Convert OSVersion to a struct that implements traits

Instead of being a type-alias to a tuple. This allows us to implement
Deserialize for OSVersion, which will be useful when parsing SDK
settings.

Author: madsmtm

Cargo.lock

@@ -4450,6 +4450,7 @@ dependencies = [
  "rustc_macros",
  "rustc_serialize",
  "rustc_span",
+ "serde",
  "serde_json",
  "tracing",
 ]

compiler/rustc_codegen_ssa/src/apple.rs

@@ -1,32 +1,19 @@
 use std::borrow::Cow;
-use std::env;
-use std::fs;
 use std::io::ErrorKind;
-use std::fmt::{Display, from_fn};
 use std::path::{Path, PathBuf};
+use std::{env, fs};
 
 use rustc_session::Session;
 use rustc_target::spec::{
     AppleOSVersion, apple_deployment_target_env_var, apple_minimum_deployment_target,
-    apple_os_minimum_deployment_target, apple_parse_version,
+    apple_os_minimum_deployment_target,
 };
 
 use crate::errors::{AppleDeploymentTarget, AppleSdkError};
 
 #[cfg(test)]
 mod tests;
 
-pub fn pretty_version(version: AppleOSVersion) -> impl Display {
-    let (major, minor, patch) = version;
-    from_fn(move |f| {
-        write!(f, "{major}.{minor}")?;
-        if patch != 0 {
-            write!(f, ".{patch}")?;
-        }
-        Ok(())
-    })
-}
-
 /// Get the deployment target based on the standard environment variables, or fall back to the
 /// minimum version supported by `rustc`.
 pub fn deployment_target(sess: &Session) -> AppleOSVersion {
@@ -35,7 +22,7 @@ pub fn deployment_target(sess: &Session) -> AppleOSVersion {
     let env_var = apple_deployment_target_env_var(&sess.target.os);
 
     if let Ok(deployment_target) = env::var(env_var) {
-        match apple_parse_version(&deployment_target) {
+        match deployment_target.parse::<AppleOSVersion>() {
             Ok(version) => {
                 // It is common that the deployment target is set a bit too low, for example on
                 // macOS Aarch64 to also target older x86_64. So we only want to warn when variable
@@ -44,8 +31,8 @@ pub fn deployment_target(sess: &Session) -> AppleOSVersion {
                 if version < os_min {
                     sess.dcx().emit_warn(AppleDeploymentTarget::TooLow {
                         env_var,
-                        version: pretty_version(version).to_string(),
-                        os_min: pretty_version(os_min).to_string(),
+                        version: version.pretty().to_string(),
+                        os_min: os_min.pretty().to_string(),
                     });
                 }
 
@@ -71,7 +58,7 @@ fn add_version_to_llvm_target(llvm_target: &str, deployment_target: AppleOSVersi
     let environment = components.next();
     assert_eq!(components.next(), None, "too many LLVM triple components");
 
-    let (major, minor, patch) = deployment_target;
+    let AppleOSVersion { major, minor, patch } = deployment_target;
 
     assert!(
         !os.contains(|c: char| c.is_ascii_digit()),

compiler/rustc_codegen_ssa/src/apple/tests.rs

@@ -2,16 +2,21 @@ use std::io;
 use std::path::PathBuf;
 use std::process::Command;
 
+use rustc_target::spec::AppleOSVersion;
+
 use super::{add_version_to_llvm_target, find_sdk_root};
 
 #[test]
 fn test_add_version_to_llvm_target() {
+    let version = AppleOSVersion { major: 10, minor: 14, patch: 1 };
     assert_eq!(
-        add_version_to_llvm_target("aarch64-apple-macosx", (10, 14, 1)),
+        add_version_to_llvm_target("aarch64-apple-macosx", version),
         "aarch64-apple-macosx10.14.1"
     );
+
+    let version = AppleOSVersion { major: 16, minor: 1, patch: 0 };
     assert_eq!(
-        add_version_to_llvm_target("aarch64-apple-ios-simulator", (16, 1, 0)),
+        add_version_to_llvm_target("aarch64-apple-ios-simulator", version),
         "aarch64-apple-ios16.1.0-simulator"
     );
 }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -38,9 +38,9 @@ use rustc_session::{Session, filesearch};
 use rustc_span::symbol::Symbol;
 use rustc_target::spec::crt_objects::CrtObjects;
 use rustc_target::spec::{
-    Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault, LinkerFeatures,
-    LinkerFlavor, LinkerFlavorCli, Lld, PanicStrategy, RelocModel, RelroLevel, SanitizerSet,
-    SplitDebuginfo,
+    AppleOSVersion, Cc, LinkOutputKind, LinkSelfContainedComponents, LinkSelfContainedDefault,
+    LinkerFeatures, LinkerFlavor, LinkerFlavorCli, Lld, PanicStrategy, RelocModel, RelroLevel,
+    SanitizerSet, SplitDebuginfo,
 };
 use tempfile::Builder as TempFileBuilder;
 use tracing::{debug, info, warn};
@@ -3038,7 +3038,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
             _ => bug!("invalid OS/ABI combination for Apple target: {target_os}, {target_abi}"),
         };
 
