diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
index ea43073..df97889 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
@@ -14,7 +14,6 @@
 package com.google.devtools.build.lib.runtime;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.base.Predicates;
 import com.google.common.base.Throwables;
@@ -51,6 +50,7 @@
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.common.options.InvocationPolicyEnforcer;
 import com.google.devtools.common.options.OpaqueOptionsData;
+import com.google.devtools.common.options.OptionDefinition;
 import com.google.devtools.common.options.OptionPriority;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsParsingException;
@@ -68,6 +68,7 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Function;
 import java.util.logging.Level;
 import javax.annotation.Nullable;
 
@@ -207,9 +208,9 @@
       OptionsParser optionsParser, Command commandAnnotation, List<String> args,
       List<String> rcfileNotes, ExtendedEventHandler eventHandler)
           throws OptionsParsingException {
-    Function<String, String> commandOptionSourceFunction =
-        input -> {
-          if (INTERNAL_COMMAND_OPTIONS.contains(input)) {
+    Function<OptionDefinition, String> commandOptionSourceFunction =
+        option -> {
+          if (INTERNAL_COMMAND_OPTIONS.contains(option.getOptionName())) {
             return "options generated by " + runtime.getProductName() + " launcher";
           } else {
             return "command line options";
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index f0414df..711c176 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -877,10 +877,13 @@
     parser.parse(OptionPriority.COMMAND_LINE, null, args);
     Map<String, String> optionSources =
         parser.getOptions(BlazeServerStartupOptions.class).optionSources;
-    Function<String, String> sourceFunction = option ->
-        !optionSources.containsKey(option) ? "default"
-            : optionSources.get(option).isEmpty() ? "command line"
-            : optionSources.get(option);
+    Function<OptionDefinition, String> sourceFunction =
+        option ->
+            !optionSources.containsKey(option.getOptionName())
+                ? "default"
+                : optionSources.get(option.getOptionName()).isEmpty()
+                    ? "command line"
+                    : optionSources.get(option.getOptionName());
 
     // Then parse the command line again, this time with the correct option sources
     parser = OptionsParser.newOptionsParser(optionClasses);
diff --git a/src/main/java/com/google/devtools/common/options/InvocationPolicyEnforcer.java b/src/main/java/com/google/devtools/common/options/InvocationPolicyEnforcer.java
index 37753a9..73c6c5e 100644
--- a/src/main/java/com/google/devtools/common/options/InvocationPolicyEnforcer.java
+++ b/src/main/java/com/google/devtools/common/options/InvocationPolicyEnforcer.java
@@ -14,6 +14,7 @@
 package com.google.devtools.common.options;
 
 import com.google.common.base.Joiner;
+import com.google.common.base.Preconditions;
 import com.google.common.base.Verify;
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableList;
@@ -51,7 +52,8 @@
 
   private static final Logger logger = Logger.getLogger(InvocationPolicyEnforcer.class.getName());
 
-  private static final Function<Object, String> INVOCATION_POLICY_SOURCE = o -> "Invocation policy";
+  private static final Function<OptionDefinition, String> INVOCATION_POLICY_SOURCE =
+      o -> "Invocation policy";
 
   @Nullable private final InvocationPolicy invocationPolicy;
 
@@ -121,11 +123,11 @@
 
       switch (flagPolicy.getOperationCase()) {
         case SET_VALUE:
-          applySetValueOperation(parser, flagPolicy, flagName, valueDescription, optionDescription);
+          applySetValueOperation(parser, flagPolicy, valueDescription, optionDescription);
           break;
 
         case USE_DEFAULT:
-          applyUseDefaultOperation(parser, "UseDefault", flagName);
+          applyUseDefaultOperation(parser, "UseDefault", optionDescription.getOptionDefinition());
           break;
 
         case ALLOW_VALUES:
@@ -135,7 +137,6 @@
               allowValues.getAllowedValuesList(),
               allowValues.hasNewValue() ? allowValues.getNewValue() : null,
               allowValues.hasUseDefault(),
-              flagName,
               valueDescription,
               optionDescription);
           break;
@@ -147,7 +148,6 @@
               disallowValues.getDisallowedValuesList(),
               disallowValues.hasNewValue() ? disallowValues.getNewValue() : null,
               disallowValues.hasUseDefault(),
-              flagName,
               valueDescription,
               optionDescription);
           break;
@@ -238,7 +238,14 @@
       return ImmutableList.of();
     }
 
-    String expansionFlagName = expansionPolicy.getFlagName();
+    Preconditions.checkArgument(
+        expansionPolicy
+            .getFlagName()
+            .equals(optionDescription.getOptionDefinition().getOptionName()),
+        String.format(
+            "The optionDescription provided (for flag %s) does not match the policy for flag %s.",
+            optionDescription.getOptionDefinition().getOptionName(),
+            expansionPolicy.getFlagName()));
 
