1 2--- 3title: "MSAN, ASAN, & TSAN" 4linkTitle: "MSAN, ASAN, & TSAN" 5 6--- 7 8 9*Testing Skia with memory, address, and thread santizers.* 10 11Compiling Skia with ASAN, UBSAN, or TSAN can be done with the latest version of Clang. 12 13- UBSAN works on Linux, Mac, Android, and Windows, though some checks are platform-specific. 14- ASAN works on Linux, Mac, Android, and Windows. 15- TSAN works on Linux and Mac. 16- MSAN works on Linux[1]. 17 18We find that testing sanitizer builds with libc++ uncovers more issues than 19with the system-provided C++ standard library, which is usually libstdc++. 20libc++ proactively hooks into sanitizers to help their analyses. 21We ship a copy of libc++ with our Linux toolchain in /lib. 22 23[1]To compile and run with MSAN, an MSAN-instrumented version of libc++ is needed. 24It's generally easiest to run one of the following 2 steps to build/download a recent version 25of Clang and the instrumented libc++, located in /msan. 26 27Downloading Clang binaries (Googlers Only) 28------------------------------------------ 29This requires gsutil, part of the [gcloud sdk](https://cloud.google.com/sdk/downloads). 30 31<!--?prettify lang=sh?--> 32 33 gcloud auth application-default login 34 CLANGDIR="${HOME}/clang" 35 ./bin/sk asset download clang_linux $CLANGDIR 36 37Building Clang binaries from scratch (Other users) 38--------------------------- 39 40<!--?prettify lang=sh?--> 41 42 CLANGDIR="${HOME}/clang" 43 44 python3 tools/git-sync-deps 45 CC= CXX= infra/bots/assets/clang_linux/create.py -t "$CLANGDIR" 46 47Configure and Compile Skia with MSAN 48------------------------------------ 49 50<!--?prettify lang=sh?--> 51 52 CLANGDIR="${HOME}/clang" 53 mkdir -p out/msan 54 cat > out/msan/args.gn <<- EOF 55 cc = "${CLANGDIR}/bin/clang" 56 cxx = "${CLANGDIR}/bin/clang++" 57 extra_cflags = [ "-B${CLANGDIR}/bin" ] 58 extra_ldflags = [ 59 "-B${CLANGDIR}/bin", 60 "-fuse-ld=lld", 61 "-L${CLANGDIR}/msan", 62 "-Wl,-rpath,${CLANGDIR}/msan" ] 63 sanitize = "MSAN" 64 skia_use_fontconfig = false 65 EOF 66 python3 tools/git-sync-deps 67 bin/gn gen out/msan 68 ninja -C out/msan 69 70Configure and Compile Skia with ASAN 71------------------------------------ 72 73<!--?prettify lang=sh?--> 74 75 CLANGDIR="${HOME}/clang" 76 mkdir -p out/asan 77 cat > out/asan/args.gn <<- EOF 78 cc = "${CLANGDIR}/bin/clang" 79 cxx = "${CLANGDIR}/bin/clang++" 80 sanitize = "ASAN" 81 extra_ldflags = [ "-fuse-ld=lld", "-Wl,-rpath,${CLANGDIR}/lib/x86_64-unknown-linux-gnu" ] 82 EOF 83 python3 tools/git-sync-deps 84 bin/gn gen out/asan 85 ninja -C out/asan 86 87Configure and Compile Skia with TSAN 88------------------------------------ 89 90<!--?prettify lang=sh?--> 91 92 CLANGDIR="${HOME}/clang" 93 mkdir -p out/tsan 94 cat > out/tsan/args.gn <<- EOF 95 cc = "${CLANGDIR}/bin/clang" 96 cxx = "${CLANGDIR}/bin/clang++" 97 sanitize = "TSAN" 98 is_debug = false 99 extra_ldflags = [ "-Wl,-rpath,${CLANGDIR}/lib" ] 100 EOF 101 python3 tools/git-sync-deps 102 bin/gn gen out/tsan 103 ninja -C out/tsan 104 105 106