-        let (major, minor, patch) = deployment_target(sess);
+        let AppleOSVersion { major, minor, patch } = deployment_target(sess);
         let min_version = format!("{major}.{minor}.{patch}");
 
         // The SDK version is used at runtime when compiling with a newer SDK / version of Xcode:
@@ -3108,7 +3108,7 @@ fn add_apple_link_args(cmd: &mut dyn Linker, sess: &Session, flavor: LinkerFlavo
 
             // The presence of `-mmacosx-version-min` makes CC default to
             // macOS, and it sets the deployment target.
-            let (major, minor, patch) = deployment_target(sess);
+            let AppleOSVersion { major, minor, patch } = deployment_target(sess);
             // Intentionally pass this as a single argument, Clang doesn't
             // seem to like it otherwise.
             cmd.cc_arg(&format!("-mmacosx-version-min={major}.{minor}.{patch}"));

compiler/rustc_codegen_ssa/src/back/metadata.rs

@@ -392,9 +392,12 @@ pub(crate) fn create_object_file(sess: &Session) -> Option<write::Object<'static
 /// Since Xcode 15, Apple's LD apparently requires object files to use this load command, so this
 /// returns the `MachOBuildVersion` for the target to do so.
 fn macho_object_build_version_for_target(sess: &Session) -> object::write::MachOBuildVersion {
+    use rustc_target::spec::AppleOSVersion;
+
     /// The `object` crate demands "X.Y.Z encoded in nibbles as xxxx.yy.zz"
     /// e.g. minOS 14.0 = 0x000E0000, or SDK 16.2 = 0x00100200
-    fn pack_version((major, minor, patch): (u16, u8, u8)) -> u32 {
+    fn pack_version(version: AppleOSVersion) -> u32 {
+        let AppleOSVersion { major, minor, patch } = version;
         let (major, minor, patch) = (major as u32, minor as u32, patch as u32);
         (major << 16) | (minor << 8) | patch
     }

compiler/rustc_codegen_ssa/src/lib.rs

@@ -6,7 +6,6 @@
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(debug_closure_helpers)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]

compiler/rustc_driver_impl/src/lib.rs

@@ -855,10 +855,10 @@ fn print_crate_info(
                 }
             }
             DeploymentTarget => {
-                use rustc_codegen_ssa::apple::{deployment_target, pretty_version};
+                use rustc_codegen_ssa::apple::deployment_target;
 
                 if sess.target.is_like_osx {
-                    println_info!("deployment_target={}", pretty_version(deployment_target(sess)))
+                    println_info!("deployment_target={}", deployment_target(sess).pretty())
                 } else {
                     #[allow(rustc::diagnostic_outside_of_impl)]
                     sess.dcx().fatal("only Apple targets currently support deployment version info")

compiler/rustc_target/Cargo.toml

@@ -14,6 +14,7 @@ rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
+serde = "1"
 serde_json = "1.0.59"
 tracing = "0.1"
 # tidy-alphabetical-end

compiler/rustc_target/src/lib.rs

@@ -12,6 +12,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
+#![feature(debug_closure_helpers)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
 #![feature(rustc_attrs)]

compiler/rustc_target/src/spec/base/apple/mod.rs

@@ -1,5 +1,9 @@
 use std::borrow::Cow;
+use std::fmt;
 use std::num::ParseIntError;
+use std::str::FromStr;
+
+use serde::de;
 
 use crate::spec::{
     Cc, DebuginfoKind, FramePointer, LinkerFlavor, Lld, SplitDebuginfo, StackProbeType, StaticCow,
@@ -200,14 +204,15 @@ pub fn os_minimum_deployment_target(os: &str) -> OSVersion {
     // ```
     // $ rustc --print deployment-target
     // ```
-    match os {
+    let (major, minor, patch) = match os {
         "macos" => (10, 12, 0),
         "ios" => (10, 0, 0),
         "tvos" => (10, 0, 0),
         "watchos" => (5, 0, 0),
         "visionos" => (1, 0, 0),
         _ => unreachable!("tried to get deployment target for non-Apple platform"),
-    }
+    };
+    OSVersion { major, minor, patch }
 }
 
