Rollup of 6 pull requests

compiler/rustc_target/src/spec/mod.rs

@@ -1600,8 +1600,10 @@ supported_targets! {
     ("aarch64-uwp-windows-msvc", aarch64_uwp_windows_msvc),
     ("x86_64-pc-windows-msvc", x86_64_pc_windows_msvc),
     ("x86_64-uwp-windows-msvc", x86_64_uwp_windows_msvc),
+    ("x86_64-win7-windows-msvc", x86_64_win7_windows_msvc),
     ("i686-pc-windows-msvc", i686_pc_windows_msvc),
     ("i686-uwp-windows-msvc", i686_uwp_windows_msvc),
+    ("i686-win7-windows-msvc", i686_win7_windows_msvc),
     ("i586-pc-windows-msvc", i586_pc_windows_msvc),
     ("thumbv7a-pc-windows-msvc", thumbv7a_pc_windows_msvc),
     ("thumbv7a-uwp-windows-msvc", thumbv7a_uwp_windows_msvc),

compiler/rustc_target/src/spec/targets/i686_win7_windows_msvc.rs

@@ -0,0 +1,32 @@
+use crate::spec::{base, LinkerFlavor, Lld, Target};
+
+pub fn target() -> Target {
+    let mut base = base::windows_msvc::opts();
+    base.cpu = "pentium4".into();
+    base.max_atomic_width = Some(64);
+
+    base.add_pre_link_args(
+        LinkerFlavor::Msvc(Lld::No),
+        &[
+            // Mark all dynamic libraries and executables as compatible with the larger 4GiB address
+            // space available to x86 Windows binaries on x86_64.
+            "/LARGEADDRESSAWARE",
+            // Ensure the linker will only produce an image if it can also produce a table of
+            // the image's safe exception handlers.
+            // https://docs.microsoft.com/en-us/cpp/build/reference/safeseh-image-has-safe-exception-handlers
+            "/SAFESEH",
+        ],
+    );
+    // Workaround for #95429
+    base.has_thread_local = false;
+
+    Target {
+        llvm_target: "i686-pc-windows-msvc".into(),
+        pointer_width: 32,
+        data_layout: "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-\
+            i64:64-f80:128-n8:16:32-a:0:32-S32"
+            .into(),
+        arch: "x86".into(),
+        options: base,
+    }
+}

compiler/rustc_target/src/spec/targets/x86_64_win7_windows_msvc.rs

@@ -0,0 +1,18 @@
+use crate::spec::{base, Target};
+
+pub fn target() -> Target {
+    let mut base = base::windows_msvc::opts();
+    base.cpu = "x86-64".into();
+    base.plt_by_default = false;
+    base.max_atomic_width = Some(64);
+    base.vendor = "win7".into();
+
+    Target {
+        llvm_target: "x86_64-win7-windows-msvc".into(),
+        pointer_width: 64,
+        data_layout: "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+            .into(),
+        arch: "x86_64".into(),
+        options: base,
+    }
+}

src/doc/rustc/src/SUMMARY.md

@@ -56,6 +56,7 @@
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
     - [wasm32-wasi-preview1-threads](platform-support/wasm32-wasi-preview1-threads.md)
     - [wasm64-unknown-unknown](platform-support/wasm64-unknown-unknown.md)
+    - [\*-win7-windows-msvc](platform-support/win7-windows-msvc.md)
     - [x86_64-fortanix-unknown-sgx](platform-support/x86_64-fortanix-unknown-sgx.md)
     - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
     - [x86_64h-apple-darwin](platform-support/x86_64h-apple-darwin.md)

