[workspace] Build NLopt from source

Compared to the Ubuntu and macOS packages, this removes the LGPL'd
"luksan" solver from the build, which means we can link the library
statically (and eventually, hidden). This might mean that NLopt is
no longer able to solve certain kinds of programs, but that is a
fair trade-off given all of the problems caused by LGPL linking.

The package.BUILD.bazel is modeled on nlopt.BUILD.bazel in a10ebb7.

Deprecate the now-unused current (host OS) nlopt external.

solvers/BUILD.bazel

@@ -975,7 +975,7 @@ drake_cc_variant_library(
     ],
     deps_enabled = [
         "//math:autodiff",
-        "@nlopt",
+        "@nlopt_internal//:nlopt",
     ],
 )
 

tools/install/libdrake/BUILD.bazel

@@ -126,7 +126,6 @@ cc_library(
     name = "dreal_deps",
     deps = select({
         "//conditions:default": [
-            "@nlopt",
             "@ibex",
         ],
         "//tools:no_dreal": [],
@@ -162,17 +161,6 @@ cc_library(
     }),
 )
 
-# Depend on NLOPT's shared library iff NLOPT is enabled.
-cc_library(
-    name = "nlopt_deps",
-    deps = select({
-        "//conditions:default": [
-            "@nlopt",
-        ],
-        "//tools:no_nlopt": [],
-    }),
-)
-
 # Depend on the subset of VTK's shared libraries that Drake uses.
 cc_library(
     name = "vtk_deps",
@@ -239,7 +227,6 @@ cc_library(
         ":gurobi_deps",
         ":ipopt_deps",
         ":mosek_deps",
-        ":nlopt_deps",
         ":vtk_deps",
         ":x11_deps",
         "//common:drake_marker_shared_library",

tools/wheel/image/packages-focal

@@ -31,8 +31,6 @@ zip
 # Build dependencies (general).
 libgl1-mesa-dev
 libglib2.0-dev
-libnlopt-dev
-libnlopt-cxx-dev
 libxt-dev
 # Build dependencies (OpenCL).
 opencl-headers

tools/workspace/BUILD.bazel

@@ -49,6 +49,7 @@ drake_py_binary(
     srcs = ["vendor_cxx.py"],
     visibility = [
         # These should all be of the form "@foo_internal//:__pkg__".
+        "@nlopt_internal//:__pkg__",
         "@qhull_internal//:__pkg__",
         "@yaml_cpp_internal//:__pkg__",
     ],

tools/workspace/default.bzl

@@ -61,6 +61,7 @@ load("@drake//tools/workspace/mosek:repository.bzl", "mosek_repository")
 load("@drake//tools/workspace/msgpack:repository.bzl", "msgpack_repository")
 load("@drake//tools/workspace/net_sf_jchart2d:repository.bzl", "net_sf_jchart2d_repository")  # noqa
 load("@drake//tools/workspace/nlopt:repository.bzl", "nlopt_repository")
+load("@drake//tools/workspace/nlopt_internal:repository.bzl", "nlopt_internal_repository")  # noqa
 load("@drake//tools/workspace/openblas:repository.bzl", "openblas_repository")
 load("@drake//tools/workspace/opencl:repository.bzl", "opencl_repository")
 load("@drake//tools/workspace/opengl:repository.bzl", "opengl_repository")
@@ -238,7 +239,11 @@ def add_default_repositories(excludes = [], mirrors = DEFAULT_MIRRORS):
     if "net_sf_jchart2d" not in excludes:
         net_sf_jchart2d_repository(name = "net_sf_jchart2d", mirrors = mirrors)
     if "nlopt" not in excludes:
+        # The @nlopt external is being removed from Drake on 2020-09-01.
+        # TODO(jwnimmer-tri) When removing @nlopt, also update install_prereqs.
         nlopt_repository(name = "nlopt")
+    if "nlopt_internal" not in excludes:
+        nlopt_internal_repository(name = "nlopt_internal", mirrors = mirrors)
     if "openblas" not in excludes:
         openblas_repository(name = "openblas")
     if "opencl" not in excludes:

