An enormous hack to try to get stdlib measurement from the very beginning of the process.

1 files changed, 41 insertions, 0 deletions

diff --git a/coverage/fullcoverage/encodings.py b/coverage/fullcoverage/encodings.py
new file mode 100644
index 00000000..48b2b2e0
--- /dev/null
+++ b/coverage/fullcoverage/encodings.py
@@ -0,0 +1,41 @@
+"""Imposter encodings module that installs a coverage-style tracer.
+
+This is NOT the encodings module; it is an imposter that sets up tracing
+instrumentation and then replaces itself with the real encodings module.
+
+If the directory that holds this file is placed first in the PYTHONPATH when
+using "coverage" to run Python's tests, then this file will become the very
+first module imported by the internals of Python 3.  It installs a
+coverage-compatible trace function that can watch Standard Library modules
+execute from the very earliest stages of Python's own boot process.  This fixes
+a problem with coverage - that it starts too late to trace the coverage of many
+of the most fundamental modules in the Standard Library.
+
+"""
+
+import sys
+
+class FullCoverageTracer(object):
+    def __init__(self):
+        self.traces = []
+
+    def fullcoverage_trace(self, *args):
+        frame, event, arg = args
+        #if "os.py" in frame.f_code.co_filename:
+        #    print("%s @ %d" % (frame.f_code.co_filename, frame.f_lineno))
+        self.traces.append(args)
+        return self.fullcoverage_trace
+
+sys.settrace(FullCoverageTracer().fullcoverage_trace)
+
+# Finally, remove our own directory from sys.path; remove ourselves from
+# sys.modules; and re-import "encodings", which will be the real package
+# this time.  Note that the delete from sys.modules dictionary has to
+# happen last, since all of the symbols in this module will become None
+# at that exact moment, including "sys".
+
+import os
+this = os.path.dirname(__file__)
+sys.path.remove(this)
+del sys.modules['encodings']
+import encodings