Rollup merge of #142053 - heiher:loong32-none, r=wesleywiser

Add new Tier-3 targets: `loongarch32-unknown-none*`

MCP: https://github.com/rust-lang/compiler-team/issues/865

NOTE: LoongArch32 ELF object support is available starting with object v0.37.0.

9 files changed, 44 insertions, 15 deletions

diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index c60c6b8db64..d8c6be78247 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -394,6 +394,7 @@ def default_build_triple(verbose):
         "i686": "i686",
         "i686-AT386": "i686",
         "i786": "i686",
+        "loongarch32": "loongarch32",
         "loongarch64": "loongarch64",
         "m68k": "m68k",
         "csky": "csky",
diff --git a/src/bootstrap/src/core/sanity.rs b/src/bootstrap/src/core/sanity.rs
index af4ec679d08..59ae303e21e 100644
--- a/src/bootstrap/src/core/sanity.rs
+++ b/src/bootstrap/src/core/sanity.rs
@@ -34,6 +34,8 @@ pub struct Finder {
 // Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "loongarch32-unknown-none",
+    "loongarch32-unknown-none-softfloat",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index e7dfaaf4fd5..e2e2ad9ac3b 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -324,6 +324,8 @@ target | std | host | notes
 [`i686-win7-windows-msvc`](platform-support/win7-windows-msvc.md) | ✓ |   | 32-bit Windows 7 support [^x86_32-floats-return-ABI] [^win32-msvc-alignment]
 [`i686-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  | [^x86_32-floats-return-ABI]
 [`loongarch64-unknown-linux-ohos`](platform-support/openharmony.md) | ✓ |   | LoongArch64 OpenHarmony
+[`loongarch32-unknown-none`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32D ABI)
+[`loongarch32-unknown-none-softfloat`](platform-support/loongarch-none.md) | * | LoongArch32 Bare-metal (ILP32S ABI)
 [`m68k-unknown-linux-gnu`](platform-support/m68k-unknown-linux-gnu.md) | ? |  | Motorola 680x0 Linux
 [`m68k-unknown-none-elf`](platform-support/m68k-unknown-none-elf.md) |  |  | Motorola 680x0
 `mips-unknown-linux-gnu` | ✓ | ✓ | MIPS Linux (kernel 4.4, glibc 2.23)
diff --git a/src/doc/rustc/src/platform-support/loongarch-none.md b/src/doc/rustc/src/platform-support/loongarch-none.md
index a2bd6e5734c..fd90b0a2763 100644
--- a/src/doc/rustc/src/platform-support/loongarch-none.md
+++ b/src/doc/rustc/src/platform-support/loongarch-none.md
@@ -1,18 +1,18 @@
 # `loongarch*-unknown-none*`
 
-**Tier: 2**
+Freestanding/bare-metal LoongArch binaries in ELF format: firmware, kernels, etc.
 
-Freestanding/bare-metal LoongArch64 binaries in ELF format: firmware, kernels, etc.
-
-| Target | Description |
-|--------|-------------|
-| `loongarch64-unknown-none` | LoongArch 64-bit, LP64D ABI (freestanding, hard-float) |
-| `loongarch64-unknown-none-softfloat` | LoongArch 64-bit, LP64S ABI (freestanding, soft-float) |
+| Target | Description | Tier |
+|--------|-------------|------|
+| `loongarch32-unknown-none` | LoongArch 32-bit, ILP32D ABI (freestanding, hard-float) | Tier 3 |
+| `loongarch32-unknown-none-softfloat` | LoongArch 32-bit, ILP32S ABI (freestanding, soft-float) | Tier 3 |
+| `loongarch64-unknown-none` | LoongArch 64-bit, LP64D ABI (freestanding, hard-float) | Tier 2 |
+| `loongarch64-unknown-none-softfloat` | LoongArch 64-bit, LP64S ABI (freestanding, soft-float) | Tier 2 |
 
 ## Target maintainers
 
-[@heiher](https://github.com/heiher)
-[@xen0n](https://github.com/xen0n)
+- [@heiher](https://github.com/heiher)
+- [@xen0n](https://github.com/xen0n)
 
 ## Requirements
 
@@ -29,13 +29,13 @@ additional CPU features via the `-C target-feature=` codegen options to rustc, o
 via the `#[target_feature]` mechanism within Rust code.
 
 By default, code generated with the soft-float target should run on any
-LoongArch64 hardware, with the hard-float target additionally requiring an FPU;
+LoongArch hardware, with the hard-float target additionally requiring an FPU;
 enabling additional target features may raise this baseline.
 
 Code generated with the targets will use the `medium` code model by default.
 You can change this using the `-C code-model=` option to rustc.
 
-On `loongarch64-unknown-none*`, `extern "C"` uses the [architecture's standard calling convention][lapcs].
+On `loongarch*-unknown-none*`, `extern "C"` uses the [architecture's standard calling convention][lapcs].
 
