compiler/rustc_target/src/spec/apple_base.rs

   1 use std::env;
   2
   3 use crate::spec::{LinkArgs, SplitDebuginfo, TargetOptions};
   4
   5 pub fn opts(os: &str) -> TargetOptions {
   6     // ELF TLS is only available in macOS 10.7+. If you try to compile for 10.6
   7     // either the linker will complain if it is used or the binary will end up
   8     // segfaulting at runtime when run on 10.6. Rust by default supports macOS
   9     // 10.7+, but there is a standard environment variable,
  10     // MACOSX_DEPLOYMENT_TARGET, which is used to signal targeting older
  11     // versions of macOS. For example compiling on 10.10 with
  12     // MACOSX_DEPLOYMENT_TARGET set to 10.6 will cause the linker to generate
  13     // warnings about the usage of ELF TLS.
  14     //
  15     // Here we detect what version is being requested, defaulting to 10.7. ELF
  16     // TLS is flagged as enabled if it looks to be supported.
  17     let version = macos_deployment_target();
  18
  19     TargetOptions {
  20         os: os.to_string(),
  21         vendor: "apple".to_string(),
  22         // macOS has -dead_strip, which doesn't rely on function_sections
  23         function_sections: false,
  24         dynamic_linking: true,
  25         executables: true,
  26         os_family: Some("unix".to_string()),
  27         is_like_osx: true,
  28         dwarf_version: Some(2),
  29         has_rpath: true,
  30         dll_prefix: "lib".to_string(),
  31         dll_suffix: ".dylib".to_string(),
  32         archive_format: "darwin".to_string(),
  33         pre_link_args: LinkArgs::new(),
  34         has_elf_tls: version >= (10, 7),
  35         abi_return_struct_as_int: true,
  36         emit_debug_gdb_scripts: false,
  37         eh_frame_header: false,
  38
  39         // The historical default for macOS targets is to run `dsymutil` which
  40         // generates a packed version of debuginfo split from the main file.
  41         split_debuginfo: SplitDebuginfo::Packed,
  42
  43         // This environment variable is pretty magical but is intended for
  44         // producing deterministic builds. This was first discovered to be used
  45         // by the `ar` tool as a way to control whether or not mtime entries in
  46         // the archive headers were set to zero or not. It appears that
  47         // eventually the linker got updated to do the same thing and now reads
  48         // this environment variable too in recent versions.
  49         //
  50         // For some more info see the commentary on #47086
  51         link_env: vec![("ZERO_AR_DATE".to_string(), "1".to_string())],
  52
  53         ..Default::default()
  54     }
  55 }
  56
  57 fn deployment_target(var_name: &str) -> Option<(u32, u32)> {
  58     let deployment_target = env::var(var_name).ok();
  59     deployment_target
  60         .as_ref()
  61         .and_then(|s| s.split_once('.'))
  62         .and_then(|(a, b)| a.parse::<u32>().and_then(|a| b.parse::<u32>().map(|b| (a, b))).ok())
  63 }
  64
  65 fn macos_deployment_target() -> (u32, u32) {
  66     deployment_target("MACOSX_DEPLOYMENT_TARGET").unwrap_or((10, 7))
  67 }
  68
  69 pub fn macos_llvm_target(arch: &str) -> String {
  70     let (major, minor) = macos_deployment_target();
  71     format!("{}-apple-macosx{}.{}.0", arch, major, minor)
  72 }
  73
  74 pub fn macos_link_env_remove() -> Vec<String> {
  75     let mut env_remove = Vec::with_capacity(2);
  76     // Remove the `SDKROOT` environment variable if it's clearly set for the wrong platform, which
  77     // may occur when we're linking a custom build script while targeting iOS for example.
  78     if let Ok(sdkroot) = env::var("SDKROOT") {
  79         if sdkroot.contains("iPhoneOS.platform") || sdkroot.contains("iPhoneSimulator.platform") {
  80             env_remove.push("SDKROOT".to_string())
  81         }
  82     }
  83     // Additionally, `IPHONEOS_DEPLOYMENT_TARGET` must not be set when using the Xcode linker at
  84     // "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld",
  85     // although this is apparently ignored when using the linker at "/usr/bin/ld".
  86     env_remove.push("IPHONEOS_DEPLOYMENT_TARGET".to_string());
  87     env_remove
  88 }
  89
  90 fn ios_deployment_target() -> (u32, u32) {
  91     deployment_target("IPHONEOS_DEPLOYMENT_TARGET").unwrap_or((7, 0))
  92 }
  93
  94 pub fn ios_sim_llvm_target(arch: &str) -> String {
  95     let (major, minor) = ios_deployment_target();
  96     format!("{}-apple-ios{}.{}.0-simulator", arch, major, minor)
  97 }