| 17 | | |
| 18 | | == Building the Apple Mac OS X port with ASan (prior to Mac OS X 10.11 El Capitan) == |
| 19 | | |
| 20 | | Building the Apple Mac OS X port with the clang Address Sanitizer currently requires a custom build of trunk clang, plus an Xcode toolchain derived from OSX10.9.xctoolchain. |
| 21 | | |
| 22 | | NOTE: These instructions are currently an '''untested''' work-in-progress, but we hope to automate it with tools soon. |
| 23 | | |
| 24 | | 1. Install Mac OS X 10.9.1 (Mavericks) on a Mac. Don't use 10.9 as it contains a bug that causes a crash on every HTTP redirect. |
| 25 | | 2. Install Xcode developer tools, including the Mac OS X 10.9 SDK. These instructions assume the 10.9 SDK is located here: |
| 26 | | {{{ |
| 27 | | /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.9.xctoolchain/ |
| 28 | | }}} |
| 29 | | With Xcode 6.1 on 10.9.5, the SDK is in: |
| 30 | | {{{ |
| 31 | | /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/ |
| 32 | | }}} |
| 33 | | 3. Make a copy of the `OSX10.9.xctoolchain`(or `XcodeDefault.xctoolchain`) and call it `ASAN.xctoolchain`: |
| 34 | | {{{ |
| 35 | | sudo ditto /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.9.xctoolchain /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain |
| 36 | | }}} |
| 37 | | 4. Edit `ASAN.xctoolchain/ToolchainInfo.plist` to change the `Identifier` string from `com.apple.dt.toolchain.OSX10_9` to `com.apple.dt.toolchain.ASAN`. (with Xcode 6.1 on 10.9.5, the `Identifier` is `com.apple.dt.toolchain.XcodeDefault`) |
| 38 | | {{{ |
| 39 | | sudo vi /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain/ToolchainInfo.plist |
| 40 | | }}} |
| 41 | | 5. Build trunk clang/llvm. The address sanitizer should be built by default for Mac OS X. See [http://www.llvm.org/docs/ LLVM Docs] for details. Subversion revision r204316 of clang/llvm is known to build WebKit for Mac OS X. Newer versions may introduce new warnings or compiler bugs that must be fixed before proceeding. Alternatively, you can download a prebuilt binary from the [http://commondatastorage.googleapis.com/chromium-browser-clang/index.html?path=Mac/ Chromium Browser Clang] page. |
| 42 | | 6. Ditto the clang/llvm build output into `/Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain` to replace the version of clang/llvm in the original toolchain. If you downloaded a build from the [http://commondatastorage.googleapis.com/chromium-browser-clang/index.html?path=Mac/ Chromium Browser Clang] page, then it should be as simple as: |
| 43 | | {{{ |
| 44 | | sudo ditto ~/Downloads/clang-218707/ /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain/usr/ |
| 45 | | }}} |
| 46 | | Replacing `~/Downloads/clang-218707/` with the location you extracted the clang archive to. Note that the trailing / on the path is important! |
| 47 | | 7. Fix the ID of `libclang_rt.asan_osx_dynamic.dylib` to its installation path using the `install_name_tool`: |
| 48 | | {{{ |
| 49 | | sudo xcrun install_name_tool -id /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain/usr/lib/clang/3.5.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain/usr/lib/clang/3.5.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib |
| 50 | | }}} |
| 51 | | You may have to change the `3.5.0` in the paths to match the version of clang you are using, especially if you download a build from the [http://commondatastorage.googleapis.com/chromium-browser-clang/index.html?path=Mac/ Chromium Browser Clang] page.. |
| 52 | | 8. Copy `libclang_rt.asan_osx_dynamic.dylib` into your `WebKitBuild/Release` directory: |
| 53 | | {{{ |
| 54 | | ditto /Applications/Xcode.app/Contents/Developer/Toolchains/ASAN.xctoolchain/usr/lib/clang/3.5.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib WebKitBuild/Release/ |
| 55 | | }}} |
| 56 | | You may have to change the `3.5.0` in the paths to match the version of clang you are using, especially if you download a build from the [http://commondatastorage.googleapis.com/chromium-browser-clang/index.html?path=Mac/ Chromium Browser Clang] page. |
| 57 | | 9. Build WebKit with additional xcodebuild arguments to load `asan.xcconfig`, find the ASan ignore list, and build with the new compiler: |
| 58 | | {{{ |
| 59 | | make release ARGS="-xcconfig $PWD/Tools/asan/asan.xcconfig ASAN_IGNORE=$PWD/Tools/asan/webkit-asan-ignore.txt TOOLCHAINS=com.apple.dt.toolchain.ASAN" |
| 60 | | }}} |
| 61 | | 10. When running apps that load WebKit built with ASan, the `ASAN_OPTIONS` environment variable needs to be set to make sure the app crashes when you hit an issue, and to prevent false-positives for some intrinsics Mac OS X (e.g., memcpy and memmove are the same function). For example, to launch Safari: |
| 62 | | {{{ |
| 63 | | ASAN_OPTIONS="replace_intrin=0:abort_on_error=1:handle_segv=0" ./Tools/Scripts/run-safari --release --no-saved-state |
| 64 | | }}} |
| 65 | | You should also be able to run DumpRenderTree and WebKitTestRunner in a similar fashion: |
| 66 | | {{{ |
| 67 | | ASAN_OPTIONS="replace_intrin=0:abort_on_error=1:handle_segv=0" ./Tools/Scripts/run-webkit-tests --release --no-build |
| 68 | | }}} |
| 69 | | 11. Please use [https://bugs.webkit.org/enter_bug.cgi?product=Security New WebKit Security Bug] link to file new bugs for crashes with ASan builds. |
