Match options against parsing result.

Checks whether an existing build options matches a set of flags provided through an option parser (for example from the command line or a file).

Step 2/N towards the platforms mapping functionality for #6426

RELNOTES: None.
PiperOrigin-RevId: 238085427

src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java

@@ -23,6 +23,8 @@
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.collect.Iterables;
+import com.google.common.collect.MapDifference;
+import com.google.common.collect.Maps;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.Ordering;
 import com.google.common.collect.Sets;
@@ -384,6 +386,61 @@ private Map<Class<? extends FragmentOptions>, FragmentOptions> toModifiedFragmen
     return replacedOptions;
   }
 
+  /**
+   * Returns true if the passed parsing result's options have the same value as these options.
+   *
+   * <p>If a native parsed option is passed whose fragment has been trimmed in these options it is
+   * considered to match.
+   *
+   * <p>If no options are present in the parsing result or all options in the parsing result have
+   * been trimmed the result is considered not to match. This is because otherwise the parsing
+   * result would match any options in a similar trimmed state, regardless of contents.
+   *
+   * @param parsingResult parsing result to be compared to these options
+   * @return true if all non-trimmed values match
+   * @throws OptionsParsingException if options cannot be parsed
+   */
+  public boolean matches(OptionsParsingResult parsingResult) throws OptionsParsingException {
+    Set<OptionDefinition> ignoredDefinitions = new HashSet<>();
+    for (ParsedOptionDescription parsedOption : parsingResult.asListOfExplicitOptions()) {
+      OptionDefinition optionDefinition = parsedOption.getOptionDefinition();
+
+      // All options obtained from an options parser are guaranteed to have been defined in an
+      // FragmentOptions class.
+      @SuppressWarnings("unchecked")
+      Class<? extends FragmentOptions> fragmentClass =
+          (Class<? extends FragmentOptions>) optionDefinition.getField().getDeclaringClass();
+
+      FragmentOptions originalFragment = fragmentOptionsMap.get(fragmentClass);
+      if (originalFragment == null) {
+        // Ignore flags set in trimmed fragments.
+        ignoredDefinitions.add(optionDefinition);
+        continue;
+      }
+      Object originalValue = originalFragment.asMap().get(optionDefinition.getOptionName());
+      if (!Objects.equals(originalValue, parsedOption.getConvertedValue())) {
+        return false;
+      }
+    }
+
+    Map<Label, Object> starlarkOptions =
+        labelizeStarlarkOptions(parsingResult.getStarlarkOptions());
+    MapDifference<Label, Object> starlarkDifference =
+        Maps.difference(skylarkOptionsMap, starlarkOptions);
+    if (starlarkDifference.entriesInCommon().size() < starlarkOptions.size()) {
+      return false;
+    }
+
+    if (ignoredDefinitions.size() == parsingResult.asListOfExplicitOptions().size()
+        && starlarkOptions.isEmpty()) {
+      // Zero options were compared, either because none were passed or because all of them were
+      // trimmed.
+      return false;
+    }
+
+    return true;
+  }
+
   /** Creates a builder object for BuildOptions */
   public static Builder builder() {
     return new Builder();

src/test/java/com/google/devtools/build/lib/analysis/config/BuildOptionsTest.java

@@ -345,17 +345,18 @@ public void testMultiValueOptionImmutability() throws Exception {
 
   @Test
   public void parsingResultTransform() throws Exception {
-    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS, "--cpu=foo");
+    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS, "--cpu=foo", "--stamp");
 
     OptionsParser parser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
-    parser.parse("--cpu=bar");
+    parser.parse("--cpu=bar", "--nostamp");
     parser.setStarlarkOptions(ImmutableMap.of("//custom:flag", "hello"));
 