 [lapcs]: https://github.com/loongson/la-abi-specs/blob/release/lapcs.adoc
 
@@ -52,6 +52,8 @@ list in `bootstrap.toml`:
 [build]
 build-stage = 1
 target = [
+  "loongarch32-unknown-none",
+  "loongarch32-unknown-none-softfloat",
   "loongarch64-unknown-none",
   "loongarch64-unknown-none-softfloat",
 ]
@@ -64,13 +66,28 @@ As the targets support a variety of different environments and do not support
 
 ## Building Rust programs
 
+### loongarch32-unknown-none*
+
+The `loongarch32-unknown-none*` targets are Tier 3, so you must build the Rust
+compiler from source to use them.
+
+```sh
+# target flag may be used with any cargo or rustc command
+cargo build --target loongarch32-unknown-none
+cargo build --target loongarch32-unknown-none-softfloat
+```
+
+### loongarch64-unknown-none*
+
 Starting with Rust 1.74, precompiled artifacts are provided via `rustup`:
 
 ```sh
 # install cross-compile toolchain
 rustup target add loongarch64-unknown-none
+rustup target add loongarch64-unknown-none-softfloat
 # target flag may be used with any cargo or rustc command
 cargo build --target loongarch64-unknown-none
+cargo build --target loongarch64-unknown-none-softfloat
 ```
 
 ## Cross-compilation toolchains and C code
@@ -79,10 +96,10 @@ For cross builds, you will need an appropriate LoongArch C/C++ toolchain for
 linking, or if you want to compile C code along with Rust (such as for Rust
 crates with C dependencies).
 
-Rust *may* be able to use an `loongarch64-unknown-linux-gnu-` toolchain with
+Rust *may* be able to use an `loongarch{32,64}-unknown-linux-{gnu,musl}-` toolchain with
 appropriate standalone flags to build for this toolchain (depending on the assumptions
 of that toolchain, see below), or you may wish to use a separate
-`loongarch64-unknown-none` toolchain.
+`loongarch{32,64}-unknown-none` toolchain.
 
 On some LoongArch hosts that use ELF binaries, you *may* be able to use the host
 C toolchain, if it does not introduce assumptions about the host environment
diff --git a/src/librustdoc/clean/cfg.rs b/src/librustdoc/clean/cfg.rs
index ebc276b38fb..a3762e4117d 100644
--- a/src/librustdoc/clean/cfg.rs
+++ b/src/librustdoc/clean/cfg.rs
@@ -508,6 +508,7 @@ impl fmt::Display for Display<'_> {
                     (sym::target_arch, Some(arch)) => match arch.as_str() {
                         "aarch64" => "AArch64",
                         "arm" => "ARM",
+                        "loongarch32" => "LoongArch LA32",
                         "loongarch64" => "LoongArch LA64",
                         "m68k" => "M68k",
                         "csky" => "CSKY",
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index f8209f2c8cd..4c53ea42793 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -113,6 +113,8 @@ static TARGETS: &[&str] = &[
     "i686-unknown-uefi",
     "loongarch64-unknown-linux-gnu",
     "loongarch64-unknown-linux-musl",
+    "loongarch32-unknown-none",
+    "loongarch32-unknown-none-softfloat",
     "loongarch64-unknown-none",
     "loongarch64-unknown-none-softfloat",
     "m68k-unknown-linux-gnu",
diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index 4f93b498741..9b9d94bbead 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -495,6 +495,7 @@ impl Config {
             "arm64ec",
             "riscv32",
             "riscv64",
+            "loongarch32",
             "loongarch64",
             "s390x",
             // These targets require an additional asm_experimental_arch feature.
diff --git a/src/tools/compiletest/src/directive-list.rs b/src/tools/compiletest/src/directive-list.rs
index 5757e422ae2..1406553c9ea 100644
--- a/src/tools/compiletest/src/directive-list.rs
+++ b/src/tools/compiletest/src/directive-list.rs
@@ -73,6 +73,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "ignore-linux",
     "ignore-lldb",
     "ignore-llvm-version",
+    "ignore-loongarch32",
     "ignore-loongarch64",
     "ignore-macabi",
     "ignore-macos",
@@ -196,6 +197,7 @@ const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
     "only-i686-unknown-linux-gnu",
     "only-ios",
     "only-linux",
+    "only-loongarch32",
     "only-loongarch64",
     "only-loongarch64-unknown-linux-gnu",
     "only-macos",
diff --git a/src/tools/miri/src/shims/alloc.rs b/src/tools/miri/src/shims/alloc.rs
index 323b95d5f5f..d7bb16f0858 100644
--- a/src/tools/miri/src/shims/alloc.rs
+++ b/src/tools/miri/src/shims/alloc.rs
@@ -13,10 +13,11 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // alignment requirement and size less than or equal to the size requested."
         // So first we need to figure out what the limits are for "fundamental alignment".
         // This is given by `alignof(max_align_t)`. The following list is taken from
-        // `library/std/src/sys/pal/common/alloc.rs` (where this is called `MIN_ALIGN`) and should
+        // `library/std/src/sys/alloc/mod.rs` (where this is called `MIN_ALIGN`) and should
         // be kept in sync.
         let max_fundamental_align = match this.tcx.sess.target.arch.as_ref() {
-            "x86" | "arm" | "mips" | "mips32r6" | "powerpc" | "powerpc64" | "wasm32" => 8,
+            "x86" | "arm" | "loongarch32" | "mips" | "mips32r6" | "powerpc" | "powerpc64"
+            | "wasm32" => 8,
             "x86_64" | "aarch64" | "mips64" | "mips64r6" | "s390x" | "sparc64" | "loongarch64" =>
                 16,
             arch => bug!("unsupported target architecture for malloc: `{}`", arch),