Fix automatic host platform detection to check the --host_cpu flag.

Also adds a new target_platform attribute that checks the --cpu flag.

Part of #2219.

Change-Id: Icc732917db127ac8377a7722adc70b1a722d538a
PiperOrigin-RevId: 158143095

1 files changed, 107 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/AutoCpuConverter.java b/src/main/java/com/google/devtools/build/lib/analysis/config/AutoCpuConverter.java
new file mode 100644
index 0000000000..d63ffdd630
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/AutoCpuConverter.java
@@ -0,0 +1,107 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.analysis.config;
+
+import com.google.devtools.build.lib.util.CPU;
+import com.google.devtools.build.lib.util.OS;
+import com.google.devtools.build.lib.util.Pair;
+import com.google.devtools.common.options.Converter;
+import com.google.devtools.common.options.OptionsParsingException;
+
+/**
+ * Converter to auto-detect the cpu of the machine on which Bazel runs.
+ *
+ * <p>If the compilation happens remotely then the cpu of the remote machine might be different from
+ * the auto-detected one and the --cpu and --host_cpu options must be set explicitly.
+ */
+public class AutoCpuConverter implements Converter<String> {
+  @Override
+  public String convert(String input) throws OptionsParsingException {
+    if (input.isEmpty()) {
+      // TODO(philwo) - replace these deprecated names with more logical ones (e.g. k8 becomes
+      // linux-x86_64, darwin includes the CPU architecture, ...).
+      switch (OS.getCurrent()) {
+        case DARWIN:
+          return "darwin";
+        case FREEBSD:
+          return "freebsd";
+        case WINDOWS:
+          switch (CPU.getCurrent()) {
+            case X86_64:
+              return "x64_windows";
+            default:
+              // We only support x64 Windows for now.
+              return "unknown";
+          }
+        case LINUX:
+          switch (CPU.getCurrent()) {
+            case X86_32:
+              return "piii";
+            case X86_64:
+              return "k8";
+            case PPC:
+              return "ppc";
+            case ARM:
+              return "arm";
+            case S390X:
+              return "s390x";
+            default:
+              return "unknown";
+          }
+        default:
+          return "unknown";
+      }
+    }
+    return input;
+  }
+
+  /** Reverses the conversion performed by {@link #convert} to return the matching OS, CPU pair. */
+  public static Pair<CPU, OS> reverse(String input) {
+    if (input == null || input.length() == 0 || "unknown".equals(input)) {
+      // Use the auto-detected values.
+      return Pair.of(CPU.getCurrent(), OS.getCurrent());
+    }
+
+    // Handle the easy cases.
+    if (input.startsWith("darwin")) {
+      return Pair.of(CPU.getCurrent(), OS.DARWIN);
+    } else if (input.startsWith("freebsd")) {
+      return Pair.of(CPU.getCurrent(), OS.FREEBSD);
+    } else if (input.startsWith("x64_windows")) {
+      return Pair.of(CPU.getCurrent(), OS.WINDOWS);
+    }
+
+    // Handle the Linux cases.
+    if (input.equals("piii")) {
+      return Pair.of(CPU.X86_32, OS.LINUX);
+    } else if (input.equals("k8")) {
+      return Pair.of(CPU.X86_64, OS.LINUX);
+    } else if (input.equals("ppc")) {
+      return Pair.of(CPU.PPC, OS.LINUX);
+    } else if (input.equals("arm")) {
+      return Pair.of(CPU.ARM, OS.LINUX);
+    } else if (input.equals("s390x")) {
+      return Pair.of(CPU.S390X, OS.LINUX);
+    }
+
+    // Use the auto-detected values.
+    return Pair.of(CPU.getCurrent(), OS.getCurrent());
+  }
+
+  @Override
+  public String getTypeDescription() {
+    return "a string";
+  }
+}