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docs/building_with_gyp.md

+<font color='darkred'><b>Build issues? File a bug at code.google.com/p/v8/issues or ask for help on v8-users@googlegroups.com.</b></font>
+
+# Building V8
+
+V8 is built with the help of [GYP](http://code.google.com/p/gyp/). GYP is a meta build system of sorts, as it generates build files for a number of other build systems. How you build therefore depends on what "back-end" build system and compiler you're using.
+The instructions below assume that you already have a [checkout of V8](using_git.md) but haven't yet installed the build dependencies.
+
+If you intend to develop on V8, i.e., send patches and work with changelists, you will need to install the dependencies as described [here](using_git.md).
+
+
+## Prerequisite: Installing GYP
+
+First, you need GYP itself. GYP is fetched together with the other dependencies by running:
+
+```
+gclient sync
+```
+
+## Building
+
+### GCC + make
+
+Requires GNU make 3.81 or later. Should work with any GCC >= 4.8 or any recent clang (3.5 highly recommended).
+
+#### Build instructions
+
+
+The top-level Makefile defines a number of targets for each target architecture (`ia32`, `x64`, `arm`, `arm64`) and mode (`debug`, `optdebug`, or `release`). So your basic command for building is:
+```
+make ia32.release
+```
+
+or analogously for the other architectures and modes. You can build both debug and release binaries with just one command:
+```
+make ia32
+```
+
+To automatically build in release mode for the host architecture:
+```
+make native
+```
+
+You can also can build all architectures in a given mode at once:
+```
+make release
+```
+
+Or everything:
+```
+make
+```
+
+#### Optional parameters
+
+  * `-j` specifies the number of parallel build processes. Set it (roughly) to the number of CPU cores your machine has. The GYP/make based V8 build also supports distcc, so you can compile with `-j100` or so, provided you have enough machines around.
+
+  * `OUTDIR=foo` specifies where the compiled binaries go. It defaults to `./out/`. In this directory, a subdirectory will be created for each architecture and mode. You will find the d8 shell's binary in `foo/ia32.release/d8`, for example.
+
+  * `library=shared` or `component=shared_library` (the two are completely equivalent) builds V8 as a shared library (`libv8.so`).
+
+  * `soname_version=1.2.3` is only relevant for shared library builds and configures the SONAME of the library. Both the SONAME and the filename of the library will be `libv8.so.1.2.3` if you specify this. Due to a peculiarity in GYP, if you specify a custom SONAME, the library's path will no longer be encoded in the binaries, so you'll have to run d8 as follows:
+```
+LD_LIBRARY_PATH=out/ia32.release/lib.target out/ia32.release/d8
+```
+
+  * `console=readline` enables readline support for the d8 shell. You need readline development headers for this (`libreadline-dev` on Ubuntu).
+
+  * `disassembler=on` enables the disassembler for release mode binaries (it's always enabled for debug binaries). This is useful if you want to inspect generated machine code.
+
+  * `snapshot=off` disables building with a heap snapshot. Compiling will be a little faster, but V8’s start up will be slightly slower.
+
+  * `gdbjit=on` enables GDB JIT support.
+
+  * `liveobjectlist=on` enables the Live Object List feature.
+
+  * `vfp3=off` is only relevant for ARM builds with snapshot and disables the use of VFP3 instructions in the snapshot.
+
+  * `debuggersupport=off` disables the javascript debugger.
+
+  * `werror=no` omits the -Werror flag. This is especially useful for not officially supported C++ compilers (e.g. newer versions of the GCC) so that compile warnings are ignored.
+
+  * `strictaliasing=off` passes the -fno-strict-aliasing flag to GCC. This may help to work around build failures on officially unsupported platforms and/or GCC versions.
+
+  * `regexp=interpreted` chooses the interpreted mode of the irregexp regular expression engine instead of the native code mode.
+
+  * `hardfp=on` creates "hardfp" binaries on ARM.
+
+### Ninja
+
+To build d8:
+```
+export GYP_GENERATORS=ninja
+build/gyp_v8
+ninja -C out/Debug d8
+```
+
+Specify `out/Release` for a release build. I recommend setting up an alias so that you don't need to type out that build directory path.
+
+If you want to build all targets, use `ninja -C out/Debug all`. It's faster to build only the target you're working on, like `d8` or `unittests`.
+
+Note: You need to set `v8_target_arch` if you want a non-native build, i.e. either
+```
+export GYP_DEFINES="v8_target_arch=arm"
+build/gyp_v8 ...
+```
+or
+```
+build/gyp_v8 -Dv8_target_arch=arm ...
+```
+
+
+#### Using goma (Googlers only)
+
+To use goma you need to set the `use_goma` gyp define, either by passing it to `gyp_v8`, i.e.
+```
+build/gyp_v8 -Duse_goma=1
+```
+or by setting the environment variable `$GYP_DEFINES` appropriately:
+```
+export GYP_DEFINES="use_goma=1"
+```
+Note: You may need to also set `gomadir` to point to the directory where you installed goma, if it's not in the default location.
+
+If you are using goma, you'll also want to bump the job limit, i.e.
+```
+ninja -j 100 -C out/Debug d8
+```
+
+
+### Cross-compiling
+
+Similar to building with Clang, you can also use a cross-compiler. Just export your toolchain (`CXX`/`LINK` environment variables should be enough) and compile. For example:
+```
+export CXX=/path/to/cross-compile-g++
+export LINK=/path/to/cross-compile-g++
+make arm.release
+```
+
+
+### Xcode
+
+From the root of your V8 checkout, run either of:
+```
+build/gyp_v8 -Dtarget_arch=ia32
+build/gyp_v8 -Dtarget_arch=x64
+```
+
+This will generate Xcode project files in `build/` that you can then either open with Xcode or compile directly from the command line:
+```
+xcodebuild -project build/all.xcodeproj -configuration Release
+xcodebuild -project build/all.xcodeproj
+```
+
+Note: If you have configured your `GYP_GENERATORS` environment variable, either unset it, or set it to `xcode` for this to work.
+
+
+#### Custom build settings
+
+You can export the `GYP_DEFINES` environment variable in your shell to configure custom build options. The syntax is `GYP_DEFINES="-Dvariable1=value1 -Dvariable2=value2"` and so on for as many variables as you wish. Possibly interesting options include:
+  * `-Dcomponent=shared_library` (see `library=shared` in the [GCC + make](#Optional_parameters.md) section above)
+  * `-Dconsole=readline` (see `console=readline`)
+  * `-Dv8_enable_disassembler=1` (see `disassembler=on`)
+  * `-Dv8_use_snapshot='false'` (see `snapshot=off`)
+  * `-Dv8_enable_gdbjit=1` (see `gdbjit=on`)
+  * `-Dv8_use_liveobjectlist=true` (see `liveobjectlist=on`)
+
+
+### Visual Studio
+
+You need Visual Studio 2013, older versions might still work at the moment, but this will probably change soon because we intend to use C++11 features.
+
+#### Prerequisites
+
+After you created [checkout of V8](using_git.md), all dependencies will be already installed.
+
+If you are getting errors during build mentioning that 'python' could not be found, add the 'python.exe' to PATH.
+
+If you have Visual Studio 2013 and 2015 installed side-by-side and set the environment variable GYP\_MSVS\_VERSION to '2013'. In that case the right project files are going to be created.
+
+#### Building
+  * If you use the command prompt:
+    1. Generate project files:
+```
+python build\gyp_v8
+```
+> > > Specify the path to `python.exe` if you don't have it in your PATH.
+> > > Append `-Dtarget_arch=x64` if you want to build 64bit binaries. If you switch between ia32 and x64 targets, you may have to manually delete the generated .vcproj/.sln files before regenerating them.
+> > > Example:
+```
+third_party/python_26/python.exe build\gyp_v8 -Dtarget_arch=x64
+```
+    1. Build:
+> > > Either open `build\All.sln` in Visual Studio, or compile on the command line as follows (adapt the path as necessary, or simply put `devenv.com` in your PATH):
+```
+"c:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\devenv.com" /build Release build\All.sln
+```
+> > > Replace `Release` with `Debug` to build in Debug mode.
+> > > The built binaries will be in build\Release\ or build\Debug\.
+
+  * If you use cygwin, the workflow is the same, but the syntax is slightly different:
+    1. Generate project files:
+```
+build/gyp_v8
+```
+> > > This will spit out a bunch of warnings about missing input files, but it seems to be OK to ignore them. (If you have time to figure this out, we'd happily accept a patch that makes the warnings go away!)
+    1. Build:
+```
+/cygdrive/c/Program\ Files\ (x86)/Microsoft\ Visual\ Studio\ 9.0/Common7/IDE/devenv.com /build Release build/all.sln
+```
+
+
+#### Custom build settings
+
+See the "custom build settings" section for [Xcode](#Xcode.md) above.

