diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index f906c8a..e4bbe64 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -756,6 +756,10 @@
 			cmd.ImplicitDepFile(PathForBazelOut(ctx, *depfile))
 		}
 
+		for _, symlinkPath := range buildStatement.SymlinkPaths {
+			cmd.ImplicitSymlinkOutput(PathForBazelOut(ctx, symlinkPath))
+		}
+
 		// This is required to silence warnings pertaining to unexpected timestamps. Particularly,
 		// some Bazel builtins (such as files in the bazel_tools directory) have far-future
 		// timestamps. Without restat, Ninja would emit warnings that the input files of a
diff --git a/bazel/aquery.go b/bazel/aquery.go
index d1119cb..8741afb 100644
--- a/bazel/aquery.go
+++ b/bazel/aquery.go
@@ -73,12 +73,13 @@
 // BuildStatement contains information to register a build statement corresponding (one to one)
 // with a Bazel action from Bazel's action graph.
 type BuildStatement struct {
-	Command     string
-	Depfile     *string
-	OutputPaths []string
-	InputPaths  []string
-	Env         []KeyValuePair
-	Mnemonic    string
+	Command      string
+	Depfile      *string
+	OutputPaths  []string
+	InputPaths   []string
+	SymlinkPaths []string
+	Env          []KeyValuePair
+	Mnemonic     string
 }
 
 // A helper type for aquery processing which facilitates retrieval of path IDs from their
@@ -234,10 +235,21 @@
 			OutputPaths: outputPaths,
 			InputPaths:  inputPaths,
 			Env:         actionEntry.EnvironmentVariables,
-			Mnemonic:    actionEntry.Mnemonic}
-		if len(actionEntry.Arguments) < 1 {
+			Mnemonic:    actionEntry.Mnemonic,
+		}
+
+		if isSymlinkAction(actionEntry) {
+			if len(inputPaths) != 1 || len(outputPaths) != 1 {
+				return nil, fmt.Errorf("Expect 1 input and 1 output to symlink action, got: input %q, output %q", inputPaths, outputPaths)
+			}
+			out := outputPaths[0]
+			outDir := proptools.ShellEscapeIncludingSpaces(filepath.Dir(out))
+			out = proptools.ShellEscapeIncludingSpaces(out)
+			in := proptools.ShellEscapeIncludingSpaces(inputPaths[0])
+			buildStatement.Command = fmt.Sprintf("mkdir -p %[1]s && rm -f %[2]s && ln -rsf %[3]s %[2]s", outDir, out, in)
+			buildStatement.SymlinkPaths = outputPaths[:]
+		} else if len(actionEntry.Arguments) < 1 {
 			return nil, fmt.Errorf("received action with no command: [%v]", buildStatement)
-			continue
 		}
 		buildStatements = append(buildStatements, buildStatement)
 	}
@@ -245,9 +257,13 @@
 	return buildStatements, nil
 }
 
+func isSymlinkAction(a action) bool {
+	return a.Mnemonic == "Symlink" || a.Mnemonic == "SolibSymlink"
+}
+
 func shouldSkipAction(a action) bool {
-	// TODO(b/180945121): Handle symlink actions.
-	if a.Mnemonic == "Symlink" || a.Mnemonic == "SourceSymlinkManifest" || a.Mnemonic == "SymlinkTree" || a.Mnemonic == "SolibSymlink" {
+	// TODO(b/180945121): Handle complex symlink actions.
+	if a.Mnemonic == "SymlinkTree" || a.Mnemonic == "SourceSymlinkManifest" {
 		return true
 	}
 	// Middleman actions are not handled like other actions; they are handled separately as a
@@ -278,6 +294,9 @@
 			return "", fmt.Errorf("undefined path fragment id %d", currId)
 		}
 		labels = append([]string{currFragment.Label}, labels...)
+		if currId == currFragment.ParentId {
+			return "", fmt.Errorf("Fragment cannot refer to itself as parent %#v", currFragment)
+		}
 		currId = currFragment.ParentId
 	}
 	return filepath.Join(labels...), nil
diff --git a/bazel/aquery_test.go b/bazel/aquery_test.go
index 7b40dcd..43e4155 100644
--- a/bazel/aquery_test.go
+++ b/bazel/aquery_test.go
@@ -805,17 +805,229 @@
 	}
 }
 
