]
+
+[[package]]
 name = "ipconfig"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1465,8 +1498,8 @@ version = "0.4.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb0889898416213fab133e1d33a0e5858a48177452750691bde3666d0fdbaf8b"
 dependencies = [
- "hermit-abi 0.3.3",
- "rustix",
+ "hermit-abi",
+ "rustix 0.38.21",
  "windows-sys",
 ]
 
@@ -1567,6 +1600,12 @@ checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
 
 [[package]]
 name = "linux-raw-sys"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ef53942eb7bf7ff43a617b3e2c1c4a5ecf5944a7c1bc12d7ee39bbb15e5c1519"
+
+[[package]]
+name = "linux-raw-sys"
 version = "0.4.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "da2479e8c062e40bf0066ffa0bc823de0a9368974af99c9f6df941d2c231e03f"
@@ -1795,7 +1834,7 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
 dependencies = [
- "hermit-abi 0.3.3",
+ "hermit-abi",
  "libc",
 ]
 
@@ -1871,12 +1910,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "os_str_bytes"
-version = "6.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2355d85b9a3786f481747ced0e0ff2ba35213a1f9bd406ed906554d7af805a1"
-
-[[package]]
 name = "p256"
 version = "0.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2352,6 +2385,20 @@ dependencies = [
 
 [[package]]
 name = "rustix"
+version = "0.37.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fea8ca367a3a01fe35e6943c400addf443c0f57670e6ec51196f71a4b8762dd2"
+dependencies = [
+ "bitflags 1.3.2",
+ "errno",
+ "io-lifetimes",
+ "libc",
+ "linux-raw-sys 0.3.8",
+ "windows-sys",
+]
+
+[[package]]
+name = "rustix"
 version = "0.38.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b426b0506e5d50a7d8dafcf2e81471400deb602392c7dd110815afb4eaf02a3"
@@ -2359,7 +2406,7 @@ dependencies = [
  "bitflags 2.4.1",
  "errno",
  "libc",
- "linux-raw-sys",
+ "linux-raw-sys 0.4.10",
  "windows-sys",
 ]
 
@@ -2465,7 +2512,7 @@ dependencies = [
  "anyhow",
  "buffered-reader",
  "capnp-rpc",
- "clap 3.2.25",
+ "clap",
  "crossbeam-utils",
  "ctor",
  "dirs",
@@ -2789,7 +2836,7 @@ dependencies = [
  "cfg-if",
  "fastrand",
  "redox_syscall 0.4.1",
- "rustix",
+ "rustix 0.38.21",
  "windows-sys",
 ]
 
@@ -2805,21 +2852,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "termcolor"
-version = "1.3.0"
+name = "terminal_size"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6093bad37da69aab9d123a8091e4be0aa4a03e4d601ec641c327398315f62b64"
+checksum = "8e6bf6f19e9f8ed8d4048dc22981458ebcf406d67e94cd422e5ecd73d63b3237"
 dependencies = [
- "winapi-util",
+ "rustix 0.37.27",
+ "windows-sys",
 ]
 
 [[package]]
-name = "textwrap"
-version = "0.16.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "222a222a5bfe1bba4a77b45ec488a741b3cb8872e5e499451fd7d0129c9c7c3d"
-
-[[package]]
 name = "thiserror"
 version = "1.0.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -3129,6 +3171,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
+[[package]]
 name = "vcpkg"
 version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/ipc/Cargo.toml b/ipc/Cargo.toml
index 4cf078f3..94a7c84b 100644
--- a/ipc/Cargo.toml
+++ b/ipc/Cargo.toml
@@ -49,7 +49,7 @@ ctor = "0.1"
 lalrpop = { version = ">=0.17, <0.21", default-features = false }
 
