Make reduced classpath computation more lenient

I changed this in [] but some code paths are relying on the old
behaviour.

GOOGLE:
RELNOTES: N/A

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=262683944

1 files changed, 7 insertions, 0 deletions

diff --git a/java/com/google/turbine/deps/Dependencies.java b/java/com/google/turbine/deps/Dependencies.java
index 4235bc2..92193e8 100644
--- a/java/com/google/turbine/deps/Dependencies.java
+++ b/java/com/google/turbine/deps/Dependencies.java
@@ -184,11 +184,18 @@ public class Dependencies {
   /**
    * Filters a transitive classpath to contain only the entries for direct dependencies, and the
    * types needed to compile those direct deps as reported by jdeps.
+   *
+   * <p>If no direct dependency information is available the full transitive classpath is returned.
    */
   public static Collection<String> reduceClasspath(
       ImmutableList<String> transitiveClasspath,
       ImmutableSet<String> directJars,
       ImmutableList<String> depsArtifacts) {
+    if (directJars.isEmpty()) {
+      // the compilation doesn't support strict deps (e.g. proto libraries)
+      // TODO(cushon): make this a usage error
+      return transitiveClasspath;
+    }
     Set<String> reduced = new HashSet<>(directJars);
     for (String path : depsArtifacts) {
       DepsProto.Dependencies.Builder deps = DepsProto.Dependencies.newBuilder();