Merge remote-tracking branch 'aosp/upstream-master' into update-shaderc

Includes the following:
8ce6e2b Fix non-Windows build error.
f97f2ce HLSL: Support the constructor idiom "(struct type)0".
98ad485 HLSL: Support {...} initializer lists that are too short.
1c98904 Fix crash by returning early from finalCheck() if there is no tree to process.
5307eb2 Non-functional: Change a bunch of 0 to nullptr.
509c421 Non-functional: Fix typos.
e50dc53 Warn on HLSL not finding entry point. Issue #588.
517fe7a Non-functional: Rename some entry-point variables to entryPoint, not main.
fca8262 Always correctly terminate main. Issue #588, PR #600.
1c573fb Merge pull request #601 from BearishSun/master
e122f05 Merge pull request #599 from steve-lunarg/gs
6e848da Merge pull request #596 from steve-lunarg/hlsl-intrinsic-parsing
d347794 Merge pull request #597 from steve-lunarg/sample-keyword-fix
32c294e Adding a way to retrieve vertex attribute TType using TProgram reflection API (required in order to query location attributes).
f49cdf4 WIP: HLSL: Add GS support
75fd223 HLSL: allow "sample" as a valid identifier.
0842dbb HLSL: use HLSL parser to parse HLSL intrinsic prototypes, enable int/bool mats
fabe7d6 Test results: Fix incorrect test result caused by parallel development. Issue #594.
0bf06d3 Merge pull request #576 from steve-lunarg/uav-registers
20b030a Merge pull request #592 from ChrisGautier/barrier-wg
c3f1cdf GLSL: The execution scope for barriers should be Workgroup.
84d11e1 Merge pull request #583 from null77/fix-unref-warning
610ff83 Merge pull request #589 from steve-lunarg/vec1-promotion-fix
d9cb832 HLSL: allow promotion from 1-vector types to scalars, e.g, float<-float1
e69e196 Merge pull request #584 from steve-lunarg/attribute-expressions
a22f7db HLSL: Allow expressions in attributes
57cb69a Fix unrefenced variable warning with AMD_EXTENSIONS disabled.
d3f1122 Whole stack: Fix stale types in the AST linker object nodes, fixing #557.
9088be4 Add UAV (image) binding offset and HLSL register support
e5e58cf Merge pull request #575 from steve-lunarg/iomap-warning-fix
5b2d667 Fix build warnings in remapper, re-indent for glslang standard
89df3c2 Merge pull request #572 from steve-lunarg/numthreads
1061acc Merge pull request #562 from TiemoJung/io_map_control_publish
909b8af Merge pull request #570 from steve-lunarg/mintypes
cf35b17 Merge pull request #574 from dneto0/android-has-no-std-stoi
e301f67 Use std::atoi instead of std::stoi
3226b08 HLSL: Add min*{float,int,uint} types
1868b14 HLSL: implement numthreads for compute shaders
e19e68d Merge pull request #571 from baldurk/explicit-lambda-returns
ca73570 Add explicit lambda return types, for compilers without C++14 support
c2016a5 New uniform mapping handling
9507885 Merge pull request #560 from jeremy-lunarg/pragmas
5163446 Merge pull request #568 from steve-lunarg/logicalop-fix
aba4440 Merge pull request #567 from steve-lunarg/compare-fix
850ac06 Merge pull request #561 from jeremy-lunarg/unused
27939ca HLSL: allow component-wise operations for logical || and &&.
85244d7 HLSL: Enable component-wise vector comparisons from operators
0d628c1 Merge pull request #565 from mre4ce/master
4e3dd20 WIP: avoid strtok
c8e60e2 WIP: apply unused variable
d130075 update
2f4c832 Merge remote-tracking branch 'upstream/master'
8e1e717 fixed MSVC 2015 compile warnings
3fc1543 Merge pull request #559 from steve-lunarg/samplecmp-fix
04e2dc1 Merge pull request #558 from steve-lunarg/image-atomics
921d315 Merge pull request #555 from steve-lunarg/promotion-fixes
720e89b Merge pull request #556 from dneto0/guard-amd-enums
6b59668 HLSL: fix defect in EOpMethodSampleCmp* texture decomposition
6cb1637 Move promote methods to TIntermediate class
2232236 HLSL: phase 4 of rwtexture support: add image atomics
bb5c02f Add missing guard to code that uses AMD extensions
e5921f1 HLSL: Fix unary and binary operator type conversion issues
e07c703 Merge remote-tracking branch 'upstream/master'
5a00501 Merge remote-tracking branch 'upstream/master'
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

