-  Mention that `depot_tools` are required and link to that repo.
-  Make `roll_deps.sh` exit on error. The script passes `shellcheck`
   with this change.
-  Reword instruction in the README.

Update DEPS ahead of the next Vulkan SDK release.

* Roll external/effcee/ 2ec8f8738..ddf5e2bb9 (1 commit)

https://github.com/google/effcee/compare/2ec8f8738118...ddf5e2bb9295

$ git log 2ec8f8738..ddf5e2bb9 --date=short --no-merges --format='%ad %ae %s'
2021-08-31 dneto Remove .travis.yml

Created with:
  roll-dep external/effcee

* Roll external/googletest/ 955c7f837..bf0701daa (32 commits)

https://github.com/google/googletest/compare/955c7f837efa...bf0701daa9f5

$ git log 955c7f837..bf0701daa --date=short --no-merges --format='%ad %ae %s'
2021-11-03 absl-team Googletest export
2021-10-28 dmauro Googletest export
2021-10-27 dmauro Googletest export
2021-10-26 absl-team Googletest export
2021-10-26 absl-team Googletest export
2021-10-25 dmauro Googletest export
2021-10-25 dmauro Googletest export
2021-10-30 dartme18 Re #3637 Show Disabled Tests in testing output
2021-10-11 absl-team Googletest export
2021-10-11 absl-team Googletest export
2021-10-11 absl-team Googletest export
2021-10-08 yesudeep Fix linker errors on FreeBSD.
2021-09-30 absl-team Googletest export
2021-09-28 absl-team Googletest export
2021-09-24 cclauss Fix remaining typos discovered by codespell
2021-09-20 absl-team Googletest export
2021-09-20 absl-team Internal change
2021-09-17 julian.amann Remove bazelbuild/rules_cc dependency
2021-09-16 cclauss Fix typos discovered by codespell
2021-09-16 cclauss Fix typos discovered by codespell
2021-09-16 cclauss Fix typo discovered by codespell
2021-09-15 absl-team Googletest export
2021-09-15 dmauro Googletest export
2021-09-15 absl-team Googletest export
2021-09-14 dmauro Googletest export
2021-09-14 dmauro Googletest export
2021-09-14 absl-team Googletest export
2021-09-15 761129+derekmauro Revert grammatically incorrect change
2021-09-10 absl-team Googletest export
2021-08-10 akashkumarsingh11032001 add a missing 'a'
2021-08-10 akashkumarsingh11032001 Create CONTRIBUTING.md
2020-12-29 julien.jemine Using auto instead of container::const_iterator

Created with:
  roll-dep external/googletest

* Roll external/spirv-headers/ 19e835041..29817199b (3 commits)

https://github.com/KhronosGroup/SPIRV-Headers/compare/19e8350415ed...29817199b706

$ git log 19e835041..29817199b --date=short --no-merges --format='%ad %ae %s'
2021-07-24 kpet Add SpecConstantSubgroupMaxSize to the clspv reflection non-semantic instruction set
2021-05-24 pmistry Implement header definitions for SPV_NV_bindless_texture
2021-10-12 ben.ashbaugh reserve SPIR-V enum block for Intel extensions

Created with:
  roll-dep external/spirv-headers

Fixes #4469

* Checks that decorations only usable with structure members are not
  used by OpDecorate or OpDecorateId
* Checks that decorations not allowed on structure members are not used
  with OpMemberDecorate
* Checks decoration targets for most core decorations
* Performs some Vulkan specific validation on deorations

The scalar replacement of a resource array/struct variable must create
OpDecorate for elements if OpMemberDecorate instructions decorate
the elements.

The JS-Tools/npm-publish flow requires a `token` attribute, even
in dry-run mode.
There is no token, so remove the step for now.

* Add wasm build

* Run wasm ci on push

* Add copyright notice to wasm files

* [wasm] Update Emscripten

* [wasm] Change global lambda to regular function

* [wasm] Show detected core count during build

* [wasm] Set JS version from CHANGES, GITHUB_RUN_ID

Also remove custom docker emscripten build with brotli, as not used

* [wasm] Change github actions to use npm-publish

* [wasm] Us docker-compose up for CI

* [wasm] pass GITHUB_RUN_ID to docker

* [wasm] Change GITHUB_RUN_ID to GITHUB_RUN_NUMBER

* [wasm] Fix GITHUB_RUN_NUMBER in docker-compose.yml

If the ids overflow when creating an integer constant in the ir_builder, there will be a nullptr dereference.  This is happening from inside merge return.

We need to propagate the error up, and make sure it is handled appropriately.

In #3404 a logical && was replaced with a bitwise & to ensure that
both side-effecting arguments were evaluated. However, this leads to
warnings from some compilers (leading to the OSS-Fuzz build breaking,
in particular).

This change reworks the relevant code so that both arguments to the
logical && are evaluated into temporaries.

Fixes #4582

* Make cxx exceptions controllable 

Found a possible link error if we compile spirv-tools by using VS2019 and link with VS2017 for another project, unresolved symbols as _CxxFrameHandler4 and __GSHandlerCheck_EH4 will be thrown. As Visual Studio updated its c++ exceptions libs.

https://devblogs.microsoft.com/cppblog/making-cpp-exception-handling-smaller-x64/

So we are making cxx exceptions controllable via a CMake option `ENABLE_EXCEPTIONS_ON_MSVC`.