 /// The deployment target for the given target.
@@ -218,7 +223,7 @@ pub fn os_minimum_deployment_target(os: &str) -> OSVersion {
 /// This matches what LLVM does, see in part:
 /// <https://github.com/llvm/llvm-project/blob/llvmorg-18.1.8/llvm/lib/TargetParser/Triple.cpp#L1900-L1932>
 pub fn minimum_deployment_target(target: &Target) -> OSVersion {
-    match (&*target.os, &*target.arch, &*target.abi) {
+    let (major, minor, patch) = match (&*target.os, &*target.arch, &*target.abi) {
         ("macos", "aarch64", _) => (11, 0, 0),
         ("ios", "aarch64", "macabi") => (14, 0, 0),
         ("ios", "aarch64", "sim") => (14, 0, 0),
@@ -227,8 +232,9 @@ pub fn minimum_deployment_target(target: &Target) -> OSVersion {
         ("ios", _, "macabi") => (13, 1, 0),
         ("tvos", "aarch64", "sim") => (14, 0, 0),
         ("watchos", "aarch64", "sim") => (7, 0, 0),
-        (os, _, _) => os_minimum_deployment_target(os),
-    }
+        (os, _, _) => return os_minimum_deployment_target(os),
+    };
+    OSVersion { major, minor, patch }
 }
 
 /// Name of the environment variable used to fetch the deployment target on the given OS.
@@ -287,18 +293,68 @@ fn link_env_remove(os: &'static str) -> StaticCow<[StaticCow<str>]> {
 /// Deployment target or SDK version.
 ///
 /// The size of the numbers in here are limited by Mach-O's `LC_BUILD_VERSION`.
-pub type OSVersion = (u16, u8, u8);
-
-/// Parse an OS version triple (SDK version or deployment target).
-pub fn parse_version(version: &str) -> Result<OSVersion, ParseIntError> {
-    if let Some((major, minor)) = version.split_once('.') {
-        let major = major.parse()?;
-        if let Some((minor, patch)) = minor.split_once('.') {
-            Ok((major, minor.parse()?, patch.parse()?))
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct OSVersion {
+    pub major: u16,
+    pub minor: u8,
+    pub patch: u8,
+}
+
+impl OSVersion {
+    pub const MIN: Self = Self { major: u16::MIN, minor: u8::MIN, patch: u8::MIN };
+
+    pub const MAX: Self = Self { major: u16::MAX, minor: u8::MAX, patch: u8::MAX };
+
+    pub fn pretty(self) -> impl fmt::Display {
+        let OSVersion { major, minor, patch } = self;
+        fmt::from_fn(move |f| {
+            write!(f, "{major}.{minor}")?;
+            if patch != 0 {
+                write!(f, ".{patch}")?;
+            }
+            Ok(())
+        })
+    }
+}
+
+impl<'de> de::Deserialize<'de> for OSVersion {
+    fn deserialize<D: de::Deserializer<'de>>(deserializer: D) -> Result<OSVersion, D::Error> {
+        struct OSVersionVisitor;
+
+        impl<'de> de::Visitor<'de> for OSVersionVisitor {
+            type Value = OSVersion;
+
+            fn expecting(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                f.write_str("a valid `major.minor.patch` version")
+            }
+
+            fn visit_str<E: de::Error>(self, value: &str) -> Result<Self::Value, E> {
+                OSVersion::from_str(value).map_err(E::custom)
+            }
+        }
+
+        deserializer.deserialize_str(OSVersionVisitor)
+    }
+}
+
+impl FromStr for OSVersion {
+    type Err = ParseIntError;
+
+    /// Parse an OS version triple (SDK version or deployment target).
+    fn from_str(version: &str) -> Result<Self, Self::Err> {
+        if let Some((major, minor)) = version.split_once('.') {
+            let major = major.parse()?;
+            if let Some((minor, patch)) = minor.split_once('.') {
+                let minor = minor.parse()?;
+                let patch = patch.parse()?;
+                Ok(Self { major, minor, patch })
+            } else {
+                let minor = minor.parse()?;
+                Ok(Self { major, minor, patch: 0 })
+            }
         } else {
-            Ok((major, minor.parse()?, 0))
+            let major = version.parse()?;
+            Ok(Self { major, minor: 0, patch: 0 })
         }
-    } else {
-        Ok((version.parse()?, 0, 0))
     }
 }