T73268: Link C/C++ unit tests into single executable

This commit introduces a new way to build unit tests. It is now possible
for each module to generate its own test library. The tests in these
libraries are then bundled into a single executable.

The test executable can be run with `ctest`. Even though the tests
reside in a single executable, they are still exposed as individual
tests to `ctest`, and thus can be selected via its `-R` argument.

Not yet ported tests still build & run as before.

The following rules apply:

- Test code should reside in the same directory as the code under test.
- Tests that target functionality in `somefile.{c,cc}` should reside in
  `somefile_test.cc`.
- The namespace for tests is the `tests` sub-namespace of the code under
  test. For example, tests for `blender::bke` should be in
  `blender::bke:tests`.
- The test files should be listed in the module's `CMakeLists.txt` in a
  `blender_add_test_lib()` call. See the `blenkernel` module for an
  example.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D7649

12 files changed, 160 insertions, 57 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 824f635e2b2..49b974596f7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1628,10 +1628,6 @@ endif()
 #-----------------------------------------------------------------------------
 # Libraries
 
-if(WITH_GTESTS)
-  include(GTestTesting)
-endif()
-
 if(WITH_BLENDER)
   add_subdirectory(intern)
   add_subdirectory(extern)
diff --git a/build_files/cmake/Modules/GTestTesting.cmake b/build_files/cmake/Modules/GTestTesting.cmake
index c36b264a300..ea9a1edeb43 100644
--- a/build_files/cmake/Modules/GTestTesting.cmake
+++ b/build_files/cmake/Modules/GTestTesting.cmake
@@ -37,6 +37,11 @@ macro(BLENDER_SRC_GTEST_EX)
     if(WIN32)
       set(MANIFEST "${CMAKE_BINARY_DIR}/tests.exe.manifest")
     endif()
+
+    add_definitions(-DBLENDER_GFLAGS_NAMESPACE=${GFLAGS_NAMESPACE})
+    add_definitions(${GFLAGS_DEFINES})
+    add_definitions(${GLOG_DEFINES})
+
     add_executable(${TARGET_NAME} ${ARG_SRC} ${MANIFEST})
     target_include_directories(${TARGET_NAME} PUBLIC "${TEST_INC}")
     target_include_directories(${TARGET_NAME} SYSTEM PUBLIC "${TEST_INC_SYS}")
diff --git a/build_files/cmake/macros.cmake b/build_files/cmake/macros.cmake
index efe05d0bf5f..708efc3d2f7 100644
--- a/build_files/cmake/macros.cmake
+++ b/build_files/cmake/macros.cmake
@@ -354,6 +354,42 @@ function(blender_add_lib
   set_property(GLOBAL APPEND PROPERTY BLENDER_LINK_LIBS ${name})
 endfunction()
 
+# blender_add_test_lib() is used to define a test library. It is intended to be
+# called in tandem with blender_add_lib(). The test library will be linked into
+# the bf_gtest_runner_test executable (see tests/gtests/CMakeLists.txt).
+function(blender_add_test_lib
+  name
+  sources
+  includes
+  includes_sys
+  library_deps
+  )
+
+  add_cc_flags_custom_test(${name} PARENT_SCOPE)
+
+  # Otherwise external projects will produce warnings that we cannot fix.
+  remove_strict_flags()
+
+  # This duplicates logic that's also in GTestTesting.cmake, macro BLENDER_SRC_GTEST_EX.
+  # TODO(Sybren): deduplicate after the general approach in D7649 has been approved.
+  LIST(APPEND includes
+    ${CMAKE_SOURCE_DIR}/tests/gtests
+  )
+  LIST(APPEND includes_sys
+    ${GLOG_INCLUDE_DIRS}
+    ${GFLAGS_INCLUDE_DIRS}
+    ${CMAKE_SOURCE_DIR}/extern/gtest/include
+    ${CMAKE_SOURCE_DIR}/extern/gmock/include
+  )
+  add_definitions(-DBLENDER_GFLAGS_NAMESPACE=${GFLAGS_NAMESPACE})
+  add_definitions(${GFLAGS_DEFINES})
+  add_definitions(${GLOG_DEFINES})
+
+  blender_add_lib__impl(${name} "${sources}" "${includes}" "${includes_sys}" "${library_deps}")
+
+  set_property(GLOBAL APPEND PROPERTY BLENDER_TEST_LIBS ${name})
+endfunction()
+
 # Ninja only: assign 'heavy pool' to some targets that are especially RAM-consuming to build.
 function(setup_heavy_lib_pool)
   if(WITH_NINJA_POOL_JOBS AND NINJA_MAX_NUM_PARALLEL_COMPILE_HEAVY_JOBS)
diff --git a/intern/libmv/CMakeLists.txt b/intern/libmv/CMakeLists.txt
index c6078268512..5bb66649529 100644
--- a/intern/libmv/CMakeLists.txt
+++ b/intern/libmv/CMakeLists.txt
@@ -212,6 +212,8 @@ if(WITH_LIBMV)
 
 
   if(WITH_GTESTS)
+    include(GTestTesting)
+
     blender_add_lib(libmv_test_dataset "./libmv/multiview/test_data_sets.cc" "" "" "")
 