     ImmutableList.Builder<OptionValueDescription> resultsBuilder = ImmutableList.builder();
     switch (expansionPolicy.getOperationCase()) {
@@ -248,16 +255,20 @@
           if (setValue.getFlagValueCount() > 0) {
             for (String value : setValue.getFlagValueList()) {
               resultsBuilder.addAll(
-                  parser.getExpansionOptionValueDescriptions(expansionFlagName, value));
+                  parser.getExpansionOptionValueDescriptions(
+                      optionDescription.getOptionDefinition(), value));
             }
           } else {
             resultsBuilder.addAll(
-                parser.getExpansionOptionValueDescriptions(expansionFlagName, null));
+                parser.getExpansionOptionValueDescriptions(
+                    optionDescription.getOptionDefinition(), null));
           }
         }
         break;
       case USE_DEFAULT:
-        resultsBuilder.addAll(parser.getExpansionOptionValueDescriptions(expansionFlagName, null));
+        resultsBuilder.addAll(
+            parser.getExpansionOptionValueDescriptions(
+                optionDescription.getOptionDefinition(), null));
         break;
       case ALLOW_VALUES:
         // All expansions originally given to the parser have been expanded by now, so these two
@@ -275,7 +286,8 @@
         logger.warning(
             String.format(
                 "Unknown operation '%s' from invocation policy for flag '%s'",
-                expansionPolicy.getOperationCase(), expansionFlagName));
+                expansionPolicy.getOperationCase(),
+                optionDescription.getOptionDefinition().getOptionName()));
         break;
     }
 
@@ -318,7 +330,7 @@
       // invocation policy does not change, so this can be a log level fine.
       List<String> subflagNames = new ArrayList<>(subflags.size());
       for (OptionValueDescription subflag : subflags) {
-        subflagNames.add("--" + subflag.getName());
+        subflagNames.add("--" + subflag.getOptionDefinition().getOptionName());
       }
 
       logger.logp(
@@ -335,16 +347,16 @@
 
     // Repeated flags are special, and could set multiple times in an expansion, with the user
     // expecting both values to be valid. Collect these separately.
-    Multimap<String, OptionValueDescription> repeatableSubflagsInSetValues =
+    Multimap<OptionDefinition, OptionValueDescription> repeatableSubflagsInSetValues =
         ArrayListMultimap.create();
 
     // Create a flag policy for the child that looks like the parent's policy "transferred" to its
     // child. Note that this only makes sense for SetValue, when setting an expansion flag, or
     // UseDefault, when preventing it from being set.
     for (OptionValueDescription currentSubflag : subflags) {
-      if (currentSubflag.getAllowMultiple()
+      if (currentSubflag.getOptionDefinition().allowsMultiple()
           && originalPolicy.getOperationCase().equals(OperationCase.SET_VALUE)) {
-        repeatableSubflagsInSetValues.put(currentSubflag.getName(), currentSubflag);
+        repeatableSubflagsInSetValues.put(currentSubflag.getOptionDefinition(), currentSubflag);
       } else {
         FlagPolicy subflagAsPolicy =
             getSingleValueSubflagAsPolicy(currentSubflag, originalPolicy, isExpansion);
@@ -356,15 +368,13 @@
     // If there are any repeatable flag SetValues, deal with them together now.
     // Note that expansion flags have no value, and so cannot have multiple values either.
     // Skipping the recursion above is fine.
-    for (String repeatableFlag : repeatableSubflagsInSetValues.keySet()) {
+    for (OptionDefinition repeatableFlag : repeatableSubflagsInSetValues.keySet()) {
       int numValues = repeatableSubflagsInSetValues.get(repeatableFlag).size();
       ArrayList<String> newValues = new ArrayList<>(numValues);
       for (OptionValueDescription setValue : repeatableSubflagsInSetValues.get(repeatableFlag)) {
         newValues.add(setValue.getOriginalValueString());
       }
-      expandedPolicies.add(
-          getSetValueSubflagAsPolicy(
-              repeatableFlag, newValues, /* allowMultiple */ true, originalPolicy));
+      expandedPolicies.add(getSetValueSubflagAsPolicy(repeatableFlag, newValues, originalPolicy));
     }
 
     // Don't add the original policy if it was an expansion flag, which have no value, but do add
@@ -381,21 +391,17 @@
    * policies that set the flag, and so interact with repeatable flags, flags that can be set
    * multiple times, in subtle ways.
    *
-   * @param subflagName, the flag the SetValue'd expansion flag expands to.
+   * @param subflag, the definition of the flag the SetValue'd expansion flag expands to.
    * @param subflagValue, the values that the SetValue'd expansion flag expands to for this flag.
-   * @param allowMultiple, whether the flag is multivalued.
    * @param originalPolicy, the original policy on the expansion flag.
    * @return the flag policy for the subflag given, this will be part of the expanded form of the
-   *  SetValue policy on the original flag.
+   *     SetValue policy on the original flag.
    */
   private static FlagPolicy getSetValueSubflagAsPolicy(
-      String subflagName,
-      List<String> subflagValue,
-      boolean allowMultiple,
-      FlagPolicy originalPolicy) {
+      OptionDefinition subflag, List<String> subflagValue, FlagPolicy originalPolicy) {
     // Some sanity checks.
     Verify.verify(originalPolicy.getOperationCase().equals(OperationCase.SET_VALUE));
-    if (!allowMultiple) {
+    if (!subflag.allowsMultiple()) {
       Verify.verify(subflagValue.size() <= 1);
     }
 
