README.md - external/github.com/KhronosGroup/SPIRV-Tools.git - Git at Google

 # SPIR-V Tools

 [![Build Status](https://travis-ci.org/KhronosGroup/SPIRV-Tools.svg?branch=master)](https://travis-ci.org/KhronosGroup/SPIRV-Tools)
 [![Build status](https://ci.appveyor.com/api/projects/status/gpue87cesrx3pi0d/branch/master?svg=true)](https://ci.appveyor.com/project/Khronoswebmaster/spirv-tools/branch/master)

 ## Overview

 The SPIR-V Tools project provides an API and commands for processing SPIR-V
 modules.

 The project includes an assembler, binary module parser, disassembler,
 validator, and optimizer for SPIR-V. Except for the optimizer, all are based
 on a common static library.  The library contains all of the implementation
 details, and is used in the standalone tools whilst also enabling integration
 into other code bases directly. The optimizer implementation resides in its
 own library.

 The interfaces are still under development, and are expected to change.

 SPIR-V is defined by the Khronos Group Inc.
 See the [SPIR-V Registry][spirv-registry] for the SPIR-V specification,
 headers, and XML registry.

 ## Verisoning SPIRV-Tools

 See [`CHANGES`](CHANGES) for a high level summary of recent changes, by version.

 SPIRV-Tools project version numbers are of the form `v`*year*`.`*index* and with
 an optional `-dev` suffix to indicate work in progress.  For exampe, the
 following versions are ordered from oldest to newest:

 * `v2016.0`
 * `v2016.1-dev`
 * `v2016.1`
 * `v2016.2-dev`
 * `v2016.2`

 Use the `--version` option on each command line tool to see the software
 version.  An API call reports the software version as a C-style string.

 ## Supported features

 ### Assembler, binary parser, and disassembler

 * Based on SPIR-V version 1.1 Rev 3
 * Support for extended instruction sets:
   * GLSL std450 version 1.0 Rev 3
   * OpenCL version 1.0 Rev 2
 * Support for SPIR-V 1.0 (with or without additional restrictions from Vulkan 1.0)
 * Assembler only does basic syntax checking.  No cross validation of
   IDs or types is performed, except to check literal arguments to
   `OpConstant`, `OpSpecConstant`, and `OpSwitch`.

 See [`syntax.md`](syntax.md) for the assembly language syntax.

 ### Validator

 *Warning:* The validator is incomplete.

 ### Optimizer

 *Warning:* The optimizer is still under development and its library interface is
 not yet published.

 Currently supported optimizations:
 * [Strip debug info](source/opt/strip_debug_info_pass.h)
 * [Freeze spec constant](source/opt/freeze_spec_constant_value_pass.h)
 * [Fold `OpSpecConstantOp` and `OpSpecConstantComposite`](source/opt/fold_spec_constant_op_and_composite_pass.h)
 * [Unify constants](source/opt/unify_const_pass.h)
 * [Eliminate dead constant](source/opt/eliminate_dead_constant_pass.h)

 For the latest list, please refer to `spirv-opt --help`.

 ## Source code

 The SPIR-V Tools are maintained by members of the The Khronos Group Inc.,
 at https://github.com/KhronosGroup/SPIRV-Tools.

 Contributions via merge request are welcome. Changes should:
 * Be provided under the [Apache 2.0](#license).
   You'll be prompted with a one-time "click-through" Contributor's License
   Agreement (CLA) dialog as part of submitting your pull request or
   other contribution to GitHub.
 * Include tests to cover updated functionality.
 * C++ code should follow the [Google C++ Style Guide][cpp-style-guide].
 * Code should be formatted with `clang-format`.  Settings are defined by
   the included [.clang-format](.clang-format) file.

 We intend to maintain a linear history on the GitHub `master` branch.

