add support for riscv64+musl

MODULE.bazel

@@ -6,7 +6,7 @@ module(
 bazel_dep(name = "bazel_features", version = "1.21.0")
 bazel_dep(name = "platforms", version = "0.0.10")
 
-bazel_dep(name = "rules_go", version = "0.54.0", dev_dependency = True)
+bazel_dep(name = "rules_go", version = "0.59.0", dev_dependency = True)
 
 go_sdk = use_extension(
     "@rules_go//go:extensions.bzl",
@@ -56,6 +56,9 @@ register_toolchains(
     "@zig_sdk//toolchain:wasip1_wasm",
     "@zig_sdk//toolchain:none_wasm",
 
+    # riscv64 toolchains for libc-aware platforms:
+    "@zig_sdk//libc_aware/toolchain:linux_riscv64_musl",
+
     # zig toolchains
     "@zig_sdk//toolchain:zig",
     dev_dependency = True,

go.mod

@@ -6,7 +6,7 @@ toolchain go1.23.6
 
 require (
 	github.com/bazelbuild/buildtools v0.0.0-20240918101019-be1c24cc9a44
-	github.com/bazelbuild/rules_go v0.54.0
+	github.com/bazelbuild/rules_go v0.59.0
 	github.com/stretchr/testify v1.8.2
 	github.com/tetratelabs/wazero v1.6.0
 )

test/glibc_hacks/BUILD

@@ -21,5 +21,6 @@ cc_binary(
         ("linux_amd64_musl", "//libc_aware/platform:linux_amd64_musl"),
         ("linux_amd64_gnu.2.28", "//libc_aware/platform:linux_amd64_gnu.2.28"),
         ("linux_arm64_musl", "//libc_aware/platform:linux_arm64_musl"),
+        ("linux_riscv64_musl_zig", "//libc_aware/platform:linux_riscv64_musl_zig"),
     ]
 ]

toolchain/defs.bzl

@@ -22,6 +22,7 @@ _DEFAULT_INCLUDE_DIRECTORIES = [
 
 _HOST_PLATFORM_EXT = {
     "linux-aarch64": "tar.xz",
+    "linux-riscv64": "tar.xz",
     "linux-x86_64": "tar.xz",
     "macos-aarch64": "tar.xz",
     "macos-x86_64": "tar.xz",
@@ -32,6 +33,7 @@ _HOST_PLATFORM_EXT = {
 # map bazel's host_platform to zig's -target= and -mcpu=
 _TARGET_MCPU = {
     "linux-aarch64": ("aarch64-linux-musl", "baseline"),
+    "linux-riscv64": ("riscv64-linux-musl", "baseline"),
     "linux-x86_64": ("x86_64-linux-musl", "baseline"),
     "macos-aarch64": ("aarch64-macos-none", "apple_a14"),
     "macos-x86_64": ("x86_64-macos-none", "baseline"),

toolchain/ext.bzl

@@ -8,7 +8,7 @@ _exec_platform = tag_class(
             mandatory = True,
         ),
         "arch": attr.string(
-            values = ["amd64", "arm64"],
+            values = ["amd64", "arm64", "riscv64"],
             mandatory = True,
         ),
     },

toolchain/platform/defs.bzl

@@ -32,18 +32,38 @@ def declare_libc_aware_platforms():
                 extra_constraints = ["//libc:{}".format(libc)],
             )
 
+    declare_platform(
+        "riscv64",
+        "riscv64",
+        "linux",
+        "linux",
+        suffix = "_{}".format("musl"),
+        extra_constraints = ["//libc:{}".format("musl")],
+    )
+
 def declare_platform(gocpu, zigcpu, bzlos, os, suffix = "", extra_constraints = []):
     constraint_values = [
         "@platforms//os:{}".format(bzlos),
         "@platforms//cpu:{}".format(zigcpu),
     ] + extra_constraints
 
+    if gocpu != zigcpu:
+        native.platform(
+            name = "{os}_{zigcpu}{suffix}".format(os = os, zigcpu = zigcpu, suffix = suffix),
+            constraint_values = constraint_values,
+        )
+        native.platform(
+            name = "{os}_{gocpu}{suffix}".format(os = os, gocpu = gocpu, suffix = suffix),
+            constraint_values = constraint_values,
+        )
+        return
+
+    # for riscv64, zigcpu==gocpu
     native.platform(
-        name = "{os}_{zigcpu}{suffix}".format(os = os, zigcpu = zigcpu, suffix = suffix),
+        name = "{os}_{zigcpu}{suffix}_zig".format(os = os, zigcpu = zigcpu, suffix = suffix),
         constraint_values = constraint_values,
     )
-
     native.platform(
-        name = "{os}_{gocpu}{suffix}".format(os = os, gocpu = gocpu, suffix = suffix),
+        name = "{os}_{gocpu}{suffix}_go".format(os = os, gocpu = gocpu, suffix = suffix),
         constraint_values = constraint_values,
     )

toolchain/private/defs.bzl

@@ -50,6 +50,7 @@ def target_structs():
             ret.append(_target_linux_gnu(gocpu, zigcpu, glibc))
     ret.append(_target_wasm())
     ret.append(_target_wasm_no_wasi())
+    ret.append(_target_linux_musl("riscv64", "riscv64"))
     return ret
 
 def _target_macos(gocpu, zigcpu):
@@ -184,7 +185,8 @@ def _target_linux_musl(gocpu, zigcpu):
                    ] +
                    # x86_64-linux-any is x86_64-linux and x86-linux combined.
                    (["libc/include/x86-linux-any"] if zigcpu == "x86_64" else []) +
-                   (["libc/include/{}-linux-any".format(zigcpu)] if zigcpu != "x86_64" else []) + [
+                   (["libc/include/aarch64-linux-any".format(zigcpu)] if zigcpu == "aarch64" else []) +
+                   (["libc/include/riscv-linux-any"] if zigcpu == "riscv64" else []) + [
             "libc/include/any-linux-any",
         ] + _INCLUDE_TAIL,
         linkopts = [],

toolchain/private/zig_sdk.bzl

@@ -2,6 +2,7 @@ VERSION = "0.12.0"
 
 HOST_PLATFORM_SHA256 = {
     "linux-aarch64": "754f1029484079b7e0ca3b913a0a2f2a6afd5a28990cb224fe8845e72f09de63",
+    "linux-riscv64": "bb2d1a78b01595a9c00ffd2e12ab46e32f8b6798f76aec643ff78e5b4f5c5afd",
     "linux-x86_64": "c7ae866b8a76a568e2d5cfd31fe89cdb629bdd161fdd5018b29a4a0a17045cad",
     "macos-aarch64": "294e224c14fd0822cfb15a35cf39aa14bd9967867999bf8bdfe3db7ddec2a27f",
     "macos-x86_64": "4d411bf413e7667821324da248e8589278180dbc197f4f282b7dbb599a689311",

toolchain/zig-wrapper.zig

@@ -285,7 +285,7 @@ fn getRunMode(self_exe: []const u8, self_base_noexe: []const u8) error{BadParent
     var it = mem.split(u8, triple, "-");
 
     const arch = it.next() orelse return error.BadParent;
-    if (mem.indexOf(u8, "aarch64,x86_64,wasm32", arch) == null)
+    if (mem.indexOf(u8, "aarch64,x86_64,wasm32,riscv64", arch) == null)
         return error.BadParent;
 
     const got_os = it.next() orelse return error.BadParent;