failtest: a new cmake-based test suite for testing stuff that should fail to build. This first batch imports some const correctness checks from bug #54.

CMakeLists.txt

@@ -5,7 +5,7 @@ cmake_minimum_required(VERSION 2.6.2)
 # guard against in-source builds
 
 if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_BINARY_DIR})
-  message(FATAL_ERROR "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there. (you may need to remove CMakeCache.txt ")
+  message(FATAL_ERROR "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there. You may need to remove CMakeCache.txt. ")
 endif()
 
 # guard against bad build-type strings
@@ -316,6 +316,10 @@ message(STATUS "")
 message(STATUS "Configured Eigen ${EIGEN_VERSION_NUMBER}")
 message(STATUS "")
 
+if(EIGEN_FAILTEST)
+  add_subdirectory(failtest)
+endif()
+
 string(TOLOWER "${CMAKE_GENERATOR}" cmake_generator_tolower)
 if(cmake_generator_tolower MATCHES "makefile")
   message(STATUS "Some things you can do now:")

cmake/EigenTesting.cmake

@@ -1,6 +1,8 @@
 option(EIGEN_NO_ASSERTION_CHECKING "Disable checking of assertions using exceptions" OFF)
 option(EIGEN_DEBUG_ASSERTS "Enable advanced debuging of assertions" OFF)
 
+include(CheckCXXSourceCompiles)
+
 macro(ei_add_property prop value)
   get_property(previous GLOBAL PROPERTY ${prop})
   set_property(GLOBAL PROPERTY ${prop} "${previous} ${value}")
@@ -69,7 +71,6 @@ macro(ei_add_test_internal testname testname_with_suffix)
 
 endmacro(ei_add_test_internal)
 
-
 # Macro to add a test
 #
 # the unique mandatory parameter testname must correspond to a file
@@ -140,6 +141,44 @@ macro(ei_add_test testname)
   endif(EIGEN_SPLIT_LARGE_TESTS AND suffixes)
 endmacro(ei_add_test)
 
+
+# adds a failtest, i.e. a test that succeed if the program fails to compile
+# note that the test runner for these is CMake itself, when passed -DEIGEN_FAILTEST=ON
+# so here we're just running CMake commands immediately, we're not adding any targets.
+macro(ei_add_failtest testname)
+  get_property(EIGEN_FAILTEST_FAILURE_COUNT GLOBAL PROPERTY EIGEN_FAILTEST_FAILURE_COUNT)
+  get_property(EIGEN_FAILTEST_COUNT GLOBAL PROPERTY EIGEN_FAILTEST_COUNT)
+
+  message(STATUS "Checking failtest: ${testname}")
+  set(filename "${testname}.cpp")
+  file(READ "${filename}" test_source)
+
+  try_compile(succeeds_when_it_should_fail
+              "${CMAKE_CURRENT_BINARY_DIR}"
+              "${CMAKE_CURRENT_SOURCE_DIR}/${filename}"
+              COMPILE_DEFINITIONS "-DEIGEN_SHOULD_FAIL_TO_BUILD")
+  if (succeeds_when_it_should_fail)
+    message(STATUS "FAILED: ${testname} build succeeded when it should have failed")
+  endif()
+
+  try_compile(succeeds_when_it_should_succeed
+              "${CMAKE_CURRENT_BINARY_DIR}"
+              "${CMAKE_CURRENT_SOURCE_DIR}/${filename}"
+              COMPILE_DEFINITIONS)
+  if (NOT succeeds_when_it_should_succeed)
+    message(STATUS "FAILED: ${testname} build failed when it should have succeeded")
+  endif()
+
+  if (succeeds_when_it_should_fail OR NOT succeeds_when_it_should_succeed)
+    math(EXPR EIGEN_FAILTEST_FAILURE_COUNT ${EIGEN_FAILTEST_FAILURE_COUNT}+1)
+  endif()
+
+  math(EXPR EIGEN_FAILTEST_COUNT ${EIGEN_FAILTEST_COUNT}+1)
+
+  set_property(GLOBAL PROPERTY EIGEN_FAILTEST_FAILURE_COUNT ${EIGEN_FAILTEST_FAILURE_COUNT})
+  set_property(GLOBAL PROPERTY EIGEN_FAILTEST_COUNT ${EIGEN_FAILTEST_COUNT})
+endmacro(ei_add_failtest)
+
 # print a summary of the different options
 macro(ei_testing_print_summary)
 
