1#!/bin/bash -eu
2#
3# Run as: CLANG=bin/clang ZLIB_SRC=src/zlib \
4#             build_symbolizer.sh runtime_build/lib/clang/4.0.0/lib/linux/
5# zlib can be downloaded from http://www.zlib.net.
6#
7# Script compiles self-contained object file with symbolization code and injects
8# it into the given set of runtime libraries. Script updates only libraries
9# which has unresolved __sanitizer_symbolize_* symbols and matches architecture.
10# Object file is be compiled from LLVM sources with dependencies like libc++ and
11# zlib. Then it internalizes symbols in the file, so that it can be linked
12# into arbitrary programs, avoiding conflicts with the program own symbols and
13# avoiding dependencies on any program symbols. The only acceptable dependencies
14# are libc and __sanitizer::internal_* from sanitizer runtime.
15#
16# Symbols exported by the object file will be used by Sanitizer runtime
17# libraries to symbolize code/data in-process.
18#
19# The script will modify the output directory which is given as the first
20# argument to the script.
21#
22# FIXME: We should really be using a simpler approach to building this object
23# file, and it should be available as a regular cmake rule. Conceptually, we
24# want to be doing "ld -r" followed by "objcopy -G" to create a relocatable
25# object file with only our entry points exposed. However, this does not work at
26# present, see PR30750.
27
28set -x
29set -e
30set -u
31
32SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
33SRC_DIR=$(readlink -f $SCRIPT_DIR/..)
34TARGE_DIR=$(readlink -f $1)
35COMPILER_RT_SRC=$(readlink -f ${SCRIPT_DIR}/../../../..)
36LLVM_SRC=${LLVM_SRC:-${COMPILER_RT_SRC}/../llvm}
37LLVM_SRC=$(readlink -f $LLVM_SRC)
38if [[ ! -d "${LLVM_SRC}/../llvm" ]] ; then
39  LLVM_SRC=$(readlink -f ${COMPILER_RT_SRC}/../../../llvm)
40fi
41LIBCXX_SRC=$(readlink -f ${COMPILER_RT_SRC}/../libcxx)
42LIBCXXABI_SRC=$(readlink -f ${COMPILER_RT_SRC}/../libcxxabi)
43
44if [[ ! -d "${LLVM_SRC}/../llvm" ||
45      ! -d "${LIBCXX_SRC}" ||
46      ! -d "${LIBCXXABI_SRC}" ]]; then
47  echo "Missing or incomplete LLVM_SRC"
48  exit 1
49fi
50
51if [[ "$ZLIB_SRC" == ""  ||
52      ! -x "${ZLIB_SRC}/configure" ||
53      ! -f "${ZLIB_SRC}/zlib.h" ]]; then
54  echo "Missing or incomplete ZLIB_SRC"
55  exit 1
56fi
57ZLIB_SRC=$(readlink -f $ZLIB_SRC)
58
59J="${J:-50}"
60
61CLANG="${CLANG:-`which clang`}"
62CLANG_DIR=$(readlink -f $(dirname "$CLANG"))
63
64BUILD_DIR=$(readlink -f ./symbolizer)
65mkdir -p $BUILD_DIR
66cd $BUILD_DIR
67
68CC=$CLANG_DIR/clang
69CXX=$CLANG_DIR/clang++
70TBLGEN=$CLANG_DIR/llvm-tblgen
71OPT=$CLANG_DIR/opt
72export AR=$CLANG_DIR/llvm-ar
73export LINK=$CLANG_DIR/llvm-link
74
75for F in $CC $CXX $TBLGEN $LINK $OPT $AR; do
76  if [[ ! -x "$F" ]]; then
77    echo "Missing $F"
78     exit 1
79  fi
80done
81
82ZLIB_BUILD=${BUILD_DIR}/zlib
83LIBCXX_BUILD=${BUILD_DIR}/libcxx
84LLVM_BUILD=${BUILD_DIR}/llvm
85SYMBOLIZER_BUILD=${BUILD_DIR}/symbolizer
86
87FLAGS=${FLAGS:-}
88FLAGS="$FLAGS -fPIC -flto -Os -g0 -DNDEBUG"
89
90# Build zlib.
91mkdir -p ${ZLIB_BUILD}
92cd ${ZLIB_BUILD}
93cp -r ${ZLIB_SRC}/* .
94CC=$CC CFLAGS="$FLAGS" RANLIB=/bin/true ./configure --static
95make -j${J} libz.a
96
97# Build and install libcxxabi and libcxx.
98if [[ ! -d ${LIBCXX_BUILD} ]]; then
99  mkdir -p ${LIBCXX_BUILD}
100  cd ${LIBCXX_BUILD}
101  LIBCXX_FLAGS="${FLAGS} -Wno-macro-redefined -I${LIBCXX_SRC}/include"
102  PROJECTS=
103  if [[ ! -d $LLVM_SRC/projects/libcxxabi ]] ; then
104    PROJECTS="-DLLVM_ENABLE_PROJECTS='libcxx;libcxxabi'"
105  fi
106  cmake -GNinja \
107    ${PROJECTS} \
108    -DCMAKE_BUILD_TYPE=Release \
109    -DCMAKE_C_COMPILER=$CC \
110    -DCMAKE_CXX_COMPILER=$CXX \
111    -DCMAKE_C_FLAGS_RELEASE="${LIBCXX_FLAGS}" \
112    -DCMAKE_CXX_FLAGS_RELEASE="${LIBCXX_FLAGS}" \
113    -DLIBCXXABI_ENABLE_ASSERTIONS=OFF \
114    -DLIBCXXABI_ENABLE_EXCEPTIONS=OFF \
115    -DLIBCXXABI_ENABLE_SHARED=OFF \
116    -DLIBCXX_ENABLE_ASSERTIONS=OFF \
117    -DLIBCXX_ENABLE_EXCEPTIONS=OFF \
118    -DLIBCXX_ENABLE_RTTI=OFF \
119    -DLIBCXX_ENABLE_SHARED=OFF \
120  $LLVM_SRC
121fi
122cd ${LIBCXX_BUILD}
123ninja cxx cxxabi
124
125FLAGS="${FLAGS} -fno-rtti -fno-exceptions"
126LLVM_FLAGS="${FLAGS} -nostdinc++ -I${ZLIB_BUILD} -I${LIBCXX_BUILD}/include/c++/v1"
127
128# Build LLVM.
