Tests: Verify policies are introduced only in "official" versions

Add the CMake.PolicyCheck test.

This test uses "git grep" to look for policies added in a "dated"
version of CMake. It will fail if a policy is added as of,
for example, CMake 2.8.11.20130828.

The intent is to prevent such constructs from making it into an
"official" release. Three instances actually appeared in the first
attempted release candidate for 2.8.12.

This test may sometimes yield false positives. After all, it's just
using a regular expression to detect this condition, and something
in a comment could possibly match it. As of right now, that's not
true, but it's easy to imagine such a comment being added.

The new test may also not catch all future problems of this sort.
However, it will catch problems of this sort for all code that follows
the present layout style in Source/cmPolicies.cxx.

2 files changed, 163 insertions, 0 deletions

diff --git a/Tests/CMakeTests/CMakeLists.txt b/Tests/CMakeTests/CMakeLists.txt
index 344b772555..4c49c6a771 100644
--- a/Tests/CMakeTests/CMakeLists.txt
+++ b/Tests/CMakeTests/CMakeLists.txt
@@ -55,6 +55,15 @@ set(GetPrerequisites_PreArgs
   )
 AddCMakeTest(GetPrerequisites "${GetPrerequisites_PreArgs}")
 
+if(GIT_EXECUTABLE)
+  set(PolicyCheck_PreArgs
+    "-DCMake_BINARY_DIR:PATH=${CMake_BINARY_DIR}"
+    "-DCMake_SOURCE_DIR:PATH=${CMake_SOURCE_DIR}"
+    "-DGIT_EXECUTABLE:STRING=${GIT_EXECUTABLE}"
+    )
+  AddCMakeTest(PolicyCheck "${PolicyCheck_PreArgs}")
+endif()
+
 # Run CheckSourceTree as the very last test in the CMake/CTest/CPack test
 # suite. It detects if any changes have been made to the CMake source tree
 # by any previous configure, build or test steps.
diff --git a/Tests/CMakeTests/PolicyCheckTest.cmake.in b/Tests/CMakeTests/PolicyCheckTest.cmake.in
new file mode 100644
index 0000000000..416dc0a75f
--- /dev/null
+++ b/Tests/CMakeTests/PolicyCheckTest.cmake.in
@@ -0,0 +1,154 @@
+# Check the CMake source tree for suspicious policy introdcutions...
+#
+message("=============================================================================")
+message("CTEST_FULL_OUTPUT (Avoid ctest truncation of output)")
+message("")
+message("CMake_BINARY_DIR='${CMake_BINARY_DIR}'")
+message("CMake_SOURCE_DIR='${CMake_SOURCE_DIR}'")
+message("GIT_EXECUTABLE='${GIT_EXECUTABLE}'")
+message("")
+
+
+# If this does not appear to be a git checkout, just pass the test here
+# and now. (Do not let the test fail if it is run in a tree *exported* from a
+# repository or unpacked from a .zip file source installer...)
+#
+set(is_git_checkout 0)
+if(EXISTS "${CMake_SOURCE_DIR}/.git")
+  set(is_git_checkout 1)
+endif()
+
+message("is_git_checkout='${is_git_checkout}'")
+message("")
+
+if(NOT is_git_checkout)
+  message("source tree is not a git checkout... test passes by early return...")
+  return()
+endif()
+
+# If no GIT_EXECUTABLE, see if we can figure out which git was used
+# for the ctest_update step on this dashboard...
+#
+if(is_git_checkout AND NOT GIT_EXECUTABLE)
+  set(ctest_ini_file "")
+  set(exe "")
+
+  # Use the old name:
+  if(EXISTS "${CMake_BINARY_DIR}/DartConfiguration.tcl")
+    set(ctest_ini_file "${CMake_BINARY_DIR}/DartConfiguration.tcl")
+  endif()
+
+  # But if it exists, prefer the new name:
+  if(EXISTS "${CMake_BINARY_DIR}/CTestConfiguration.ini")
+    set(ctest_ini_file "${CMake_BINARY_DIR}/CTestConfiguration.ini")
+  endif()
+
+  # If there is a ctest ini file, read the update command or git command
+  # from it:
+  #
+  if(ctest_ini_file)
+    file(STRINGS "${ctest_ini_file}" line REGEX "^GITCommand: (.*)$")
