Commit Graph

24 Commits

Author SHA1 Message Date
Kevin Lubick
2c65579aad [bazel] Add in hierarchical filegroup Bazel rules.
The primary goal of this organization structure is to keep
our top level BUILD.bazel file short, with as little logic
as feasible. The logic required to control which files to
include, which third_party deps are needed, what system libraries
should be linked again, etc, should be in the BUILD.bazel
file best should be as close to the affected files as feasible.

In essence, we use filegroup() rules to bubble up the files
needed to build Skia (all as one big cc_library call) and
cc_library rules to bubble up the other components needed to build.

For example, //src/ports/SkFontHost_FreeType.cpp needs FreeType,
but only if we are compiling Skia with that type of font
support. With the new organization structure in this CL,
//src/ports/BUILD.bazel should have the logic that determines
if the cpp file should be included in the build of Skia and
if it is, that the Skia build should depend on //third_party:freetype2

Another example is //src/gpu/ganesh/BUILD.bazel, which
chooses which of the dawn, gl, vulkan, etc backend sources,
and the associated dependencies to include in the build.
It does not specify what those are, but delegates to the
BUILD.bazel files in the subdirectories housing the
backend-specific code.

The structure guidelines for BUILD.bazel files are as follows:
 - Have a filegroup() called "hdrs" (for public headers) or
   "srcs" (for private headers and all .cpp files) that is
   visible to the parent directory. This should list the
   files from the containing directory to include in the
   build.
   See //include/core/BUILD.bazel and //src/effects/BUILD.bazel
   as examples.
 - filegroup() rules can list a child directory's "hdrs"
   or "srcs" in their "srcs" attributes, but should not contain
   select statements pertaining to child directory files.
   See //include/gpu/BUILD.bazel and //src/gpu/ganesh/BUILD.bazel
   as examples.
 - May have a cc_library() called "deps". This can specify
   dependencies, cc_opts, and linkopts, but not srcs or hdrs. [1]
   See //src/codec/BUILD.bazel as an example. These should
   be visible to the parent directory.
 - "hdrs", "srcs", and "deps" for the primary Skia build
   (currently called "skia_core") should bubble up through
   //include/BUILD.bazel and //src/BUILD.bazel, one directory
   at a time.

This CL demonstrates a very basic build of Skia with many features
turned off (CPU only, no fonts, no codecs). Follow-on CLs will
add to these rules as more targets are supported. See bazel/Makefile
for the builds that work with just this CL.

Suggested Review Order:
 - //BUILD.bazel to see the very small skia_core rule which
   delegates all the logic down stack. Note that it has a
   dependency on //bazel:defines_from_flags which will set
   all the defines listed there when compiling all the
   .cpp and .h files in skia_core *and* anything that depends
   on skia_core, but *not* //src:deps.
 - //include/BUILD.bazel and other BUILD.bazel files in the
   subdirectories of that folder. Note that the filegroups in
   //include/private/... are called "srcs" to be similar to
   how Bazel wants "private headers" to be in the "srcs" of
   cc_library, cc_binary, etc. and only public headers are
   to be in "hdrs" [2].
 - //src/BUILD.bazel and other BUILD.bazel files in the
   subdirectories of that folder. //src/gpu/ganesh/...
   will be filled in for dawn, vulkan, and GL in the next CL.
 - //PRESUBMIT.py, which adds a check that runs buildifier [3]
   on modified BUILD.bazel files to make sure they stay
   consistently formatted.
 - //bazel/... to see the new option I added to make sksl
   opt-in or opt-out, so one could build Skia with sksl,
   but not with a gpu backend.
 - Misc .h and .cpp files, whose includes were removed if
   unnecessary or #ifdef'd out to make the minimal build
   work without GPU or SkSL includes.
 - //bazel/Makefile to see the builds that work with this CL.

[1] Setting srcs or hdrs is error-prone at best, because those
   files will be compiled with a different set of defines than
   the rest of skia_core, because they wouldn't depend on
   //bazel:defines_from_flags.
[2] https://bazel.build/reference/be/c-cpp#cc_library.hdrs
[3] https://github.com/bazelbuild/buildtools/releases
Change-Id: I5e0e3ae01ad42d672506d5aad1239f2512188191
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/543977
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-05-31 14:14:54 +00:00
Kevin Lubick
46eaab3959 [bazel] Add shims to help translation into G3
Ran the following commands:
find -name "BUILD.bazel" -exec sed -i -e '1iload("//bazel:macros.bzl", "cc_library", "exports_files_legacy")\nexports_files_legacy()' {} +
buildifier --lint=fix --mode=fix -r .

