core: Add script to check for possible shared library duplication

Running dupcheck.sh after a build on an image performs two checks:

  * Check for duplicate shared libraries by MD5.
  * Check for possible duplicate shared libraries by comparing .note
    and .text ELF sections.

This helps looking for unnecessary file duplication in the final images.

Test: after running the script, reports will be generated in the 'out'
directory.

Change-Id: I91c044a52002557fdc8dc65bfc9fd5f313ca00f3

core/dupcheck.sh

@@ -0,0 +1,118 @@
+#!/bin/bash
+
+# Find duplicate shared libraries by md5 checksum and possible duplicates by size.
+# Results will be available in the out directory of the build.
+# Usage:
+# ./dupcheck.sh <out_dir> <image>
+
+OUT_DIR="$1"
+IMG="$2"
+TMP_MD5="${OUT_DIR}/_dup_md5"
+TMP_SIZE="${OUT_DIR}/_dup_size"
+TMP_CHECK="${OUT_DIR}/_dup_tmp_check"
+TMP_SIZE_REAL="${OUT_DIR}/_dup_size_real"
+TMP_FILE1="${OUT_DIR}/_dup_f1"
+TMP_FILE2="${OUT_DIR}/_dup_f2"
+MD5_DUPLICATES="${OUT_DIR}/duplicate-libs-md5-${IMG}.txt"
+SIZE_DUPLICATES="${OUT_DIR}/duplicate-libs-size-${IMG}.txt"
+
+# Check arguments
+if [ "$#" -ne 2 ]; then
+	echo "Usage: ./dupcheck.sh <out_dir> <image>"
+	exit 1
+fi
+
+# Check host and toolchain version
+CHECK_HOST=$(uname)
+if [ "${CHECK_HOST}" == "Linux" ]; then
+	ARCH="linux-x86"
+else
+	ARCH="darwin-x86"
+fi
+BINUTILS_PATH="./prebuilts/clang/host/${ARCH}/llvm-binutils-stable"
+
+# Remove any old files if they exist.
+if [ -f "${MD5_DUPLICATES}" ]; then
+	rm "${MD5_DUPLICATES}"
+fi
+
+if [ -f "${SIZE_DUPLICATES}" ]; then
+	rm "${SIZE_DUPLICATES}"
+fi
+
+# Find all .so files and calculate their md5.
+find ./"${OUT_DIR}"/${IMG}/ -name "lib*.so" -type f -print0 | xargs -0 md5sum | sed -e "s# .*/# #" | sort | uniq -c | sort -g | sed "/^.*1 /d" | sed "s/^. *[0-9] //" > "${TMP_MD5}" 2>&1
+
+if [ -s "${TMP_MD5}" ]; then
+	while read -r list; do
+		checksum=$(echo "${list}" | cut -f1 -d ' ')
+		filename=$(echo "${list}" | cut -f2 -d ' ')
+		# For each md5, list the file paths that match.
+		{
+			echo "MD5: ${checksum}";											                \
+			find ./"${OUT_DIR}"/${IMG}/ -name "${filename}" -type f -print0 | xargs -0 md5sum | grep "${checksum}" | sed 's/^.* //';	\
+			echo "";													                \
+		} >> "${MD5_DUPLICATES}"
+	done <"${TMP_MD5}"
+else
+	echo "No duplicate files by md5 found." >> "${MD5_DUPLICATES}"
+fi
+
+# Cleanup
+rm "${TMP_MD5}"
+
+# Find possible duplicate .so files by size.
+find ./"${OUT_DIR}"/${IMG}/ -name "*.so" -type f -print0 | xargs -0 stat --format="%s %n" 2>/dev/null | sed -e "s# .*/# #" | sort | uniq -c | sort -g | sed "/^.*1 /d" > "${TMP_SIZE}" 2>&1
+if [ -s "${TMP_SIZE}" ]; then
+	while read -r list; do
+		size=$(echo "${list}" | cut -f2 -d ' ')
+		filename=$(echo "${list}" | cut -f3 -d ' ')
+		# Check if the files are not in the md5sum list and do nothing if that is the case.
+		find ./"${OUT_DIR}"/${IMG}/ -name "${filename}" -type f -print0 | xargs -0 stat --format="%s %n" 2>/dev/null | grep "${size}" | sed "s/^.* //" | sort > "${TMP_CHECK}" 2>&1
+		while read -r filepath; do
+			found=$(grep -F "${filepath}" "${MD5_DUPLICATES}")
+			if [ -z "${found}" ]; then
+				echo "${filepath}" >> "${TMP_SIZE_REAL}"
+			fi
+		done<"${TMP_CHECK}"
+		# For every duplication found, diff the .note and .text sections.
+		if [ -s "${TMP_SIZE_REAL}" ]; then
+			{
+				echo "File: ${filename}, Size: ${size}";	\
+				cat "${TMP_SIZE_REAL}";				\
+				echo "";					\
+			} >> "${SIZE_DUPLICATES}"
+			count=$(wc -l "${TMP_SIZE_REAL}" | cut -f1 -d ' ')
+			# Limitation: this only works for file pairs. If more than two possible duplications are found, the user need to check manually
+			# all the possible combinations using the llvm-readelf and llvm-objdump commands below.
+			if [ "${count}" = 2 ]; then
+				file1=$(head -n 1 "${TMP_SIZE_REAL}")
+				file2=$(tail -n 1 "${TMP_SIZE_REAL}")
+				# Check .note section
+				${BINUTILS_PATH}/llvm-readelf --wide --notes "${file1}" > "${TMP_FILE1}" 2>&1
+				${BINUTILS_PATH}/llvm-readelf --wide --notes "${file2}" > "${TMP_FILE2}" 2>&1
+				{
+					diff -u "${TMP_FILE1}" "${TMP_FILE2}" | sed "1d;2d;3d";	\
+					echo "";
+				} >> "${SIZE_DUPLICATES}"
+				# Check .text section
+				${BINUTILS_PATH}/llvm-objdump --line-numbers --disassemble --demangle --reloc --no-show-raw-insn --section=.text "${file1}" | sed "1d;2d"> "${TMP_FILE1}" 2>&1
+				${BINUTILS_PATH}/llvm-objdump --line-numbers --disassemble --demangle --reloc --no-show-raw-insn --section=.text "${file2}" | sed "1d;2d"> "${TMP_FILE2}" 2>&1
+				{
+					diff -u "${TMP_FILE1}" "${TMP_FILE2}" | sed "1d;2d;3d";	\
+					echo "";
+				} >> "${SIZE_DUPLICATES}"
+				# Cleanup
+				rm "${TMP_FILE1}" "${TMP_FILE2}"
+			else
+				echo "*Note: more than one duplicate. Manually verify all possible combinations." >> "${SIZE_DUPLICATES}"
+			fi
+			rm "${TMP_SIZE_REAL}"
+			echo "" >> "${SIZE_DUPLICATES}"
+		fi
+	done <"${TMP_SIZE}"
+	# Cleanup
+	rm "${TMP_SIZE}" "${TMP_CHECK}"
+else
+	echo "No duplicate files by size found." >> "${SIZE_DUPLICATES}"
+fi