More options for CTestCoverageCollectGCOV

This commit introduces two new options to CTestCoverageCollectGCOV.

When GLOB is set we recursively search in the source & binary
directories for .gcda files.  Otherwise the default behavior is to
parse TargetDirectories.txt for a list of locations to search.

When DELETE is set we remove any .gcda file found after it has
been used to generate the corresponding .gcov file.  The .gcov
file is also removed after the result tarball has been created.

Together these two new features help support the use case of
computing coverage across subprojects.

Modules/CTestCoverageCollectGCOV.cmake

@@ -46,6 +46,13 @@
 #     is run as ``gcov <options>... -o <gcov-dir> <file>.gcda``.
 #     If not specified, the default option is just ``-b``.
 #
+#   ``GLOB``
+#     Recursively search for .gcda files in build_dir rather than
+#     determining search locations by reading TargetDirectories.txt.
+#
+#   ``DELETE``
+#     Delete coverage files after they've been packaged into the .tar.
+#
 #   ``QUIET``
 #     Suppress non-error messages that otherwise would have been
 #     printed out by this function.
@@ -64,7 +71,7 @@
 #  License text for the above reference.)
 include(CMakeParseArguments)
 function(ctest_coverage_collect_gcov)
-  set(options QUIET)
+  set(options QUIET GLOB DELETE)
   set(oneValueArgs TARBALL SOURCE BUILD GCOV_COMMAND)
   set(multiValueArgs GCOV_OPTIONS)
   cmake_parse_arguments(GCOV  "${options}" "${oneValueArgs}"
@@ -91,22 +98,32 @@ function(ctest_coverage_collect_gcov)
   # run gcov on each gcda file in the binary tree
   set(gcda_files)
   set(label_files)
-  # look for gcda files in the target directories
-  # could do a glob from the top of the binary tree but
-  # this will be faster and only look where the files will be
-  file(STRINGS "${binary_dir}/CMakeFiles/TargetDirectories.txt" target_dirs
-       ENCODING UTF-8)
-  foreach(target_dir ${target_dirs})
-    file(GLOB_RECURSE gfiles RELATIVE ${binary_dir} "${target_dir}/*.gcda")
-    list(LENGTH gfiles len)
-    # if we have gcda files then also grab the labels file for that target
-    if(${len} GREATER 0)
-      file(GLOB_RECURSE lfiles RELATIVE ${binary_dir}
-        "${target_dir}/Labels.json")
-      list(APPEND gcda_files ${gfiles})
-      list(APPEND label_files ${lfiles})
-    endif()
-  endforeach()
+  if (GCOV_GLOB)
+      file(GLOB_RECURSE gfiles RELATIVE ${binary_dir} "*.gcda")
+      list(LENGTH gfiles len)
+      # if we have gcda files then also grab the labels file for that target
+      if(${len} GREATER 0)
+        file(GLOB_RECURSE lfiles RELATIVE ${binary_dir} "Labels.json")
+        list(APPEND gcda_files ${gfiles})
+        list(APPEND label_files ${lfiles})
+      endif()
+  else()
+    # look for gcda files in the target directories
+    # this will be faster and only look where the files will be
+    file(STRINGS "${binary_dir}/CMakeFiles/TargetDirectories.txt" target_dirs
+         ENCODING UTF-8)
+    foreach(target_dir ${target_dirs})
+      file(GLOB_RECURSE gfiles RELATIVE ${binary_dir} "${target_dir}/*.gcda")
+      list(LENGTH gfiles len)
+      # if we have gcda files then also grab the labels file for that target
+      if(${len} GREATER 0)
+        file(GLOB_RECURSE lfiles RELATIVE ${binary_dir}
+          "${target_dir}/Labels.json")
+        list(APPEND gcda_files ${gfiles})
+        list(APPEND label_files ${lfiles})
+      endif()
+    endforeach()
+  endif()
   # return early if no coverage files were found
   list(LENGTH gcda_files len)
   if(len EQUAL 0)
@@ -134,6 +151,11 @@ function(ctest_coverage_collect_gcov)
       OUTPUT_VARIABLE out
       RESULT_VARIABLE res
       WORKING_DIRECTORY ${coverage_dir})
+
+    if (GCOV_DELETE)
+      file(REMOVE ${gcda_file})
+    endif()
+
   endforeach()
   if(NOT "${res}" EQUAL 0)
     if (NOT GCOV_QUIET)
@@ -201,4 +223,12 @@ ${label_files}
     "--format=gnutar"
     --files-from=${coverage_dir}/coverage_file_list.txt
     WORKING_DIRECTORY ${binary_dir})
+
+  if (GCOV_DELETE)
+    string(REPLACE "\n" ";" gcov_files "${gcov_files}")
+    foreach(gcov_file ${gcov_files})
+      file(REMOVE ${binary_dir}/${gcov_file})
+    endforeach()
+  endif()
+
 endfunction()