This had the effect of making sure we can export all of our
files in G3 (until we no longer have legacy targets) and
making all of our cc_libraries shim-able.

bazel/macros.bzl has the human-contributed changes, the rest
were mechanical.

Change-Id: I8e24e30e74b038cfd072cdbe4078bfd1d213dd46
Bug: skia:13211
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/535359
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-29 19:27:54 +00:00
Jorge Betancourt
a2fbd43671 add compiler flags for zlib when building for mac (intel processors)
Change-Id: If62a0ba82fee63bc0e30d946e3aa385eb0970ce7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/533678
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>
2022-04-26 14:41:32 +00:00
Kevin Lubick
83cee23c98 [bazel] Run buildifier on BUILD.bazel files
buildifier --lint=fix -r .

Change-Id: I6a41858270d20137978f8271c8f6160b51120777
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529751
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-14 18:13:43 +00:00
Kevin Lubick
458f4ded2b [bazel] Consolidate skylib loads
For importing into G3, this will simplify the regex needed
and allow us to stub out things not supported (e.g. gazelle)

Change-Id: I770f5dee6f29e555356742dae36212ad6cfb713a
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529836
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-14 11:37:08 +00:00
Kevin Lubick
b98328a27b [bazel] Add license to all our BUILD.bazel files
find -name "BUILD.bazel" -exec sed -i -e '1i licenses(["notice"])\n' {} +

Change-Id: Ie48f163b7d8d6ede9ba5f952e87232dd5c9fa8e6
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529808
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-13 19:50:29 +00:00
Kevin Lubick
196b172650 [sksl] Make sksl tracing optional
This removes the required dependency on our JSON code. In the Bazel
rules, this dependency is pushed down into sksl instead of required
by the cc_binary rules.

It adds a stub version of SkVMDebugTrace.cpp and removes
SkVMDebugTracePlayer unless the appropriate GN or Bazel flag
is set (skia_enable_sksl_tracing and enable_sksl_tracing,
respectively). There was an existing #define that CanvasKit
used (CK_INCLUDE_SKSL_TRACE) and this was changed to
SKSL_ENABLE_TRACING.

Users of //:skia_core no longer need to specify a JSON dep,
if sksl needs it (e.g. for tracing), then it will specify
the dependency.

This is a reland of https://skia-review.googlesource.com/c/skia/+/528837

Bug: skia:12541
Change-Id: I79612c69fdbefd3db9822a2b66df7552f7c13865
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529278
Reviewed-by: John Stiles <johnstiles@google.com>
2022-04-12 13:59:25 +00:00
Kevin Lubick
e4047903db [bazel] Unify boolean flags to be enable*
I think they read better when it is enable_foo. I have to
do less double-negation in my head if they are set to false
then.

Reland of https://skia-review.googlesource.com/c/skia/+/528838

Change-Id: I15075687cbee98b41364518384b656e897d716d8
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529276
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-11 19:52:12 +00:00
John Stiles
471fd2eb09 Revert "[sksl] Make sksl tracing optional"
This reverts commit 6bc4bdf645.

Reason for revert: Android roll

Original change's description:
> [sksl] Make sksl tracing optional
>
> This removes the required dependency on our JSON code. In the Bazel
> rules, this dependency is pushed down into sksl instead of required
> by the cc_binary rules.
>
> It adds a stub version of SkVMDebugTrace.cpp and removes
> SkVMDebugTracePlayer unless the appropriate GN or Bazel flag
> is set (skia_enable_sksl_tracing and enable_sksl_tracing,
> respectively). There was an existing #define that CanvasKit
> used (CK_INCLUDE_SKSL_TRACE) and this was changed to
> SKSL_ENABLE_TRACING.
>
> Users of //:skia_core no longer need to specify a JSON dep,
> if sksl needs it (e.g. for tracing), then it will specify
> the dependency.
>
> Change-Id: I2fcd29cde118fc391c269ba2d8f8a40a6f164c99
> Bug: skia:12541
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528837
> Reviewed-by: John Stiles <johnstiles@google.com>
> Commit-Queue: Kevin Lubick <kjlubick@google.com>

Bug: skia:12541
Change-Id: Icf75495f19e409d96925ca4dca9e839eca4057ec
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529129
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
2022-04-11 17:42:17 +00:00
John Stiles
d459e5c70f Revert "[bazel] Unify boolean flags to be enable*"
This reverts commit 02986aed2a.

