Fixed ccov-all targets on Windows

When running ccov-run-* targets in parrallel on
Windows, multiple processes would attempt to write to the profile data
files, causing contention and failure. This job has been split in two
and the call to write to file has been serialized through a specified
job pool 'ccov_serial_pool'.

For the ccov-all targets, added a Windows-specific set that utilizes
Powershell commands to work.

code-coverage.cmake

@@ -89,6 +89,7 @@ mark_as_advanced(FORCE LLVM_COV_PATH LLVM_PROFDATA_PATH LCOV_PATH GENHTML_PATH)
 
 # Variables
 set(CMAKE_COVERAGE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/ccov)
+set_property(GLOBAL PROPERTY JOB_POOLS ccov_serial_pool=1)
 
 # Common initialization/checks
 if(CODE_COVERAGE AND NOT CODE_COVERAGE_ADDED)
@@ -297,6 +298,16 @@ function(target_code_coverage TARGET_NAME)
         endforeach()
 
         # Run the executable, generating raw profile data
+        add_custom_target(
+          ccov-run-${target_code_coverage_COVERAGE_TARGET_NAME}-1
+          COMMAND
+            ${CMAKE_COMMAND} -E env
+            LLVM_PROFILE_FILE=${target_code_coverage_COVERAGE_TARGET_NAME}.profraw
+            $<TARGET_FILE:${TARGET_NAME}> ${target_code_coverage_ARGS}
+          DEPENDS ccov-preprocessing ccov-libs ${TARGET_NAME})
+
+        # Make the run data available for further processing. Separated to allow
+        # Windows to run this target serially.
         add_custom_target(
           ccov-run-${target_code_coverage_COVERAGE_TARGET_NAME}
           COMMAND
@@ -308,9 +319,10 @@ function(target_code_coverage TARGET_NAME)
             ${SO_OBJECTS} >> ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/binaries.list
           COMMAND
             ${CMAKE_COMMAND} -E echo
-            "${CMAKE_CURRENT_BINARY_DIR}/${target_code_coverage_COVERAGE_TARGET_NAME}.profraw "
+            "${CMAKE_CURRENT_BINARY_DIR}/${target_code_coverage_COVERAGE_TARGET_NAME}.profraw"
             >> ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/profraw.list
-          DEPENDS ccov-preprocessing ccov-libs ${TARGET_NAME})
+          JOB_POOL ccov_serial_pool
+          DEPENDS ccov-run-${target_code_coverage_COVERAGE_TARGET_NAME}-1)
 
         # Merge the generated profile data so llvm-cov can process it
         add_custom_target(
@@ -500,42 +512,44 @@ function(add_code_coverage_all_targets)
     if(CMAKE_C_COMPILER_ID MATCHES "(Apple)?[Cc]lang"
        OR CMAKE_CXX_COMPILER_ID MATCHES "(Apple)?[Cc]lang")
 
+      # Merge the profile data for all of the run executables
       if(WIN32)
         add_custom_target(
           ccov-all-processing
-          COMMENT
-            "The ccov-all-processing target is a stub on Windows, individual ccov targets still work"
-        )
-
-        add_custom_target(
-          ccov-all-report
-          COMMENT
-            "The ccov-all-report target is a stub on Windows, individual ccov targets still work"
-          DEPENDS ccov-all-processing)
-
-        add_custom_target(
-          ccov-all
-          COMMENT
-            "The ccov-all target is a stub on Windows, individual ccov targets still work"
-          DEPENDS ccov-all-processing)
+          COMMAND
+            powershell -Command $$FILELIST = Get-Content
+            ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/profraw.list\; llvm-profdata.exe
+            merge -o ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata
+            -sparse $$FILELIST)
       else()
-        # Merge the profile data for all of the run executables
         add_custom_target(
           ccov-all-processing
           COMMAND
             ${LLVM_PROFDATA_PATH} merge -o
             ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata -sparse `cat
             ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/profraw.list`)
+      endif()
 
-        # Regex exclude only available for LLVM >= 7
-        if(LLVM_COV_VERSION VERSION_GREATER_EQUAL "7.0.0")
-          foreach(EXCLUDE_ITEM ${add_code_coverage_all_targets_EXCLUDE})
-            set(EXCLUDE_REGEX ${EXCLUDE_REGEX}
-                              -ignore-filename-regex='${EXCLUDE_ITEM}')
-          endforeach()
-        endif()
+      # Regex exclude only available for LLVM >= 7
+      if(LLVM_COV_VERSION VERSION_GREATER_EQUAL "7.0.0")
+        foreach(EXCLUDE_ITEM ${add_code_coverage_all_targets_EXCLUDE})
+          set(EXCLUDE_REGEX ${EXCLUDE_REGEX}
+                            -ignore-filename-regex='${EXCLUDE_ITEM}')
+        endforeach()
+      endif()
 
-        # Print summary of the code coverage information to the command line
+      # Print summary of the code coverage information to the command line
+      if(WIN32)
+        add_custom_target(
+          ccov-all-report
+          COMMAND
+            powershell -Command $$FILELIST = Get-Content
+            ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/binaries.list\; llvm-cov.exe
+            report $$FILELIST
+            -instr-profile=${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata
+            ${EXCLUDE_REGEX}
+          DEPENDS ccov-all-processing)
+      else()
         add_custom_target(
           ccov-all-report
           COMMAND
@@ -544,20 +558,34 @@ function(add_code_coverage_all_targets)
             -instr-profile=${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata
             ${EXCLUDE_REGEX}
           DEPENDS ccov-all-processing)
+      endif()
 
-        # Export coverage information so continuous integration tools (e.g.
-        # Jenkins) can consume it
+      # Export coverage information so continuous integration tools (e.g.
+      # Jenkins) can consume it
+      add_custom_target(
+        ccov-all-export
+        COMMAND
+          ${LLVM_COV_PATH} export `cat
+          ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/binaries.list`
+          -instr-profile=${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata
+          -format="text" ${EXCLUDE_REGEX} >
+          ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/coverage.json
+        DEPENDS ccov-all-processing)
+
+      # Generate HTML output of all added targets for perusal
+      if(WIN32)
         add_custom_target(
-          ccov-all-export
+          ccov-all
           COMMAND
-            ${LLVM_COV_PATH} export `cat
-            ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/binaries.list`
+            powershell -Command $$FILELIST = Get-Content
+            ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/binaries.list\; llvm-cov.exe show
+            $$FILELIST
             -instr-profile=${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged.profdata
-            -format="text" ${EXCLUDE_REGEX} >
-            ${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/coverage.json
+            -show-line-counts-or-regions
+            -output-dir=${CMAKE_COVERAGE_OUTPUT_DIRECTORY}/all-merged
+            -format="html" ${EXCLUDE_REGEX}
           DEPENDS ccov-all-processing)
-
-        # Generate HTML output of all added targets for perusal
+      else()
         add_custom_target(
           ccov-all
           COMMAND