 ### Source code organization

 * `external/googletest`: Intended location for the
   [googletest][googletest] sources, not provided
 * `include/`: API clients should add this directory to the include search path
 * `external/spirv-headers`: Intended location for
   [SPIR-V headers][spirv-headers], not provided
 * `include/spirv-tools/libspirv.h`: C API public interface
 * `source/`: API implementation
 * `test/`: Tests, using the [googletest][googletest] framework
 * `tools/`: Command line executables

 ### Tests

 The project contains a number of tests, used to drive development
 and ensure correctness.  The tests are written using the
 [googletest][googletest] framework.  The `googletest`
 source is not provided with this project.  There are two ways to enable
 tests:
 * If SPIR-V Tools is configured as part of an enclosing project, then the
   enclosing project should configure `googletest` before configuring SPIR-V Tools.
 * If SPIR-V Tools is configured as a standalone project, then download the
   `googletest` source into the `<spirv-dir>/external/googletest` directory before
   configuring and building the project.

 *Note*: You must use a version of googletest that includes
 [a fix][googletest-pull-612] for [googletest issue 610][googletest-issue-610].
 The fix is included on the googletest master branch any time after 2015-11-10.
 In particular, googletest must be newer than version 1.7.0.

 ## Build

 The project uses [CMake][cmake] to generate platform-specific build
 configurations. Assume that `<spirv-dir>` is the root directory of the checked
 out code:

 ```sh
 cd <spirv-dir>
 git clone https://github.com/KhronosGroup/SPIRV-Headers.git external/spirv-headers
 git clone https://github.com/google/googletest.git external/googletest # optional

 mkdir build && cd build
 cmake [-G <platform-generator>] <spirv-dir>
 ```

 Once the build files have been generated, build using your preferred
 development environment.

 ### CMake options

 The following CMake options are supported:

 * `SPIRV_COLOR_TERMINAL={ON|OFF}`, default `ON` - Enables color console output.
 * `SPIRV_SKIP_TESTS={ON|OFF}`, default `OFF`- Build only the library and
   the command line tools.  This will prevent the tests from being built.
 * `SPIRV_SKIP_EXECUTABLES={ON|OFF}`, default `OFF`- Build only the library, not
   the command line tools and tests.
 * `SPIRV_USE_SANITIZER=<sanitizer>`, default is no sanitizing - On UNIX
   platforms with an appropriate version of `clang` this option enables the use
   of the sanitizers documented [here][clang-sanitizers].
   This should only be used with a debug build.
 * `SPIRV_WARN_EVERYTHING={ON|OFF}`, default `OFF` - On UNIX platforms enable
   more strict warnings.  The code might not compile with this option enabled.
   For Clang, enables `-Weverything`.  For GCC, enables `-Wpedantic`.
   See [`CMakeLists.txt`](CMakeLists.txt) for details.
 * `SPIRV_WERROR={ON|OFF}`, default `ON` - Forces a compilation error on any
   warnings encountered by enabling the compiler-specific compiler front-end
   option.

 ## Library

 ### Usage

 The library provides a C API, but the internals use C++11.

 In order to use the library from an application, the include path should point
 to `<spirv-dir>/include`, which will enable the application to include the
 header `<spirv-dir>/include/spirv-tools/libspirv.h` then linking against the
 static library in `<spirv-build-dir>/source/libSPIRV-Tools.a` or
 `<spirv-build-dir>/source/SPIRV-Tools.lib`.

 * `SPIRV-Tools` CMake target: Creates the static library:
   * `<spirv-build-dir>/source/libSPIRV-Tools.a` on Linux and OS X.
   * `<spirv-build-dir>/source/libSPIRV-Tools.lib` on Windows.

 #### Entry points

 The interfaces are still under development, and are expected to change.

 There are three main entry points into the library.

 * `spvTextToBinary`: An assembler, translating text to a binary SPIR-V module.
 * `spvBinaryToText`: A disassembler, translating a binary SPIR-V module to
   text.
 * `spvBinaryParse`: The entry point to a binary parser API.  It issues callbacks
   for the header and each parsed instruction.  The disassembler is implemented
   as a client of `spvBinaryParse`.
 * `spvValidate` implements the validator functionality. *Incomplete*

 ## Command line tools

 Command line tools, which wrap the above library functions, are provided to
 assemble or disassemble shader files.  It's a convention to name SPIR-V
 assembly and binary files with suffix `.spvasm` and `.spv`, respectively.

 ### Assembler tool

 The assembler reads the assembly language text, and emits the binary form.

 The standalone assembler is the exectuable called `spirv-as`, and is located in
 `<spirv-build-dir>/tools/spirv-as`.  The functionality of the assembler is implemented
 by the `spvTextToBinary` library function.

