diff --git a/java/hiddenapi.go b/java/hiddenapi.go
index f8e41c4..da2c48f 100644
--- a/java/hiddenapi.go
+++ b/java/hiddenapi.go
@@ -15,8 +15,6 @@
 package java
 
 import (
-	"strings"
-
 	"github.com/google/blueprint"
 
 	"android/soong/android"
@@ -29,8 +27,8 @@
 
 type hiddenAPI struct {
 	// The name of the module as it would be used in the boot jars configuration, e.g. without any
-	// prebuilt_ prefix (if it is a prebuilt), without any "-hiddenapi" suffix if it just provides
-	// annotations and without any ".impl" suffix if it is a java_sdk_library implementation library.
+	// prebuilt_ prefix (if it is a prebuilt) and without any ".impl" suffix if it is a
+	// java_sdk_library implementation library.
 	configurationName string
 
 	// True if the module containing this structure contributes to the hiddenapi information or has
@@ -49,11 +47,6 @@
 	// annotation information.
 	primary bool
 
-	// True if the module only contains additional annotations and so does not require hiddenapi
-	// information to be encoded in its dex file and should not be used to generate the
-	// hiddenAPISingletonPathsStruct.stubFlags file.
-	annotationsOnly bool
-
 	// The path to the dex jar that is in the boot class path. If this is nil then the associated
 	// module is not a boot jar, but could be one of the <x>-hiddenapi modules that provide additional
 	// annotations for the <x> boot dex jar but which do not actually provide a boot dex jar
@@ -119,48 +112,40 @@
 var _ hiddenAPIIntf = (*hiddenAPI)(nil)
 
 // Initialize the hiddenapi structure
-func (h *hiddenAPI) initHiddenAPI(ctx android.BaseModuleContext, name string) {
+func (h *hiddenAPI) initHiddenAPI(ctx android.BaseModuleContext, configurationName string) {
 	// If hiddenapi processing is disabled treat this as inactive.
 	if ctx.Config().IsEnvTrue("UNSAFE_DISABLE_HIDDENAPI_FLAGS") {
 		return
 	}
 
-	// Modules whose names are of the format <x>-hiddenapi provide hiddenapi information for the boot
-	// jar module <x>. Otherwise, the module provides information for itself. Either way extract the
-	// configurationName of the boot jar module.
-	configurationName := strings.TrimSuffix(name, "-hiddenapi")
 	h.configurationName = configurationName
 
 	// It is important that hiddenapi information is only gathered for/from modules that are actually
 	// on the boot jars list because the runtime only enforces access to the hidden API for the
 	// bootclassloader. If information is gathered for modules not on the list then that will cause
 	// failures in the CtsHiddenApiBlocklist... tests.
-	h.active = inList(configurationName, ctx.Config().BootJars())
+	module := ctx.Module()
+	h.active = isModuleInBootClassPath(ctx, module)
 	if !h.active {
 		// The rest of the properties will be ignored if active is false.
 		return
 	}
 
-	// If this module has a suffix of -hiddenapi then it only provides additional annotation
-	// information for a module on the boot jars list.
-	h.annotationsOnly = strings.HasSuffix(name, "-hiddenapi")
-
 	// Determine whether this module is the primary module or not.
 	primary := true
 
 	// A prebuilt module is only primary if it is preferred and conversely a source module is only
 	// primary if it has not been replaced by a prebuilt module.
-	module := ctx.Module()
 	if pi, ok := module.(android.PrebuiltInterface); ok {
 		if p := pi.Prebuilt(); p != nil {
 			primary = p.UsePrebuilt()
 		}
 	} else {
-		// The only module that will pass a different name to its module name to this method is the
-		// implementation library of a java_sdk_library. It has a configuration name of <x> the same
-		// as its parent java_sdk_library but a module name of <x>.impl. It is not the primary module,
-		// the java_sdk_library with the name of <x> is.
-		primary = name == ctx.ModuleName()
+		// The only module that will pass a different configurationName to its module name to this
+		// method is the implementation library of a java_sdk_library. It has a configuration name of
+		// <x> the same as its parent java_sdk_library but a module name of <x>.impl. It is not the
+		// primary module, the java_sdk_library with the name of <x> is.
+		primary = configurationName == ctx.ModuleName()
 
 		// A source module that has been replaced by a prebuilt can never be the primary module.
 		primary = primary && !module.IsReplacedByPrebuilt()
@@ -168,6 +153,15 @@
 	h.primary = primary
 }
 