@@ -405,7 +411,7 @@
     for (String value : subflagValue) {
       setValueExpansion.addFlagValue(value);
     }
-    if (allowMultiple) {
+    if (subflag.allowsMultiple()) {
       setValueExpansion.setAppend(originalPolicy.getSetValue().getOverridable());
     } else {
       setValueExpansion.setOverridable(originalPolicy.getSetValue().getOverridable());
@@ -413,10 +419,10 @@
 
     // Commands from the original policy, flag name of the expansion
     return FlagPolicy.newBuilder()
-            .addAllCommands(originalPolicy.getCommandsList())
-            .setFlagName(subflagName)
-            .setSetValue(setValueExpansion)
-            .build();
+        .addAllCommands(originalPolicy.getCommandsList())
+        .setFlagName(subflag.getOptionName())
+        .setSetValue(setValueExpansion)
+        .build();
   }
 
   /**
@@ -429,7 +435,7 @@
     FlagPolicy subflagAsPolicy = null;
     switch (originalPolicy.getOperationCase()) {
       case SET_VALUE:
-        if (currentSubflag.getAllowMultiple()) {
+        if (currentSubflag.getOptionDefinition().allowsMultiple()) {
           throw new AssertionError(
               "SetValue subflags with allowMultiple should have been dealt with separately and "
                   + "accumulated into a single FlagPolicy.");
@@ -444,7 +450,7 @@
         }
         subflagAsPolicy =
             getSetValueSubflagAsPolicy(
-                currentSubflag.getName(), subflagValue, /*allowMultiple=*/ false, originalPolicy);
+                currentSubflag.getOptionDefinition(), subflagValue, originalPolicy);
         break;
 
       case USE_DEFAULT:
@@ -452,10 +458,8 @@
         subflagAsPolicy =
             FlagPolicy.newBuilder()
                 .addAllCommands(originalPolicy.getCommandsList())
-                .setFlagName(currentSubflag.getName())
-                .setUseDefault(
-                    UseDefault
-                        .getDefaultInstance())
+                .setFlagName(currentSubflag.getOptionDefinition().getOptionName())
+                .setUseDefault(UseDefault.getDefaultInstance())
                 .build();
         break;
 
@@ -499,19 +503,18 @@
   private static void applySetValueOperation(
       OptionsParser parser,
       FlagPolicy flagPolicy,
-      String flagName,
       OptionValueDescription valueDescription,
       OptionDescription optionDescription)
       throws OptionsParsingException {
-
     SetValue setValue = flagPolicy.getSetValue();
+    OptionDefinition optionDefinition = optionDescription.getOptionDefinition();
 
     // SetValue.flag_value must have at least 1 value.
     if (setValue.getFlagValueCount() == 0) {
       throw new OptionsParsingException(
           String.format(
               "SetValue operation from invocation policy for flag '%s' does not have a value",
-              flagName));
+              optionDefinition.getOptionName()));
     }
 
     // Flag must allow multiple values if multiple values are specified by the policy.
@@ -521,7 +524,7 @@
           String.format(
               "SetValue operation from invocation policy sets multiple values for flag '%s' which "
                   + "does not allow multiple values",
-              flagName));
+              optionDefinition.getOptionName()));
     }
 
     if (setValue.getOverridable() && valueDescription != null) {
@@ -532,13 +535,13 @@
               + "because the invocation policy specifying the value(s) '%s' is overridable",
           valueDescription.getValue(),
           valueDescription.getSource(),
-          flagName,
+          optionDefinition.getOptionName(),
           setValue.getFlagValueList());
     } else {
 
       if (!setValue.getAppend()) {
         // Clear the value in case the flag is a repeated flag so that values don't accumulate.
-        parser.clearValue(flagName);
+        parser.clearValue(optionDescription.getOptionDefinition());
       }
 
       // Set all the flag values from the policy.
@@ -547,24 +550,28 @@
           logInApplySetValueOperation(
               "Setting value for flag '%s' from invocation "
                   + "policy to '%s', overriding the default value '%s'",
-              flagName, flagValue, optionDescription.getOptionDefinition().getDefaultValue());
+              optionDefinition.getOptionName(), flagValue, optionDefinition.getDefaultValue());
         } else {
           logInApplySetValueOperation(
               "Setting value for flag '%s' from invocation "
                   + "policy to '%s', overriding value '%s' from '%s'",
-              flagName, flagValue, valueDescription.getValue(), valueDescription.getSource());
+              optionDefinition.getOptionName(),
+              flagValue,
+              valueDescription.getValue(),
+              valueDescription.getSource());
         }
-        setFlagValue(parser, flagName, flagValue);
+        setFlagValue(parser, optionDefinition, flagValue);
       }
     }
   }
 
   private static void applyUseDefaultOperation(
-      OptionsParser parser, String policyType, String flagName) throws OptionsParsingException {
-    OptionValueDescription clearedValueDescription = parser.clearValue(flagName);
+      OptionsParser parser, String policyType, OptionDefinition option)
+      throws OptionsParsingException {
+    OptionValueDescription clearedValueDescription = parser.clearValue(option);
     if (clearedValueDescription != null) {
       // Log the removed value.
-      String clearedFlagName = clearedValueDescription.getName();
+      String clearedFlagName = clearedValueDescription.getOptionDefinition().getOptionName();
       String originalValue = clearedValueDescription.getValue().toString();
       String source = clearedValueDescription.getSource();
 
