Commit Graph

10 Commits

Author SHA1 Message Date
Kevin Lubick
98d664096d [bazel] Regenerate files and build with c++17
See toolchain/clang_toolchain_config.bzl for the c++17 switch.
Most of the other changes were automatically generated
(with the exception of //third_party).

Change-Id: I8c0f4b29b5967da3f48b17eb298a7e92156277ac
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/502407
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-02-01 13:15:22 +00:00
Kevin Lubick
7a14f783bd [bazel] Sketching out HelloWorld sk_app using GL
bazel run //example:hello_world --config=clang
causes a window to open and draws a circle and a square.
Text to follow in a future CL.

To make this work, I had to get rid of musl and use glibc.
All the shared libraries (.so files) that were pre-built
and available for download (e.g. from https://packages.debian.org/bullseye/amd64/libgl1/download)
were compiled against glibc. When I tried to run a
program statically linked with musl and dynamically linked
against things using glibc, I got a segmentation fault
on things like calloc().

Initial attempts to use glibc had failed because it was thought
that the libc.so.6 file could only be referred to by absolute
path (and thus Bazel would not be happy about it). As it turns out,
that was simply a misconfiguration of the builtin_sysroot
parameter to cc_common.create_cc_toolchain_config_info
(see //toolchain/clang_toolchain_config.bzl). By setting that
to `external/clang_linux_amd64` and not
`external/clang_linux_amd64/usr`, the libc binary which had
been extracted to `external/clang_linux_amd64/lib/x86_64-linux-gnu`
was perfectly reachable from
`external/clang_linux_amd64/usr/usr/lib/x86_64-linux-gnu/libc.so`

To bring in the shared libraries to link against (e.g. X11, GL)
I made build_toolchain.bzl easier to modify in that we simply need
to add a debian download url and sha256 hash to a list (rather than
having to plumb this through via arguments).

Recommended Review Order:
 - example/BUILD.bazel (not sure if we always want to set bare
   link arguments like that or if we want to use "features" to
   pass those along to the toolchain).
 - tools/sk_app/BUILD.bazel to see initial cc_library for
   wrapping sk_app code.
 - toolchain/build_toolchain.bzl to see removal of musl and
   new list of debs.
 - toolchain/clang_toolchain_config.bzl (where use of the
   no-canonical-prefixes was key to compilation success).
   Notice also that we statically linked libc++ (I did not
   have any shared libraries for it locally, so I guessed
   a typical developer might not either).
 - Rest of toolchain/ for trivial renames.
 - bazel/Makefile to see extra docs on those targets and
   a new target that compiles all the exes so far for a
   quick way to test the build.
 - third_party/BUILD.bazel and src/gpu/BUILD.bazel which have
   non-generated changes. (all other BUILD.bazel files do).
 - go.mod, which needed to update the infra repo version in
   order to pick up http://review.skia.org/491736).

Change-Id: I8687bd227353040eca2dffa9465798d8bd395027
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/492117
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2022-01-11 13:06:19 +00:00
Kevin Lubick
96e4053be7 Update Bazel files
- Use latest emscripten toolchain (3.1.0)
 - Autogenerate the atoms and manually fix some of the file lists.
 - Add a known_good_builds target to bazel/Makefile to help
   check the things we expect to work with Bazel.

Change-Id: Ia5f51e7b9eb5c108386820ad59180c8f862f5a70
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/491438
Reviewed-by: Ben Wagner <bungeman@google.com>
2022-01-06 18:10:57 +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
6ba9f702ba [bazel] Try adding cc_binary rules that use generated rules
To make the atomic rules a bit easier to work with, in many
of the folders, this adds in cc_library rules to group
together the sources from that folder (and subfolders
where prudent). We only needs sources because those atoms
should have their headers as deps.

One issue that was pointed out is that there is currently
no way to restrict the inclusion of certain packages,
a la, `gn check`. For example, there is no mechanism from
stopping a dev from adding
#include "modules/canvaskit/WasmCommon.h"
to something in //src/core (except circular dependencies).
We can probably address that using Bazel's visibility
rules as needed:
https://docs.bazel.build/versions/main/visibility.html
https://docs.bazel.build/versions/main/be/functions.html#package_group

It is recommended to look at this CL patchset by patchset.
PS1: Update gazelle command to generate rules in more folders.
PS2: A few changes to make generation work better.
PS3: The result of running make generate in //bazel
PS4: Adding the rules to build sksllex, the simplest binary I
     could find in the Skia repo.
PS5: Adding the rules to build skdiff, a more complex binary.
     I tried a few approaches, but ended up gravitating back
     towards the layout where we have each folder/package
     group up the sources. I imagine at some point, we'll have
     skdiff depend on skia_core or something, which will
     have things like //src/core, //src/codecs, //src/pathops
     all bundled together.
PS7: Added in the groupings of sources, similar to what we had
     earlier. I liked these for readability. These helped fix
     up the //:skia_core build, and by extension, the CanvasKit
     build.

Change-Id: I3faa7c4e821c876b243617aacf0246efa524cbde
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/476219
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-11-30 18:18:53 +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
Kevin Lubick
4d41304def [infra] Add hermetic toolchain for C/C++ using Clang+Musl
This can successfully build a C library:
   bazel build --config=clang //third_party:libpng

This can build and run a statically-linked executable:
   bazel test --config=clang //:bazel_test

For more verbose compile and linking output, add the
`--features diagnostic`
flag to a Bazel command (see _make_diagnostic_flags() in
toolchain/clang_toolchain_config.bzl. Similarly, a
`--features print_search_dirs` can be used to show where
clang is looking for libraries etc to link against.
These features are made available for easier debugging.

Suggested review order:
 - Read https://docs.bazel.build/versions/4.2.1/tutorial/cc-toolchain-config.html
   if unfamiliar with setting up C++ toolchains in Bazel
 - .bazelrc and WORKSPACE.bazel that configure use and download
   of the toolchain (Clang 13, musl 1.2.2)
 - toolchain/build_toolchain.bzl which downloads and assembles
   the toolchain (w/o installing anything on the host machine)
 - toolchain/BUILD.bazel and toolchain/*trampoline.sh to see
   the setup of the toolchain rules.
 - toolchain/clang_toolchain_config.bzl to see the configuration
   of the toolchain. Pay special attention to the various
   command line flags that are set.
 - See that tools/bazel_test.cc has made a new home in
   experimental/bazel_test/bazel_test.cpp, with a companion
   BUILD.bazel. Note the addition of some function calls
   that test use of the C++ standard library.
   The number being used to test the PNG library is the latest
   and greatest that verifies we are compiling the one brought
   in via DEPS (and not a local one).
 - third_party/* to see how png (and its dependent zlib) have
   been built. Pay special attention to the musl_compat hack
   to fix static linking (any idea what the real cause is?)
- //BUILD.bazel to see definition of the bazel_test executable.

Change-Id: I7b0922d0d45cb9be8df2fd5fa5a1f48492654d5f
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/461178
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
2021-10-21 12:43:49 +00:00