 [dev-dependencies]
-clap = "3"
+clap = { version = "4", features = ["derive", "env", "string", "wrap_help"] }
 quickcheck = { version = "1", default-features = false }
 tokio = { version = "1", features = [ "macros" ] }
 
diff --git a/ipc/examples/assuan-client.rs b/ipc/examples/assuan-client.rs
index aa7f3ed8..5fb0dc93 100644
--- a/ipc/examples/assuan-client.rs
+++ b/ipc/examples/assuan-client.rs
@@ -1,24 +1,53 @@
+use std::path::PathBuf;
+
+use clap::CommandFactory;
+use clap::FromArgMatches;
+use clap::Parser;
+
 use futures::StreamExt;
 use sequoia_ipc as ipc;
 use crate::ipc::assuan::Client;
 
-fn main() {
-    let matches = clap::App::new("assuan-client")
-        .version(env!("CARGO_PKG_VERSION"))
-        .about("Connects to and sends commands to assuan servers.")
-        .arg(clap::Arg::with_name("server").value_name("PATH")
-             .required(true)
-             .help("Server to connect to"))
-        .arg(clap::Arg::with_name("commands").value_name("COMMAND")
-             .required(true)
-             .multiple(true)
-             .help("Commands to send to the server"))
-        .get_matches();
+use sequoia_openpgp as openpgp;
+use openpgp::Result;
+
+/// Defines the CLI.
+#[derive(Parser, Debug)]
+#[clap(
+    name = "assuan-client",
+    about = "Connects to and sends commands to assuan servers.",
+)]
+pub struct Cli {
+    #[clap(
+        long,
+        value_name = "PATH",
+        help = "Server to connect to",
+    )]
+    server: PathBuf,
+
+    #[clap(
+        long,
+        value_name = "COMMAND",
+        help = "Commands to send to the server",
+        required = true,
+    )]
+    commands: Vec<String>,
+}
+
+fn main() -> Result<()> {
+    let version = format!(
+        "{} (sequoia-openpgp {}, using {})",
+        env!("CARGO_PKG_VERSION"),
+        sequoia_openpgp::VERSION,
+        sequoia_openpgp::crypto::backend()
+    );
+    let cli = Cli::command().version(version);
+    let matches = Cli::from_arg_matches(&cli.get_matches())?;
 
     let rt = tokio::runtime::Runtime::new().unwrap();
     rt.block_on(async {
-        let mut c = Client::connect(matches.value_of("server").unwrap()).await.unwrap();
-        for command in matches.values_of("commands").unwrap() {
+        let mut c = Client::connect(matches.server).await.unwrap();
+        for command in matches.commands {
             eprintln!("> {}", command);
             c.send(command).unwrap();
             while let Some(response) = c.next().await {
@@ -26,4 +55,6 @@ fn main() {
             }
         }
     });
+
+    Ok(())
 }
diff --git a/ipc/examples/gpg-agent-client.rs b/ipc/examples/gpg-agent-client.rs
index 8f2d7415..6e4067c7 100644
--- a/ipc/examples/gpg-agent-client.rs
+++ b/ipc/examples/gpg-agent-client.rs
@@ -1,33 +1,63 @@
 /// Connects to and sends commands to gpg-agent.
 
+use std::path::PathBuf;
+
+use clap::CommandFactory;
+use clap::FromArgMatches;
+use clap::Parser;
+
 use futures::StreamExt;
+
 use sequoia_ipc as ipc;
 use crate::ipc::gnupg::{Context, Agent};
 