@@ -625,11 +632,10 @@
         List<String> policyValues,
         String newValue,
         boolean useDefault,
-        String flagName,
         OptionValueDescription valueDescription,
         OptionDescription optionDescription)
         throws OptionsParsingException {
-
+      OptionDefinition optionDefinition = optionDescription.getOptionDefinition();
       // Convert all the allowed values from strings to real objects using the options'
       // converters so that they can be checked for equality using real .equals() instead
       // of string comparison. For example, "--foo=0", "--foo=false", "--nofoo", and "-f-"
@@ -637,18 +643,15 @@
       // can be arbitrarily complex.
       Set<Object> convertedPolicyValues = new HashSet<>();
       for (String value : policyValues) {
-        Object convertedValue =
-            optionDescription.getOptionDefinition().getConverter().convert(value);
+        Object convertedValue = optionDefinition.getConverter().convert(value);
         // Some converters return lists, and if the flag is a repeatable flag, the items in the
         // list from the converter should be added, and not the list itself. Otherwise the items
         // from invocation policy will be compared to lists, which will never work.
         // See OptionsParserImpl.ParsedOptionEntry.addValue.
-        if (optionDescription.getOptionDefinition().allowsMultiple()
-            && convertedValue instanceof List<?>) {
+        if (optionDefinition.allowsMultiple() && convertedValue instanceof List<?>) {
           convertedPolicyValues.addAll((List<?>) convertedValue);
         } else {
-          convertedPolicyValues.add(
-              optionDescription.getOptionDefinition().getConverter().convert(value));
+          convertedPolicyValues.add(optionDefinition.getConverter().convert(value));
         }
       }
 
@@ -666,7 +669,9 @@
               String.format(
                   "%sValues policy disallows the default value '%s' for flag '%s' but also "
                       + "specifies to use the default value",
-                  policyType, optionDescription.getOptionDefinition().getDefaultValue(), flagName));
+                  policyType,
+                  optionDefinition.getDefaultValue(),
+                  optionDefinition.getOptionName()));
         }
       }
 
@@ -676,35 +681,28 @@
         // the flag allowing multiple values, however, flags that allow multiple values cannot have
         // default values, and their value is always the empty list if they haven't been specified,
         // which is why new_default_value is not a repeated field.
-        checkDefaultValue(
-            parser,
-            policyValues,
-            newValue,
-            flagName,
-            optionDescription,
-            convertedPolicyValues);
+        checkDefaultValue(parser, optionDescription, policyValues, newValue, convertedPolicyValues);
       } else {
         checkUserValue(
             parser,
+            optionDescription,
+            valueDescription,
             policyValues,
             newValue,
             useDefault,
-            flagName,
-            valueDescription,
-            optionDescription,
             convertedPolicyValues);
       }
     }
 
     void checkDefaultValue(
         OptionsParser parser,
+        OptionDescription optionDescription,
         List<String> policyValues,
         String newValue,
-        String flagName,
-        OptionDescription optionDescription,
         Set<Object> convertedPolicyValues)
         throws OptionsParsingException {
 
+      OptionDefinition optionDefinition = optionDescription.getOptionDefinition();
       if (!isFlagValueAllowed(
           convertedPolicyValues, optionDescription.getOptionDefinition().getDefaultValue())) {
         if (newValue != null) {
@@ -713,13 +711,13 @@
               String.format(
                   "Overriding default value '%s' for flag '%s' with value '%s' "
                       + "specified by invocation policy. %sed values are: %s",
-                  optionDescription.getOptionDefinition().getDefaultValue(),
-                  flagName,
+                  optionDefinition.getDefaultValue(),
+                  optionDefinition.getOptionName(),
                   newValue,
                   policyType,
                   policyValues));
-          parser.clearValue(flagName);
-          setFlagValue(parser, flagName, newValue);
+          parser.clearValue(optionDefinition);
+          setFlagValue(parser, optionDefinition, newValue);
         } else {
           // The operation disallows the default value, but doesn't supply a new value.
           throw new OptionsParsingException(
@@ -728,7 +726,7 @@
                       + "the policy does not provide a new value. "
                       + "%sed values are: %s",
                   optionDescription.getOptionDefinition().getDefaultValue(),
-                  flagName,
+                  optionDefinition.getOptionName(),
                   policyType,
                   policyValues));
         }
@@ -737,15 +735,14 @@
 