Reason for revert: Android roll

Original change's description:
> [bazel] Unify boolean flags to be enable*
>
> I think they read better when it is enable_foo. I have to
> do less double-negation in my head if they are set to false
> then.
>
> Change-Id: I53bc5575c11d489029904965d991abc5a9d0fd89
> Bug: skia:12541
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528838
> Reviewed-by: Ben Wagner <bungeman@google.com>

Bug: skia:12541
Change-Id: I63f827c41ddc8a149cd190179ad099ff8671579a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/529128
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
2022-04-11 17:41:29 +00:00
Kevin Lubick
02986aed2a [bazel] Unify boolean flags to be enable*
I think they read better when it is enable_foo. I have to
do less double-negation in my head if they are set to false
then.

Change-Id: I53bc5575c11d489029904965d991abc5a9d0fd89
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528838
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-04-11 15:48:39 +00:00
Kevin Lubick
6bc4bdf645 [sksl] Make sksl tracing optional
This removes the required dependency on our JSON code. In the Bazel
rules, this dependency is pushed down into sksl instead of required
by the cc_binary rules.

It adds a stub version of SkVMDebugTrace.cpp and removes
SkVMDebugTracePlayer unless the appropriate GN or Bazel flag
is set (skia_enable_sksl_tracing and enable_sksl_tracing,
respectively). There was an existing #define that CanvasKit
used (CK_INCLUDE_SKSL_TRACE) and this was changed to
SKSL_ENABLE_TRACING.

Users of //:skia_core no longer need to specify a JSON dep,
if sksl needs it (e.g. for tracing), then it will specify
the dependency.

Change-Id: I2fcd29cde118fc391c269ba2d8f8a40a6f164c99
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528837
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-04-11 15:22:41 +00:00
Kevin Lubick
a9f6ceebed [bazel] Add executable for skslc
This ports the GN skia_executable [1] and adds third_party
Bazel rules for spirv_cross, translated from [2]. spirv_cross,
unlike spirv_tools, did not have pre-made Bazel rules.

This binary compiles and links with

    bazelisk build //tools/skslc --config=clang

[1] ad324a31e6/BUILD.gn (L712)
[2] ad324a31e6/third_party/spirv-cross/BUILD.gn (L10)

Change-Id: I4abd51889552153fc7e64a5f7f3d9f0f597524e7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/528044
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-04-08 17:25:24 +00:00
Kevin Lubick
95bcc8837f [bazel] Move vma down to //src/gpu
This adds a flag to enable or disable the vulkan memory allocator
(enabled by default). This flag only makes sense when vulkan is
also enabled, so the flag is marked private and a public
config_setting_group is made that ANDs "vulkan backend" and
"user wants vma" which is what we base our rules on.

There are few buildifier lint rules that get tidied up
as well here.

Change-Id: I089951050282afb87f01f505661c66fed920c73c
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/527696
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2022-04-06 18:06:08 +00:00
Kevin Lubick
14abec45f0 [bazel] Add support for Dawn (via Vulkan)
sk_app has existing support for Dawn on top of Vulkan, and
this adds support to build //example:hello_world_dawn and
get this to run on Linux.

Dawn depends on Tint and abseil-cpp. Tint further depends on
spirv_tools and spirv_headers (for writing to the SPIR-V format).
Dawn and Tint only have GN and CMake support, so we need to make
our Bazel rules for them (see //third_party/BUILD.bazel).

abseil-cpp and the SPIR-V libraries have Bazel support, so we
can just include them (see //WORKSPACE.bazel). It is important
that @spirv_headers be called that exactly because @spirv_tools
depends on it by that name.

The hand-crafted cc_library rules for Dawn and Tint were produced
by reading the appropriate GN files and using the parts necessary
for a supporting Vulkan+Linux. If we use Dawn for other backends
(e.g. WebGPU), we will need to expand the Bazel rules. One day,
we might contribute the Bazel rules to Dawn and Tint so they
can support them and avoid breaking us if new files are added.