Test: on Linux x86; unit tests on Windows
Change-Id: I9f2774801b1feeaf26ad9577507570f61a2ecff5
tree: e52f1695cd011b8b295ff3f0f42977c22ee6413a
  1. .appveyor.yml
  2. .clang-format
  3. .gitattributes
  4. .gitignore
  5. .travis.yml
  6. CMakeLists.txt
  7. ChooseMSVCCRT.cmake
  8. External/
  9. OGLCompilersDLL/
  10. README-spirv-remap.txt
  12. SPIRV/
  13. StandAlone/
  14. Test/
  15. glslang/
  16. gtests/
  17. hlsl/
  18. make-revision

Also see the Khronos landing page for glslang as a reference front end:

The above page includes where to get binaries, and is kept up to date regarding the feature level of glslang.


Build Status Build status

An OpenGL and OpenGL ES shader front end and validator.

There are several components:

  1. A GLSL/ESSL front-end for reference validation and translation of GLSL/ESSL into an AST.

  2. An HLSL front-end for translation of a broad generic HLL into the AST.

  3. A SPIR-V back end for translating the AST to SPIR-V.

  4. A standalone wrapper, glslangValidator, that can be used as a command-line tool for the above.

How to add a feature protected by a version/extension/stage/profile: See the comment in glslang/MachineIndependent/Versions.cpp.

Tasks waiting to be done are documented as GitHub issues.

Execution of Standalone Wrapper

To use the standalone binary form, execute glslangValidator, and it will print a usage statement. Basic operation is to give it a file containing a shader, and it will print out warnings/errors and optionally an AST.

The applied stage-specific rules are based on the file extension:

  • .vert for a vertex shader
  • .tesc for a tessellation control shader
  • .tese for a tessellation evaluation shader
  • .geom for a geometry shader
  • .frag for a fragment shader
  • .comp for a compute shader

There is also a non-shader extension

  • .conf for a configuration file of limits, see usage statement for example



  • CMake: for generating compilation targets.
  • bison: optional, but needed when changing the grammar (glslang.y).
  • googletest: optional, but should use if making any changes to glslang.

Build steps

1) Check-Out this project

cd <parent of where you want glslang to be>
# If using SSH
git clone
# Or if using HTTPS
git clone

2) Check-Out External Projects

cd <the directory glslang was cloned to, "External" will be a subdirectory>
git clone External/googletest

3) Configure

Assume the source directory is $SOURCE_DIR and the build directory is $BUILD_DIR:

For building on Linux (assuming using the Ninja generator):


cmake -GNinja -DCMAKE_BUILD_TYPE={Debug|Release|RelWithDebInfo} \

For building on Windows:

# The CMAKE_INSTALL_PREFIX part is for testing (explained later).

The CMake GUI also works for Windows (version 3.4.1 tested).

4) Build and Install

# for Linux:
ninja install

# for Windows:
cmake --build . --config {Release|Debug|MinSizeRel|RelWithDebInfo} \
      --target install

If using MSVC, after running CMake to configure, use the Configuration Manager to check the INSTALL project.

If you need to change the GLSL grammar

The grammar in glslang/MachineIndependent/glslang.y has to be recompiled with bison if it changes, the output files are committed to the repo to avoid every developer needing to have bison configured to compile the project when grammar changes are quite infrequent. For windows you can get binaries from GnuWin32.

The command to rebuild is:

bison --defines=MachineIndependent/glslang_tab.cpp.h
      -t MachineIndependent/glslang.y
      -o MachineIndependent/glslang_tab.cpp

The above command is also available in the bash script at glslang/updateGrammar.


Right now, there are two test harnesses existing in glslang: one is Google Test, one is the runtests script. The former runs unit tests and single-shader single-threaded integration tests, while the latter runs multiple-shader linking tests and multi-threaded tests.

Running tests

The runtests script requires compiled binaries to be installed into $BUILD_DIR/install. Please make sure you have supplied the correct configuration to CMake (using -DCMAKE_INSTALL_PREFIX) when building; otherwise, you may want to modify the path in the runtests script.