     void checkUserValue(
         OptionsParser parser,
+        OptionDescription optionDescription,
+        OptionValueDescription valueDescription,
         List<String> policyValues,
         String newValue,
         boolean useDefault,
-        String flagName,
-        OptionValueDescription valueDescription,
-        OptionDescription optionDescription,
         Set<Object> convertedPolicyValues)
         throws OptionsParsingException {
-
+      OptionDefinition option = optionDescription.getOptionDefinition();
       if (optionDescription.getOptionDefinition().allowsMultiple()) {
         // allowMultiple requires that the type of the option be List<T>, so cast from Object
         // to List<?>.
@@ -753,16 +750,13 @@
         for (Object value : optionValues) {
           if (!isFlagValueAllowed(convertedPolicyValues, value)) {
             if (useDefault) {
-              applyUseDefaultOperation(parser, policyType + "Values", flagName);
+              applyUseDefaultOperation(parser, policyType + "Values", option);
             } else {
               throw new OptionsParsingException(
                   String.format(
                       "Flag value '%s' for flag '%s' is not allowed by invocation policy. "
                           + "%sed values are: %s",
-                      value,
-                      flagName,
-                      policyType,
-                      policyValues));
+                      value, option.getOptionName(), policyType, policyValues));
             }
           }
         }
@@ -775,33 +769,34 @@
                 String.format(
                     "Overriding disallowed value '%s' for flag '%s' with value '%s' "
                         + "specified by invocation policy. %sed values are: %s",
-                    valueDescription.getValue(), flagName, newValue, policyType, policyValues));
-            parser.clearValue(flagName);
-            setFlagValue(parser, flagName, newValue);
+                    valueDescription.getValue(),
+                    option.getOptionName(),
+                    newValue,
+                    policyType,
+                    policyValues));
+            parser.clearValue(option);
+            setFlagValue(parser, option, newValue);
           } else if (useDefault) {
-            applyUseDefaultOperation(parser, policyType + "Values", flagName);
+            applyUseDefaultOperation(parser, policyType + "Values", option);
           } else {
             throw new OptionsParsingException(
                 String.format(
                     "Flag value '%s' for flag '%s' is not allowed by invocation policy and the "
                         + "policy does not specify a new value. %sed values are: %s",
-                    valueDescription.getValue(),
-                    flagName,
-                    policyType,
-                    policyValues));
+                    valueDescription.getValue(), option.getOptionName(), policyType, policyValues));
           }
         }
       }
     }
   }
 
-  private static void setFlagValue(OptionsParser parser, String flagName, String flagValue)
+  private static void setFlagValue(OptionsParser parser, OptionDefinition flag, String flagValue)
       throws OptionsParsingException {
 
     parser.parseWithSourceFunction(
         OptionPriority.INVOCATION_POLICY,
         INVOCATION_POLICY_SOURCE,
-        ImmutableList.of(String.format("--%s=%s", flagName, flagValue)));
+        ImmutableList.of(String.format("--%s=%s", flag.getOptionName(), flagValue)));
   }
 }
 
diff --git a/src/main/java/com/google/devtools/common/options/OptionDefinition.java b/src/main/java/com/google/devtools/common/options/OptionDefinition.java
index 08962bb..a42a624 100644
--- a/src/main/java/com/google/devtools/common/options/OptionDefinition.java
+++ b/src/main/java/com/google/devtools/common/options/OptionDefinition.java
@@ -274,6 +274,25 @@
     return defaultValue;
   }
 
+  /**
+   * {@link OptionDefinition} is really a wrapper around a {@link Field} that caches information
+   * obtained through reflection. Checking that the fields they represent are equal is sufficient
+   * to check that two {@link OptionDefinition} objects are equal.
+   */
+  @Override
+  public boolean equals(Object object) {
+    if (!(object instanceof OptionDefinition)) {
+      return false;
+    }
+    OptionDefinition otherOption = (OptionDefinition) object;
+    return field.equals(otherOption.field);
+  }
+
+  @Override
+  public int hashCode() {
+    return field.hashCode();
+  }
+
   static final Comparator<OptionDefinition> BY_OPTION_NAME =
       Comparator.comparing(OptionDefinition::getOptionName);
 
diff --git a/src/main/java/com/google/devtools/common/options/OptionsParser.java b/src/main/java/com/google/devtools/common/options/OptionsParser.java
index 54642a1..5bf1b4d 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsParser.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsParser.java
@@ -278,8 +278,8 @@
     @Nullable private final Object value;
     @Nullable private final OptionPriority priority;
     @Nullable private final String source;
-    @Nullable private final String implicitDependant;
-    @Nullable private final String expandedFrom;
+    @Nullable private final OptionDefinition implicitDependant;
+    @Nullable private final OptionDefinition expandedFrom;
 
     private OptionValueDescription(
         OptionDefinition optionDefinition,
@@ -288,8 +288,8 @@
         @Nullable Object value,
         @Nullable OptionPriority priority,
         @Nullable String source,
-        @Nullable String implicitDependant,
-        @Nullable String expandedFrom) {
+        @Nullable OptionDefinition implicitDependant,
+        @Nullable OptionDefinition expandedFrom) {
       this.optionDefinition = optionDefinition;
       this.isDefaultValue = isDefaultValue;
       this.originalValueString = originalValueString;
@@ -306,8 +306,8 @@
         @Nullable Object value,
         @Nullable OptionPriority priority,
         @Nullable String source,
-        @Nullable String implicitDependant,
-        @Nullable String expandedFrom) {
+        @Nullable OptionDefinition implicitDependant,
+        @Nullable OptionDefinition expandedFrom) {
       return new OptionValueDescription(
           optionDefinition,
           false,
@@ -377,7 +377,7 @@
       return source;
     }
 