[Michael Achenbach, 2015/09/28 14:40:13]

s/(#Xcode.md)/(#Xcode)

+
+
+#### Running tests
+
+You can abuse the test driver's --buildbot flag to make it find the executables where MSVC puts them:
+```
+python tools/run-tests.py --buildbot --outdir build --arch ia32 --mode Release
+```
+
+
+### MinGW
+
+Building on MinGW is not officially supported, but it is possible. You even have two options:
+
+#### Option 1: With Cygwin Installed
+
+Requirements:
+  * MinGW
+  * Cygwin, including Python
+  * Python from www.python.org _(yes, you need two Python installations!)_
+
+Building:
+  1. Open a MinGW shell
+  1. `export PATH=$PATH:/c/cygwin/bin` _(or wherever you installed Cygwin)_
+  1. `make ia32.release -j8`
+
+Running tests:
+  1. Open a MinGW shell
+  1. `export PATH=/c/Python27:$PATH` _(or wherever you installed Python)_
+  1. `make ia32.release.check -j8`
+
+#### Option 2: Without Cygwin, just MinGW
+
+Requirements:
+  * MinGW
+  * Python from www.python.org
+
+Building and testing:
+  1. Open a MinGW shell
+  1. `tools/mingw-generate-makefiles.sh` _(re-run this any time a `*`.gyp`*` file changed, such as after updating your checkout)_
+  1. `make ia32.release` _(unfortunately -jX doesn't seem to work here)_
+  1. `make ia32.release.check -j8`
+
+
+# Final Note
+<font color='darkred'><b>If you have problems or questions, please file bugs at code.google.com/p/v8/issues or send mail to v8-users@googlegroups.com. Comments on this page are likely to go unnoticed and unanswered.</b></font>