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 CLANGDIR="${HOME}/clang" 34 python2 infra/bots/assets/clang_linux/download.py -t $CLANGDIR 35 36Building Clang binaries from scratch (Other users) 37--------------------------- 38 39<!--?prettify lang=sh?--> 40 41 CLANGDIR="${HOME}/clang" 42 43 python2 tools/git-sync-deps 44 CC= CXX= infra/bots/assets/clang_linux/create.py -t "$CLANGDIR" 45 46Configure and Compile Skia with MSAN 47------------------------------------ 48 49<!--?prettify lang=sh?--> 50 51 CLANGDIR="${HOME}/clang" 52 mkdir -p out/msan 53 cat > out/msan/args.gn <<- EOF 54 cc = "${CLANGDIR}/bin/clang" 55 cxx = "${CLANGDIR}/bin/clang++" 56 extra_cflags = [ "-B${CLANGDIR}/bin" ] 57 extra_ldflags = [ 58 "-B${CLANGDIR}/bin", 59 "-fuse-ld=lld", 60 "-L${CLANGDIR}/msan", 61 "-Wl,-rpath,${CLANGDIR}/msan" ] 62 sanitize = "MSAN" 63 skia_use_fontconfig = false 64 EOF 65 python2 tools/git-sync-deps 66 bin/gn gen out/msan 67 ninja -C out/msan 68 69Configure and Compile Skia with ASAN 70------------------------------------ 71 72<!--?prettify lang=sh?--> 73 74 CLANGDIR="${HOME}/clang" 75 mkdir -p out/asan 76 cat > out/asan/args.gn <<- EOF 77 cc = "${CLANGDIR}/bin/clang" 78 cxx = "${CLANGDIR}/bin/clang++" 79 sanitize = "ASAN" 80 extra_ldflags = [ "-fuse-ld=lld", "-Wl,-rpath,${CLANGDIR}/lib" ] 81 EOF 82 python2 tools/git-sync-deps 83 bin/gn gen out/asan 84 ninja -C out/asan 85 86Configure and Compile Skia with TSAN 87------------------------------------ 88 89<!--?prettify lang=sh?--> 90 91 CLANGDIR="${HOME}/clang" 92 mkdir -p out/tsan 93 cat > out/tsan/args.gn <<- EOF 94 cc = "${CLANGDIR}/bin/clang" 95 cxx = "${CLANGDIR}/bin/clang++" 96 sanitize = "TSAN" 97 is_debug = false 98 extra_ldflags = [ "-Wl,-rpath,${CLANGDIR}/lib" ] 99 EOF 100 python2 tools/git-sync-deps 101 bin/gn gen out/tsan 102 ninja -C out/tsan 103 104 105