-    public String getImplicitDependant() {
+    public OptionDefinition getImplicitDependant() {
       return implicitDependant;
     }
 
@@ -385,7 +385,7 @@
       return implicitDependant != null;
     }
 
-    public String getExpansionParent() {
+    public OptionDefinition getExpansionParent() {
       return expandedFrom;
     }
 
@@ -443,6 +443,7 @@
    * <p>Note that the unparsed value and the source parameters can both be null.
    */
   public static class UnparsedOptionValueDescription {
+
     private final OptionDefinition optionDefinition;
     @Nullable private final String unparsedValue;
     private final OptionPriority priority;
@@ -672,15 +673,15 @@
   }
 
   /**
-   * Returns a description of the options values that get expanded from this flag with the given
-   * flag value.
+   * Returns a description of the options values that get expanded from this option with the given
+   * value.
    *
    * @return The {@link ImmutableList<OptionValueDescription>} for the option, or null if there is
    *     no option by the given name.
    */
   ImmutableList<OptionValueDescription> getExpansionOptionValueDescriptions(
-      String flagName, @Nullable String flagValue) throws OptionsParsingException {
-    return impl.getExpansionOptionValueDescriptions(flagName, flagValue);
+      OptionDefinition option, @Nullable String optionValue) throws OptionsParsingException {
+    return impl.getExpansionOptionValueDescriptions(option, optionValue);
   }
 
   /**
@@ -729,15 +730,14 @@
   }
 
   /**
-   * Parses {@code args}, using the classes registered with this parser.
-   * {@link #getOptions(Class)} and {@link #getResidue()} return the results. May be called
-   * multiple times; later options override existing ones if they have equal or higher priority.
-   * The source of options is given as a function that maps option names to the source of the
-   * option. Strings that cannot be parsed as options accumulates as* residue, if this parser
-   * allows it.
+   * Parses {@code args}, using the classes registered with this parser. {@link #getOptions(Class)}
+   * and {@link #getResidue()} return the results. May be called multiple times; later options
+   * override existing ones if they have equal or higher priority. The source of options is given as
+   * a function that maps option names to the source of the option. Strings that cannot be parsed as
+   * options accumulates as* residue, if this parser allows it.
    */
-  public void parseWithSourceFunction(OptionPriority priority,
-      Function<? super String, String> sourceFunction, List<String> args)
+  public void parseWithSourceFunction(
+      OptionPriority priority, Function<OptionDefinition, String> sourceFunction, List<String> args)
       throws OptionsParsingException {
     Preconditions.checkNotNull(priority);
     Preconditions.checkArgument(priority != OptionPriority.DEFAULT);
@@ -754,13 +754,12 @@
    * <p>This will not affect options objects that have already been retrieved from this parser
    * through {@link #getOptions(Class)}.
    *
-   * @param optionName The full name of the option to clear.
-   * @return A map of an option name to the old value of the options that were cleared.
+   * @param option The option to clear.
+   * @return The old value of the option that was cleared.
    * @throws IllegalArgumentException If the flag does not exist.
    */
-  public OptionValueDescription clearValue(String optionName)
-      throws OptionsParsingException {
-    return impl.clearValue(optionName);
+  public OptionValueDescription clearValue(OptionDefinition option) throws OptionsParsingException {
+    return impl.clearValue(option);
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/common/options/OptionsParserImpl.java b/src/main/java/com/google/devtools/common/options/OptionsParserImpl.java
index 0260606..7478ab8 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsParserImpl.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsParserImpl.java
@@ -196,12 +196,11 @@
   // Warnings should not end with a '.' because the internal reporter adds one automatically.
   private void setValue(
       OptionDefinition optionDefinition,
-      String name,
       Object value,
       OptionPriority priority,
       String source,
-      String implicitDependant,
-      String expandedFrom) {
+      OptionDefinition implicitDependant,
+      OptionDefinition expandedFrom) {
     OptionValueDescription entry = parsedValues.get(optionDefinition);
     if (entry != null) {
       // Override existing option if the new value has higher or equal priority.
@@ -211,40 +210,45 @@
           if (!implicitDependant.equals(entry.getImplicitDependant())) {
             warnings.add(
                 "Option '"
-                    + name
+                    + optionDefinition.getOptionName()
                     + "' is implicitly defined by both option '"
-                    + entry.getImplicitDependant()
+                    + entry.getImplicitDependant().getOptionName()
                     + "' and option '"
-                    + implicitDependant
+                    + implicitDependant.getOptionName()
                     + "'");
           }
         } else if ((implicitDependant != null) && priority.equals(entry.getPriority())) {
           warnings.add(
               "Option '"
-                  + name
+                  + optionDefinition.getOptionName()
                   + "' is implicitly defined by option '"
-                  + implicitDependant
+                  + implicitDependant.getOptionName()
                   + "'; the implicitly set value overrides the previous one");
         } else if (entry.getImplicitDependant() != null) {
           warnings.add(
               "A new value for option '"
-                  + name
+                  + optionDefinition.getOptionName()
                   + "' overrides a previous implicit setting of that option by option '"
-                  + entry.getImplicitDependant()
+                  + entry.getImplicitDependant().getOptionName()
                   + "'");
         } else if ((priority == entry.getPriority())
             && ((entry.getExpansionParent() == null) && (expandedFrom != null))) {
           // Create a warning if an expansion option overrides an explicit option:
-          warnings.add("The option '" + expandedFrom + "' was expanded and now overrides a "
-              + "previous explicitly specified option '" + name + "'");
+          warnings.add(
+              "The option '"
+                  + expandedFrom.getOptionName()
+                  + "' was expanded and now overrides a "
+                  + "previous explicitly specified option '"
+                  + optionDefinition.getOptionName()
+                  + "'");
         } else if ((entry.getExpansionParent() != null) && (expandedFrom != null)) {
           warnings.add(
               "The option '"
-                  + name
+                  + optionDefinition.getOptionName()
                   + "' was expanded to from both options '"
-                  + entry.getExpansionParent()
+                  + entry.getExpansionParent().getOptionName()
                   + "' and '"
-                  + expandedFrom
+                  + expandedFrom.getOptionName()
                   + "'");
         }
 