-fn main() {
-    let matches = clap::App::new("gpg-agent-client")
-        .version(env!("CARGO_PKG_VERSION"))
-        .about("Connects to and sends commands to gpg-agent.")
-        .arg(clap::Arg::with_name("homedir").value_name("PATH")
-             .long("homedir")
-             .help("Use this GnuPG home directory, default: $GNUPGHOME"))
-        .arg(clap::Arg::with_name("commands").value_name("COMMAND")
-             .required(true)
-             .multiple(true)
-             .help("Commands to send to the server"))
-        .get_matches();
-
-    let ctx = if let Some(homedir) = matches.value_of("homedir") {
-        Context::with_homedir(homedir).unwrap()
+use sequoia_openpgp as openpgp;
+use openpgp::Result;
+
+/// Defines the CLI.
+#[derive(Parser, Debug)]
+#[clap(
+    name = "gpg-agent-client",
+    about = "Connects to and sends commands to gpg-agent.",
+)]
+pub struct Cli {
+    #[clap(
+        long,
+        value_name = "PATH",
+        env = "GNUPGHOME",
+        help = "Use this GnuPG home directory, default: $GNUPGHOME",
+    )]
+    homedir: Option<PathBuf>,
+
+    #[clap(
+        long,
+        value_name = "commands",
+        help = "Commands to send to the server",
+        required = true,
+    )]
+    commands: Vec<String>,
+}
+
+fn main() -> Result<()> {
+    let version = format!(
+        "{} (sequoia-openpgp {}, using {})",
+        env!("CARGO_PKG_VERSION"),
+        sequoia_openpgp::VERSION,
+        sequoia_openpgp::crypto::backend());
+    let cli = Cli::command().version(version);
+    let matches = Cli::from_arg_matches(&cli.get_matches())?;
+
+    let ctx = if let Some(homedir) = matches.homedir {
+        Context::with_homedir(homedir)?
     } else {
-        Context::new().unwrap()
+        Context::new()?
     };
 
     let rt = tokio::runtime::Runtime::new().unwrap();
     rt.block_on(async {
         let mut agent = Agent::connect(&ctx).await.unwrap();
 
-        for command in matches.values_of("commands").unwrap() {
+        for command in matches.commands {
             eprintln!("> {}", command);
             agent.send(command).unwrap();
             while let Some(response) = agent.next().await {
@@ -35,4 +65,6 @@ fn main() {
             }
         }
     });
+
+    Ok(())
 }
diff --git a/ipc/examples/gpg-agent-decrypt.rs b/ipc/examples/gpg-agent-decrypt.rs
index ebb311ac..f0777718 100644
--- a/ipc/examples/gpg-agent-decrypt.rs
+++ b/ipc/examples/gpg-agent-decrypt.rs
@@ -2,6 +2,11 @@
 
 use std::collections::HashMap;
 use std::io;
+use std::path::PathBuf;
+
+use clap::CommandFactory;
+use clap::FromArgMatches;
+use clap::Parser;
 
 use sequoia_openpgp as openpgp;
 use sequoia_ipc as ipc;
@@ -25,22 +30,42 @@ use openpgp::policy::Policy;
 use openpgp::policy::StandardPolicy as P;
 use ipc::gnupg::{Context, KeyPair};
 
+/// Defines the CLI.
+#[derive(Parser, Debug)]
+#[clap(
+    name = "gpg-agent-decrypt",
+    about = "Connects to gpg-agent and decrypts a message.",
+)]
+pub struct Cli {
+    #[clap(
+        long,
+        value_name = "PATH",
+        env = "GNUPGHOME",
+        help = "Use this GnuPG home directory, default: $GNUPGHOME",
+    )]
+    homedir: Option<PathBuf>,
+
+    #[clap(
+        long,
+        value_name = "CERT",
+        help = "Public part of the secret keys managed by gpg-agent",
+        required = true,
+    )]
+    cert: Vec<PathBuf>,
+}
+
 fn main() -> openpgp::Result<()> {
     let p = &P::new();
 