Suggested Review Order
 - bazel/common_config_settings/BUILD.bazel to see introduction
   of new select-able option "has_gpu_backend" which cleans up
   some of our code that is enabled for any GPU backend.
 - src/*/BUILD.bazel to see has_gpu_backend rolled out.
 - WORKSPACE.bazel to see DEPS declared there (using the files
   in third_party/externals, which are brought in via
   tools/git-sync-deps).
 - third_party/BUILD.bazel which adds Dawn and Tint rules.
   It may be helpful to look in third_party/externals for
   the Dawn [1] and Tint [2] GN files. Especially interesting
   are the Python scripts [3] Dawn uses to generate some
   header and source files.
 - All other files.

[1] https://dawn.googlesource.com/dawn/+/d9f22ce0346b222759d5510be3d1cd93caa5ab86/src/dawn/native/BUILD.gn#183
[2] https://dawn.googlesource.com/tint/+/453d5ae84ec30ab51ac592c13d472412ae8b5fc9/src/tint/BUILD.gn#174
[3] https://dawn.googlesource.com/dawn/+/d9f22ce0346b222759d5510be3d1cd93caa5ab86/generator/dawn_json_generator.py#774
Change-Id: Ied5b162045d8e841b9666457f0158457e2b078d4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/516996
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-03-22 13:05:52 +00:00
Kevin Lubick
9cb74e9079 [bazel] Compile gms for wasm and WebGL
PS 1 is re-generating existing BUILD.bazel files
PS 2 is generating BUILD.bazel files for tests/gms
PS 3+ makes modifications to build all of the gms and tests.

It is recommended to view this CL with just a diff between
PS 2 and the end, due to the large amount of generated changes
in PS 1 and 2.

We make a filegroup for the gms and tests because they need
to be compiled as one large blob in order for the registries
to work. Maybe in the future we will break these up, but at least
for WASM/JS, the overhead of starting a browser for each new
test would likely grind things to a halt, so we just group them
all together for now. It's also the most similar to what we
currently do.

In gm/BUILD.bazel and tests/BUILD.bazel, we add a cc_library
that encapsulates all of the deps of the tests, so we can
easily include that the build. These were discovered via
trial and error, not anything automatic or systematic.

The is_skia_dev_build config_setting is very similar to the
GN equivalent from which it was based.

The list of gms and tests to skip (e.g. which are incompatible
with WASM) was determined by building the wasm bundle:

modules/canvaskit$ make bazel_gms_release
tools/run-wasm-gm-tests$ make run_local_debug
# Don't forget to click the button on the screen after the
# browser loads

This way of invoking the tests will be replace soon with
`bazel test <something>`. As such, I didn't bother fully
documenting the current way.

Suggested review order:
 - modules/canvaskit/BUILD.bazel taking note that we always
   use profiling-funcs to make the stacktraces human readable.
 - gm/BUILD.bazel and tests/BUILD.bazel to see the lists of
   gms/tests. Notice the tests are roughly partitioned because
   we don't support things like vulkan/PDF in the wasm build
   and we will want a way to not build certain tests for
   certain configurations
 - tools/* noting some of the cc_libraries added to make
   dependencies easier to add when needed.
 - All other files.

Change-Id: I43059cd93c28af1c4c12b93d6ebd9c46a12d381f
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/506256
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-02-09 18:56:17 +00:00
Kevin Lubick
a803794df7 [canvaskit] Add more features to Bazel build
PS 1 adds particles to the build
PS 2+ ports many of the options from //modules/canvaskit/compile.sh

With this CL, all the CanvasKit tests pass with both the
debug and release build.

Change-Id: Id70f0c16a087109c56949417f940849f2e3b5200
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/504537
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-02-04 21:33:20 +00:00
Kevin Lubick
6e63f4925e [bazel] Use font manager in HelloWorld.
This documents the various factory settings (I kept getting
confused as to what each was doing).

Additionally, this makes setting the factory flag bring in
the dependent code as well (like our current GN rules do).

Change-Id: I93437651b078baac04433c14c573a95982b7bc15
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/493396
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-01-11 16:22:52 +00:00
Kevin Lubick
4bd08c52c0 [infra] Add SkParagraph (harfbuzz, ICU) to Canvaskit Bazel build.
As a follow-up to https://skia-review.googlesource.com/c/skia/+/476219,
this sketches out how we can maybe use cc_library for the things
in //modules to make sure something in //src doesn't depend on
anything in //modules, for example.