src/doc/rustc/src/platform-support.md

@@ -276,6 +276,7 @@ target | std | host | notes
 [`i686-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 32-bit OpenBSD [^x86_32-floats-return-ABI]
 `i686-uwp-windows-gnu` | ? |  | [^x86_32-floats-return-ABI]
 `i686-uwp-windows-msvc` | ? |  | [^x86_32-floats-return-ABI]
+[`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI]
 `i686-wrs-vxworks` | ? |  | [^x86_32-floats-return-ABI]
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
 `mips-unknown-linux-gnu` | ✓ | ✓ | MIPS Linux (kernel 4.4, glibc 2.23)
@@ -352,6 +353,7 @@ target | std | host | notes
 [`x86_64-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | 64-bit OpenBSD
 `x86_64-uwp-windows-gnu` | ✓ |  |
 `x86_64-uwp-windows-msvc` | ✓ |  |
+[`x86_64-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 64-bit Windows 7 support
 `x86_64-wrs-vxworks` | ? |  |
 [`x86_64h-apple-darwin`](platform-support/x86_64h-apple-darwin.md) | ✓ | ✓ | macOS with late-gen Intel (at least Haswell)
 

src/doc/rustc/src/platform-support/win7-windows-msvc.md

@@ -0,0 +1,80 @@
+# *-win7-windows-msvc
+
+**Tier: 3**
+
+Windows targets continuing support of windows7.
+
+## Target maintainers
+
+- @roblabla
+
+## Requirements
+
+This target supports all of core, alloc, std and test. This is automatically
+tested every night on private infrastructure hosted by the maintainer. Host
+tools may also work, though those are not currently tested.
+
+Those targets follow Windows calling convention for extern "C".
+
+Like any other Windows target, the created binaries are in PE format.
+
+## Building the target
+
+You can build Rust with support for the targets by adding it to the target list in config.toml:
+
+```toml
+[build]
+build-stage = 1
+target = [ "x86_64-win7-windows-msvc" ]
+```
+
+## Building Rust programs
+
+Rust does not ship pre-compiled artifacts for this target. To compile for this
+target, you will either need to build Rust with the target enabled (see
+"Building the target" above), or build your own copy by using `build-std` or
+similar.
+
+## Testing
+
+Created binaries work fine on Windows or Wine using native hardware. Remote
+testing is possible using the `remote-test-server` described [here](https://rustc-dev-guide.rust-lang.org/tests/running.html#running-tests-on-a-remote-machine).
+
+## Cross-compilation toolchains and C code
+
+Compatible C code can be built with either MSVC's `cl.exe` or LLVM's clang-cl.
+
+Cross-compilation is possible using clang-cl/lld-link. It also requires the
+Windows SDK, which can be acquired using [`xwin`](https://github.com/Jake-Shadle/xwin).
+
+- Install `clang-cl` and `lld-link` on your machine, and make sure they are in
+  your $PATH.
+- Install `xwin`: `cargo install xwin`
+- Use `xwin` to install the Windows SDK: `xwin splat --output winsdk`
+- Create an `xwin-lld-link` script with the following content:
+
+  ```bash
+  #!/usr/bin/env bash
+  set -e
+  XWIN=/path/to/winsdk
+  lld-link "$@" /libpath:$XWIN/crt/lib/x86_64 /libpath:$XWIN/sdk/lib/um/x86_64 /libpath:$XWIN/sdk/lib/ucrt/x86_64
+  ```
+
+- Create an `xwin-clang-cl` script with the following content:
+
+  ```bash
+  #!/usr/bin/env bash
+  set -e
+  XWIN=/path/to/winsdk
+  clang-cl /imsvc "$XWIN/crt/include" /imsvc "$XWIN/sdk/include/ucrt" /imsvc "$XWIN/sdk/include/um" /imsvc "$XWIN/sdk/include/shared" --target="x86_64-pc-windows-msvc" "$@"
+  ```
+
+- In your config.toml, add the following lines:
+
+  ```toml
+  [target.x86_64-win7-windows-msvc]
+  linker = "path/to/xwin-lld-link"
+  cc = "path/to/xwin-clang-cl"
+  ```
+
+You should now be able to cross-compile the Rust std, and any rust program.