Merge pull request #1775 from harlanhaskins/profdata-sparse

[build_support] Added -sparse option for llvm-profdata if supported

Author: Harlan

utils/profdata_merge/process.py

@@ -14,11 +14,25 @@
 import logging
 import os
 import pipes
-import subprocess
+import sys
 
 from multiprocessing import Process
 
 
+# hack to import SwiftBuildSupport and swift_build_support
+parent_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..')
+sys.path.append(parent_dir)
+support_dir = os.path.join(parent_dir, 'swift_build_support')
+sys.path.append(support_dir)
+from swift_build_support import xcrun  # noqa (E402)
+from SwiftBuildSupport import check_output, check_call  # noqa (E402)
+
+# FIXME: This doesn't work on non-Darwin platforms.
+LLVM_PROFDATA_PATH = xcrun.find('default', 'llvm-profdata')
+_profdata_help = check_output([LLVM_PROFDATA_PATH, 'merge', '-help'])
+LLVM_PROFDATA_SUPPORTS_SPARSE = 'sparse' in _profdata_help
+
+
 class ProfdataMergerProcess(Process):
     def __init__(self, config, file_queue):
         super(ProfdataMergerProcess, self).__init__()
@@ -45,13 +59,13 @@ def merge_file_buffer(self):
         if os.path.exists(self.profdata_path):
             os.rename(self.profdata_path, self.profdata_tmp_path)
             self.filename_buffer.append(self.profdata_tmp_path)
-        cleaned_files = ' '.join(pipes.quote(f) for f in self.filename_buffer)
-        # FIXME: This doesn't necessarily always line up with the version
-        #        of clang++ used to build the binaries.
-        llvm_cmd = ("xcrun llvm-profdata merge -o %s %s"
-                    % (self.profdata_path, cleaned_files))
+        cleaned_files = [pipes.quote(f) for f in self.filename_buffer]
+        llvm_cmd = [LLVM_PROFDATA_PATH, "merge", "-o", self.profdata_path]
+        if LLVM_PROFDATA_SUPPORTS_SPARSE:
+            llvm_cmd.append("-sparse")
+        llvm_cmd += cleaned_files
         self.report(llvm_cmd)
-        ret = subprocess.call(llvm_cmd, shell=True)
+        ret = check_call(llvm_cmd)
         if ret != 0:
             self.report("llvm profdata command failed -- Exited with code %d"
                         % ret, level=logging.ERROR)