Add check for missing sysroot libraries

Linking on arm64 can fail when dependent libraries are missing.
That is, when linking against liba which depends on libb, linking
will fail when only libb is missing.

This CL adds a check to prevent these types of missing libraries.

BUG=webrtc:8535
R=thestig@chromium.org

Change-Id: I14e15ce534bd8ac5602f84dedcaab2db041656fb
Reviewed-on: https://chromium-review.googlesource.com/773200Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517222}

build/linux/sysroot_scripts/sysroot-creator.sh

@@ -420,6 +420,59 @@ CleanupJailSymlinks() {
   cd "$SAVEDPWD"
 }
 
+
+VerifyLibraryDepsCommon() {
+  local arch=$1
+  local os=$2
+  local find_dirs=(
+    "${INSTALL_ROOT}/lib/${arch}-${os}/"
+    "${INSTALL_ROOT}/usr/lib/${arch}-${os}/"
+  )
+  local needed_libs="$(
+    find ${find_dirs[*]} -name "*\.so*" -type f -exec file {} \; | \
+      grep ': ELF' | sed 's/^\(.*\): .*$/\1/' | xargs readelf -d | \
+      grep NEEDED | sort | uniq | sed 's/^.*Shared library: \[\(.*\)\]$/\1/g')"
+  local all_libs="$(find ${find_dirs[*]} -printf '%f\n')"
+  local missing_libs="$(grep -vFxf <(echo "${all_libs}") \
+    <(echo "${needed_libs}"))"
+  if [ ! -z "${missing_libs}" ]; then
+    echo "Missing libraries:"
+    echo "${missing_libs}"
+    exit 1
+  fi
+}
+
+
+VerifyLibraryDepsAmd64() {
+  VerifyLibraryDepsCommon x86_64 linux-gnu
+}
+
+
+VerifyLibraryDepsI386() {
+  VerifyLibraryDepsCommon i386 linux-gnu
+}
+
+
+VerifyLibraryDepsARM() {
+  VerifyLibraryDepsCommon arm linux-gnueabihf
+}
+
+
+VerifyLibraryDepsARM64() {
+  VerifyLibraryDepsCommon aarch64 linux-gnu
+}
+
+
+VerifyLibraryDepsMips() {
+  VerifyLibraryDepsCommon mipsel linux-gnu
+}
+
+
+VerifyLibraryDepsMips64el() {
+  VerifyLibraryDepsCommon mips64el linux-gnuabi64
+}
+
+
 #@
 #@ BuildSysrootAmd64
 #@
@@ -437,6 +490,7 @@ BuildSysrootAmd64() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesAmd64
+  VerifyLibraryDepsAmd64
   CreateTarBall
 }
 
@@ -457,6 +511,7 @@ BuildSysrootI386() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesI386
+  VerifyLibraryDepsI386
   CreateTarBall
 }
 
@@ -477,6 +532,7 @@ BuildSysrootARM() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesARM
+  VerifyLibraryDepsARM
   CreateTarBall
 }
 
@@ -497,6 +553,7 @@ BuildSysrootARM64() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesARM64
+  VerifyLibraryDepsARM64
   CreateTarBall
 }
 
@@ -518,6 +575,7 @@ BuildSysrootMips() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesMips
+  VerifyLibraryDepsMips
   CreateTarBall
 }
 
@@ -539,6 +597,7 @@ BuildSysrootMips64el() {
   InstallIntoSysroot ${files_and_sha256sums}
   CleanupJailSymlinks
   HacksAndPatchesMips64el
+  VerifyLibraryDepsMips64el
   CreateTarBall
 }