[matter] add exception handler that also prints local variables in the stack

matter/matter/main.py

@@ -22,6 +22,27 @@ from matter.lock import MatterResourceLock
 from matter.output import purple, darkgreen, print_info, \
     print_warning, print_error, is_stdout_a_tty, nocolor
 from matter.spec import SpecParser, MatterSpec
+from matter.utils import print_exception
+
+
+def install_exception_handler():
+    sys.excepthook = handle_exception
+
+
+def uninstall_exception_handler():
+    sys.excepthook = sys.__excepthook__
+
+
+def handle_exception(exc_class, exc_instance, exc_tb):
+
+    # restore original exception handler, to avoid loops
+    uninstall_exception_handler()
+
+    if exc_class is KeyboardInterrupt:
+        raise SystemExit(1)
+
+    # always slap exception data (including stack content)
+    print_exception(tb_data = exc_tb)
 
 
 def matter_main(binary_pms, nsargs, cwd, specs):
@@ -172,6 +193,7 @@ def main():
     """
     Main App.
     """
+    install_exception_handler()
 
     # disable color if standard output is not a TTY
     if not is_stdout_a_tty():

matter/matter/utils.py

@@ -15,6 +15,8 @@ import sys
 import tempfile
 import traceback
 
+from matter.output import print_generic
+
 
 MATTER_TMPDIR = os.getenv("MATTER_TMPDIR", "/var/tmp/matter")
 _ENCODING = "UTF-8"
@@ -31,6 +33,66 @@ def print_traceback(f = None):
     traceback.print_exc(file = f)
 
 
+def print_exception(silent=False, tb_data=None, all_frame_data=False):
+    """
+    Print last Python exception and frame variables values (if available)
+    to stdout.
+
+    @keyword silent: do not print to stdout
+    @type silent: bool
+    @keyword tb_data: Python traceback object
+    @type tb_data: Python traceback instance
+    @keyword all_frame_data: print all variables in every frame
+    @type all_frame_data: bool
+    @return: exception data
+    @rtype: list of strings
+    """
+    if not silent:
+        traceback.print_last()
+    data = []
+    if tb_data is not None:
+        tb = tb_data
+    else:
+        last_type, last_value, last_traceback = sys.exc_info()
+        tb = last_traceback
+
+    stack = []
+    while True:
+        if not tb:
+            break
+        if not tb.tb_next:
+            break
+        tb = tb.tb_next
+        if all_frame_data:
+            stack.append(tb.tb_frame)
+
+    if not all_frame_data:
+        stack.append(tb.tb_frame)
+
+    #if not returndata: print
+    for frame in stack:
+        if not silent:
+            print_generic("")
+            print_generic("Frame %s in %s at line %s" % (frame.f_code.co_name,
+                frame.f_code.co_filename, frame.f_lineno))
+        data.append("Frame %s in %s at line %s\n" % (frame.f_code.co_name,
+            frame.f_code.co_filename, frame.f_lineno))
+
+        for key, value in list(frame.f_locals.items()):
+            cur_str = ''
+            cur_str = "\t%20s = " % key
+            try:
+                cur_str += repr(value) + "\n"
+            except (AttributeError, NameError, TypeError):
+                cur_str += "<ERROR WHILE PRINTING VALUE>\n"
+
+            if not silent:
+                sys.stdout.write(cur_str)
+            data.append(cur_str)
+
+    return data
+
+
 def mkstemp(prefix=None, suffix=None):
     """
     Create temporary file into matter temporary directory.