+func isModuleInBootClassPath(ctx android.BaseModuleContext, module android.Module) bool {
+	// Get the configured non-updatable and updatable boot jars.
+	nonUpdatableBootJars := ctx.Config().NonUpdatableBootJars()
+	updatableBootJars := ctx.Config().UpdatableBootJars()
+	active := isModuleInConfiguredList(ctx, module, nonUpdatableBootJars) ||
+		isModuleInConfiguredList(ctx, module, updatableBootJars)
+	return active
+}
+
 // hiddenAPIExtractAndEncode is called by any module that could contribute to the hiddenapi
 // processing.
 //
@@ -191,15 +185,13 @@
 
 	h.hiddenAPIExtractInformation(ctx, dexJar, implementationJar)
 
-	if !h.annotationsOnly {
-		hiddenAPIJar := android.PathForModuleOut(ctx, "hiddenapi", h.configurationName+".jar").OutputPath
+	hiddenAPIJar := android.PathForModuleOut(ctx, "hiddenapi", h.configurationName+".jar").OutputPath
 
-		// Create a copy of the dex jar which has been encoded with hiddenapi flags.
-		hiddenAPIEncodeDex(ctx, hiddenAPIJar, dexJar, uncompressDex)
+	// Create a copy of the dex jar which has been encoded with hiddenapi flags.
+	hiddenAPIEncodeDex(ctx, hiddenAPIJar, dexJar, uncompressDex)
 
-		// Use the encoded dex jar from here onwards.
-		dexJar = hiddenAPIJar
-	}
+	// Use the encoded dex jar from here onwards.
+	dexJar = hiddenAPIJar
 
 	return dexJar
 }
@@ -262,6 +254,7 @@
 	rule.Command().
 		BuiltTool("merge_csv").
 		Flag("--zip_input").
+		Flag("--key_field signature").
 		FlagWithOutput("--output=", indexCSV).
 		Inputs(classesJars)
 	rule.Build("merged-hiddenapi-index", "Merged Hidden API index")
diff --git a/java/hiddenapi_singleton.go b/java/hiddenapi_singleton.go
index 6341a34..82e8b3f 100644
--- a/java/hiddenapi_singleton.go
+++ b/java/hiddenapi_singleton.go
@@ -217,10 +217,6 @@
 
 	var bootDexJars android.Paths
 
-	// Get the configured non-updatable and updatable boot jars.
-	nonUpdatableBootJars := ctx.Config().NonUpdatableBootJars()
-	updatableBootJars := ctx.Config().UpdatableBootJars()
-
 	ctx.VisitAllModules(func(module android.Module) {
 		// Collect dex jar paths for the modules listed above.
 		if j, ok := module.(UsesLibraryDependency); ok {
@@ -235,11 +231,6 @@
 		// Collect dex jar paths for modules that had hiddenapi encode called on them.
 		if h, ok := module.(hiddenAPIIntf); ok {
 			if jar := h.bootDexJar(); jar != nil {
-				if !isModuleInConfiguredList(ctx, module, nonUpdatableBootJars) &&
-					!isModuleInConfiguredList(ctx, module, updatableBootJars) {
-					return
-				}
-
 				bootDexJars = append(bootDexJars, jar)
 			}
 		}
@@ -291,8 +282,8 @@
 // there too.
 //
 // TODO(b/179354495): Avoid having to perform this type of check or if necessary dedup it.
-func isModuleInConfiguredList(ctx android.SingletonContext, module android.Module, configuredBootJars android.ConfiguredJarList) bool {
-	name := ctx.ModuleName(module)
+func isModuleInConfiguredList(ctx android.BaseModuleContext, module android.Module, configuredBootJars android.ConfiguredJarList) bool {
+	name := ctx.OtherModuleName(module)
 
 	// Strip a prebuilt_ prefix so that this can match a prebuilt module that has not been renamed.
 	name = android.RemoveOptionalPrebuiltPrefix(name)
@@ -305,11 +296,11 @@
 
 	// It is an error if the module is not an ApexModule.
 	if _, ok := module.(android.ApexModule); !ok {
-		ctx.Errorf("module %q configured in boot jars does not support being added to an apex", module)
+		ctx.ModuleErrorf("is configured in boot jars but does not support being added to an apex")
 		return false
 	}
 
