Add powerpc64-unknown-linux-gnuelfv2 target

This is virtually the same target as the existing -gnu target, but using
the ELFv2 ABI instead of the ELFv1 ABI and made possible now that we
expose target_abi = "elfv1" or "elfv2" on the 64-bit PowerPC targets.

Author: Gelbpunkt

compiler/rustc_target/src/spec/mod.rs

@@ -1465,6 +1465,7 @@ supported_targets! {
     ("powerpc-unknown-linux-muslspe", powerpc_unknown_linux_muslspe),
     ("powerpc64-ibm-aix", powerpc64_ibm_aix),
     ("powerpc64-unknown-linux-gnu", powerpc64_unknown_linux_gnu),
+    ("powerpc64-unknown-linux-gnuelfv2", powerpc64_unknown_linux_gnuelfv2),
     ("powerpc64-unknown-linux-musl", powerpc64_unknown_linux_musl),
     ("powerpc64le-unknown-linux-gnu", powerpc64le_unknown_linux_gnu),
     ("powerpc64le-unknown-linux-musl", powerpc64le_unknown_linux_musl),

compiler/rustc_target/src/spec/targets/powerpc64_unknown_linux_gnuelfv2.rs

@@ -0,0 +1,30 @@
+use rustc_abi::Endian;
+
+use crate::spec::{
+    Arch, Cc, CfgAbi, LinkerFlavor, Lld, LlvmAbi, StackProbeType, Target, TargetMetadata,
+    TargetOptions, base,
+};
+
+pub(crate) fn target() -> Target {
+    let mut base = base::linux_gnu::opts();
+    base.cpu = "ppc64".into();
+    base.add_pre_link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-m64"]);
+    base.max_atomic_width = Some(64);
+    base.stack_probes = StackProbeType::Inline;
+    base.cfg_abi = CfgAbi::ElfV2;
+    base.llvm_abiname = LlvmAbi::ElfV2;
+
+    Target {
+        llvm_target: "powerpc64-unknown-linux-gnu".into(),
+        metadata: TargetMetadata {
+            description: Some("PPC64 Linux (ELFv2 ABI, kernel 3.2, glibc 2.17)".into()),
+            tier: Some(3),
+            host_tools: Some(false),
+            std: Some(true),
+        },
+        pointer_width: 64,
+        data_layout: "E-m:e-Fn32-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512".into(),
+        arch: Arch::PowerPC64,
+        options: TargetOptions { endian: Endian::Big, mcount: "_mcount".into(), ..base },
+    }
+}

src/bootstrap/src/core/sanity.rs

@@ -37,6 +37,7 @@ pub struct Finder {
 /// when the newly-bumped stage 0 compiler now knows about the formerly-missing targets.
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "powerpc64-unknown-linux-gnuelfv2",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM

src/doc/rustc/src/SUMMARY.md

@@ -107,6 +107,7 @@
     - [powerpc-unknown-linux-gnuspe](platform-support/powerpc-unknown-linux-gnuspe.md)
     - [powerpc-unknown-linux-muslspe](platform-support/powerpc-unknown-linux-muslspe.md)
     - [powerpc64-ibm-aix](platform-support/aix.md)
+    - [powerpc64-unknown-linux-gnuelfv2](platform-support/powerpc64-unknown-linux-gnuelfv2.md)
     - [powerpc64-unknown-linux-musl](platform-support/powerpc64-unknown-linux-musl.md)
     - [powerpc64le-unknown-linux-gnu](platform-support/powerpc64le-unknown-linux-gnu.md)
     - [powerpc64le-unknown-linux-musl](platform-support/powerpc64le-unknown-linux-musl.md)

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

@@ -385,6 +385,7 @@ target | std | host | notes
 [`powerpc-wrs-vxworks-spe`](platform-support/vxworks.md) | ✓ |  |
 [`powerpc64-ibm-aix`](platform-support/aix.md) | ? |  | 64-bit AIX (7.2 and newer)
 [`powerpc64-unknown-freebsd`](platform-support/freebsd.md) | ✓ | ✓ | PPC64 FreeBSD (ELFv2)
+[`powerpc64-unknown-linux-gnuelfv2`](platform-support/powerpc64-unknown-linux-gnuelfv2.md) | ✓ | ✓ | PPC64 Linux (ELFv2 ABI, kernel 3.2, glibc 2.17)
 [`powerpc64-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | OpenBSD/powerpc64
 [`powerpc64-wrs-vxworks`](platform-support/vxworks.md) | ✓ |  |
 [`powerpc64le-unknown-freebsd`](platform-support/freebsd.md) | ✓ | ✓ | PPC64LE FreeBSD

src/doc/rustc/src/platform-support/powerpc64-unknown-linux-gnuelfv2.md

@@ -0,0 +1,50 @@
+# powerpc64-unknown-linux-gnuelfv2
+
+**Tier: 3**
+
+Target for 64-bit big endian PowerPC Linux programs using the ELFv2 ABI and
+the GNU C library.
+
+## Target maintainers
+
+[@Gelbpunkt](https://github.com/Gelbpunkt)
+
+## Requirements
+
+Building the target itself requires a 64-bit big endian PowerPC compiler that
+uses the ELFv2 ABI and is supported by `cc-rs`.
+
+## Building the target
+
+The target can be built by enabling it for a `rustc` build.
+
+```toml
+[build]
+target = ["powerpc64-unknown-linux-gnuelfv2"]
+```
+
+Make sure your C compiler is included in `$PATH`, then add it to the
+`bootstrap.toml`:
+
+```toml
+[target.powerpc64-unknown-linux-gnuelfv2]
+cc = "powerpc64-linux-gnu-gcc"
+cxx = "powerpc64-linux-gnu-g++"
+ar = "powerpc64-linux-gnu-ar"
+linker = "powerpc64-linux-gnu-gcc"
+```
+
+## Building Rust programs
+
+Rust does not yet ship pre-compiled artifacts for this target. To compile for
+this target, you will first need to build Rust with the target enabled (see
+"Building the target" above).
+
+## Cross-compilation
+
+This target can be cross-compiled from any host.
+
+## Testing
+
+This target can be tested as normal with `x.py` on a 64-bit big endian PowerPC
+host or via QEMU emulation.

tests/assembly-llvm/targets/targets-elf.rs

@@ -394,6 +394,10 @@
 //@ revisions: powerpc64_unknown_linux_gnu
 //@ [powerpc64_unknown_linux_gnu] compile-flags: --target powerpc64-unknown-linux-gnu
 //@ [powerpc64_unknown_linux_gnu] needs-llvm-components: powerpc
+//@ revisions: powerpc64_unknown_linux_gnuelfv2
+//@ [powerpc64_unknown_linux_gnuelfv2] compile-flags: --target powerpc64-unknown-linux-gnuelfv2
+//@ [powerpc64_unknown_linux_gnuelfv2] min-llvm-version: 22
+//@ [powerpc64_unknown_linux_gnuelfv2] needs-llvm-components: powerpc
 //@ revisions: powerpc64_unknown_linux_musl
 //@ [powerpc64_unknown_linux_musl] compile-flags: --target powerpc64-unknown-linux-musl
 //@ [powerpc64_unknown_linux_musl] needs-llvm-components: powerpc