     BLENDER_SRC_GTEST("libmv_predict_tracks" "./libmv/autotrack/predict_tracks_test.cc" "libmv_test_dataset;bf_intern_libmv;extern_ceres")
diff --git a/source/blender/blenkernel/CMakeLists.txt b/source/blender/blenkernel/CMakeLists.txt
index 25710ef29ca..97a283abbfb 100644
--- a/source/blender/blenkernel/CMakeLists.txt
+++ b/source/blender/blenkernel/CMakeLists.txt
@@ -701,3 +701,16 @@ blender_add_lib(bf_blenkernel "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
 
 # Needed so we can use dna_type_offsets.h for defaults initialization.
 add_dependencies(bf_blenkernel bf_dna)
+
+
+if(WITH_GTESTS)
+  set(TEST_SRC
+    intern/armature_test.cc
+    intern/fcurve_test.cc
+  )
+  set(TEST_INC
+    ../editors/include
+  )
+  include(GTestTesting)
+  blender_add_test_lib(bf_blenkernel_tests "${TEST_SRC}" "${INC};${TEST_INC}" "${INC_SYS}" "${LIB}")
+endif()
diff --git a/tests/gtests/blenkernel/BKE_armature_test.cc b/source/blender/blenkernel/intern/armature_test.cc
index ed6045081d4..cf17c37bc69 100644
--- a/tests/gtests/blenkernel/BKE_armature_test.cc
+++ b/source/blender/blenkernel/intern/armature_test.cc
@@ -23,6 +23,8 @@
 
 #include "testing/testing.h"
 
+namespace blender::bke::tests {
+
 static const float FLOAT_EPSILON = 1.2e-7;
 
 TEST(mat3_vec_to_roll, UnitMatrix)
@@ -87,3 +89,5 @@ TEST(mat3_vec_to_roll, Rotationmatrix)
     EXPECT_NEAR(0.57158958f, roll, FLOAT_EPSILON);
   }
 }
+
+}  // namespace blender::bke::tests
diff --git a/tests/gtests/blenkernel/BKE_fcurve_test.cc b/source/blender/blenkernel/intern/fcurve_test.cc
index e994dd43af9..2248cce37e5 100644
--- a/tests/gtests/blenkernel/BKE_fcurve_test.cc
+++ b/source/blender/blenkernel/intern/fcurve_test.cc
@@ -27,6 +27,8 @@ extern "C" {
 #include "DNA_anim_types.h"
 }
 
+namespace blender::bke::tests {
+
 // Epsilon for floating point comparisons.
 static const float EPSILON = 1e-7f;
 
@@ -209,3 +211,5 @@ TEST(evaluate_fcurve, ExtrapolationBezierKeys)
 
   BKE_fcurve_free(fcu);
 }
+
+}  // namespace blender::bke::tests
diff --git a/tests/gtests/CMakeLists.txt b/tests/gtests/CMakeLists.txt
index 0dfe041974e..4ce68a6f4c0 100644
--- a/tests/gtests/CMakeLists.txt
+++ b/tests/gtests/CMakeLists.txt
@@ -1,18 +1,13 @@
 
-# GTest
 if(WITH_GTESTS)
-
-  include(GTestTesting)
-
-  add_definitions(${GFLAGS_DEFINES})
-  add_definitions(${GLOG_DEFINES})
-  add_definitions(-DBLENDER_GFLAGS_NAMESPACE=${GFLAGS_NAMESPACE})
-
   # Otherwise we get warnings here that we cant fix in external projects
   remove_strict_flags()
 
