- fix bug in gdb support: script hook masks python hook?

src/libfibre/libfibre.so-gdb.py

@@ -6,21 +6,17 @@ import gdb
 from contextlib import contextmanager
 
 class FibreSupport():
-    def __init__(self):
-        FibreSupport.list = []
-        FibreSupport.active = {}
-        FibreSupport.saved = False
-
     def stop_handler(event):
         if (gdb.lookup_symbol("_globalStackList")[0] == None):
             print("WARNING: no fibre debugging support - did you enable TESTING_ENABLE_DEBUGGING?")
             return
+        FibreSupport.list = []
+        FibreSupport.active = {}
         # save register context for later continuation
         FibreSupport.rsp = str(gdb.parse_and_eval("$rsp")).split(None, 1)[0]
         FibreSupport.rbp = str(gdb.parse_and_eval("$rbp")).split(None, 1)[0]
         FibreSupport.rip = str(gdb.parse_and_eval("$rip")).split(None, 1)[0]
         FibreSupport.currStack = str(gdb.parse_and_eval("Context::currStack"))
-        FibreSupport.saved = True
         # traverse runtime stack list to build internal list of fibres
         _globalStackList = gdb.parse_and_eval("_globalStackList")
         first = _globalStackList['anchor'].address
@@ -41,21 +37,14 @@ class FibreSupport():
             }
         orig_thread.switch()
 
-    def cont_handler(event):
-        FibreSupport.list = []
-        FibreSupport.active = {}
-
-    # ideally restore() would be hooked up with cont_handler,
-    # but gdb currently fails with segmentation fault when trying
+    # restore() is hooked to continue events via basic script hooks
     def restore():
-        if (FibreSupport.saved):
-            FibreSupport.prep_frame()
-            # restore original register context
-            gdb.execute("set $rsp = " + str(FibreSupport.rsp))
-            gdb.execute("set $rbp = " + str(FibreSupport.rbp))
-            gdb.execute("set $rip = " + str(FibreSupport.rip))
-            gdb.execute("set Context::currStack = " + str(FibreSupport.currStack))
-            FibreSupport.saved = False
+        FibreSupport.prep_frame()
+        # restore original register context
+        gdb.execute("set $rsp = " + str(FibreSupport.rsp))
+        gdb.execute("set $rbp = " + str(FibreSupport.rbp))
+        gdb.execute("set $rip = " + str(FibreSupport.rip))
+        gdb.execute("set Context::currStack = " + str(FibreSupport.currStack))
 
     def prep_frame():
         # walk stack down to innermost frame
@@ -234,4 +223,3 @@ FibreSetPtr()
 FibreSetIdx()
 FibreReset()
 gdb.events.stop.connect(FibreSupport.stop_handler)
-gdb.events.cont.connect(FibreSupport.cont_handler)