@@ -226,6 +265,12 @@ macro(ei_init_testing)
   set_property(GLOBAL PROPERTY EIGEN_MISSING_BACKENDS "")
   set_property(GLOBAL PROPERTY EIGEN_TESTING_SUMMARY "")
   set_property(GLOBAL PROPERTY EIGEN_TESTS_LIST "")
+
+  define_property(GLOBAL PROPERTY EIGEN_FAILTEST_FAILURE_COUNT BRIEF_DOCS " " FULL_DOCS " ")
+  define_property(GLOBAL PROPERTY EIGEN_FAILTEST_COUNT BRIEF_DOCS " " FULL_DOCS " ")
+
+  set_property(GLOBAL PROPERTY EIGEN_FAILTEST_FAILURE_COUNT "0")
+  set_property(GLOBAL PROPERTY EIGEN_FAILTEST_COUNT "0")
 endmacro(ei_init_testing)
 
 if(CMAKE_COMPILER_IS_GNUCXX)

failtest/CMakeLists.txt

@@ -0,0 +1,17 @@
+message(STATUS "Running the failtests")
+
+ei_add_failtest("failtest_sanity_check")
+ei_add_failtest("block_nonconst_ctor_on_const_xpr_0")
+ei_add_failtest("block_nonconst_ctor_on_const_xpr_1")
+ei_add_failtest("block_nonconst_ctor_on_const_xpr_2")
+ei_add_failtest("transpose_nonconst_ctor_on_const_xpr")
+ei_add_failtest("diagonal_nonconst_ctor_on_const_xpr")
+
+if (EIGEN_FAILTEST_FAILURE_COUNT)
+  message(FATAL_ERROR "${EIGEN_FAILTEST_FAILURE_COUNT} out of ${EIGEN_FAILTEST_COUNT} failtests FAILED. "
+                      "Failtests succeed when they generate build errors. "
+                      "To debug these failures, manually compile these programs in ${CMAKE_CURRENT_SOURCE_DIR}.")
+else()
+  message(STATUS "Failtest SUCCESS: all ${EIGEN_FAILTEST_COUNT} failtests passed.")
+  message(STATUS "")
+endif()

failtest/block_nonconst_ctor_on_const_xpr_0.cpp

@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    Block<Matrix3d,3,3> b(m,0,0);
+}
+
+int main() {}

failtest/block_nonconst_ctor_on_const_xpr_1.cpp

@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    Block<Matrix3d> b(m,0,0,3,3);
+}
+
+int main() {}

failtest/block_nonconst_ctor_on_const_xpr_2.cpp

@@ -0,0 +1,16 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    // row/column constructor
+    Block<Matrix3d,3,1> b(m,0);
+}
+
+int main() {}

failtest/diagonal_nonconst_ctor_on_const_xpr.cpp

@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    Diagonal<Matrix3d> d(m);
+}
+
+int main() {}

failtest/failtest_sanity_check.cpp

@@ -0,0 +1,5 @@
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+This is just some text that won't compile as a C++ file, as a basic sanity check for failtest.
+#else
+int main() {}
+#endif

failtest/transpose_nonconst_ctor_on_const_xpr.cpp

@@ -0,0 +1,15 @@
+#include "../Eigen/Core"
+
+#ifdef EIGEN_SHOULD_FAIL_TO_BUILD
+#define CV_QUALIFIER const
+#else
+#define CV_QUALIFIER
+#endif
+
+using namespace Eigen;
+
+void foo(CV_QUALIFIER Matrix3d &m){
+    Transpose<Matrix3d> t(m);
+}
+
+int main() {}