The following succeeds:
bazel build //modules/skparagraph:skparagraph --config=clang \
  --shaper_backend=harfbuzz_shaper --with_icu

As does `make bazel_canvaskit_debug` in //modules/canvaskit

Suggested Review Order:
 - third_party/BUILD.bazel for ICU and harfbuzz rules. Pay
   special attention to the genrules used to call the python
   script for turning the icu .dat file into .S or .cpp.
 - bazelrc and bazel/ for new flags and defines that control
   use of ICU and harfbuzz. Unlike GN, with the public_defines
   that get added in automatically if icu or harfbuzz is
   depended upon, we need to set the defines at the top level.
   This necessity might go away if we change the atoms to
   depend on //modules/skshaper, which could define that flag.
 - Top level BUILD.bazel files in //modules/skparagraph,
   //modules/skshaper, //modules/skunicode, //modules/canvaskit
 - All other .bazel file changes are automatic.

Bug: skia:12541
Change-Id: I38a9e0a9261d7e142eeb271c2ddb23f362f91473
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/478116
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-11-30 21:01:06 +00:00
Kevin Lubick
cf1e959c65 [canvaskit] Expand Bazel rules to include Canvas2D compat layer
Importantly, this adds options for encoding using
certain codecs, not just decoding.

Change-Id: I4a610ebf985b67d4545c71b3f3eed4c7807e6a26
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/472277
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-11-17 13:06:35 +00:00
Kevin Lubick
888d4efa77 [canvaskit] Add Freetype/Fonts to Bazel Build
This re-works src/ports/BUILD.bazel to work like our other
BUILD files, i.e. one rule "srcs" that brings in the necessary
private filegroups.

To work around an abort with LLVM [1], we have to go back to an
earlier version of emscripten (temporarily?).

Future work should look at using transitions [2] to allow various
executables (e.g. CanvasKit, DM) to set their own set of Bazel
flags, w/o the build invokers having to specify them.

These transitions might be able to handle more complex cases
that we currently use if statements in GN to deal with.

The Freetype build rule was created by taking the BUILD.gn
rule, adding in all the sources listed there and then playing
compile-whack-a-mole to add in all the headers and included
.c files.

Suggested Review Order:
 - third_party/BUILD.bazel to see freetype build rules
 - bazel/common_config_settings/ to see treatment of fontmgr
   like codecs (many possible) and fontmgr_factory (only one).
 - src/ports/BUILD.bazel
 - BUILD.bazel
 - modules/canvaskit/BUILD.bazel. Take note of the gen_rule that
   calls tools/embed_resources.py to produce the .cpp file
   containing the embedded font data.
 - Everything else.

[1] https://github.com/emscripten-core/emscripten/issues/15528
[2] https://github.com/bazelbuild/examples/tree/main/rules/starlark_configurations/cc_binary_selectable_copts
Bug: skia:12541
Change-Id: I08dab82a901d80507007b354ca20cbfad2c2388f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/471636
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-11-17 13:06:35 +00:00
Kevin Lubick
8ed49ea6e3 [infra] Add Bazel rules for codecs.
This ports the third_party BUILD.gn files related to codecs
(with a best-effort on arm/SIMD stuff). This includes:
 - libpng
 - libjpeg-turbo
 - libwebp
 - wuffs (gif)
 - libgifcodec
 - dng_sdk and piex (raw codec)

This expands the string_flag_with_values macro to allow
multiple values to be set at once. This was added in Bazel 5.0.0,
however the latest pre-release version of that has a bug [1]
which slows down compilation dramatically. This was fixed at
ToT, but not released. As a result, I started using the Bazel
6 pre-release (via bazelisk).

The macro select_multi makes writing select() where multiple
elements could be on possible/easier.

One can try compiling certain codecs by running:
bazel build :skia-core --config clang --include_codec=raw_codec --include_codec=png_codec

Suggested Review Order:
 - bazel/macros.bzl
 - bazel/common_config_settings/defs.bzl and its BUILD.bazel
   to see how the codec options are defined.
 - BUILD.bazel to see how the codec settings are used.
 - src/codec/BUILD.bazel to see the inclusion of Skia files to
   deal with specific codecs.
 - third_party/BUILD.bazel (while referencing the corresponding
   BUILD.gn files, such as third_party/libwebp/BUILD.gn)
 - Everything else.