 * `spirv-as` - the standalone assembler
   * `<spirv-dir>/tools/as`

 Use option `-h` to print help.

 ### Disassembler tool

 The disassembler reads the binary form, and emits assembly language text.

 The standalone disassembler is the executable called `spirv-dis`, and is located in
 `<spirv-build-dir>/tools/spirv-dis`. The functionality of the disassembler is implemented
 by the `spvBinaryToText` library function.

 * `spirv-dis` - the standalone disassembler
   * `<spirv-dir>/tools/dis`

 Use option `-h` to print help.

 The output includes syntax colouring when printing to the standard output stream,
 on Linux, Windows, and OS X.

 ### Optimizer tool

 The optimizer processes a SPIR-V binary module, applying transformations
 in the specified order.

 This is a work in progress, with initially only few available transformations.

 * `spirv-opt` - the standalone optimizer
   * `<spirv-dir>/tools/opt`

 ### Validator tool

 *Warning:* This functionality is under development, and is incomplete.

 The standalone validator is the executable called `spirv-val`, and is located in
 `<spirv-build-dir>/tools/spirv-val`. The functionality of the validator is implemented
 by the `spvValidate` library function.

 The validator operates on the binary form.

 * `spirv-val` - the standalone validator
   * `<spirv-dir>/tools/val`

 ### Control flow dumper tool

 The control flow dumper prints the control flow graph for a SPIR-V module as a
 [GraphViz](http://www.graphviz.org/) graph.

 This is experimental.

 * `spirv-cfg` - the control flow graph dumper
   * `<spirv-dir>/tools/cfg`

 ### Utility filters

 * `spirv-lesspipe.sh` - Automatically disassembles `.spv` binary files for the
   `less` program, on compatible systems.  For example, set the `LESSOPEN`
   environment variable as follows, assuming both `spirv-lesspipe.sh` and
   `spirv-dis` are on your executable search path:
   ```
    export LESSOPEN='| spirv-lesspipe.sh "%s"'
   ```
   Then you page through a disassembled module as follows:
   ```
   less foo.spv
   ```
   * The `spirv-lesspipe.sh` script will pass through any extra arguments to
     `spirv-dis`.  So, for example, you can turn off colours and friendly ID
     naming as follows:
     ```
     export LESSOPEN='| spirv-lesspipe.sh "%s" --no-color --raw-id'
     ```

 * `50spirv-tools.el` - Automatically disassembles '.spv' binary files when
   loaded into the emacs text editor, and re-assembles them when saved,
   provided any modifications to the file are valid.  This functionality
   must be explicitly requested by defining the symbol
   SPIRV_TOOLS_INSTALL_EMACS_HELPERS as follows:
   ```
   cmake -DSPIRV_TOOLS_INSTALL_EMACS_HELPERS=true ...
   ```

   In addition, this helper is only installed if the directory /etc/emacs/site-start.d
   exists, which is typically true if emacs is installed on the system.

   Note that symbol IDs are not currently preserved through a load/edit/save operation.
   This may change if the ability is added to spirv-as.


 ### Tests

 Tests are only built when googletest is found. Use `ctest` to run all the
 tests.

 ## Future Work
 <a name="future"></a>

 ### Assembler and disassembler

 * The disassembler could emit helpful annotations in comments.  For example:
   * Use variable name information from debug instructions to annotate
     key operations on variables.
   * Show control flow information by annotating `OpLabel` instructions with
     that basic block's predecessors.
 * Error messages could be improved.

 ### Validator

 This is a work in progress.