+  # Build common test runner
+  add_subdirectory(runner)
+
+  # Build tests not yet ported to the common runner
   add_subdirectory(testing)
-  add_subdirectory(blenkernel)
   add_subdirectory(blenlib)
   add_subdirectory(blenloader)
   add_subdirectory(guardedalloc)
diff --git a/tests/gtests/blenkernel/CMakeLists.txt b/tests/gtests/blenkernel/CMakeLists.txt
deleted file mode 100644
index 5cf4c7a27af..00000000000
--- a/tests/gtests/blenkernel/CMakeLists.txt
+++ /dev/null
@@ -1,44 +0,0 @@
-# ***** BEGIN GPL LICENSE BLOCK *****
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License
-# as published by the Free Software Foundation; either version 2
-# of the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software Foundation,
-# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-#
-# The Original Code is Copyright (C) 2020, Blender Foundation
-# All rights reserved.
-# ***** END GPL LICENSE BLOCK *****
-
-set(INC
-  .
-  ..
-  ../../../source/blender/blenkernel
-  ../../../source/blender/blenlib
-  ../../../source/blender/editors/include
-  ../../../source/blender/makesdna
-  ../../../source/blender/makesrna
-  ../../../intern/guardedalloc
-  ../../../intern/atomic
-)
-
-setup_libdirs()
-include_directories(${INC})
-
-set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${PLATFORM_LINKFLAGS}")
-set(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} ${PLATFORM_LINKFLAGS_DEBUG}")
-
-if(WITH_BUILDINFO)
-  set(BUILDINFO buildinfoobj)
-endif()
-
-BLENDER_TEST(BKE_armature "bf_blenloader;bf_blenkernel;bf_blenlib;${BUILDINFO}")
-BLENDER_TEST(BKE_fcurve "bf_blenloader;bf_blenkernel;bf_editor_animation;${BUILDINFO}")
diff --git a/tests/gtests/runner/CMakeLists.txt b/tests/gtests/runner/CMakeLists.txt
new file mode 100644
index 00000000000..e7cbabfe7c6
--- /dev/null
+++ b/tests/gtests/runner/CMakeLists.txt
@@ -0,0 +1,63 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# The Original Code is Copyright (C) 2020, Blender Foundation
+# All rights reserved.
+# ***** END GPL LICENSE BLOCK *****
+
+# Build the test runner. This runner takes care of running all GTests, i.e.
+# the code that was built using the blender_add_test_lib() CMake macro (see
+# macros.cmake).
+set(SRC
+  blender_test.cc
+)
+
+if(WITH_BUILDINFO)
+  list(APPEND SRC
+    "$<TARGET_OBJECTS:buildinfoobj>"
+  )
+endif()
+
+
+# Test libraries need to be linked "whole archive", because they're not
+# directly referenced from other code.
+get_property(_test_libs GLOBAL PROPERTY BLENDER_TEST_LIBS)
+if(WIN32)
+  list(APPEND TEST_LIBS ${_test_libs})
+elseif(APPLE)
+  list(APPEND TEST_LIBS "-Wl,-force_load" ${_test_libs})
+elseif(UNIX)
+  list(APPEND TEST_LIBS "-Wl,--whole-archive" ${_test_libs} "-Wl,--no-whole-archive")
+else()
+  message(FATAL_ERROR "Unknown how to link whole-archive with your compiler ${CMAKE_CXX_COMPILER_ID}")
+endif()
+unset(_test_libs)
+
+# This builds `bin/tests/blender_test`, but does not add it as a single test.
+setup_libdirs()
+BLENDER_SRC_GTEST_EX(
+  NAME blender
+  SRC "${SRC}"
+  EXTRA_LIBS "${TEST_LIBS}"
+  SKIP_ADD_TEST
+)
+setup_liblinks(blender_test)
+
+# This runs the blender_test executable with `--gtest_list_tests`, then
+# exposes those tests individually to the ctest runner.
+# See https://cmake.org/cmake/help/v3.18/module/GoogleTest.html
+include(GoogleTest)
+gtest_discover_tests(blender_test)
diff --git a/tests/gtests/runner/blender_test.cc b/tests/gtests/runner/blender_test.cc
new file mode 100644
index 00000000000..fbce7a4283f
--- /dev/null
+++ b/tests/gtests/runner/blender_test.cc
@@ -0,0 +1,25 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/* This file is intentionally left blank. It is necessary for CMake to have a source file for each
+ * executable. However, the blender_tests test runner only comprises of statically linked library
+ * files, including its main function.
+ *
+ * See source/blender/blenkernel/CMakeLists.txt for an example of how to add unit tests to the test
+ * runner. */
diff --git a/tests/gtests/testing/CMakeLists.txt b/tests/gtests/testing/CMakeLists.txt
index e08ee486933..c8a7f487c5d 100644
--- a/tests/gtests/testing/CMakeLists.txt
+++ b/tests/gtests/testing/CMakeLists.txt
@@ -18,6 +18,10 @@
 # All rights reserved.
 # ***** END GPL LICENSE BLOCK *****
 
+add_definitions(${GFLAGS_DEFINES})
+add_definitions(${GLOG_DEFINES})
+add_definitions(-DBLENDER_GFLAGS_NAMESPACE=${GFLAGS_NAMESPACE})
+
 set(INC
   .
   ..