+func TestSimpleSymlink(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 3
+  }, {
+    "id": 2,
+    "pathFragmentId": 5
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "Symlink",
+    "inputDepSetIds": [1],
+    "outputIds": [2],
+    "primaryOutputId": 2
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "file_subdir",
+    "parentId": 1
+  }, {
+    "id": 3,
+    "label": "file",
+    "parentId": 2
+  }, {
+    "id": 4,
+    "label": "symlink_subdir",
+    "parentId": 1
+  }, {
+    "id": 5,
+    "label": "symlink",
+    "parentId": 4
+  }]
+}`
+
+	actual, err := AqueryBuildStatements([]byte(inputString))
+
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+	}
+
+	expectedBuildStatements := []BuildStatement{
+		BuildStatement{
+			Command: "mkdir -p one/symlink_subdir && " +
+				"rm -f one/symlink_subdir/symlink && " +
+				"ln -rsf one/file_subdir/file one/symlink_subdir/symlink",
+			InputPaths:   []string{"one/file_subdir/file"},
+			OutputPaths:  []string{"one/symlink_subdir/symlink"},
+			SymlinkPaths: []string{"one/symlink_subdir/symlink"},
+			Mnemonic:     "Symlink",
+		},
+	}
+	assertBuildStatements(t, actual, expectedBuildStatements)
+}
+
+func TestSymlinkQuotesPaths(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 3
+  }, {
+    "id": 2,
+    "pathFragmentId": 5
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "SolibSymlink",
+    "inputDepSetIds": [1],
+    "outputIds": [2],
+    "primaryOutputId": 2
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "file subdir",
+    "parentId": 1
+  }, {
+    "id": 3,
+    "label": "file",
+    "parentId": 2
+  }, {
+    "id": 4,
+    "label": "symlink subdir",
+    "parentId": 1
+  }, {
+    "id": 5,
+    "label": "symlink",
+    "parentId": 4
+  }]
+}`
+
+	actual, err := AqueryBuildStatements([]byte(inputString))
+
+	if err != nil {
+		t.Errorf("Unexpected error %q", err)
+	}
+
+	expectedBuildStatements := []BuildStatement{
+		BuildStatement{
+			Command: "mkdir -p 'one/symlink subdir' && " +
+				"rm -f 'one/symlink subdir/symlink' && " +
+				"ln -rsf 'one/file subdir/file' 'one/symlink subdir/symlink'",
+			InputPaths:   []string{"one/file subdir/file"},
+			OutputPaths:  []string{"one/symlink subdir/symlink"},
+			SymlinkPaths: []string{"one/symlink subdir/symlink"},
+			Mnemonic:     "SolibSymlink",
+		},
+	}
+	assertBuildStatements(t, actual, expectedBuildStatements)
+}
+
+func TestSymlinkMultipleInputs(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }, {
+    "id": 3,
+    "pathFragmentId": 3
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "Symlink",
+    "inputDepSetIds": [1],
+    "outputIds": [3],
+    "primaryOutputId": 3
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1,2]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "file"
+  }, {
+    "id": 2,
+    "label": "other_file"
+  }, {
+    "id": 3,
+    "label": "symlink"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, `Expect 1 input and 1 output to symlink action, got: input ["file" "other_file"], output ["symlink"]`)
+}
+
+func TestSymlinkMultipleOutputs(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }, {
+    "id": 3,
+    "pathFragmentId": 3
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "Symlink",
+    "inputDepSetIds": [1],
+    "outputIds": [2,3],
+    "primaryOutputId": 2
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "file"
+  }, {
+    "id": 2,
+    "label": "symlink"
+  }, {
+    "id": 3,
+    "label": "other_symlink"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, `Expect 1 input and 1 output to symlink action, got: input ["file"], output ["symlink" "other_symlink"]`)
+}
+
 func assertError(t *testing.T, err error, expected string) {
+	t.Helper()
 	if err == nil {
 		t.Errorf("expected error '%s', but got no error", expected)
 	} else if err.Error() != expected {
-		t.Errorf("expected error '%s', but got: %s", expected, err.Error())
+		t.Errorf("expected error:\n\t'%s', but got:\n\t'%s'", expected, err.Error())
 	}
 }
 
 // Asserts that the given actual build statements match the given expected build statements.
 // Build statement equivalence is determined using buildStatementEquals.
 func assertBuildStatements(t *testing.T, expected []BuildStatement, actual []BuildStatement) {
+	t.Helper()
 	if len(expected) != len(actual) {
 		t.Errorf("expected %d build statements, but got %d,\n expected: %v,\n actual: %v",
 			len(expected), len(actual), expected, actual)
@@ -852,6 +1064,12 @@
 	if !reflect.DeepEqual(stringSet(first.OutputPaths), stringSet(second.OutputPaths)) {
 		return false
 	}
+	if !reflect.DeepEqual(stringSet(first.SymlinkPaths), stringSet(second.SymlinkPaths)) {
+		return false
+	}
+	if first.Depfile != second.Depfile {
+		return false
+	}
 	return true
 }
 
diff --git a/java/hiddenapi.go b/java/hiddenapi.go
index e9693c6..f901434 100644
--- a/java/hiddenapi.go
+++ b/java/hiddenapi.go
@@ -219,7 +219,6 @@
 		BuiltTool("merge_csv").
 		Flag("--zip_input").
 		Flag("--key_field signature").
-		FlagWithArg("--header=", "signature,file,startline,startcol,endline,endcol,properties").
 		FlagWithOutput("--output=", indexCSV).
 		Inputs(classesJars)
 	rule.Build(desc, desc)
diff --git a/scripts/hiddenapi/merge_csv.py b/scripts/hiddenapi/merge_csv.py
index b047aab..a65326c 100755
--- a/scripts/hiddenapi/merge_csv.py
+++ b/scripts/hiddenapi/merge_csv.py
@@ -55,14 +55,15 @@
                 if entry.endswith('.uau'):
                     csv_readers.append(dict_reader(io.TextIOWrapper(zip.open(entry, 'r'))))
 
-headers = set()
 if args.header:
     fieldnames = args.header.split(',')
 else:
+    headers = {}
     # Build union of all columns from source files:
     for reader in csv_readers:
-        headers = headers.union(reader.fieldnames)
-    fieldnames = sorted(headers)
+        for fieldname in reader.fieldnames:
+            headers[fieldname] = ""
+    fieldnames = list(headers.keys())
 
 # By default chain the csv readers together so that the resulting output is
 # the concatenation of the rows from each of them: