Commit Graph

9 Commits

Author SHA1 Message Date
Kevin Lubick
ee62fad9a4 [bazel] Add "skia_internal" target that exposes private API for tests/tools.
Organization v3.5, if we are keeping track :)

This splits the "srcs" filegroup into "srcs" and "private_hdrs",
and renames "hdrs" to "public_hdrs".

To assist with the split, I created the macro split_srcs_and_hdrs.
Rather than keep two separate lists of header and source files,
I figured it would be easiest, at least for the common case,
to keep one list of files and then have a for loop split them
apart. I've tried to be consistent with having the list
of files be named with a _FILES suffix - maybe we can use this
as a marker to generate .gni files in the future?

Suggested review order:
 - //bazel/macros.bzl. Note this needs a corresponding
   G3 change (http://cl/452279799) as well. The exports_files_legacy
   change is the better approach to something I manually
   handled yesterday when fixing the G3 roll.
 - //BUILD.bazel to see the new target skia_internal and
   the previous skia_core renamed to skia_public.
 - //src/core/BUILD.bazel to see a typical usage of
   split_srcs_and_hdrs.
 - //include/... to see the change to public_hdrs and
   private_hdrs
 - //src/... to see many more usages of split_srcs_and_hdrs
 - //tools/... to see changes to skia_internal where
   appropriate.
 - Everything else. Note that //modules/... might also need
   to be built with skia_internal instead of skia_public,
   but we can fix that up later, if necessary.

Change-Id: Ie1cc969455d97b029b2d77faa222c4a9bad70671
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/545716
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2022-06-02 11:23:50 +00:00
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
4511c7b7fb [bazel] Delete gazelle-based BUILD.bazel files
gazelle ended up being more liability than asset for our C++ rules.

It required devs to manually run the command frequently (and was
easy to forget until the CQ failed). The fact that we still had to
edit the source files (e.g. the "srcs" cc_libraries) meant that
the mixture between generated and hand-written caused some
tension (see include/third_party/vulkan for a good example).

The combination of gazelle and our IWYU enforcement added several
bits of churn without any real benefit. The generated rules
also didn't help identify cases where we were not keeping tight
boundaries (e.g. non-gpu code and gpu code).

Identifying third_party deps automatically ended up being trickier
than anticipated (see the deleted //third_party/file_map_for_bazel.json)

Using the "maximum set of dependencies" worked ok, but ended up
increasing build time unnecessarily. For example, compiling
CanvasKit for WebGL always needed to compile Dawn because
SkSLCompiler.cpp sometimes needs to include tint/tint.h.

Follow-up CLs will rebuild the BUILD.bazel rules without gazelle.

Note to Reviewers:
 - The only file worth manually reviewing here is bazel/Makefile.

Change-Id: I36d6fc3747487fabaf699690780c95f1f6765770
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/543976
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-05-31 14:14:54 +00:00
Kevin Lubick
c3a448ec61 [bazel] Put licenses() after legacy_exports
G3 prefers license() first.

This was done mechanically with a big find/replace

Change-Id: I8c33c7bc10a6bec42e966cad81c259954e841811
Bug: skia:13211
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/535898
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-05-02 15:04:33 +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
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
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
9301fe3779 [bazel] Test enforcement of IWYU on SkSVG backend.
This will use the recently added Bazel toolchain feature
to enforce proper includes for all files in //src/svg/...

In the future, I envision a CI/CQ job that will run
bazel build with a few different configurations and the
--feature skia_enforce_iwyu on to make sure we don't
regress.

Change-Id: Ibb9f816ab626415c11bd2b9b74c503297c4b0723
Bug: skia:13052
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/521036
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-03-16 14:20:14 +00:00
Kevin Lubick
9488e0237d [infra] Experiment generating BUILD.bazel files
This uses the gazelle extension from
https://skia-review.googlesource.com/c/buildbot/+/473357

Review Tips:
 - Ignore any changes to .h or .cpp files. Those have been
   pulled out into their own CLs.
 - Start with bazel/macros.bzl.
 - Read the CL with the generation code, if you haven't already.
 - Look at third_party/file_map_for_bazel.json.
 - See experimental/bazel_test for an idea of how a cc_binary
   would be made.
 - Spot check one or two of the BUILD.bazel files.

This CL generates the "atomic" rules for src/, include/ and
modules/skshaper, as a starting point.

`bazel build --config clang //include/...` works

`bazel build --config clang //src/...` starts compiling,
(which verifies that the BUILD.bazel files are all valid),
but runs into errors because not all third_party deps have
been resolved, and there are some files missing from the
toolchain still (e.g. EGL headers).

Change-Id: Ib7e0fb0efdb9f08655f06cbc56e9bb4cf416294b
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/474240
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-11-23 18:53:16 +00:00