From 47474f10558a473258510b0e5dea13d607a5d34c Mon Sep 17 00:00:00 2001
From: Tobias Kortkamp <t@tobik.me>
Date: Sat, 27 Nov 2021 07:23:55 +0100
Subject: [PATCH] Add riscv64gc-unknown-freebsd

---
 compiler/rustc_llvm/build.rs                   |  2 +-
 compiler/rustc_target/src/spec/mod.rs          |  1 +
 .../src/spec/riscv64gc_unknown_freebsd.rs      | 18 ++++++++++++++++++
 library/std/src/os/raw/mod.rs                  |  6 ++++--
 src/bootstrap/bootstrap.py                     |  2 +-
 src/bootstrap/native.rs                        |  2 +-
 src/doc/rustc/src/platform-support.md          |  1 +
 7 files changed, 27 insertions(+), 5 deletions(-)
 create mode 100644 compiler/rustc_target/src/spec/riscv64gc_unknown_freebsd.rs

diff --git a/compiler/rustc_llvm/build.rs b/compiler/rustc_llvm/build.rs
index 943ce589c4f..7f3345d2a70 100644
--- a/compiler/rustc_llvm/build.rs
+++ b/compiler/rustc_llvm/build.rs
@@ -277,7 +277,7 @@ fn main() {
     };
 
     // RISC-V requires libatomic for sub-word atomic operations
-    if target.starts_with("riscv") {
+    if !target.contains("freebsd") && target.starts_with("riscv") {
         println!("cargo:rustc-link-lib=atomic");
     }
 
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 69b90bf10fe..35a7ec5f946 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -813,6 +813,7 @@ supported_targets! {
     ("powerpc-unknown-freebsd", powerpc_unknown_freebsd),
     ("powerpc64-unknown-freebsd", powerpc64_unknown_freebsd),
     ("powerpc64le-unknown-freebsd", powerpc64le_unknown_freebsd),
+    ("riscv64gc-unknown-freebsd", riscv64gc_unknown_freebsd),
     ("x86_64-unknown-freebsd", x86_64_unknown_freebsd),
 
     ("x86_64-unknown-dragonfly", x86_64_unknown_dragonfly),
diff --git a/compiler/rustc_target/src/spec/riscv64gc_unknown_freebsd.rs b/compiler/rustc_target/src/spec/riscv64gc_unknown_freebsd.rs
new file mode 100644
index 00000000000..1ea1b9bea2e
--- /dev/null
+++ b/compiler/rustc_target/src/spec/riscv64gc_unknown_freebsd.rs
@@ -0,0 +1,18 @@
+use crate::spec::{CodeModel, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "riscv64-unknown-freebsd".to_string(),
+        pointer_width: 64,
+        data_layout: "e-m:e-p:64:64-i64:64-i128:128-n64-S128".to_string(),
+        arch: "riscv64".to_string(),
+        options: TargetOptions {
+            code_model: Some(CodeModel::Medium),
+            cpu: "generic-rv64".to_string(),
+            features: "+m,+a,+f,+d,+c".to_string(),
+            llvm_abiname: "lp64d".to_string(),
+            max_atomic_width: Some(64),
+            ..super::freebsd_base::opts()
+        },
+    }
+}
diff --git a/library/std/src/os/raw/mod.rs b/library/std/src/os/raw/mod.rs
index 01392ffab79..f0b38d29845 100644
--- a/library/std/src/os/raw/mod.rs
+++ b/library/std/src/os/raw/mod.rs
@@ -69,7 +69,8 @@ type_alias! { "char.md", c_char = u8, NonZero_c_char = NonZeroU8;
             target_arch = "aarch64",
             target_arch = "arm",
             target_arch = "powerpc",
-            target_arch = "powerpc64"
+            target_arch = "powerpc64",
+            target_arch = "riscv64"
         )
     ),
     all(
@@ -112,7 +113,8 @@ type_alias! { "char.md", c_char = i8, NonZero_c_char = NonZeroI8;
             target_arch = "aarch64",
             target_arch = "arm",
             target_arch = "powerpc",
-            target_arch = "powerpc64"
+            target_arch = "powerpc64",
+            target_arch = "riscv64"
         )
     ),
     all(
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 38d3c7aec49..6b6cefe487a 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -265,7 +265,7 @@ def default_build_triple(verbose):
         err = "unknown OS type: {}".format(ostype)
         sys.exit(err)
 
-    if cputype == 'powerpc' and ostype == 'unknown-freebsd':
+    if cputype in ['powerpc', 'riscv'] and ostype == 'unknown-freebsd':
         cputype = subprocess.check_output(
               ['uname', '-p']).strip().decode(default_encoding)
     cputype_mapper = {
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index 37578e30f6d..f50797285d2 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -249,7 +249,7 @@ impl Step for Llvm {
             }
         }
 
-        if target.starts_with("riscv") {
+        if !target.contains("freebsd") && target.starts_with("riscv") {
             // In RISC-V, using C++ atomics require linking to `libatomic` but the LLVM build
             // system check cannot detect this. Therefore it is set manually here.
             if !builder.config.llvm_tools_enabled {
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 6b0c336b3c7..eb54edc16f5 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -267,6 +267,7 @@ target | std | host | notes
 `riscv32gc-unknown-linux-gnu` |   |   | RISC-V Linux (kernel 5.4, glibc 2.33)
 `riscv32gc-unknown-linux-musl` |   |   | RISC-V Linux (kernel 5.4, musl + RISCV32 support patches)
 `riscv32imc-esp-espidf` | ✓ |  | RISC-V ESP-IDF
+`riscv64gc-unknown-freebsd` |   |   | RISC-V FreeBSD
 `riscv64gc-unknown-linux-musl` |   |   | RISC-V Linux (kernel 4.20, musl 1.2.0)
 `s390x-unknown-linux-musl` |  |  | S390x Linux (kernel 2.6.32, MUSL)
 `sparc-unknown-linux-gnu` | ✓ |  | 32-bit SPARC Linux