 ## Licence
 <a name="license"></a>
 Full license terms are in [LICENSE](LICENSE)
 ```
 Copyright (c) 2015-2016 The Khronos Group Inc.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 ```

 [spirv-registry]: https://www.khronos.org/registry/spir-v/
 [spirv-headers]: https://github.com/KhronosGroup/SPIRV-Headers
 [googletest]: https://github.com/google/googletest
 [googletest-pull-612]: https://github.com/google/googletest/pull/612
 [googletest-issue-610]: https://github.com/google/googletest/issues/610
 [CMake]: https://cmake.org/
 [cpp-style-guide]: https://google.github.io/styleguide/cppguide.html
 [clang-sanitizers]: http://clang.llvm.org/docs/UsersManual.html#controlling-code-generation
	# SPIR-V Tools

	[![Build Status](https://travis-ci.org/KhronosGroup/SPIRV-Tools.svg?branch=master)](https://travis-ci.org/KhronosGroup/SPIRV-Tools)
	[![Build status](https://ci.appveyor.com/api/projects/status/gpue87cesrx3pi0d/branch/master?svg=true)](https://ci.appveyor.com/project/Khronoswebmaster/spirv-tools/branch/master)

	## Overview

	The SPIR-V Tools project provides an API and commands for processing SPIR-V
	modules.

	The project includes an assembler, binary module parser, disassembler,
	validator, and optimizer for SPIR-V. Except for the optimizer, all are based
	on a common static library. The library contains all of the implementation
	details, and is used in the standalone tools whilst also enabling integration
	into other code bases directly. The optimizer implementation resides in its
	own library.

	The interfaces are still under development, and are expected to change.

	SPIR-V is defined by the Khronos Group Inc.
	See the [SPIR-V Registry][spirv-registry] for the SPIR-V specification,
	headers, and XML registry.

	## Verisoning SPIRV-Tools

	See [`CHANGES`](CHANGES) for a high level summary of recent changes, by version.

	SPIRV-Tools project version numbers are of the form `v`year`.`index and with
	an optional `-dev` suffix to indicate work in progress. For exampe, the
	following versions are ordered from oldest to newest:

	* `v2016.0`
	* `v2016.1-dev`
	* `v2016.1`
	* `v2016.2-dev`
	* `v2016.2`

	Use the `--version` option on each command line tool to see the software
	version. An API call reports the software version as a C-style string.

	## Supported features

	### Assembler, binary parser, and disassembler

	* Based on SPIR-V version 1.1 Rev 3
	* Support for extended instruction sets:
	* GLSL std450 version 1.0 Rev 3
	* OpenCL version 1.0 Rev 2
	* Support for SPIR-V 1.0 (with or without additional restrictions from Vulkan 1.0)
	* Assembler only does basic syntax checking. No cross validation of
	IDs or types is performed, except to check literal arguments to
	`OpConstant`, `OpSpecConstant`, and `OpSwitch`.

	See [`syntax.md`](syntax.md) for the assembly language syntax.

	### Validator

	Warning: The validator is incomplete.

	### Optimizer

	Warning: The optimizer is still under development and its library interface is
	not yet published.

	Currently supported optimizations:
	* [Strip debug info](source/opt/strip_debug_info_pass.h)
	* [Freeze spec constant](source/opt/freeze_spec_constant_value_pass.h)
	* [Fold `OpSpecConstantOp` and `OpSpecConstantComposite`](source/opt/fold_spec_constant_op_and_composite_pass.h)
	* [Unify constants](source/opt/unify_const_pass.h)
	* [Eliminate dead constant](source/opt/eliminate_dead_constant_pass.h)

	For the latest list, please refer to `spirv-opt --help`.

	## Source code

	The SPIR-V Tools are maintained by members of the The Khronos Group Inc.,
	at https://github.com/KhronosGroup/SPIRV-Tools.

	Contributions via merge request are welcome. Changes should:
	* Be provided under the [Apache 2.0](#license).
	You'll be prompted with a one-time "click-through" Contributor's License
	Agreement (CLA) dialog as part of submitting your pull request or
	other contribution to GitHub.
	* Include tests to cover updated functionality.
	* C++ code should follow the [Google C++ Style Guide][cpp-style-guide].
	* Code should be formatted with `clang-format`. Settings are defined by
	the included [.clang-format](.clang-format) file.

	We intend to maintain a linear history on the GitHub `master` branch.

	### Source code organization

	* `external/googletest`: Intended location for the
	[googletest][googletest] sources, not provided
	* `include/`: API clients should add this directory to the include search path
	* `external/spirv-headers`: Intended location for
	[SPIR-V headers][spirv-headers], not provided
	* `include/spirv-tools/libspirv.h`: C API public interface
	* `source/`: API implementation
	* `test/`: Tests, using the [googletest][googletest] framework
	* `tools/`: Command line executables

	### Tests

	The project contains a number of tests, used to drive development
	and ensure correctness. The tests are written using the
	[googletest][googletest] framework. The `googletest`
	source is not provided with this project. There are two ways to enable
	tests:
	* If SPIR-V Tools is configured as part of an enclosing project, then the
	enclosing project should configure `googletest` before configuring SPIR-V Tools.
	* If SPIR-V Tools is configured as a standalone project, then download the
	`googletest` source into the `<spirv-dir>/external/googletest` directory before
	configuring and building the project.

	Note: You must use a version of googletest that includes
	[a fix][googletest-pull-612] for [googletest issue 610][googletest-issue-610].
	The fix is included on the googletest master branch any time after 2015-11-10.
	In particular, googletest must be newer than version 1.7.0.

	## Build

	The project uses [CMake][cmake] to generate platform-specific build
	configurations. Assume that `<spirv-dir>` is the root directory of the checked
	out code:

