Use yaml-cpp from system on Xenial and homebrew on MacOS. (#7602)

* Use yaml_cpp from Ubuntu Xenial.

This removes the bazel external yaml_cpp and replaces it with system
yaml_cpp found via pkg-config.

Using the system version cuts down on the size of libdrake.so and
improves linking compatibility when using Drake within systems that
use the system yaml-cpp version.

This change was previously introduced in #7352 and later reverted
(#7403) due to issues with the MacOS build. Other portions of that
original pull request were reintroduced in #7453.

WORKSPACE

@@ -315,12 +315,11 @@ github_archive(
  build_file = "tools/workspace/tinyobjloader/tinyobjloader.BUILD.bazel",
 )
 
-github_archive(
+pkg_config_package(
  name = "yaml_cpp",
- repository = "jbeder/yaml-cpp",
- commit = "85af926ddc5f3c8fb438001743e65ec3a039ceec",
- sha256 = "907fb42a502e1448a73959f9a648771b070d6d8513f16d74149f775fc56550ef", # noqa
- build_file = "tools/workspace/yaml_cpp/yaml_cpp.BUILD.bazel",
+ atleast_version = "0.5.2",
+ build_file_template = "@drake//tools/workspace/yaml_cpp:yaml_cpp.BUILD.tpl", # noqa
+ modname = "yaml-cpp",
 )
 
 load("//tools/workspace/buildifier:buildifier.bzl", "buildifier_repository")

tools/install/libdrake/drake.cps

@@ -80,11 +80,6 @@
  "Version": "1.0.4",
  "Hints": ["@prefix@/lib/cmake/tinyobjloader"],
  "X-CMake-Find-Args": ["CONFIG"]
- },
- "yaml-cpp": {
- "Version": "0.5.5",
- "Hints": ["@prefix@/lib/cmake/yaml-cpp"],
- "X-CMake-Find-Args": ["CONFIG"]
  }
  },
  "Default-Components": [":drake"],
@@ -94,12 +89,14 @@
  "Location": "@prefix@/lib/libdrake.so",
  "Includes": ["@prefix@/include"],
  "Compile-Features": ["c++14"],
- "Link-Flags": ["-ltinyxml2"],
+ "Link-Flags": [
+ "-ltinyxml2",
+ "-lyaml-cpp"
+ ],
  "Link-Requires": [
  "fmt:fmt",
  "SDFormat:sdformat",
- "tinyobjloader:tinyobjloader",
- "yaml-cpp:yaml-cpp"
+ "tinyobjloader:tinyobjloader"
  ],
  "Requires": [
  ":drake-lcmtypes-cpp",

tools/workspace/BUILD.bazel

@@ -37,7 +37,6 @@ _DRAKE_EXTERNAL_PACKAGE_INSTALLS = ["@%s//:install" % p for p in [
  "tinydir",
  "tinyobjloader",
  "vtk",
- "yaml_cpp",
 ]] + ["//tools/workspace/%s:install" % p for p in [
  "jchart2d",
  "optitrack_driver",

tools/workspace/yaml_cpp/BUILD.bazel

@@ -2,9 +2,4 @@
 
 load("//tools/lint:lint.bzl", "add_lint_tests")
 
-exports_files(
- ["yaml_cpp-create-cps.py"],
- visibility = ["@yaml_cpp//:__pkg__"],
-)
-
 add_lint_tests()

tools/workspace/yaml_cpp/yaml_cpp.BUILD.tpl

@@ -0,0 +1,18 @@
+# Altered copy of the pkg_config_package build template.
+# Adds a hard-coded dependency on "@boost" to work around a yaml-cpp
+# misconfiguration.
+# https://github.com/RobotLocomotion/drake/pull/7602#issuecomment-353093726
+
+package(
+ default_visibility = ["//visibility:public"],
+)
+
+cc_library(
+ name = "%{name}",
+ srcs = ["%{srcs}"],
+ hdrs = glob(["include/**"]),
+ defines = ["%{defines}"],
+ includes = ["%{includes}"],
+ linkopts = ["%{linkopts}"],
+ deps = ["@boost//:boost_headers"]
+)