Fix bugs in is_def_stmt and nextlineno

With wordcode will use offset+2 to advance to the next opcode

Author: rocky

test/data/step-311.right

@@ -16,7 +16,8 @@ line - gcd.py:11
 Set stopping is off.
 line - gcd.py:13
 line - gcd.py:26
-(gcd.py:26): <module>
--- 26 def gcd(a,b):
- 26  ->	def gcd(a,b):
+line - gcd.py:40
+(gcd.py:40): <module>
+-- 40 if __name__=='__main__':
+ 40  ->	if __name__=='__main__':
 trepan3k: That's all, folks...

test/functional/example/skip.py

@@ -0,0 +1,23 @@
+# This code fragment what is embedded inside ../test_skippy
+# We have it here to make it easy to test things when things go wrong.
+
+
+# commands are:
+#   step
+#   skip
+#   continue
+##############################
+x = 3
+x = 4
+y = 5
+y = 7  # NOQA
+##############################
+# commands are:
+#   step
+#   skip 2
+#   continue
+x = 7
+x = 8
+x = 9
+y = 10  # NOQA
+##############################

test/functional/test_skip.py

@@ -17,33 +17,41 @@
 
 def test_skip():
     # See that we can skip without parameter. (Same as 'skip 1'.)
-    cmds = ["skip", "continue"]
+    cmds = ["step", "skip", "continue"]
     d = strarray_setup(cmds)
     d.core.start()
     ##############################
+    x = 3
     x = 4
-    x = 5
+    y = 5
     y = 7  # NOQA
     ##############################
     d.core.stop()
-    out = ["-- x = 4", "-- x = 5"]  # x = 4 is shown in prompt, but not *run*.
+    # x = 4 is shown in prompt, but not *run*.
+    out = [
+        "-- x = 3",
+        "-- x = 4",
+        "-- y = 5"
+    ]
     compare_output(out, d)
-    assert x == 5, "should have skipped lines"
+    assert x == 3, "should have skipped x=4"
 
     # See that we can skip with a count value
-    cmds = ["skip 2", "continue"]
+    cmds = ["step", "skip 2", "continue"]
     d = strarray_setup(cmds)
     d.core.start()
     ##############################
-    x = 10
+    x = 7
+    x = 8
     x = 9
-    z = 7  # NOQA
+    y = 10  # NOQA
     ##############################
     d.core.stop(options={"remove": True})
     out = [
-        "-- x = 10",
-        "-- z = 7  # NOQA",
-    ]  # x = 10 is shown in prompt, but not run.
+        "-- x = 7",
+        "-- x = 8",
+        "-- y = 10  # NOQA",
+    ]  # x = 8 is shown in prompt, but not run.
     compare_output(out, d)
-    assert x == 5, "x = 10 should have been skipped"
+    assert x == 7, "x = 8..9 should have been skipped"
     return

trepan/lib/bytecode.py

@@ -19,7 +19,7 @@
 
 import re
 
-from opcode import HAVE_ARGUMENT, opname
+from opcode import opname
 from typing import Optional
 from xdis import PYTHON_VERSION_TRIPLE, get_opcode_module
 
@@ -50,10 +50,8 @@ def next_opcode(code, offset):
     n = len(code)
     while offset < n:
         op = code[offset]
-        offset += 1
-        if op >= HAVE_ARGUMENT:
-            offset += 2
-            pass
+        yield op, offset
+        offset = offset + 2
         yield op, offset
         pass
     yield -100, -1000
@@ -64,37 +62,40 @@ def next_linestart(co, offset: int, count=1) -> int:
     code = co.co_code
 
     linestarts = dict(opcode_module.findlinestarts(co))
-    # n = len(code)
+    n = len(code)
     # contains_cond_jump = False
-    for op, offset in next_opcode(code, offset):
+    while offset < len(code):
         if offset in linestarts:
             count -= 1
             if 0 == count:
                 return linestarts[offset]
             pass
-        pass
+        offset += 2
 
     return -1000
 
 
-def stmt_contains_opcode(co, lineno, query_opcode) -> bool:
+def stmt_contains_opcode(co, lineno, query_opname) -> bool:
     linestarts = dict(opcode_module.findlinestarts(co))
     code = co.co_code
     found_start = False
     offset = 0
+    start_line = None
     for offset, start_line in list(linestarts.items()):
         if start_line == lineno:
+            print("=" * 30)
             found_start = True
             break
         pass
     if not found_start:
         return False
     for op, offset in next_opcode(code, offset):
-        if -1000 == offset or linestarts.get(offset):
+        linestart = linestarts.get(offset)
+        if -1000 == offset or linestart and linestart != start_line:
             return False
-        opcode = opname[op]
-        # debug: print opcode
-        if query_opcode == opcode:
+        op_name = opname[op]
+        # debug: print opname
+        if query_opname == op_name:
             return True
         pass
     return False
@@ -104,7 +105,7 @@ def stmt_contains_opcode(co, lineno, query_opcode) -> bool:
 _re_def = re.compile(_re_def_str)
 
 
-def is_def_stmt(line, frame):
+def is_def_stmt(line: Optional[str], frame) -> bool:
     """Return True if we are looking at a def statement"""
     # Should really also check that operand of 'LOAD_CONST' is a code object
     return (

trepan/processor/command/skip.py

@@ -46,7 +46,7 @@ def run(self, args):
             return False
 
         if self.proc.curframe.f_trace is None:
-            self.errmsg("Sigh - operation can't be done here.")
+            self.errmsg("Sigh - operation can't be done here. Frame tracing is not recorded")
             return False
 
         if len(args) == 1:
@@ -59,7 +59,7 @@ def run(self, args):
         offset = self.proc.curframe.f_lasti
         if count is None:
             return False
-        lineno = next_linestart(co, offset, count)
+        lineno = next_linestart(co, offset+2, count)
 
         if lineno < 0:
             self.errmsg("No next line found")