129if [[ ! -d ${LLVM_BUILD} ]]; then
130  mkdir -p ${LLVM_BUILD}
131  cd ${LLVM_BUILD}
132  cmake -GNinja \
133    -DCMAKE_BUILD_TYPE=Release \
134    -DCMAKE_C_COMPILER=$CC \
135    -DCMAKE_CXX_COMPILER=$CXX \
136    -DCMAKE_C_FLAGS_RELEASE="${LLVM_FLAGS}" \
137    -DCMAKE_CXX_FLAGS_RELEASE="${LLVM_FLAGS}" \
138    -DLLVM_TABLEGEN=$TBLGEN \
139    -DLLVM_ENABLE_ZLIB=ON \
140    -DLLVM_ENABLE_TERMINFO=OFF \
141    -DLLVM_ENABLE_THREADS=OFF \
142  $LLVM_SRC
143fi
144cd ${LLVM_BUILD}
145ninja LLVMSymbolize LLVMObject LLVMBinaryFormat LLVMDebugInfoDWARF LLVMSupport LLVMDebugInfoPDB LLVMMC LLVMDemangle LLVMTextAPI
146
147cd ${BUILD_DIR}
148rm -rf ${SYMBOLIZER_BUILD}
149mkdir ${SYMBOLIZER_BUILD}
150cd ${SYMBOLIZER_BUILD}
151
152echo "Compiling..."
153SYMBOLIZER_FLAGS="$LLVM_FLAGS -I${LLVM_SRC}/include -I${LLVM_BUILD}/include -std=c++14"
154$CXX $SYMBOLIZER_FLAGS ${SRC_DIR}/sanitizer_symbolize.cpp ${SRC_DIR}/sanitizer_wrappers.cpp -c
155$AR rc symbolizer.a sanitizer_symbolize.o sanitizer_wrappers.o
156
157SYMBOLIZER_API_LIST=__sanitizer_symbolize_code,__sanitizer_symbolize_data,__sanitizer_symbolize_flush,__sanitizer_symbolize_demangle
158
159# Merge all the object files together and copy the resulting library back.
160$SCRIPT_DIR/ar_to_bc.sh $LIBCXX_BUILD/lib/libc++.a \
161                        $LIBCXX_BUILD/lib/libc++abi.a \
162                        $LLVM_BUILD/lib/libLLVMSymbolize.a \
163                        $LLVM_BUILD/lib/libLLVMObject.a \
164                        $LLVM_BUILD/lib/libLLVMBinaryFormat.a \
165                        $LLVM_BUILD/lib/libLLVMDebugInfoDWARF.a \
166                        $LLVM_BUILD/lib/libLLVMSupport.a \
167                        $LLVM_BUILD/lib/libLLVMDebugInfoPDB.a \
168                        $LLVM_BUILD/lib/libLLVMDebugInfoMSF.a \
169                        $LLVM_BUILD/lib/libLLVMDebugInfoCodeView.a \
170                        $LLVM_BUILD/lib/libLLVMDemangle.a \
171                        $LLVM_BUILD/lib/libLLVMMC.a \
172                        $LLVM_BUILD/lib/libLLVMTextAPI.a \
173                        $ZLIB_BUILD/libz.a \
174                        symbolizer.a \
175                        all.bc
176
177echo "Optimizing..."
178$OPT -internalize -internalize-public-api-list=${SYMBOLIZER_API_LIST} all.bc -o opt.bc
179$CC $FLAGS -fno-lto -c opt.bc -o symbolizer.o
180
181echo "Checking undefined symbols..."
182nm -f posix -g symbolizer.o | cut -f 1,2 -d \  | LC_COLLATE=C sort -u > undefined.new
183(diff -u $SCRIPT_DIR/global_symbols.txt undefined.new | grep -E "^\+[^+]") && \
184  (echo "Failed: unexpected symbols"; exit 1)
185
186arch() {
187  objdump -f $1 | grep -m1 -Po "(?<=file format ).*$"
188}
189
190SYMBOLIZER_FORMAT=$(arch symbolizer.o)
191echo "Injecting $SYMBOLIZER_FORMAT symbolizer..."
192for A in $TARGE_DIR/libclang_rt.*san*.a; do
193  A_FORMAT=$(arch $A)
194  if [[ "$A_FORMAT" != "$SYMBOLIZER_FORMAT" ]] ; then
195    continue
196  fi
197  (nm -u $A 2>/dev/null | grep -E "__sanitizer_symbolize_code" >/dev/null) || continue
198  echo "$A"
199  $AR rcs $A symbolizer.o
200done
201
202echo "Success!"
203