Add support for toc optimization in soong

Skip relinking against shared libraries whose interface hasn't changed.

Test: mmma -j frameworks/native/libs/gui
Test: touch frameworks/native/libs/gui/BufferItem.cpp
Test: mmma -j frameworks/native/libs/gui, see nothing relinks past libgui
Bug: 26014946
Change-Id: I4d4b8da6a35c682341ae51869f5c72b51e192053

scripts/strip.sh

@@ -5,6 +5,7 @@
 #  Environment:
 #   CROSS_COMPILE: prefix added to readelf, objcopy tools
 #  Arguments:
+#   -i ${file}: input file (required)
 #   -o ${file}: output file (required)
 #   -d ${file}: deps file (required)
 #   --keep-symbols

scripts/toc.sh

@@ -0,0 +1,75 @@
+#!/bin/bash -eu
+
+# Script to handle generating a .toc file from a .so file
+# Inputs:
+#  Environment:
+#   CROSS_COMPILE: prefix added to readelf tool
+#  Arguments:
+#   -i ${file}: input file (required)
+#   -o ${file}: output file (required)
+#   -d ${file}: deps file (required)
+
+OPTSTRING=d:i:o:-:
+
+usage() {
+    cat <<EOF
+Usage: toc.sh [options] -i in-file -o out-file -d deps-file
+Options:
+EOF
+    exit 1
+}
+
+do_elf() {
+    ("${CROSS_COMPILE}readelf" -d "${infile}" | grep SONAME || echo "No SONAME for ${infile}") > "${outfile}.tmp"
+    "${CROSS_COMPILE}readelf" --dyn-syms "${infile}" | awk '{$2=""; $3=""; print}' >> "${outfile}.tmp"
+}
+
+do_macho() {
+    otool -l "${infile}" | grep LC_ID_DYLIB -A 5 > "${outfile}.tmp"
+    nm -gP "${infile}" | cut -f1-2 -d" " | grep -v 'U$' >> "${outfile}.tmp"
+}
+
+
+while getopts $OPTSTRING opt; do
+    case "$opt" in
+        d) depsfile="${OPTARG}" ;;
+        i) infile="${OPTARG}" ;;
+        o) outfile="${OPTARG}" ;;
+        -)
+            case "${OPTARG}" in
+                *) echo "Unknown option --${OPTARG}"; usage ;;
+            esac;;
+        ?) usage ;;
+        *) echo "'${opt}' '${OPTARG}'"
+    esac
+done
+
+if [ -z "${infile}" ]; then
+    echo "-i argument is required"
+    usage
+fi
+
+if [ -z "${outfile}" ]; then
+    echo "-o argument is required"
+    usage
+fi
+
+if [ -z "${depsfile}" ]; then
+    echo "-d argument is required"
+    usage
+fi
+
+rm -f "${outfile}.tmp"
+
+cat <<EOF > "${depsfile}"
+${outfile}: \\
+  ${CROSS_COMPILE}readelf \\
+EOF
+
+do_elf
+
+if cmp "${outfile}" "${outfile}.tmp" > /dev/null 2> /dev/null; then
+    rm -f "${outfile}.tmp"
+else
+    mv -f "${outfile}.tmp" "${outfile}"
+fi