From 69f0a247623bc2081c318ca8f120404f2e26c301 Mon Sep 17 00:00:00 2001
From: Colin Cross <ccross@android.com>
Date: Mon, 8 Feb 2021 16:49:57 -0800
Subject: [PATCH] Pass list of module libraries to gen_ndk_backed_by_apex.sh

Running find on the entire module directory can lead to flaky failures
when a directory is modified by another rule while find is traversing
it.  Pass a list of libraries in the module into the script instead
of finding them on disk.

Fixes: 178509901
Test: TARGET_BUILD_APPS=com.android.runtime dist
Change-Id: Ie4bf288f0e3d99cbbed5ca8770687a9bbe5377e4
---
 apex/builder.go                  | 11 ++++++---
 scripts/gen_ndk_backedby_apex.sh | 39 +++++++++++++++++++++++---------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/apex/builder.go b/apex/builder.go
index 16ca74cf2..2663a679f 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -700,15 +700,20 @@ func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext) {
 		})
 		a.apisUsedByModuleFile = apisUsedbyOutputFile
 
+		var libNames []string
+		for _, f := range a.filesInfo {
+			if f.class == nativeSharedLib {
+				libNames = append(libNames, f.stem())
+			}
+		}
 		apisBackedbyOutputFile := android.PathForModuleOut(ctx, a.Name()+"_backing.txt")
 		ndkLibraryList := android.PathForSource(ctx, "system/core/rootdir/etc/public.libraries.android.txt")
 		rule := android.NewRuleBuilder(pctx, ctx)
 		rule.Command().
 			Tool(android.PathForSource(ctx, "build/soong/scripts/gen_ndk_backedby_apex.sh")).
-			Text(imageDir.String()).
-			Implicits(implicitInputs).
 			Output(apisBackedbyOutputFile).
-			Input(ndkLibraryList)
+			Input(ndkLibraryList).
+			Flags(libNames)
 		rule.Build("ndk_backedby_list", "Generate API libraries backed by Apex")
 		a.apisBackedByModuleFile = apisBackedbyOutputFile
 
diff --git a/scripts/gen_ndk_backedby_apex.sh b/scripts/gen_ndk_backedby_apex.sh
index e0da60236..4abaaba41 100755
--- a/scripts/gen_ndk_backedby_apex.sh
+++ b/scripts/gen_ndk_backedby_apex.sh
@@ -23,33 +23,50 @@ printHelp() {
     echo "**************************** Usage Instructions ****************************"
     echo "This script is used to generate the Mainline modules backed-by NDK symbols."
     echo ""
-    echo "To run this script use: ./ndk_backedby_module.sh \$BINARY_IMAGE_DIRECTORY \$OUTPUT_FILE_PATH \$NDK_LIB_NAME_LIST"
-    echo "For example: If all the module image files that you would like to run is under directory '/myModule' and output write to /backedby.txt then the command would be:"
-    echo "./ndk_usedby_module.sh /myModule /backedby.txt /ndkLibList.txt"
+    echo "To run this script use: ./gen_ndk_backed_by_apex.sh \$OUTPUT_FILE_PATH \$NDK_LIB_NAME_LIST \$MODULE_LIB1 \$MODULE_LIB2..."
+    echo "For example: If output write to /backedby.txt then the command would be:"
+    echo "./gen_ndk_backed_by_apex.sh /backedby.txt /ndkLibList.txt lib1.so lib2.so"
     echo "If the module1 is backing lib1 then the backedby.txt would contains: "
     echo "lib1"
 }
 
+contains() {
+  val="$1"
+  shift
+  for x in "$@"; do
+    if [ "$x" = "$val" ]; then
+      return 0
+    fi
+  done
+  return 1
+}
+
+
 genBackedByList() {
-  dir="$1"
-  [[ ! -e "$2" ]] && echo "" >> "$2"
+  out="$1"
+  shift
+  ndk_list="$1"
+  shift
+  rm -f "$out"
+  touch "$out"
   while IFS= read -r line
   do
     soFileName=$(echo "$line" | sed 's/\(.*so\).*/\1/')
     if [[ ! -z "$soFileName" && "$soFileName" != *"#"* ]]
     then
-      find "$dir" -type f -name "$soFileName" -exec echo "$soFileName" >> "$2" \;
+      if contains "$soFileName" "$@"; then
+        echo "$soFileName" >> "$out"
+      fi
     fi
-  done < "$3"
+  done < "$ndk_list"
 }
 
 if [[ "$1" == "help" ]]
 then
   printHelp
-elif [[ "$#" -ne 3 ]]
+elif [[ "$#" -lt 2 ]]
 then
-  echo "Wrong argument length. Expecting 3 argument representing image file directory, output path, path to ndk library list."
+  echo "Wrong argument length. Expecting at least 2 argument representing output path, path to ndk library list, followed by a list of libraries in the Mainline module."
 else
-  [[ -e "$2" ]] && rm "$2"
-  genBackedByList "$1" "$2" "$3"
+  genBackedByList "$@"
 fi