4d41304def
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>
88 lines
2.8 KiB
Python
88 lines
2.8 KiB
Python
load("@rules_cc//cc:defs.bzl", "cc_library")
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package(default_visibility = ["//:__subpackages__"])
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cc_library(
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name = "libpng",
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srcs = [
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"externals/libpng/png.c",
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"externals/libpng/pngerror.c",
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"externals/libpng/pngget.c",
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"externals/libpng/pngmem.c",
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"externals/libpng/pngpread.c",
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"externals/libpng/pngread.c",
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"externals/libpng/pngrio.c",
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"externals/libpng/pngrtran.c",
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"externals/libpng/pngrutil.c",
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"externals/libpng/pngset.c",
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"externals/libpng/pngtrans.c",
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"externals/libpng/pngwio.c",
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"externals/libpng/pngwrite.c",
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"externals/libpng/pngwtran.c",
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"externals/libpng/pngwutil.c",
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# TODO(kjlubick) arm/x86 support
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],
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hdrs = ["libpng/pnglibconf.h"] + glob([
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"externals/libpng/*.h",
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]),
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copts = [
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"-Ithird_party/libpng/",
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"-Wno-unused-but-set-variable",
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],
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includes = [
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# This adds -isystem "third_party/externals/libpng" to any dependent
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# compilation steps. This allows #include <png.h> to work
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"externals/libpng",
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# png.h attempts to #include "pnglibconf.h" , which we store in //third_party/libpng/
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# This rule adds -isystem "third_party/externals/libpng" to any dependent
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# rule on this, which avoids having to add "-Ithird_party/libpng/" to copts for
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# those dependent rules.
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"libpng",
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],
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textual_hdrs = ["externals/libpng/scripts/pnglibconf.h.prebuilt"],
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deps = [":zlib"],
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)
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cc_library(
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name = "zlib",
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srcs = [
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"externals/zlib/adler32.c",
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"externals/zlib/compress.c",
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"externals/zlib/cpu_features.c",
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"externals/zlib/crc32.c",
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"externals/zlib/deflate.c",
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"externals/zlib/gzclose.c",
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"externals/zlib/gzlib.c",
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"externals/zlib/gzread.c",
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"externals/zlib/gzwrite.c",
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"externals/zlib/infback.c",
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"externals/zlib/inffast.c",
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"externals/zlib/inflate.c",
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"externals/zlib/inftrees.c",
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"externals/zlib/trees.c",
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"externals/zlib/uncompr.c",
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"externals/zlib/zutil.c",
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] + glob([
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"externals/zlib/**/*.h",
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]),
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hdrs = glob([
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"externals/zlib/*.h",
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]),
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copts = [
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"-Wno-unused-function",
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],
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strip_include_prefix = "externals/zlib/",
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)
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# This library is used to fix linking errors when trying to statically link in some symbols
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# The symbols defined here:
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# https://github.com/llvm/llvm-project/blob/main/libcxx/include/__support/musl/xlocale.h
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# are defined to be inlined, however they are missing during the final linking of a static
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# executable. By re-defining them in our own .a file, this makes the linker happy.
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cc_library(
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name = "musl_compat",
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srcs = [
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"musl_compat/locale.c",
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],
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)
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