[bazel] Add option for SkSVGCanvas (and expat third_party DEP)

Our SVG code depends on our XML code which depends on expat.

See also cl/457481999

Change-Id: I83b61f5d73570d0aa7e851a01ccd019b4b1019e4
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/553376
Reviewed-by: Florin Malita <fmalita@google.com>

.bazelrc

@@ -54,6 +54,8 @@ build --flag_alias=disable_skslc=no//bazel/common_config_settings:enable_skslc
 build --flag_alias=enable_skslc=//bazel/common_config_settings:enable_skslc
 build --flag_alias=disable_sksl_tracing=no//bazel/common_config_settings:enable_sksl_tracing
 build --flag_alias=enable_sksl_tracing=//bazel/common_config_settings:enable_sksl_tracing
+build --flag_alias=disable_svg_canvas=no//bazel/common_config_settings:enable_svg_canvas
+build --flag_alias=enable_svg_canvas=//bazel/common_config_settings:enable_svg_canvas
 build --flag_alias=disable_tracing=no//bazel/common_config_settings:enable_tracing
 build --flag_alias=enable_tracing=//bazel/common_config_settings:enable_tracing
 build --flag_alias=disable_vma=no//bazel/common_config_settings:use_vulkan_memory_allocator

WORKSPACE.bazel

@@ -217,6 +217,13 @@ new_local_repository(
     workspace_file_content = "",
 )
 
+new_local_repository(
+    name = "expat",
+    build_file = "bazel/external/expat/BUILD.bazel",
+    path = "third_party/externals/expat",
+    workspace_file_content = "",
+)
+
 new_local_repository(
     name = "libjpeg_turbo",
     build_file = "bazel/external/libjpeg_turbo/BUILD.bazel",

bazel/common_config_settings/BUILD.bazel

@@ -227,6 +227,11 @@ bool_flag(
     flag_name = "enable_tracing",
 )
 
+bool_flag(
+    default = False,
+    flag_name = "enable_svg_canvas",
+)
+
 bool_flag(
     default = False,
     flag_name = "is_skia_dev_build",

bazel/external/expat/BUILD.bazel

@@ -0,0 +1,68 @@
+# This file will be copied into //third_party/externals/libjpeg-turbo via the new_local_repository
+# rule in WORKSPACE.bazel, so all files should be relative to that path.
+
+genrule(
+    name = "create_expat_config_file",
+    srcs = [],
+    outs = ["include/expat_config.h"],
+    cmd = """cat > $@ << 'EOF'
+#define HAVE_INTTYPES_H 1
+#define HAVE_MEMORY_H 1
+#define HAVE_STDINT_H 1
+#define HAVE_STDLIB_H 1
+#define HAVE_STRING_H 1
+#define STDC_HEADERS 1
+#define XML_CONTEXT_BYTES 1024
+#define XML_DTD 1
+#define XML_NS 1
+EOF""",
+)
+
+EXPAT_HDRS = [
+    "expat/lib/expat.h",
+]
+
+EXPAT_SRCS = [
+    "expat/lib/ascii.h",
+    "expat/lib/asciitab.h",
+    "expat/lib/expat.h",
+    "expat/lib/expat_external.h",
+    "expat/lib/iasciitab.h",
+    "expat/lib/internal.h",
+    "expat/lib/latin1tab.h",
+    "expat/lib/nametab.h",
+    "expat/lib/siphash.h",
+    "expat/lib/utf8tab.h",
+    "expat/lib/winconfig.h",
+    "expat/lib/xmlparse.c",
+    "expat/lib/xmlrole.c",
+    "expat/lib/xmlrole.h",
+    "expat/lib/xmltok.c",
+    "expat/lib/xmltok.h",
+    "expat/lib/xmltok_impl.h",
+    # Our generated configuration file
+    "include/expat_config.h",
+]
+
+TEXTUAL_HDRS = [
+    "expat/lib/xmltok_impl.c",
+    "expat/lib/xmltok_ns.c",
+]
+
+cc_library(
+    name = "expat",
+    srcs = EXPAT_SRCS,
+    hdrs = EXPAT_HDRS,
+    defines = [
+        "HAVE_MEMMOVE",
+        "XML_DEV_URANDOM",
+        "XML_STATIC",
+    ],
+    includes = [
+        "expat/lib",
+        "include",
+    ],
+    # strip_include_prefix = "expat/lib",
+    textual_hdrs = TEXTUAL_HDRS,
+    visibility = ["//visibility:public"],
+)

bazel/external/libjpeg_turbo/BUILD.bazel

@@ -120,7 +120,6 @@ cc_library(
         "jpeglibmangler.h",
     ],
     local_defines = JPEGTURBO_DEFINES,
-    strip_include_prefix = "",
     textual_hdrs = [
         "jccolext.c",
         "jdmrgext.c",

bazel/macros.bzl

@@ -8,13 +8,16 @@ load("@rules_python//python:defs.bzl", _py_binary = "py_binary")
 load("@py_deps//:requirements.bzl", _requirement = "requirement")
 load("@bazel_gazelle//:def.bzl", _gazelle = "gazelle")
 load("@emsdk//emscripten_toolchain:wasm_rules.bzl", _wasm_cc_binary = "wasm_cc_binary")
+load("@io_bazel_rules_go//go:def.bzl", _go_binary = "go_binary", _go_library = "go_library")
 