@@ -268,8 +272,8 @@
       Object value,
       OptionPriority priority,
       String source,
-      String implicitDependant,
-      String expandedFrom) {
+      OptionDefinition implicitDependant,
+      OptionDefinition expandedFrom) {
     OptionValueDescription entry = parsedValues.get(optionDefinition);
     if (entry == null) {
       entry =
@@ -287,13 +291,8 @@
     entry.addValue(priority, value);
   }
 
-  OptionValueDescription clearValue(String optionName)
+  OptionValueDescription clearValue(OptionDefinition optionDefinition)
       throws OptionsParsingException {
-    OptionDefinition optionDefinition = optionsData.getOptionDefinitionFromName(optionName);
-    if (optionDefinition == null) {
-      throw new IllegalArgumentException("No such option '" + optionName + "'");
-    }
-
     // Actually remove the value from various lists tracking effective options.
     canonicalizeValues.removeAll(optionDefinition);
     return parsedValues.remove(optionDefinition);
@@ -317,7 +316,7 @@
         optionDefinition,
         optionsData.getExpansionDataForField(optionDefinition),
         getImplicitDependantDescriptions(
-            ImmutableList.copyOf(optionDefinition.getImplicitRequirements()), name));
+            ImmutableList.copyOf(optionDefinition.getImplicitRequirements()), optionDefinition));
   }
 
   /**
@@ -327,7 +326,8 @@
    *     no conversion has taken place.
    */
   private ImmutableList<OptionValueDescription> getImplicitDependantDescriptions(
-      ImmutableList<String> options, String implicitDependant) throws OptionsParsingException {
+      ImmutableList<String> options, OptionDefinition implicitDependant)
+      throws OptionsParsingException {
     ImmutableList.Builder<OptionValueDescription> builder = ImmutableList.builder();
     Iterator<String> optionsIterator = options.iterator();
 
@@ -354,11 +354,10 @@
    *     is also a string, no conversion has taken place.
    */
   ImmutableList<OptionValueDescription> getExpansionOptionValueDescriptions(
-      String flagName, @Nullable String flagValue) throws OptionsParsingException {
+      OptionDefinition expansionFlag, @Nullable String flagValue) throws OptionsParsingException {
     ImmutableList.Builder<OptionValueDescription> builder = ImmutableList.builder();
-    OptionDefinition optionDefinition = optionsData.getOptionDefinitionFromName(flagName);
 
-    ImmutableList<String> options = optionsData.getEvaluatedExpansion(optionDefinition, flagValue);
+    ImmutableList<String> options = optionsData.getEvaluatedExpansion(expansionFlag, flagValue);
     Iterator<String> optionsIterator = options.iterator();
 
     while (optionsIterator.hasNext()) {
@@ -372,7 +371,7 @@
               /* priority */ null,
               /* source */ null,
               /* implicitDependant */ null,
-              flagName));
+              expansionFlag));
     }
     return builder.build();
   }
@@ -386,34 +385,34 @@
   }
 
