[5.1] Add "arch" struct field to repository_os

src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkOS.java

@@ -17,6 +17,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.docgen.annot.DocCategory;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import java.util.Locale;
 import java.util.Map;
 import net.starlark.java.annot.StarlarkBuiltin;
 import net.starlark.java.annot.StarlarkMethod;
@@ -49,8 +50,20 @@ public ImmutableMap<String, String> getEnvironmentVariables() {
   @StarlarkMethod(
       name = "name",
       structField = true,
-      doc = "A string identifying the current system Bazel is running on.")
+      doc =
+          "A string identifying the operating system Bazel is running on (the value of the"
+              + " \"os.name\" Java property).")
   public String getName() {
-    return System.getProperty("os.name").toLowerCase();
+    return System.getProperty("os.name").toLowerCase(Locale.ROOT);
+  }
+
+  @StarlarkMethod(
+      name = "arch",
+      structField = true,
+      doc =
+          "A string identifying the architecture Bazel is running on (the value of the \"os.arch\""
+              + " Java property).")
+  public String getArch() {
+    return System.getProperty("os.arch").toLowerCase(Locale.ROOT);
   }
 }

tools/cpp/lib_cc_configure.bzl

@@ -179,38 +179,34 @@ def execute(
 
 def get_cpu_value(repository_ctx):
     """Compute the cpu_value based on the OS name. Doesn't %-escape the result!"""
-    os_name = repository_ctx.os.name.lower()
+    os_name = repository_ctx.os.name
+    arch = repository_ctx.os.arch
     if os_name.startswith("mac os"):
         # Check if we are on x86_64 or arm64 and return the corresponding cpu value.
-        result = repository_ctx.execute(["uname", "-m"])
-        return "darwin" + ("_arm64" if result.stdout.strip() == "arm64" else "")
+        return "darwin" + ("_arm64" if arch == "aarch64" else "")
     if os_name.find("freebsd") != -1:
         return "freebsd"
     if os_name.find("openbsd") != -1:
         return "openbsd"
     if os_name.find("windows") != -1:
-        arch = (get_env_var(repository_ctx, "PROCESSOR_ARCHITECTURE", "", False) or
-                get_env_var(repository_ctx, "PROCESSOR_ARCHITEW6432", "", False))
-        if arch == "ARM64":
+        if arch == "aarch64":
             return "arm64_windows"
         else:
             return "x64_windows"
 
-    # Use uname to figure out whether we are on x86_32 or x86_64
-    result = repository_ctx.execute(["uname", "-m"])
-    if result.stdout.strip() in ["power", "ppc64le", "ppc", "ppc64"]:
+    if arch in ["power", "ppc64le", "ppc", "ppc64"]:
         return "ppc"
-    if result.stdout.strip() in ["s390x"]:
+    if arch in ["s390x"]:
         return "s390x"
-    if result.stdout.strip() in ["mips64"]:
+    if arch in ["mips64"]:
         return "mips64"
-    if result.stdout.strip() in ["riscv64"]:
+    if arch in ["riscv64"]:
         return "riscv64"
-    if result.stdout.strip() in ["arm", "armv7l"]:
+    if arch in ["arm", "armv7l"]:
         return "arm"
-    if result.stdout.strip() in ["aarch64"]:
+    if arch in ["aarch64"]:
         return "aarch64"
-    return "k8" if result.stdout.strip() in ["amd64", "x86_64", "x64"] else "piii"
+    return "k8" if arch in ["amd64", "x86_64", "x64"] else "piii"
 
 def is_cc_configure_debug(repository_ctx):
     """Returns True if CC_CONFIGURE_DEBUG is set to 1."""

tools/jdk/local_java_repository.bzl

@@ -132,7 +132,7 @@ def _local_java_repository_impl(repository_ctx):
         "workspace(name = \"{name}\")\n".format(name = repository_ctx.name),
     )
 
-    extension = ".exe" if repository_ctx.os.name.lower().find("windows") != -1 else ""
+    extension = ".exe" if repository_ctx.os.name.find("windows") != -1 else ""
     java_bin = java_home_path.get_child("bin").get_child("java" + extension)
 
     if not java_bin.exists:

tools/osx/xcode_configure.bzl

@@ -271,7 +271,7 @@ def _impl(repository_ctx):
       repository_ctx: The repository context.
     """
 
-    os_name = repository_ctx.os.name.lower()
+    os_name = repository_ctx.os.name
     build_contents = "package(default_visibility = ['//visibility:public'])\n\n"
     if (os_name.startswith("mac os")):
         build_contents += _darwin_build_file(repository_ctx)