-    let matches = clap::App::new("gpg-agent-decrypt")
-        .version(env!("CARGO_PKG_VERSION"))
-        .about("Connects to gpg-agent and decrypts a message.")
-        .arg(clap::Arg::with_name("homedir").value_name("PATH")
-             .long("homedir")
-             .help("Use this GnuPG home directory, default: $GNUPGHOME"))
-        .arg(clap::Arg::with_name("cert").value_name("Cert")
-             .required(true)
-             .multiple(true)
-             .help("Public part of the secret keys managed by gpg-agent"))
-        .get_matches();
-
-    let ctx = if let Some(homedir) = matches.value_of("homedir") {
+    let version = format!(
+        "{} (sequoia-openpgp {}, using {})",
+        env!("CARGO_PKG_VERSION"),
+        sequoia_openpgp::VERSION,
+        sequoia_openpgp::crypto::backend());
+    let cli = Cli::command().version(version);
+    let matches = Cli::from_arg_matches(&cli.get_matches())?;
+
+    let ctx = if let Some(homedir) = matches.homedir {
         Context::with_homedir(homedir)?
     } else {
         Context::new()?
@@ -48,7 +73,7 @@ fn main() -> openpgp::Result<()> {
 
     // Read the Certs from the given files.
     let certs =
-        matches.values_of("cert").expect("required").map(
+        matches.cert.into_iter().map(
             openpgp::Cert::from_file
         ).collect::<Result<_, _>>()?;
 
diff --git a/ipc/examples/gpg-agent-sign.rs b/ipc/examples/gpg-agent-sign.rs
index b3204ec9..6e27c239 100644
--- a/ipc/examples/gpg-agent-sign.rs
+++ b/ipc/examples/gpg-agent-sign.rs
@@ -1,6 +1,11 @@
 /// Signs data using the openpgp crate and secrets in gpg-agent.
 
 use std::io;
+use std::path::PathBuf;
+
+use clap::CommandFactory;
+use clap::FromArgMatches;
+use clap::Parser;
 
 use sequoia_openpgp as openpgp;
 use sequoia_ipc as ipc;
@@ -10,30 +15,49 @@ use openpgp::serialize::stream::{Armorer, Message, LiteralWriter, Signer};
 use openpgp::policy::StandardPolicy as P;
 use ipc::gnupg::{Context, KeyPair};
 
+/// Defines the CLI.
+#[derive(Parser, Debug)]
+#[clap(
+    name = "gpg-agent-sign",
+    about = "Connects to gpg-agent and creates a dummy signature.",
+)]
+pub struct Cli {
+    #[clap(
+        long,
+        value_name = "PATH",
+        env = "GNUPGHOME",
+        help = "Use this GnuPG home directory, default: $GNUPGHOME",
+    )]
+    homedir: Option<PathBuf>,
+
+    #[clap(
+        long,
+        value_name = "CERT",
+        help = "Public part of the secret keys managed by gpg-agent",
+        required = true,
+    )]
+    cert: Vec<PathBuf>,
+}
+
 fn main() -> openpgp::Result<()> {
     let p = &P::new();
 
-    let matches = clap::App::new("gpg-agent-sign")
-        .version(env!("CARGO_PKG_VERSION"))
-        .about("Connects to gpg-agent and creates a dummy signature.")
-        .arg(clap::Arg::with_name("homedir").value_name("PATH")
-             .long("homedir")
-             .help("Use this GnuPG home directory, default: $GNUPGHOME"))
-        .arg(clap::Arg::with_name("cert").value_name("Cert")
-             .required(true)
-             .multiple(true)
-             .help("Public part of the secret keys managed by gpg-agent"))
-        .get_matches();
-
-    let ctx = if let Some(homedir) = matches.value_of("homedir") {
+    let version = format!(
+        "{} (sequoia-openpgp {}, using {})",
+        env!("CARGO_PKG_VERSION"),
+        sequoia_openpgp::VERSION,
+        sequoia_openpgp::crypto::backend());
+    let cli = Cli::command().version(version);
+    let matches = Cli::from_arg_matches(&cli.get_matches())?;
+
+    let ctx = if let Some(homedir) = matches.homedir {
         Context::with_homedir(homedir)?
     } else {
         Context::new()?
     };
 
     // Read the Certs from the given files.
-    let certs =
-        matches.values_of("cert").expect("required").map(
+    let certs = matches.cert.into_iter().map(
             openpgp::Cert::from_file
         ).collect::<Result<Vec<_>, _>>()?;