Automated rollback of commit 363413110f3a63a11d900864be1852adbaed2899.

*** Reason for rollback ***

Breaks //src/test/shell/bazel:bazel_bootstrap_distfile_test:

INFO: You can skip this first step by providing a path to the bazel binary as second argument:
INFO:    ./compile.sh compile /path/to/bazel
🍃  Building Bazel from scratch......
🍃  Building Bazel with Bazel.
.WARNING: /tmp/bazel_cHivhPBc/out/external/bazel_tools/WORKSPACE:1: Workspace name in /tmp/bazel_cHivhPBc/out/external/bazel_tools/WORKSPACE (@io_bazel) does not match the name given in the repository's definition (@bazel_tools); this will cause a build error in future versions.
ERROR: in target '//external:cc_toolchain': error loading package '@local_config_cc//': Extension file not found. Unable to load file '@local_config_cc//:dummy_toolchain.bzl': file doesn't exist or isn't a file.
INFO: Elapsed time: 3.343s

ERROR: Could not build Bazel

Found by git bisect.

*** Original change description ***

Add a new toolchain type for c++.  In order to do this, PlatformConfiguration is made a legal configuration fragment for every rule class.

Add a default "dummy" c++ toolchain to prevent resolution errors when legacy toolchain selection logic is used.  Add toolchain mocks to java and shell tests.

PiperOrigin-RevId: 166750885

1 files changed, 3 insertions, 7 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/PlatformSemantics.java b/src/main/java/com/google/devtools/build/lib/analysis/PlatformSemantics.java
index 45c967e551..d93c5a6dea 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/PlatformSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/PlatformSemantics.java
@@ -26,7 +26,6 @@ import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClass;
 import java.util.List;
-import javax.annotation.Nullable;
 
 /** Helper class to manage rules' use of platforms. */
 public class PlatformSemantics {
@@ -41,22 +40,19 @@ public class PlatformSemantics {
         @Override
         public List<Label> resolve(
             Rule rule, AttributeMap attributes, BuildConfiguration configuration) {
-          // rule may be null for tests
-          if (rule == null || rule.getRuleClassObject().getRequiredToolchains().isEmpty()) {
-            return ImmutableList.of();
+          if (rule.getRuleClassObject().getRequiredToolchains().isEmpty()) {
+            return null;
           }
           return configuration.getFragment(PlatformConfiguration.class).getTargetPlatforms();
         }
       };
 
   /** Implementation for the :execution_platform attribute. */
-  @Nullable
   public static final Attribute.LateBoundLabel<BuildConfiguration> EXECUTION_PLATFORM =
       new Attribute.LateBoundLabel<BuildConfiguration>(PlatformConfiguration.class) {
         @Override
         public Label resolve(Rule rule, AttributeMap attributes, BuildConfiguration configuration) {
-          // rule may be null for tests
-          if (rule == null || rule.getRuleClassObject().getRequiredToolchains().isEmpty()) {
+          if (rule.getRuleClassObject().getRequiredToolchains().isEmpty()) {
             return null;
           }
           return configuration.getFragment(PlatformConfiguration.class).getExecutionPlatform();