We no longer derive a performance benefit from this pass in practice,
and it is a very expensive compilation step. It is also prone to fuzz-
related errors.
Doc: http://go/optimization-in-sksl
Change-Id: Ief08ffac659a8fe7fe92c92b9a5da14c9f713bc2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381261
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
It turned out that everywhere we were using or testing DSL code either
directly or indirectly imported big chunks of the SkSL library. These
imports turned out to be necessary; code written using just DSL.h would
fail with various template instantiation errors.
Change-Id: Iae72d15b0d6ef14614ac1a4ff08c36bc1876cd4d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381638
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
These were accidentally omitted from the supported operator list.
Change-Id: Idecd17adb8b3f5043e36328c65ca12be33e990f4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381637
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Expressions like `x * 1`, `x *= 1`, `x + 0`, `x * 0`, or `0 / x` don't
actually do anything, and can be simplified to just `x` or `0`. (The
zero case must also check that `x` doesn't have side effects, because
`0 * myFunction()` still needs to call `myFunction`.)
`0 - x` is also detected and rewritten as `-x`.
`0 / 0` is left as-is.
This logic works for scalars and vectors; matrices are left as-is.
A similar optimization also occurs in the constant-propagation pass, so
we see almost no diffs in the tests. If control-flow analysis is turned
off, we do see some improvements. (I didn't reuse the existing code at
all, since it was designed around rewriting the CFG tree, but the
concept was identical.)
Change-Id: Ia99cd81f1d4cd3dafaa43ccac6a2261e3257a185
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/380356
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Declare
This solves several issues caused by the lack of ordering guarantees in
C++; it was possible for the SkSL backend to look for the value of a
variable before its Declare() call gets processed. Moving the initial
value out of Declare should fix this whole class of problems.
Change-Id: I428fe230f1c312a0128c1f00c2a36cb95f4590a6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/380358
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Swizzle optimizations now occur at IR generation time. These
optimizations are redundant with the control-flow optimization phase so
they are mostly not visible in our test output, but they do affect DSL
test results. Interestingly, they do improve our test output slightly
as well, for various reasons (e.g. we do not fully optimize lvalues in
the control-flow pass).
Change-Id: I6ebe6d71a5c22d9823b5fa500e43078915cbfb45
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372257
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
This performs the same simplifications as the control-flow phase, but at
IR generation time. There's no visible difference in the tests (besides
DSL) because these aren't new optimizations; they're just happening
at a different phase of compilation.
Change-Id: I26d241167b0e690b23f8f4370339714783c8d6fd
Bug: skia:11343
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371482
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
This check now runs at function finalization time, before constant
propagation has occurred; this affected the "DeadIfStatement" test.
Our detection isn't smart enough to realize that a loop will run zero
times, so it treats `for` and `while` loops as always running at least
once. This isn't strictly correct, but it actually mirrors how the CFG
implementation works anyway. The only downside is that we would not flag
code like `for (i=0; i<0; ++i) { return x; }` as an error.
Change-Id: I5e43a6ee3a3993045559f0fb0646d36112543a94
Bug: skia:11377
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379056
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
In addition to the unsurprising changes to eliminate references to
src/, we also had to tighten up some C++17-isms as they are not
permitted in public headers.
Change-Id: Ie5005a33d7a135e69fb66beca5e7a5f960dbd453
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/378496
Reviewed-by: Brian Osman <brianosman@google.com>
Rather than have the inliner own this responsibility, the function
finalizer now detects if a function is supposed to return a value but
never actually does. This will allow us to detect this error case even
if the inliner is disabled. The inliner should no longer encounter
functions that claim to return a value but don't, so it will now assert
if one is encountered. (The inliner still has the logic to handle this
case gracefully, just in case.)
The check is currently very simple and doesn't analyze the structure of
the function, so it won't report cases where some paths return a value
and others don't, e.g. this will pass the test:
int func() { if (something()) return 123; }
(This is good enough to resolve the inliner issue, though, as it only
occurred in functions with no value-returns at all.)
Change-Id: I21f13daffe66c8f2e72932b320ee268ba9207bfa
Bug: oss-fuzz:31469, oss-fuzz:31525, skia:11377
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/377196
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
This reverts commit 4903482a2a.
Change-Id: Ie56583344897fcb2c072bcac4d97d582edeadf07
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375660
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This reverts commit d42932a1b5.
Reason for revert: Breaking CMake and SKQP builds.
Original change's description:
> Add DSL PossibleExpression & PossibleStatement
>
> These are currently unused, but in future CLs they will be used to
> capture line number information in DSL error handling.
>
> Change-Id: Ieee730e0ad8323043437972fedb5bec471c367e4
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375069
> Reviewed-by: John Stiles <johnstiles@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
Change-Id: I2062c9964569c9129a2145f9e45f849310129687
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375658
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>
This reverts commit 8a43a2889e.