-	apexInfo := ctx.ModuleProvider(module, android.ApexInfoProvider).(android.ApexInfo)
+	apexInfo := ctx.OtherModuleProvider(module, android.ApexInfoProvider).(android.ApexInfo)
 
 	// Now match the apex part of the boot image configuration.
 	requiredApex := configuredBootJars.Apex(index)
@@ -433,6 +424,7 @@
 
 	rule.Command().
 		BuiltTool("merge_csv").
+		Flag("--key_field signature").
 		FlagWithOutput("--output=", outputPath).
 		Inputs(metadataCSV)
 
@@ -544,6 +536,7 @@
 	rule := android.NewRuleBuilder(pctx, ctx)
 	rule.Command().
 		BuiltTool("merge_csv").
+		Flag("--key_field signature").
 		FlagWithArg("--header=", "signature,file,startline,startcol,endline,endcol,properties").
 		FlagWithOutput("--output=", hiddenAPISingletonPaths(ctx).index).
 		Inputs(indexes)
diff --git a/java/hiddenapi_singleton_test.go b/java/hiddenapi_singleton_test.go
index 4670d03..c0f0e38 100644
--- a/java/hiddenapi_singleton_test.go
+++ b/java/hiddenapi_singleton_test.go
@@ -89,12 +89,6 @@
 		}
 
 		java_library {
-			name: "foo-hiddenapi",
-			srcs: ["a.java"],
-			compile_dex: true,
-		}
-
-		java_library {
 			name: "foo-hiddenapi-annotations",
 			srcs: ["a.java"],
 			compile_dex: true,
@@ -118,7 +112,6 @@
 	indexRule := hiddenAPIIndex.Rule("singleton-merged-hiddenapi-index")
 	CheckHiddenAPIRuleInputs(t, `
 .intermediates/bar/android_common/hiddenapi/index.csv
-.intermediates/foo-hiddenapi/android_common/hiddenapi/index.csv
 .intermediates/foo/android_common/hiddenapi/index.csv
 `,
 		indexRule)
diff --git a/scripts/hiddenapi/merge_csv.py b/scripts/hiddenapi/merge_csv.py
index 5ad61b2..b047aab 100755
--- a/scripts/hiddenapi/merge_csv.py
+++ b/scripts/hiddenapi/merge_csv.py
@@ -20,6 +20,9 @@
 import argparse
 import csv
 import io
+import heapq
+import itertools
+import operator
 
 from zipfile import ZipFile
 
@@ -28,6 +31,10 @@
                                           'if missing determines the header from input files.')
 args_parser.add_argument('--zip_input', help='Treat files as ZIP archives containing CSV files to merge.',
                          action="store_true")
+args_parser.add_argument('--key_field', help='The name of the field by which the rows should be sorted. '
+                                             'Must be in the field names. '
+                                             'Will be the first field in the output. '
+                                             'All input files must be sorted by that field.')
 args_parser.add_argument('--output', help='Output file for merged CSV.',
                          default='-', type=argparse.FileType('w'))
 args_parser.add_argument('files', nargs=argparse.REMAINDER)
@@ -57,10 +64,29 @@
         headers = headers.union(reader.fieldnames)
     fieldnames = sorted(headers)
 
-# Concatenate all files to output:
+# By default chain the csv readers together so that the resulting output is
+# the concatenation of the rows from each of them:
+all_rows = itertools.chain.from_iterable(csv_readers)
+
+if len(csv_readers) > 0:
+    keyField = args.key_field
+    if keyField:
+        assert keyField in fieldnames, (
+            "--key_field {} not found, must be one of {}\n").format(
+            keyField, ",".join(fieldnames))
+        # Make the key field the first field in the output
+        keyFieldIndex = fieldnames.index(args.key_field)
+        fieldnames.insert(0, fieldnames.pop(keyFieldIndex))
+        # Create an iterable that performs a lazy merge sort on the csv readers
+        # sorting the rows by the key field.
+        all_rows = heapq.merge(*csv_readers, key=operator.itemgetter(keyField))
+
+# Write all rows from the input files to the output:
 writer = csv.DictWriter(args.output, delimiter=',', quotechar='|', quoting=csv.QUOTE_MINIMAL,
                         dialect='unix', fieldnames=fieldnames)
 writer.writeheader()
-for reader in csv_readers:
-    for row in reader:
-        writer.writerow(row)
+
+# Read all the rows from the input and write them to the output in the correct
+# order:
+for row in all_rows:
+  writer.writerow(row)