Running Google Test-backed tests:


# for Linux:

# for Windows:
ctest -C {Debug|Release|RelWithDebInfo|MinSizeRel}

# or, run the test binary directly
# (which gives more fine-grained control like filtering):

Running runtests script-backed tests:

cd $SOURCE_DIR/Test && ./runtests

Contributing tests

Test results should always be included with a pull request that modifies functionality.

If you are writing unit tests, please use the Google Test framework and place the tests under the gtests/ directory.

Integration tests are placed in the Test/ directory. It contains test input and a subdirectory baseResults/ that contains the expected results of the tests. Both the tests and baseResults/ are under source-code control.

Google Test runs those integration tests by reading the test input, compiling them, and then compare against the expected results in baseResults/. The integration tests to run via Google Test is registered in various gtests/*.FromFile.cpp source files. glslangtests provides a command-line option --update-mode, which, if supplied, will overwrite the golden files under the baseResults/ directory with real output from that invocation. For more information, please check gtests/ directory's README.

For the runtests script, it will generate current results in the localResults/ directory and diff them against the baseResults/. When you want to update the tracked test results, they need to be copied from localResults/ to baseResults/. This can be done by the bump shell script.

You can add your own private list of tests, not tracked publicly, by using localtestlist to list non-tracked tests. This is automatically read by runtests and included in the diff and bump process.

Programmatic Interfaces

Another piece of software can programmatically translate shaders to an AST using one of two different interfaces:

  • A new C++ class-oriented interface, or
  • The original C functional interface

The main() in StandAlone/StandAlone.cpp shows examples using both styles.

C++ Class Interface (new, preferred)

This interface is in roughly the last 1/3 of ShaderLang.h. It is in the glslang namespace and contains the following.

const char* GetEsslVersionString();
const char* GetGlslVersionString();
bool InitializeProcess();
void FinalizeProcess();

class TShader
    bool parse(...);
    void setStrings(...);
    const char* getInfoLog();

class TProgram
    void addShader(...);
    bool link(...);
    const char* getInfoLog();
    Reflection queries

See ShaderLang.h and the usage of it in StandAlone/StandAlone.cpp for more details.

C Functional Interface (orignal)

This interface is in roughly the first 2/3 of ShaderLang.h, and referred to as the Sh*() interface, as all the entry points start Sh.

The Sh*() interface takes a “compiler” call-back object, which it calls after building call back that is passed the AST and can then execute a backend on it.

The following is a simplified resulting run-time call stack:

ShCompile(shader, compiler) -> compiler(AST) -> <back end>

In practice, ShCompile() takes shader strings, default version, and warning/error and other options for controlling compilation.

Basic Internal Operation

  • Initial lexical analysis is done by the preprocessor in MachineIndependent/Preprocessor, and then refined by a GLSL scanner in MachineIndependent/Scan.cpp. There is currently no use of flex.

  • Code is parsed using bison on MachineIndependent/glslang.y with the aid of a symbol table and an AST. The symbol table is not passed on to the back-end; the intermediate representation stands on its own. The tree is built by the grammar productions, many of which are offloaded into ParseHelper.cpp, and by Intermediate.cpp.

  • The intermediate representation is very high-level, and represented as an in-memory tree. This serves to lose no information from the original program, and to have efficient transfer of the result from parsing to the back-end. In the AST, constants are propogated and folded, and a very small amount of dead code is eliminated.

    To aid linking and reflection, the last top-level branch in the AST lists all global symbols.

  • The primary algorithm of the back-end compiler is to traverse the tree (high-level intermediate representation), and create an internal object code representation. There is an example of how to do this in MachineIndependent/intermOut.cpp.

  • Reduction of the tree to a linear byte-code style low-level intermediate representation is likely a good way to generate fully optimized code.

  • There is currently some dead old-style linker-type code still lying around.

  • Memory pool: parsing uses types derived from C++ std types, using a custom allocator that puts them in a memory pool. This makes allocation of individual container/contents just few cycles and deallocation free. This pool is popped after the AST is made and processed.

    The use is simple: if you are going to call new, there are three cases:

    • the object comes from the pool (its base class has the macro POOL_ALLOCATOR_NEW_DELETE in it) and you do not have to call delete

    • it is a TString, in which case call NewPoolTString(), which gets it from the pool, and there is no corresponding delete

    • the object does not come from the pool, and you have to do normal C++ memory management of what you new