   /**
-   * Parses the args, and returns what it doesn't parse. May be called multiple
-   * times, and may be called recursively. In each call, there may be no
-   * duplicates, but separate calls may contain intersecting sets of options; in
-   * that case, the arg seen last takes precedence.
+   * Parses the args, and returns what it doesn't parse. May be called multiple times, and may be
+   * called recursively. In each call, there may be no duplicates, but separate calls may contain
+   * intersecting sets of options; in that case, the arg seen last takes precedence.
    */
-  List<String> parse(OptionPriority priority, Function<? super String, String> sourceFunction,
-      List<String> args) throws OptionsParsingException {
+  List<String> parse(
+      OptionPriority priority, Function<OptionDefinition, String> sourceFunction, List<String> args)
+      throws OptionsParsingException {
     return parse(priority, sourceFunction, null, null, args);
   }
 
   /**
-   * Parses the args, and returns what it doesn't parse. May be called multiple
-   * times, and may be called recursively. Calls may contain intersecting sets
-   * of options; in that case, the arg seen last takes precedence.
+   * Parses the args, and returns what it doesn't parse. May be called multiple times, and may be
+   * called recursively. Calls may contain intersecting sets of options; in that case, the arg seen
+   * last takes precedence.
    *
-   * <p>The method uses the invariant that if an option has neither an implicit
-   * dependent nor an expanded from value, then it must have been explicitly
-   * set.
+   * <p>The method uses the invariant that if an option has neither an implicit dependent nor an
+   * expanded from value, then it must have been explicitly set.
    */
   private List<String> parse(
       OptionPriority priority,
-      Function<? super String, String> sourceFunction,
-      String implicitDependent,
-      String expandedFrom,
-      List<String> args) throws OptionsParsingException {
+      Function<OptionDefinition, String> sourceFunction,
+      OptionDefinition implicitDependent,
+      OptionDefinition expandedFrom,
+      List<String> args)
+      throws OptionsParsingException {
 
     List<String> unparsedArgs = new ArrayList<>();
-    LinkedHashMap<String, List<String>> implicitRequirements = new LinkedHashMap<>();
+    LinkedHashMap<OptionDefinition, List<String>> implicitRequirements = new LinkedHashMap<>();
 
     Iterator<String> argsIterator = argsPreProcessor.preProcess(args).iterator();
     while (argsIterator.hasNext()) {
@@ -479,7 +478,7 @@
                 optionDefinition,
                 value,
                 priority,
-                sourceFunction.apply(optionDefinition.getOptionName()),
+                sourceFunction.apply(optionDefinition),
                 expandedFrom == null);
         unparsedValues.add(unparsedOptionValueDescription);
         if (optionDefinition.allowsMultiple()) {
@@ -499,16 +498,11 @@
             "expanded from option --"
                 + optionDefinition.getOptionName()
                 + " from "
-                + sourceFunction.apply(optionDefinition.getOptionName());
-        Function<Object, String> expansionSourceFunction = o -> sourceMessage;
+                + sourceFunction.apply(optionDefinition);
+        Function<OptionDefinition, String> expansionSourceFunction = o -> sourceMessage;
         maybeAddDeprecationWarning(optionDefinition);
         List<String> unparsed =
-            parse(
-                priority,
-                expansionSourceFunction,
-                null,
-                optionDefinition.getOptionName(),
-                expansion);
+            parse(priority, expansionSourceFunction, null, optionDefinition, expansion);
         if (!unparsed.isEmpty()) {
           // Throw an assertion, because this indicates an error in the code that specified the
           // expansion for the current option.
@@ -535,10 +529,9 @@
         if (!optionDefinition.allowsMultiple()) {
           setValue(
               optionDefinition,
-              optionDefinition.getOptionName(),
               convertedValue,
               priority,
-              sourceFunction.apply(optionDefinition.getOptionName()),
+              sourceFunction.apply(optionDefinition),
               implicitDependent,
               expandedFrom);
         } else {
@@ -551,7 +544,7 @@
               optionDefinition,
               convertedValue,
               priority,
-              sourceFunction.apply(optionDefinition.getOptionName()),
+              sourceFunction.apply(optionDefinition),
               implicitDependent,
               expandedFrom);
         }
@@ -560,22 +553,20 @@
       // Collect any implicit requirements.
       if (optionDefinition.getImplicitRequirements().length > 0) {
         implicitRequirements.put(
-            optionDefinition.getOptionName(),
-            Arrays.asList(optionDefinition.getImplicitRequirements()));
+            optionDefinition, Arrays.asList(optionDefinition.getImplicitRequirements()));
       }
     }
 
     // Now parse any implicit requirements that were collected.
     // TODO(bazel-team): this should happen when the option is encountered.
     if (!implicitRequirements.isEmpty()) {
-      for (Map.Entry<String, List<String>> entry : implicitRequirements.entrySet()) {
+      for (Map.Entry<OptionDefinition, List<String>> entry : implicitRequirements.entrySet()) {
         String sourceMessage =
             "implicit requirement of option --"
                 + entry.getKey()
                 + " from "
                 + sourceFunction.apply(entry.getKey());
-        Function<Object, String> requirementSourceFunction =
-            o -> sourceMessage;
+        Function<OptionDefinition, String> requirementSourceFunction = o -> sourceMessage;
 
         List<String> unparsed = parse(priority, requirementSourceFunction, entry.getKey(), null,
             entry.getValue());