Added an help command to dump all options for completion
`bazel help completion` dump all options completion pattern
for each command, giving hints on the format of the completion
residue (e.g., `label`, `path`, `{a,enum}`, ...). This
dump can be used to generate completion scripts.
--
MOS_MIGRATED_REVID=90743024
diff --git a/src/main/java/com/google/devtools/common/options/OptionsUsage.java b/src/main/java/com/google/devtools/common/options/OptionsUsage.java
index c48a532..fdd997c 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsUsage.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsUsage.java
@@ -15,6 +15,7 @@
import static com.google.devtools.common.options.OptionsParserImpl.findConverter;
+import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
import com.google.common.collect.Lists;
@@ -31,6 +32,7 @@
class OptionsUsage {
private static final Splitter NEWLINE_SPLITTER = Splitter.on('\n');
+ private static final Joiner COMMA_JOINER = Joiner.on(",");
/**
* Given an options class, render the usage string into the usage,
@@ -124,6 +126,57 @@
}
}
+ /**
+ * Returns the available completion for the given option field. The completions are the exact
+ * command line option (with the prepending '--') that one should pass. It is suitable for
+ * completion script to use. If the option expect an argument, the kind of argument is given
+ * after the equals. If the kind is a enum, the various enum values are given inside an accolade
+ * in a comma separated list. For other special kind, the type is given as a name (e.g.,
+ * <code>label</code>, <code>float</ode>, <code>path</code>...). Example outputs of this
+ * function are for, respectively, a tristate flag <code>tristate_flag</code>, a enum
+ * flag <code>enum_flag</code> which can take <code>value1</code>, <code>value2</code> and
+ * <code>value3</code>, a path fragment flag <code>path_flag</code>, a string flag
+ * <code>string_flag</code> and a void flag <code>void_flag</code>:
+ * <pre>
+ * --tristate_flag={auto,yes,no}
+ * --notristate_flag
+ * --enum_flag={value1,value2,value3}
+ * --path_flag=path
+ * --string_flag=
+ * --void_flag
+ * </pre>
+ *
+ * @param field The field to return completion for
+ * @param builder the string builder to store the completion values
+ */
+ static void getCompletion(Field field, StringBuilder builder) {
+ // Return the list of possible completions for this option
+ String flagName = field.getAnnotation(Option.class).name();
+ Class<?> fieldType = field.getType();
+ builder.append("--").append(flagName);
+ if (fieldType.equals(boolean.class)) {
+ builder.append("\n");
+ builder.append("--no").append(flagName).append("\n");
+ } else if (fieldType.equals(TriState.class)) {
+ builder.append("={auto,yes,no}\n");
+ builder.append("--no").append(flagName).append("\n");
+ } else if (fieldType.isEnum()) {
+ builder.append("={")
+ .append(COMMA_JOINER.join(fieldType.getEnumConstants()).toLowerCase()).append("}\n");
+ } else if (fieldType.getSimpleName().equals("Label")) {
+ // String comparison so we don't introduce a dependency to com.google.devtools.build.lib.
+ builder.append("=label\n");
+ } else if (fieldType.getSimpleName().equals("PathFragment")) {
+ builder.append("=path\n");
+ } else if (Void.class.isAssignableFrom(fieldType)) {
+ builder.append("\n");
+ } else {
+ // TODO(bazel-team): add more types. Maybe even move the completion type
+ // to the @Option annotation?
+ builder.append("=\n");
+ }
+ }
+
private static final Comparator<Field> BY_NAME = new Comparator<Field>() {
@Override
public int compare(Field left, Field right) {
