Raise minimum supported iOS version to 10.0

Drop the armv7-apple-ios target too because its no longer supported
with the hardware iOS 10 requires.

compiler/rustc_target/src/spec/apple_base.rs

@@ -11,7 +11,6 @@ use Arch::*;
 #[allow(non_camel_case_types)]
 #[derive(Copy, Clone)]
 pub enum Arch {
-    Armv7,
     Armv7k,
     Armv7s,
     Arm64,
@@ -29,7 +28,6 @@ pub enum Arch {
 impl Arch {
     pub fn target_name(self) -> &'static str {
         match self {
-            Armv7 => "armv7",
             Armv7k => "armv7k",
             Armv7s => "armv7s",
             Arm64 | Arm64_macabi | Arm64_sim => "arm64",
@@ -43,7 +41,7 @@ impl Arch {
 
     pub fn target_arch(self) -> Cow<'static, str> {
         Cow::Borrowed(match self {
-            Armv7 | Armv7k | Armv7s => "arm",
+            Armv7k | Armv7s => "arm",
             Arm64 | Arm64_32 | Arm64_macabi | Arm64_sim => "aarch64",
             I386 | I686 => "x86",
             X86_64 | X86_64_sim | X86_64_macabi | X86_64h => "x86_64",
@@ -52,7 +50,7 @@ impl Arch {
 
     fn target_abi(self) -> &'static str {
         match self {
-            Armv7 | Armv7k | Armv7s | Arm64 | Arm64_32 | I386 | I686 | X86_64 | X86_64h => "",
+            Armv7k | Armv7s | Arm64 | Arm64_32 | I386 | I686 | X86_64 | X86_64h => "",
             X86_64_macabi | Arm64_macabi => "macabi",
             // x86_64-apple-ios is a simulator target, even though it isn't
             // declared that way in the target like the other ones...
@@ -62,9 +60,8 @@ impl Arch {
 
     fn target_cpu(self) -> &'static str {
         match self {
-            Armv7 => "cortex-a8", // iOS7 is supported on iPhone 4 and higher
             Armv7k => "cortex-a8",
-            Armv7s => "cortex-a9",
+            Armv7s => "swift", // iOS 10 is only supported on iPhone 5 or higher.
             Arm64 => "apple-a7",
             Arm64_32 => "apple-s4",
             // Only macOS 10.12+ is supported, which means
@@ -118,9 +115,6 @@ fn pre_link_args(os: &'static str, arch: Arch, abi: &'static str) -> LinkArgs {
 }
 
 pub fn opts(os: &'static str, arch: Arch) -> TargetOptions {
-    // TODO: iOS 10+ always has TLS too.
-    let has_thread_local = os == "macos";
-
     let abi = arch.target_abi();
 
     TargetOptions {
@@ -136,12 +130,17 @@ pub fn opts(os: &'static str, arch: Arch) -> TargetOptions {
         pre_link_args: pre_link_args(os, arch, abi),
         families: cvs!["unix"],
         is_like_osx: true,
-        default_dwarf_version: 2,
+        // LLVM notes that macOS 10.11+ and iOS 9+ default
+        // to v4, so we do the same.
+        // https://github.com/llvm/llvm-project/blob/378778a0d10c2f8d5df8ceff81f95b6002984a4b/clang/lib/Driver/ToolChains/Darwin.cpp#L1203
+        default_dwarf_version: 4,
         frame_pointer: FramePointer::Always,
         has_rpath: true,
         dll_suffix: ".dylib".into(),
         archive_format: "darwin".into(),
-        has_thread_local,
+        // Thread locals became available with iOS 8 and macOS 10.7,
+        // and both are far below our minimum.
+        has_thread_local: true,
         abi_return_struct_as_int: true,
         emit_debug_gdb_scripts: false,
         eh_frame_header: false,
@@ -281,8 +280,8 @@ fn link_env_remove(arch: Arch, os: &'static str) -> StaticCow<[StaticCow<str>]>
         // Otherwise if cross-compiling for a different OS/SDK, remove any part
         // of the linking environment that's wrong and reversed.
         match arch {
-            Armv7 | Armv7k | Armv7s | Arm64 | Arm64_32 | I386 | I686 | X86_64 | X86_64_sim
-            | X86_64h | Arm64_sim => {
+            Armv7k | Armv7s | Arm64 | Arm64_32 | I386 | I686 | X86_64 | X86_64_sim | X86_64h
+            | Arm64_sim => {
                 cvs!["MACOSX_DEPLOYMENT_TARGET"]
             }
             X86_64_macabi | Arm64_macabi => cvs!["IPHONEOS_DEPLOYMENT_TARGET"],
@@ -292,7 +291,7 @@ fn link_env_remove(arch: Arch, os: &'static str) -> StaticCow<[StaticCow<str>]>
 
 fn ios_deployment_target() -> (u32, u32) {
     // If you are looking for the default deployment target, prefer `rustc --print deployment-target`.
-    from_set_deployment_target("IPHONEOS_DEPLOYMENT_TARGET").unwrap_or((7, 0))
+    from_set_deployment_target("IPHONEOS_DEPLOYMENT_TARGET").unwrap_or((10, 0))
 }
 
 fn mac_catalyst_deployment_target() -> (u32, u32) {

compiler/rustc_target/src/spec/armv7_apple_ios.rs

@@ -1,21 +0,0 @@
-use super::apple_base::{ios_llvm_target, opts, Arch};
-use crate::spec::{Target, TargetOptions};
-
-pub fn target() -> Target {
-    let arch = Arch::Armv7;
-    Target {
-        // Clang automatically chooses a more specific target based on
-        // IPHONEOS_DEPLOYMENT_TARGET.
-        // This is required for the target to pick the right
-        // MACH-O commands, so we do too.
-        llvm_target: ios_llvm_target(arch).into(),
-        pointer_width: 32,
-        data_layout: "e-m:o-p:32:32-Fi8-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32".into(),
-        arch: arch.target_arch(),
-        options: TargetOptions {
-            features: "+v7,+vfp3,+neon".into(),
-            max_atomic_width: Some(64),
-            ..opts("ios", arch)
-        },
-    }
-}

compiler/rustc_target/src/spec/armv7s_apple_ios.rs

@@ -1,10 +1,10 @@
-use super::apple_base::{opts, Arch};
+use super::apple_base::{ios_llvm_target, opts, Arch};
 use crate::spec::{Target, TargetOptions};
 
 pub fn target() -> Target {
     let arch = Arch::Armv7s;
     Target {
-        llvm_target: "armv7s-apple-ios".into(),
+        llvm_target: ios_llvm_target(arch).into(),
         pointer_width: 32,
         data_layout: "e-m:o-p:32:32-Fi8-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32".into(),
         arch: arch.target_arch(),

compiler/rustc_target/src/spec/mod.rs

@@ -1390,7 +1390,6 @@ supported_targets! {
     ("i386-apple-ios", i386_apple_ios),
     ("x86_64-apple-ios", x86_64_apple_ios),
     ("aarch64-apple-ios", aarch64_apple_ios),
-    ("armv7-apple-ios", armv7_apple_ios),
     ("armv7s-apple-ios", armv7s_apple_ios),
     ("x86_64-apple-ios-macabi", x86_64_apple_ios_macabi),
     ("aarch64-apple-ios-macabi", aarch64_apple_ios_macabi),