	```sh
	cd <spirv-dir>
	git clone https://github.com/KhronosGroup/SPIRV-Headers.git external/spirv-headers
	git clone https://github.com/google/googletest.git external/googletest # optional

	mkdir build && cd build
	cmake [-G <platform-generator>] <spirv-dir>
	```

	Once the build files have been generated, build using your preferred
	development environment.

	### CMake options

	The following CMake options are supported:

	* `SPIRV_COLOR_TERMINAL={ON\|OFF}`, default `ON` - Enables color console output.
	* `SPIRV_SKIP_TESTS={ON\|OFF}`, default `OFF`- Build only the library and
	the command line tools. This will prevent the tests from being built.
	* `SPIRV_SKIP_EXECUTABLES={ON\|OFF}`, default `OFF`- Build only the library, not
	the command line tools and tests.
	* `SPIRV_USE_SANITIZER=<sanitizer>`, default is no sanitizing - On UNIX
	platforms with an appropriate version of `clang` this option enables the use
	of the sanitizers documented [here][clang-sanitizers].
	This should only be used with a debug build.
	* `SPIRV_WARN_EVERYTHING={ON\|OFF}`, default `OFF` - On UNIX platforms enable
	more strict warnings. The code might not compile with this option enabled.
	For Clang, enables `-Weverything`. For GCC, enables `-Wpedantic`.
	See [`CMakeLists.txt`](CMakeLists.txt) for details.
	* `SPIRV_WERROR={ON\|OFF}`, default `ON` - Forces a compilation error on any
	warnings encountered by enabling the compiler-specific compiler front-end
	option.

	## Library

	### Usage

	The library provides a C API, but the internals use C++11.

	In order to use the library from an application, the include path should point
	to `<spirv-dir>/include`, which will enable the application to include the
	header `<spirv-dir>/include/spirv-tools/libspirv.h` then linking against the
	static library in `<spirv-build-dir>/source/libSPIRV-Tools.a` or
	`<spirv-build-dir>/source/SPIRV-Tools.lib`.

	* `SPIRV-Tools` CMake target: Creates the static library:
	* `<spirv-build-dir>/source/libSPIRV-Tools.a` on Linux and OS X.
	* `<spirv-build-dir>/source/libSPIRV-Tools.lib` on Windows.

	#### Entry points

	The interfaces are still under development, and are expected to change.

	There are three main entry points into the library.

	* `spvTextToBinary`: An assembler, translating text to a binary SPIR-V module.
	* `spvBinaryToText`: A disassembler, translating a binary SPIR-V module to
	text.
	* `spvBinaryParse`: The entry point to a binary parser API. It issues callbacks
	for the header and each parsed instruction. The disassembler is implemented
	as a client of `spvBinaryParse`.
	* `spvValidate` implements the validator functionality. Incomplete

	## Command line tools

	Command line tools, which wrap the above library functions, are provided to
	assemble or disassemble shader files. It's a convention to name SPIR-V
	assembly and binary files with suffix `.spvasm` and `.spv`, respectively.

	### Assembler tool

	The assembler reads the assembly language text, and emits the binary form.

	The standalone assembler is the exectuable called `spirv-as`, and is located in
	`<spirv-build-dir>/tools/spirv-as`. The functionality of the assembler is implemented
	by the `spvTextToBinary` library function.

	* `spirv-as` - the standalone assembler
	* `<spirv-dir>/tools/as`

	Use option `-h` to print help.

	### Disassembler tool

	The disassembler reads the binary form, and emits assembly language text.

	The standalone disassembler is the executable called `spirv-dis`, and is located in
	`<spirv-build-dir>/tools/spirv-dis`. The functionality of the disassembler is implemented
	by the `spvBinaryToText` library function.

	* `spirv-dis` - the standalone disassembler
	* `<spirv-dir>/tools/dis`

