Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -430,6 +430,18 @@
   set(LLVM_ADD_NATIVE_VISUALIZERS_TO_SOLUTION FALSE CACHE INTERNAL "For Visual Studio 2013, manually copy natvis files to Documents\\Visual Studio 2013\\Visualizers" FORCE)
 endif()
 
+if (LLVM_BUILD_INSTRUMENTED OR LLVM_BUILD_INSTRUMENTED_COVERAGE)
+  if(NOT LLVM_PROFILE_DATA_DIR)
+    message(FATAL_ERROR "Must set LLVM_PROFILE_DATA_DIR to point to a directory")
+  endif()
+  if(NOT LLVM_PROFILE_MERGE_POOL_SIZE)
+    set(LLVM_PROFILE_MERGE_POOL_SIZE "9")
+  endif()
+  if(NOT LLVM_PROFILE_FILE_PATTERN)
+    file(TO_NATIVE_PATH "${LLVM_PROFILE_DATA_DIR}/%${LLVM_PROFILE_MERGE_POOL_SIZE}m.profraw" LLVM_PROFILE_FILE_PATTERN)
+  endif()
+endif()
+
 # All options referred to from HandleLLVMOptions have to be specified
 # BEFORE this include, otherwise options will not be correctly set on
 # first cmake run
Index: cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- cmake/modules/HandleLLVMOptions.cmake
+++ cmake/modules/HandleLLVMOptions.cmake
@@ -598,7 +598,15 @@
 
 option(LLVM_BUILD_INSTRUMENTED "Build LLVM and tools with PGO instrumentation (experimental)" Off)
 mark_as_advanced(LLVM_BUILD_INSTRUMENTED)
-append_if(LLVM_BUILD_INSTRUMENTED "-fprofile-instr-generate"
+append_if(LLVM_BUILD_INSTRUMENTED "-fprofile-instr-generate=${LLVM_PROFILE_FILE_PATTERN}"
+  CMAKE_CXX_FLAGS
+  CMAKE_C_FLAGS
+  CMAKE_EXE_LINKER_FLAGS
+  CMAKE_SHARED_LINKER_FLAGS)
+
+option(LLVM_BUILD_INSTRUMENTED_COVERAGE "Build LLVM and tools with Code Coverage instrumentation (experimental)" Off)
+mark_as_advanced(LLVM_BUILD_INSTRUMENTED_COVERAGE)
+append_if(LLVM_BUILD_INSTRUMENTED_COVERAGE "-fprofile-instr-generate=${LLVM_PROFILE_FILE_PATTERN} -fcoverage-mapping"
   CMAKE_CXX_FLAGS
   CMAKE_C_FLAGS
   CMAKE_EXE_LINKER_FLAGS
Index: utils/prepare-code-coverage-artifact.sh
===================================================================
--- /dev/null
+++ utils/prepare-code-coverage-artifact.sh
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+if [ "$#" -ne 4 ]; then
+	echo "Usage:"
+	echo "$0 <HOST_LLVM_PROFDATA> <HOST_LLVM_COV> <LLVM_PROFILE_DATA_DIR> <LLVM_BIN_DIR>"
+	exit 1
+fi
+
+HOST_LLVM_PROFDATA=$1
+HOST_LLVM_COV=$2
+LLVM_PROFILE_DATA_DIR=$3
+LLVM_BIN_DIR=$4
+
+echo ":: llvm-profdata = " $HOST_LLVM_PROFDATA
+echo ":: llvm-cov = " $HOST_LLVM_COV
+
+echo ":: Merging raw profiles in $LLVM_PROFILE_DATA_DIR"
+find $LLVM_PROFILE_DATA_DIR -name \*.profraw > $LLVM_PROFILE_DATA_DIR/profiles.list
+$HOST_LLVM_PROFDATA merge -sparse -f $LLVM_PROFILE_DATA_DIR/profiles.list -o $LLVM_PROFILE_DATA_DIR/Coverage.profdata
+
+echo ":: Deleting raw profiles in $LLVM_PROFILE_DATA_DIR"
+find $LLVM_PROFILE_DATA_DIR -name \*.profraw -exec rm {} \;
+
+echo ":: Copying covmappings from $LLVM_BIN_DIR into $LLVM_PROFILE_DATA_DIR"
+for prog in $(find $LLVM_BIN_DIR -type f | grep -v llvm-lit); do
+	$HOST_LLVM_COV convert-for-testing $prog -o $LLVM_PROFILE_DATA_DIR/$(basename $prog).covmapping
+done