[sanitizer] Support sandboxing in sanitizer coverage.

Summary:
Sandboxed code may now pass additional arguments to
__sanitizer_sandbox_on_notify() to force all coverage data to be dumped to a
single file (the default is one file per module). The user may supply a file or
socket to write to. The latter option can be used to broker out the file writing
functionality. If -1  is passed, we pre-open a file.

llvm-svn: 209121

1 files changed, 40 insertions, 7 deletions

diff --git a/compiler-rt/lib/sanitizer_common/scripts/sancov.py b/compiler-rt/lib/sanitizer_common/scripts/sancov.py
index aa791bc4eb0..4354359b039 100755
--- a/compiler-rt/lib/sanitizer_common/scripts/sancov.py
+++ b/compiler-rt/lib/sanitizer_common/scripts/sancov.py
@@ -4,6 +4,7 @@
 # We need to merge these integers into a set and then
 # either print them (as hex) or dump them into another file.
 import array
+import struct
 import sys
 
 prog_name = "";
@@ -11,16 +12,16 @@ prog_name = "";
 def Usage():
   print >> sys.stderr, "Usage: \n" + \
       " " + prog_name + " merge file1 [file2 ...]  > output\n" \
-      " " + prog_name + " print file1 [file2 ...]\n"
+      " " + prog_name + " print file1 [file2 ...]\n" \
+      " " + prog_name + " unpack file1 [file2 ...]\n"
   exit(1)
 
 def ReadOneFile(path):
-  f = open(path, mode="rb")
-  f.seek(0, 2)
-  size = f.tell()
-  f.seek(0, 0)
-  s = set(array.array('I', f.read(size)))
-  f.close()
+  with open(path, mode="rb") as f:
+    f.seek(0, 2)
+    size = f.tell()
+    f.seek(0, 0)
+    s = set(array.array('I', f.read(size)))
   print >>sys.stderr, "%s: read %d PCs from %s" % (prog_name, size / 4, path)
   return s
 
@@ -44,6 +45,36 @@ def MergeAndPrint(files):
   a = array.array('I', s)
   a.tofile(sys.stdout)
 
+
+def UnpackOneFile(path):
+  with open(path, mode="rb") as f:
+    print >> sys.stderr, "%s: unpacking %s" % (prog_name, path)
+    while True:
+      header = f.read(12)
+      if not header: return
+      if len(header) < 12:
+        break
+      pid, module_length, blob_size = struct.unpack('iII', header)
+      module = f.read(module_length)
+      blob = f.read(blob_size)
+      assert(len(module) == module_length)
+      assert(len(blob) == blob_size)
+      extracted_file = "%s.%d.sancov" % (module, pid)
+      print >> sys.stderr, "%s: extracting %s" % \
+        (prog_name, extracted_file)
+      # The packed file may contain multiple blobs for the same pid/module
+      # pair. Append to the end of the file instead of overwriting.
+      with open(extracted_file, 'ab') as f2:
+        f2.write(blob)
+    # fail
+    raise Exception('Error reading file %s' % path)
+
+
+def Unpack(files):
+  for f in files:
+    UnpackOneFile(f)
+
+
 if __name__ == '__main__':
   prog_name = sys.argv[0]
   if len(sys.argv) <= 2:
@@ -52,5 +83,7 @@ if __name__ == '__main__':
     PrintFiles(sys.argv[2:])
   elif sys.argv[1] == "merge":
     MergeAndPrint(sys.argv[2:])
+  elif sys.argv[1] == "unpack":
+    Unpack(sys.argv[2:])
   else:
     Usage()