	Use option `-h` to print help.

	The output includes syntax colouring when printing to the standard output stream,
	on Linux, Windows, and OS X.

	### Optimizer tool

	The optimizer processes a SPIR-V binary module, applying transformations
	in the specified order.

	This is a work in progress, with initially only few available transformations.

	* `spirv-opt` - the standalone optimizer
	* `<spirv-dir>/tools/opt`

	### Validator tool

	Warning: This functionality is under development, and is incomplete.

	The standalone validator is the executable called `spirv-val`, and is located in
	`<spirv-build-dir>/tools/spirv-val`. The functionality of the validator is implemented
	by the `spvValidate` library function.

	The validator operates on the binary form.

	* `spirv-val` - the standalone validator
	* `<spirv-dir>/tools/val`

	### Control flow dumper tool

	The control flow dumper prints the control flow graph for a SPIR-V module as a
	[GraphViz](http://www.graphviz.org/) graph.

	This is experimental.

	* `spirv-cfg` - the control flow graph dumper
	* `<spirv-dir>/tools/cfg`

	### Utility filters

	* `spirv-lesspipe.sh` - Automatically disassembles `.spv` binary files for the
	`less` program, on compatible systems. For example, set the `LESSOPEN`
	environment variable as follows, assuming both `spirv-lesspipe.sh` and
	`spirv-dis` are on your executable search path:
	```
	export LESSOPEN='\| spirv-lesspipe.sh "%s"'
	```
	Then you page through a disassembled module as follows:
	```
	less foo.spv
	```
	* The `spirv-lesspipe.sh` script will pass through any extra arguments to
	`spirv-dis`. So, for example, you can turn off colours and friendly ID
	naming as follows:
	```
	export LESSOPEN='\| spirv-lesspipe.sh "%s" --no-color --raw-id'
	```

	* `50spirv-tools.el` - Automatically disassembles '.spv' binary files when
	loaded into the emacs text editor, and re-assembles them when saved,
	provided any modifications to the file are valid. This functionality
	must be explicitly requested by defining the symbol
	SPIRV_TOOLS_INSTALL_EMACS_HELPERS as follows:
	```
	cmake -DSPIRV_TOOLS_INSTALL_EMACS_HELPERS=true ...
	```

	In addition, this helper is only installed if the directory /etc/emacs/site-start.d
	exists, which is typically true if emacs is installed on the system.

	Note that symbol IDs are not currently preserved through a load/edit/save operation.
	This may change if the ability is added to spirv-as.


	### Tests

	Tests are only built when googletest is found. Use `ctest` to run all the
	tests.

	## Future Work
	<a name="future"></a>

	### Assembler and disassembler

	* The disassembler could emit helpful annotations in comments. For example:
	* Use variable name information from debug instructions to annotate
	key operations on variables.
	* Show control flow information by annotating `OpLabel` instructions with
	that basic block's predecessors.
	* Error messages could be improved.

	### Validator

	This is a work in progress.

	## Licence
	<a name="license"></a>
	Full license terms are in [LICENSE](LICENSE)
	```
	Copyright (c) 2015-2016 The Khronos Group Inc.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	```

	[spirv-registry]: https://www.khronos.org/registry/spir-v/
	[spirv-headers]: https://github.com/KhronosGroup/SPIRV-Headers
	[googletest]: https://github.com/google/googletest
	[googletest-pull-612]: https://github.com/google/googletest/pull/612
	[googletest-issue-610]: https://github.com/google/googletest/issues/610
	[CMake]: https://cmake.org/
	[cpp-style-guide]: https://google.github.io/styleguide/cppguide.html
	[clang-sanitizers]: http://clang.llvm.org/docs/UsersManual.html#controlling-code-generation