Change-Id: I797375a35fa345d9835e7b2a2ab23371c45953c3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/469456
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
2021-11-11 20:10:01 +00:00
Kevin Lubick
1f8c31b101 [infra] Add initial Bazel rules and files
These rules can be used to build our GMs on WASM+WebGL and
libskia.a with just the CPU backend (and most other features
turned off).

This can be done with the following commands:
  - bazel build //modules/canvaskit:gm-bindings-wasm --gpu_backend=gl_backend --with_gl_standard=webgl_standard
  - bazel build :skia-core --config clang

This pivots slightly from http://review.skia.org/463517
by using config_settings [1] instead of platforms for
the optional features that we control. This pivot was
suggested in [2]

We have BUILD.bazel files in many of the subdirectories
that specify filegroups for the appropriate files. In
an effort to make //BUILD.bazel more readable, it is
the responsibility of these subfolders to deal with
conditionally including certain .h or .cpp files.
This is done using select statements and config_settings
or platform constraints as necessary.

For example, src/gpu/BUILD.bazel will different private
filegroups for each of the supported gpu backends [3]
and a more-visible filegroup called "srcs" that has
the right selection of the private files to be used
for compilation.

An effort has been made to avoid using glob() in our
BUILD.bazel files. These file lists were made by using
`ls -1` and some regex to add in quotes. We might want
to make a helper script to assist with that, if necessary.

To specify which options we have, the settings in
//bazel/common_config_settings/BUILD.bazel have been
redesigned. They make use of a macro `string_flag_with_values`
that removes the boilerplate. Patchset 36 shows what the
file looks like w/o the macro.

The top level BUILD.bazel file will still need to use
some logic to handle defines, because local_defines is
a list of strings, not a list of labels [4].

Suggested Review Order:
  - WORKSPACE.bazel to see the new dependencies on the
    emsdk toolchain and bazel_skylib
  - bazel/common_config_settings/* to see the few settings
    defined (we have more to define, see BUILD.gn and
    //gn/skia.gni for ideas)
  - BUILD.bazel to see the "skia-core" cc_library rule.
    See also "gms" and "tests"
  - modules/canvaskit/BUILD.bazel to see the use of
    the emscripten "wasm_cc_binary" rule, which depends
    on the "skia-core", "gms", and "tests" rule. Note that
    it only builds some of the gms as a proof of concept.
  - The other BUILD.bazel files. Some of these are not
    platform or feature dependent (e.g. pathops). Others
    are (e.g. gpu).
  - All other files.

[1] https://docs.bazel.build/versions/4.2.1/skylark/config.html#user-defined-build-settings
[2] https://github.com/emscripten-core/emsdk/pull/920
[3] In this CL, that's just the webgl one.
[4] https://docs.bazel.build/versions/main/be/c-cpp.html#cc_library.local_defines

Change-Id: Ieecf9c106d5e3a6ae97d13d66be06b4b3c207089
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/458637
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Owners-Override: Kevin Lubick <kjlubick@google.com>
2021-11-09 12:32:25 +00:00
Kevin Lubick
97284f255b [infra] Add initial platforms and constraint values
This makes use of Bazel's pre-defined platforms
https://github.com/bazelbuild/platforms
and some of our own defined values (see
//bazel/common_config_settings/BUILD.bazel) to customize
the build rules.

I verified this by building bazel_test locally for
linux x64 as well as using the third_party deps for
a WASM build (using build files not seen in this CL).

Suggested Review Order:
 - https://docs.bazel.build/versions/main/platforms.html if not
   already familiar with Bazel Platforms
 - third_party/BUILD.bazel to see that 1) all globs have
   been removed and 2) select() targets various
   platform constants or groups of constants to control
   sources, headers, and local_defines.
 - common_config_settings/ to see the groups of constraints
   created, as well as new constraint_settings defined
   (skdebug_impl)
 - supported_combinations/ to see how we can define supported
   sets of the constraint values (aka Bazel platforms).
   I imagine expanding this more, so we might have platforms
   named "linux_x64_emptyfontmgr_vulkan" or such.
 - //BUILD.bazel and bazel_test.cpp to see use of SkDebugf.
 - Everything else.

Change-Id: I49e4abdbcf7b76f0674efdbb1f53dc8823d110ee
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/463517
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Owners-Override: Kevin Lubick <kjlubick@google.com>
2021-10-26 18:27:13 +00:00