     BuildOptions modified = original.applyParsingResult(parser);
 
     assertThat(original.get(BuildConfiguration.Options.class).cpu)
         .isNotEqualTo(modified.get(BuildConfiguration.Options.class).cpu);
     assertThat(modified.get(BuildConfiguration.Options.class).cpu).isEqualTo("bar");
+    assertThat(modified.get(Options.class).stampBinaries).isFalse();
     assertThat(modified.getStarlarkOptions().get(Label.parseAbsoluteUnchecked("//custom:flag")))
         .isEqualTo("hello");
   }
@@ -387,4 +388,110 @@ public void parsingResultTransformIllegalStarlarkLabel() throws Exception {
 
     assertThrows(IllegalArgumentException.class, () -> original.applyParsingResult(parser));
   }
+
+  @Test
+  public void parsingResultMatch() throws Exception {
+    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS, "--cpu=foo", "--stamp");
+
+    OptionsParser matchingParser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    matchingParser.parse("--cpu=foo", "--stamp");
+
+    OptionsParser notMatchingParser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    notMatchingParser.parse("--cpu=foo", "--nostamp");
+
+    assertThat(original.matches(matchingParser)).isTrue();
+    assertThat(original.matches(notMatchingParser)).isFalse();
+  }
+
+  @Test
+  public void parsingResultMatchStarlark() throws Exception {
+    BuildOptions original =
+        BuildOptions.builder()
+            .addStarlarkOption(Label.parseAbsoluteUnchecked("//custom:flag"), "hello")
+            .build();
+
+    OptionsParser matchingParser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    matchingParser.setStarlarkOptions(ImmutableMap.of("//custom:flag", "hello"));
+
+    OptionsParser notMatchingParser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    notMatchingParser.setStarlarkOptions(ImmutableMap.of("//custom:flag", "foo"));
+
+    assertThat(original.matches(matchingParser)).isTrue();
+    assertThat(original.matches(notMatchingParser)).isFalse();
+  }
+
+  @Test
+  public void parsingResultMatchMissingFragment() throws Exception {
+    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS, "--cpu=foo");
+
+    ImmutableList<Class<? extends FragmentOptions>> fragmentClasses =
+        ImmutableList.<Class<? extends FragmentOptions>>builder()
+            .add(BuildConfiguration.Options.class)
+            .add(CppOptions.class)
+            .build();
+
+    OptionsParser parser = OptionsParser.newOptionsParser(fragmentClasses);
+    parser.parse("--cpu=foo", "--cxxopt=bar");
+
+    assertThat(original.matches(parser)).isTrue();
+  }
+
+  @Test
+  public void parsingResultMatchEmptyNativeMatch() throws Exception {
+    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS, "--cpu=foo");
+
+    ImmutableList<Class<? extends FragmentOptions>> fragmentClasses =
+        ImmutableList.<Class<? extends FragmentOptions>>builder()
+            .add(BuildConfiguration.Options.class)
+            .add(CppOptions.class)
+            .build();
+
+    OptionsParser parser = OptionsParser.newOptionsParser(fragmentClasses);
+    parser.parse("--cxxopt=bar");
+
+    assertThat(original.matches(parser)).isFalse();
+  }
+
+  @Test
+  public void parsingResultMatchEmptyNativeMatchWithStarlark() throws Exception {
+    BuildOptions original =
+        BuildOptions.builder()
+            .addStarlarkOption(Label.parseAbsoluteUnchecked("//custom:flag"), "hello")
+            .build();
+
+    ImmutableList<Class<? extends FragmentOptions>> fragmentClasses =
+        ImmutableList.<Class<? extends FragmentOptions>>builder()
+            .add(BuildConfiguration.Options.class)
+            .add(CppOptions.class)
+            .build();
+
+    OptionsParser parser = OptionsParser.newOptionsParser(fragmentClasses);
+    parser.parse("--cxxopt=bar");
+    parser.setStarlarkOptions(ImmutableMap.of("//custom:flag", "hello"));
+
+    assertThat(original.matches(parser)).isTrue();
+  }
+
+  @Test
+  public void parsingResultMatchStarlarkOptionMissing() throws Exception {
+    BuildOptions original =
+        BuildOptions.builder()
+            .addStarlarkOption(Label.parseAbsoluteUnchecked("//custom:flag1"), "hello")
+            .build();
+
+    OptionsParser parser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    parser.setStarlarkOptions(ImmutableMap.of("//custom:flag2", "foo"));
+
+    assertThat(original.matches(parser)).isFalse();
+  }
+
+  @Test
+  public void parsingResultMatchNullOption() throws Exception {
+    BuildOptions original = BuildOptions.of(BUILD_CONFIG_OPTIONS);
+
+    OptionsParser parser = OptionsParser.newOptionsParser(BUILD_CONFIG_OPTIONS);
+    parser.parse("--platform_suffix=foo"); // Note: platform_suffix is null by default.
+
+    assertThat(original.matches(parser)).isFalse();
+  }
 }