Consider the new test case.  The conditional branch in the continue
block is never marked as live.  However, `IsDead` will say it is not
dead, so it does not get deleted.  Because it was never marked as live,
`%false` was not mark as live either, but it gets deleted.  This results
in invalid code.

To fix this properly, we had to reconsider how branches are handle.  We
make the following changes:

1) Terminator instructions that are not branch or OpUnreachable must be
kept, so they are marked as live when initializing the worklist.

2) Branches and OpUnreachable instructions are marked as live if
  a) the block does not have a merge instruction and another instruction
     in the block is marked as live, or
  b) the merge instruction in the same block is marked as live.

3) Any instruction that is not marked as live is removed.

4) If a terminator is to be removed, an OpUnreachable is added.  This
happens when the entire block is dead, and the block will be removed.
The OpUnreachable is generated to make sure the block still has a
terminator, and is valid.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/4509.

The generator ID is located in the upper 16 bits. The lower bits are
reserved for a version number.

Co-authored-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

Fixes #4537

* Only validate the layout of workgroup variables if the
  WorkgroupMemoryExplicitLayoutKHR capability is declared

When checking the OpBranchConditional for selection headers,
we intend to register both the true and false targets.
Short circuiting was getting in the way.

Co-authored-by: Steven Perron <stevenperron@google.com>

Spirv-opt has not had to handle module with function declarations.  This
lead many passes to assume that every function has a body.  This is not
always true.  This commit will modify a number of passes to handle
function declarations.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/4443

If we do not delete the decoration before all ReplaceAllUses, the decorations will be transferred to the new id.  This can cause problems.

Fixes #4442.

When the variable value is INT_MIN, we cannot fold the negate into the divide, so we have to turn off that folding rule.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/4487.

This commit adds a spirv-opt pass to replace accesses to
descriptor array based on variable indices with constant
elements.

Before:
```
%descriptor = OpVariable %_ptr_array_Image Uniform
...
%ac = OpAccessChain %_ptr_Image %descriptor %variable_index
(some image instructions using %ac)
```
After:
```
%descriptor = OpVariable %_ptr_array_Image Uniform
...
OpSwitch %variable_index 0 %case0 1 %case1 ...
...
%case0 = OpLabel
%ac = OpAccessChain %_ptr_Image %descriptor %uint_0
...
%case1 = OpLabel
%ac = OpAccessChain %_ptr_Image %descriptor %uint_1
...
(use OpPhi for value with concrete type)
```

Having IsLocalVar work only sometimes is something that could easily
lead to an error.  This change refactors the code so that the function
can be called at any point.  The current implementation was used because
we did not want to do multiple searches to see if a function was an
entry point or if it had a call.  This was maintained by added a cache
that will store of a given function is an entry point with no calls.

Fixes #4431.

Fixes https://crbug.com/40216

* Handle entry points with no execution modes when checking implicit
  derivative execution model checks

When setting default value for spec constants, for numeric bit types smaller
than 32 bits, follow the SPIR-V rules for narrow literals:
- signed integers are sign-extended
- otherwise, upper bits are zero.

Followup to #4588

* test: add a test to show 8/16-bit

* opt/spec_constants: fix bit pattern width checks.

The input bit patterns are always at least 32-bits, so let the test
pass for 8/16-bit values as well. This shouldn't have any effect on the
64-bit patterns I assume this was introduced for.

The OSS-Fuzz i386 build has been failing due to errors about
64-to-32-bit conversions, relating to random generation code. This
changre fixes the problem by explicitly using a 64-bit random generator,
and by adding a cast to size_t to avoid an implicit conversion.

Do this if Constant or DefUse managers are invalid. Using the
ConstantManager attempts to regenerate the DefUseManager
which is not valid during inlining.

Bot failures are unrelated. 

I checked this against the Kokoro output.

This is follow-up to the commit
https://github.com/KhronosGroup/SPIRV-Tools/commit/bd3a271ce3fcc8b9ed8e6eb2e94392d1b220adc9

Fixes #4561

* When checking for offsets, don't accept 0xffffffff

* Account for strided components in arrays

Fixes #4567

* If the element type of an array takes less than a location in size,
  calculate the location usage in a strided manner

* formatting

- Remove Appveyor CI
- Write new "Getting the source" subsection, consolidating material
  from a couple of places.  Emphasize using the utils/git-sync-deps
  script for getting a known-good combination of sources.
- Built artifacts:
   - top of tree artifacts are from Kokoro CI bots
   - mention Vulkan SDK and Android NDK as alternatives

Fixes: #4577

Otherwise KillInst() tries to generate it when the module is
inconsistent.

According to spec this opcode is a constant instruction - that's it
can appear outside of function bodies.

Co-authored-by: DmitryBushev <dmitry.bushev@intel.com>

Fixes #4552.

* Add pass-through validation for Offsets image operand
  * it is counted as an offset parameter though
* Update DEPS