Reason for revert: Prereq revert for https://skia-review.googlesource.com/c/skia/+/375069
Original change's description:
> SkSL DSL now reports the C++ line numbers of errors
>
> This is done a best-effort basis. Positions will only be reported in
> Clang and GCC, and may not be reported in every possible situation.
>
> Change-Id: I7efb15781546b95e667fee34e488366174bb5f36
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374600
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
Change-Id: I173cb355533d6f99c9561177b68f56924fe8a98f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375657
Reviewed-by: Florin Malita <fmalita@google.com>
Commit-Queue: Florin Malita <fmalita@google.com>
This is done a best-effort basis. Positions will only be reported in
Clang and GCC, and may not be reported in every possible situation.
Change-Id: I7efb15781546b95e667fee34e488366174bb5f36
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374600
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
These are currently unused, but in future CLs they will be used to
capture line number information in DSL error handling.
Change-Id: Ieee730e0ad8323043437972fedb5bec471c367e4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375069
Reviewed-by: John Stiles <johnstiles@google.com>
At IR generation time, this CL limits our optimizations to only
@switch statements. A regular switch statement will only be optimized
during the optimization phase even if the switch-value is a known
compile-time constant. This is done to avoid upsetting our reachability
analysis.
Most of this CL is moving existing logic from SkSLCompiler into
SkSLAnalysis and SkSLSwitchStatement. Although the diffs look large, the
actual changes are very small.
Change-Id: I90920f41bc386dfa7a980ae7510f6681231a5120
Bug: skia:11340, skia:11342, skia:11319
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372679
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Change-Id: I10d561eec456a7917681d7bdf0b1bd2f5ee5ad5f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374217
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
This splits switch() construction into two stages.
- One version of Make takes an array of case-values and case-statement
lists, and is responsible for reporting errors if the case-values are
not unique or are improperly typed. This is what the IR generator or DSL
will start with on its first encounter with the switch statement.
- The other version of Make takes an array of already-processed
SwitchCases and can assume the invariant that they're all correctly-
typed with unique values. This is what we will have when a statement
is inlined or otherwise cloned. (We still assert this invariant, for
correctness' sake, but in release mode we assume it.)
This CL doesn't perform any optimizations at Make time yet; it does work
equivalent to how `switch` works in the IR generator today. It does
improve duplicate case-label checking slightly; duplicate case labels
are now reported, and duplicate `default:` labels are detected.
(Multiple `default` labels won't pass the parser, but they can be
constructed in DSL.)
Change-Id: I537ce2c8236152d58641fb1793619d66a62c01a8
Bug: skia:11342
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372616
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
This allows things to align better between the IR and DSL sides
and gives us equivalent error handling on both sides.
Change-Id: I6d5569e29df51a4d1a6cb0ad1e6611d419dfe30c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/373737
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
The IRGenerator's `convertConstructor` and `coerce` were tied at the
hip--coercion can create a constructor, and creating a constructor can
cause type-coercion. This CL migrates IRGenerator::coerce to
Type::coerceExpression, and migrates IRGenerator::convertConstructor to
Constructor::Make.
Most constructor creation should go through Constructor::Make instead of
make_unique<Constructor> for best results. There are exceptions to this
rule:
- during the Compiler's `optimize` phase, we hold raw pointers to
unique_ptrs of existing expression trees, and are manually tracking
variable usage counts, so adjusting the IR tree should be done with
extreme care. Continue to use make_unique here to avoid any "surprise
improvements."
- the Rehydrator is attempting to recreate an IR tree exactly as it used
to be and doesn't want additional optimization or fixups
There are still Constructor-related optimizations in simplifyExpression
which are not yet implemented in Constructor::Make. These are migrated
to Constructor::Make at http://review.skia.org/371482
Change-Id: I0f3876f932835fc2e347ae95414bc490085f120c
Bug: skia:11342
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370876
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Previously, a DSL unit test failure would not report the actual text
generated by the DSL, or the line number of the failure.
Added a new macro EXPECT_EQUAL which
- supports DSL statements, DSL expressions, and IR nodes equally
- reports both the expected string and actual DSL output
- reports the line number of the failure
- always compares in a whitespace-insensitive fashion
- supports passing rvalue DSL expressions directly, rather than forcing
us to create single-use lvalues for each test
Existing DSL tests have been updated to use this macro.
A failing test looks like this:
FAILURE: ../../tests/SkSLDSLTest.cpp:107 (Failed on line 146)
Expected: float4(0.0, 1.0, 2.0, 3.0)
Actual: float4(0.0, 1.0, 2.0, 4.0)
[DSLFloat, Mock]
Change-Id: Ie99d449690252f289bf48a66ab9c58e19dda9a07
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/372198
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Change-Id: Idd0d49d3564dc3a24455db3c504ffa124f34dd05
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371336
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
SkSL.
It would previously catch 1 / 0, but fail to detect x / 0.
Bug: skia:11051
Change-Id: I3adb5942cce03a7ad40a13a8ca5d5a7f2029d6ad
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/366720
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Change-Id: Ifa5fa8bd80ffc48408f133f96951f8a74d572751
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/366959
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
separate pass.