+    string(REGEX REPLACE "^GITCommand: (.*)$" "\\1" line "${line}")
+    if("${line}" MATCHES "^\"")
+      string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+    else()
+      string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+    endif()
+    set(exe "${line}")
+    if("${exe}" STREQUAL "GITCOMMAND-NOTFOUND")
+      set(exe "")
+    endif()
+    if(exe)
+      message("info: GIT_EXECUTABLE set by 'GITCommand:' from '${ctest_ini_file}'")
+    endif()
+
+    if(NOT exe)
+      file(STRINGS "${ctest_ini_file}" line REGEX "^UpdateCommand: (.*)$")
+      string(REGEX REPLACE "^UpdateCommand: (.*)$" "\\1" line "${line}")
+      if("${line}" MATCHES "^\"")
+        string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+      else()
+        string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+      endif()
+      set(exe "${line}")
+      if("${exe}" STREQUAL "GITCOMMAND-NOTFOUND")
+        set(exe "")
+      endif()
+      if(exe)
+        message("info: GIT_EXECUTABLE set by 'UpdateCommand:' from '${ctest_ini_file}'")
+      endif()
+    endif()
+  else()
+    message("info: no DartConfiguration.tcl or CTestConfiguration.ini file...")
+  endif()
+
+  # If we have still not grokked the exe, look in the Update.xml file to see
+  # if we can parse it from there...
+  #
+  if(NOT exe)
+    file(GLOB_RECURSE update_xml_file "${CMake_BINARY_DIR}/Testing/Update.xml")
+    if(update_xml_file)
+      file(STRINGS "${update_xml_file}" line
+        REGEX "^.*<UpdateCommand>(.*)</UpdateCommand>$" LIMIT_COUNT 1)
+      string(REPLACE "&quot\;" "\"" line "${line}")
+      string(REGEX REPLACE "^.*<UpdateCommand>(.*)</UpdateCommand>$" "\\1" line "${line}")
+      if("${line}" MATCHES "^\"")
+        string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+      else()
+        string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+      endif()
+      if(line)
+        set(exe "${line}")
+      endif()
+      if(exe)
+        message("info: GIT_EXECUTABLE set by '<UpdateCommand>' from '${update_xml_file}'")
+      endif()
+    else()
+      message("info: no Update.xml file...")
+    endif()
+  endif()
+
+  if(exe)
+    set(GIT_EXECUTABLE "${exe}")
+    message("GIT_EXECUTABLE='${GIT_EXECUTABLE}'")
+    message("")
+
+    if(NOT EXISTS "${GIT_EXECUTABLE}")
+      message(FATAL_ERROR "GIT_EXECUTABLE does not exist...")
+    endif()
+  else()
+    message(FATAL_ERROR "could not determine GIT_EXECUTABLE...")
+  endif()
+endif()
+
+
+if(is_git_checkout AND GIT_EXECUTABLE)
+  # Check with "git grep" if there are any unacceptable cmPolicies additions
+  #
+  message("=============================================================================")
+  message("This is a git checkout, using git grep to verify no unacceptable policies")
+  message("are being introduced....")
+  message("")
+
+  execute_process(COMMAND ${GIT_EXECUTABLE} grep -En "[0-9][0-9][0-9][0-9][0-9].*cmPolicies"
+    WORKING_DIRECTORY ${CMake_SOURCE_DIR}
+    OUTPUT_VARIABLE grep_output
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  message("=== output of 'git grep -En \"[0-9][0-9][0-9][0-9][0-9].*cmPolicies\"' ===")
+  message("${grep_output}")
+  message("=== end output ===")
+  message("")
+
+  if(NOT "${grep_output}" STREQUAL "")
+    message(FATAL_ERROR "git grep output is non-empty...
+New CMake policies must be introduced in a non-date-based version number.
+Send email to the cmake-developers list to figure out what the target
+version number for this policy should be...")
+  endif()
+endif()
+
+
+# Still here? Good then...
+#
+message("test passes")
+message("")