tools/workspace/dreal/patches/warnings.patch

@@ -0,0 +1,18 @@
+Silence this warning:
+  dreal/dreal/optimization/nlopt_optimizer.h:44:7: warning:
+  'dreal::NloptOptimizer' declared with greater visibility than the type
+  of its field 'dreal::NloptOptimizer::opt_' [-Wattributes]
+
+TODO(jwnimmer-tri) Try to use a hidden inline namespace for dReal as well,
+to silence this warning.
+
+--- tools/dreal.bzl
++++ tools/dreal.bzl
+@@ -25,6 +25,7 @@
+     "-Woverloaded-virtual",
+     "-Wpedantic",
+     "-Wshadow",
++    "-Wno-attributes",
+ ]
+
+ # The CLANG_FLAGS will be enabled for all C++ rules in the project when

tools/workspace/dreal/repository.bzl

@@ -12,6 +12,10 @@ def dreal_repository(
         sha256 = "7bbd328a25c14cff814753694b1823257bb7cff7f84a7b705b9f111624d5b2e4",  # noqa
         mirrors = mirrors,
         patches = [
-            "@drake//tools/workspace/dreal:ibex_2.8.6.patch",
+            "@drake//tools/workspace/dreal:patches/ibex_2.8.6.patch",
+            "@drake//tools/workspace/dreal:patches/warnings.patch",
         ],
+        repo_mapping = {
+            "@nlopt": "@nlopt_internal",
+        },
     )

tools/workspace/nlopt/package-macos.BUILD.bazel

@@ -21,4 +21,5 @@ cc_library(
         "-lnlopt",
     ],
     visibility = ["//visibility:public"],
+    deprecation = "DRAKE DEPRECATED: The @nlopt external is being removed from Drake on or after 2020-09-01.  Downstream projects should add it to their own WORKSPACE if needed.",  # noqa
 )

tools/workspace/nlopt/package-ubuntu-20.04.BUILD.bazel

@@ -15,4 +15,5 @@ cc_library(
         "-lnlopt_cxx",
     ],
     visibility = ["//visibility:public"],
+    deprecation = "DRAKE DEPRECATED: The @nlopt external is being removed from Drake on or after 2020-09-01.  Downstream projects should add it to their own WORKSPACE if needed.",  # noqa
 )

tools/workspace/nlopt_internal/BUILD.bazel

@@ -0,0 +1,45 @@
+# -*- python -*-
+
+load("//tools/skylark:drake_py.bzl", "drake_py_unittest")
+load("//tools/lint:lint.bzl", "add_lint_tests")
+
+exports_files(
+    ["patches/gen_enums.patch"],
+    visibility = ["@nlopt_internal//:__pkg__"],
+)
+
+# Creates api/nlopt.hpp using NLopt upstream's codegen so that we can
+# cross-check it versus our Drake-local patch file.
+genrule(
+    name = "cmake_genrule",
+    srcs = [
+        "@nlopt_internal//:cmake/generate-cpp.cmake",
+        "@nlopt_internal//:src/api/nlopt-in.hpp",
+        "@nlopt_internal//:src/api/nlopt.h",
+    ],
+    outs = ["test/nlopt-upstream.hpp"],
+    cmd = " ".join([
+        "cmake",
+        "-DAPI_SOURCE_DIR=$$(dirname $(execpath @nlopt_internal//:src/api/nlopt.h))",  # noqa
+        "-P $(execpath @nlopt_internal//:cmake/generate-cpp.cmake)",
+        "&&",
+        "mv nlopt.hpp $@",
+    ]),
+    tags = [
+        "manual",
+        "nolint",
+    ],
+)
+
+drake_py_unittest(
+    name = "enum_test",
+    data = [
+        ":test/nlopt-upstream.hpp",
+        "@nlopt_internal//:genrule/nlopt.hpp",
+    ],
+    deps = [
+        "@bazel_tools//tools/python/runfiles",
+    ],
+)
+
+add_lint_tests()