Add examples to the Bazel build

Also moves the gflags namespace define
into the ceres_library() target.

Change-Id: Ibb8f3fdd9a8c371fe96b475f752f8320ffe63cdc

BUILD

diff --git a/BUILD b/BUILD
index e488f29..9c6a48c 100644
--- a/BUILD
+++ b/BUILD
@@ -59,9 +59,6 @@
         "-Wno-sign-compare",
         "-DCERES_TEST_SRCDIR_SUFFIX=\\\"data/\\\"",
     ],
-    defines = [
-        "CERES_GFLAGS_NAMESPACE=gflags",
-    ],
     includes = [
         "internal",
         "internal/ceres",
@@ -157,6 +154,7 @@
 ]
 
 TEST_COPTS = [
+    # Needed to silence GFlags complaints.
     "-Wno-sign-compare",
 
     # These two warnings don't work well in conjunction with GMock, and

bazel/ceres.bzl

diff --git a/bazel/ceres.bzl b/bazel/ceres.bzl
index e6aac07..ef5969a 100644
--- a/bazel/ceres.bzl
+++ b/bazel/ceres.bzl
@@ -130,7 +130,9 @@
 # TODO(rodrigoq): add support to configure Ceres into various permutations,
 # like SuiteSparse or not, threading or not, glog or not, and so on.
 # See https://github.com/ceres-solver/ceres-solver/issues/335.
-def ceres_library(name, restrict_schur_specializations=False):
+def ceres_library(name,
+                  restrict_schur_specializations=False,
+                  gflags_namespace="gflags"):
     # The path to internal/ depends on whether Ceres is the main workspace or
     # an external repository.
     if native.repository_name() != '@':
@@ -188,6 +190,7 @@
             "CERES_NO_THREADS",
             "CERES_NO_LAPACK",
             "CERES_STD_UNORDERED_MAP",
+            "CERES_GFLAGS_NAMESPACE=" + gflags_namespace,
         ],
         includes = [
             "config",

examples/BUILD

diff --git a/examples/BUILD b/examples/BUILD
new file mode 100644
index 0000000..4d8f1bb
--- /dev/null
+++ b/examples/BUILD
@@ -0,0 +1,126 @@
+# Ceres Solver - A fast non-linear least squares minimizer
+# Copyright 2018 Google Inc. All rights reserved.
+# http://ceres-solver.org/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice,
+#   this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+# * Neither the name of Google Inc. nor the names of its contributors may be
+#   used to endorse or promote products derived from this software without
+#   specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# Author: mierle@gmail.com (Keir Mierle)
+
+EXAMPLE_COPTS = [
+    # Needed to silence GFlags complaints.
+    "-Wno-sign-compare",
+]
+
+EXAMPLE_DEPS = [
+    "//:ceres",
+    "@com_github_eigen_eigen//:eigen",
+    "@com_github_gflags_gflags//:gflags",
+]
+
+cc_binary(
+    name = "bundle_adjuster",
+    srcs = [
+        "bal_problem.cc",
+        "bal_problem.h",
+        "bundle_adjuster.cc",
+        "random.h",
+        "snavely_reprojection_error.h",
+    ],
+    copts = EXAMPLE_COPTS,
+    deps = EXAMPLE_DEPS,
+)
+
+cc_binary(
+    name = "denoising",
+    srcs = [
+        "denoising.cc",
+        "fields_of_experts.cc",
+        "fields_of_experts.h",
+        "pgm_image.h",
+    ],
+    copts = EXAMPLE_COPTS,
+    deps = EXAMPLE_DEPS,
+)
+
+cc_binary(
+    name = "robot_pose_mle",
+    srcs = [
+        "random.h",
+        "robot_pose_mle.cc",
+    ],
+    copts = EXAMPLE_COPTS,
+    deps = EXAMPLE_DEPS,
+)
+
+SLAM_COPTS = EXAMPLE_COPTS + ["-Iexamples/slam"]
+
+cc_binary(
+    name = "pose_graph_2d",
+    srcs = [
+        "slam/common/read_g2o.h",
+        "slam/pose_graph_2d/angle_local_parameterization.h",
+        "slam/pose_graph_2d/normalize_angle.h",
+        "slam/pose_graph_2d/pose_graph_2d.cc",
+        "slam/pose_graph_2d/pose_graph_2d_error_term.h",
+        "slam/pose_graph_2d/types.h",
+    ],
+    copts = SLAM_COPTS,
+    deps = EXAMPLE_DEPS,
+)
+
+cc_binary(
+    name = "pose_graph_3d",
+    srcs = [
+        "slam/common/read_g2o.h",
+        "slam/pose_graph_3d/pose_graph_3d.cc",
+        "slam/pose_graph_3d/pose_graph_3d_error_term.h",
+        "slam/pose_graph_3d/types.h",
+    ],
+    copts = SLAM_COPTS,
+    deps = EXAMPLE_DEPS,
+)
+
+[cc_binary(
+    name = example,
+    srcs = [example + ".cc"],
+    copts = EXAMPLE_COPTS,
+    deps = EXAMPLE_DEPS,
+) for example in [
+    "circle_fit",
+    "curve_fitting",
+    "ellipse_approximation",
+    "helloworld",
+    "helloworld_analytic_diff",
+    "helloworld_numeric_diff",
+    "libmv_bundle_adjuster",
+    "libmv_homography",
+    "more_garbow_hillstrom",
+    "nist",
+    "powell",
+    "robust_curve_fitting",
+    "rosenbrock",
+    "sampled_function/sampled_function",
+    "simple_bundle_adjuster",
+]]