This makes things easier for the DSL, which allows us to create
nodes without knowing whether they're going to be valid until they
are inserted. Moving these checks into a separate pass allows the
DSL to use the same error handling and type coercion as the normal
code path.
Change-Id: I9c26bd7a15a6c819df39a2214fdeab47ed6d8ee4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/362496
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Change-Id: Ibc995e908e5b4f8d1516e13d56854a4fcf5cc809
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/360556
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Change-Id: I4e771083e90f3c60b61f7ce7c8e6697e7bf7c7e1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/358518
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
(and Ternary for good measure)
Change-Id: I4afa121d54ab9ba8d0814693ce53da7cb73ef340
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353626
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Change-Id: I9859081a14b110731f943e09fdd94dc10e0c9dfc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353580
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This adds basic operator overloading (everything but array indexing) and
related tests to the SkSL DSL.
Change-Id: Ic9fdc9a02a5496e2706d18fb435d838b4ee53ad7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/353103
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Change-Id: I0bbda6a41391fc2a11dc812be5e9c0c0d14c4d75
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/351921
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
The code at this point doesn't do anything useful, but establishes some
of the basic types and patterns.
Change-Id: I580a9e75ffa3162879893450fb7d1f0905a10687
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/350697
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
This reverts commit 4129b6b65f.
Reason for revert: WASM breakage: https://task-driver.skia.org/td/UBRwnWYfbc5IwUWqtFMv
Original change's description:
> Revert "Reland "Reland "Reland "Revert "Initial land of SkSL DSL."""""
>
> This reverts commit 346dd53ac0.
>
> Change-Id: I93bb18438cc6c2ad43d058d6c3f95bcc65d0cea9
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343916
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: John Stiles <johnstiles@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
# Not skipping CQ checks because this is a reland.
Change-Id: If05145cf9d9c51f4c76fe523f6050a670b5da669
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/345169
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
This reverts commit b37a693254.
Reason for revert: Breaking Flutter roll
Original change's description:
> Revert "Reland "Reland "Revert "Initial land of SkSL DSL.""""
>
> This reverts commit 6b07e0eb49.
>
> Change-Id: Ic01f31edf55b2d1a7533e0e8ed33b39b4846d937
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343106
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
# Not skipping CQ checks because this is a reland.
Change-Id: I3373f186f4d0531bc8ab1e4392c512608389734f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343518
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This reverts commit 6b07e0eb49.
Change-Id: Ic01f31edf55b2d1a7533e0e8ed33b39b4846d937
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343106
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
This reverts commit 52e5850065.
Reason for revert: Failing on Build-Debian9-Clang-arm-Release-Flutter_Android_Docker: https://logs.chromium.org/logs/skia/5066a8ed31374c11/+/steps/Run_build_script_in_Docker/0/stdout
Original change's description:
> Revert "Reland "Revert "Initial land of SkSL DSL."""
>
> This reverts commit 53f69f1539.
>
> Change-Id: I374b016c8a08d83c99cbab800f30b882244b87f1
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342919
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Commit-Queue: John Stiles <johnstiles@google.com>
> Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: John Stiles <johnstiles@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
# Not skipping CQ checks because this is a reland.
Change-Id: Ia04ee404478314b3ae034e0a7740ef667364b2f8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/343100
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This reverts commit 53f69f1539.
Change-Id: I374b016c8a08d83c99cbab800f30b882244b87f1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342919
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
This reverts commit a3b8ac76e5.
Reason for revert: Need to revert again, red tree.
Original change's description:
> Revert "Revert "Initial land of SkSL DSL.""
>
> This reverts commit dd213e9d46.
>
> Change-Id: I43be020dd1b07dc13862150a9d95493f8c48b3b1
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342622
> Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
# Not skipping CQ checks because this is a reland.
No-Presubmit: true
No-Try: true
Change-Id: I8e967ef8ecb7f01dc578d38264e2600b04e9b62d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342917
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This reverts commit dd213e9d46.
Change-Id: I43be020dd1b07dc13862150a9d95493f8c48b3b1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342622
Auto-Submit: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
This reverts commit 6e599511d4.
Reason for revert: Breaking bots: https://logs.chromium.org/logs/skia/5061fbd134144011/+/steps/dm/0/stdout
Original change's description:
> Initial land of SkSL DSL.
>
> This is not 100% complete: it lacks support for several kinds of nodes
> and supports only a bare handful of builtin functions, but it
> demonstrates the core functionality and it should be relatively
> straightforward to fill in the missing pieces.
>
> Change-Id: I3058089338e20eebc3da18ac5571801abcaab564
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/331177
> Reviewed-by: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
TBR=brianosman@google.com,ethannicholas@google.com,johnstiles@google.com
Change-Id: Iee77e5322a0b1efb0f3718ec1f5976a4d4e7323a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/342620
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>