 # re-export symbols that are commonly used or that are not supported in G3
 # (and thus we need to stub out)
-selects = _selects
+gazelle = _gazelle
+go_binary = _go_binary
+go_library = _go_library
 py_binary = _py_binary
 requirement = _requirement
-gazelle = _gazelle
+selects = _selects
 wasm_cc_binary = _wasm_cc_binary
 
 def select_multi(values_map, default):
@@ -64,6 +67,11 @@ def select_multi(values_map, default):
         })
     return rv
 
+# buildifier: disable=unnamed-macro
+def cc_binary(**kwargs):
+    """A shim around cc_binary that lets us tweak settings for G3 if necessary."""
+    native.cc_binary(**kwargs)
+
 # buildifier: disable=unnamed-macro
 def cc_library(**kwargs):
     """A shim around cc_library that lets us tweak settings for G3 if necessary."""

include/BUILD.bazel

@@ -16,7 +16,6 @@ filegroup(
         "//include/encode:public_hdrs",
         "//include/pathops:public_hdrs",
         "//include/ports:public_hdrs",
-        "//include/svg:public_hdrs",
         "//include/third_party/skcms:public_hdrs",
         "//include/utils:public_hdrs",
     ] + select({
@@ -25,6 +24,9 @@ filegroup(
     }) + select({
         "//bazel/common_config_settings:has_gpu_backend": ["//include/gpu:public_hdrs"],
         "//conditions:default": [],
+    }) + select({
+        "//bazel/common_config_settings:enable_svg_canvas_true": ["//include/svg:public_hdrs"],
+        "//conditions:default": [],
     }),
     visibility = ["//:__pkg__"],
 )

src/BUILD.bazel

@@ -29,6 +29,12 @@ filegroup(
     }) + select({
         "//bazel/common_config_settings:needs_sksl": ["//src/sksl:srcs"],
         "//conditions:default": [],
+    }) + select({
+        "//bazel/common_config_settings:enable_svg_canvas_true": [
+            "//src/svg:srcs",
+            "//src/xml:srcs",
+        ],
+        "//conditions:default": [],
     }),
     visibility = ["//:__pkg__"],
 )
@@ -57,6 +63,12 @@ filegroup(
     }) + select({
         "//bazel/common_config_settings:needs_sksl": ["//src/sksl:private_hdrs"],
         "//conditions:default": [],
+    }) + select({
+        "//bazel/common_config_settings:enable_svg_canvas_true": [
+            "//src/svg:private_hdrs",
+            "//src/xml:private_hdrs",
+        ],
+        "//conditions:default": [],
     }),
     visibility = ["//:__pkg__"],
 )
@@ -75,5 +87,10 @@ cc_library(
     }) + select({
         "//bazel/common_config_settings:needs_sksl": ["//src/sksl:deps"],
         "//conditions:default": [],
+    }) + select({
+        "//bazel/common_config_settings:enable_svg_canvas_true": [
+            "//src/xml:deps",
+        ],
+        "//conditions:default": [],
     }),
 )

src/svg/BUILD.bazel

@@ -0,0 +1,22 @@
+load("//bazel:macros.bzl", "exports_files_legacy")
+
+licenses(["notice"])
+
+exports_files_legacy()
+
+filegroup(
+    name = "srcs",
+    srcs = [
+        "SkSVGCanvas.cpp",
+        "SkSVGDevice.cpp",
+    ],
+    visibility = ["//src:__pkg__"],
+)
+
+filegroup(
+    name = "private_hdrs",
+    srcs = [
+        "SkSVGDevice.h",
+    ],
+    visibility = ["//src:__pkg__"],
+)

src/xml/BUILD.bazel

@@ -1,5 +1,37 @@
-load("//bazel:macros.bzl", "exports_files_legacy")
+load("//bazel:macros.bzl", "cc_library", "exports_files_legacy", "split_srcs_and_hdrs")
 
 licenses(["notice"])
 
 exports_files_legacy()
+
+XML_FILES = [
+    "SkDOM.cpp",
+    "SkDOM.h",
+    "SkXMLParser.cpp",
+    "SkXMLParser.h",
+    "SkXMLWriter.cpp",
+    "SkXMLWriter.h",
+]
+
+split_srcs_and_hdrs(
+    name = "xml",
+    files = XML_FILES,
+)
+
+filegroup(
+    name = "srcs",
+    srcs = [":xml_srcs"],
+    visibility = ["//src:__pkg__"],
+)
+
+filegroup(
+    name = "private_hdrs",
+    srcs = [":xml_hdrs"],
+    visibility = ["//src:__pkg__"],
+)
+
+cc_library(
+    name = "deps",
+    visibility = ["//src:__pkg__"],
+    deps = ["@expat"],
+)