Do better with exec/eval strings

rocky · rocky · commit 43254f03d3c1 · 2026-01-03T11:05:21.000-05:00
diff --git a/trepan/lib/stack.py b/trepan/lib/stack.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 
 #   Copyright (C) 2008-2010, 2013, 2015, 2017-2018, 2020-2021,
-#   2023-2025 Rocky Bernstein <rocky@gnu.org>
+#   2023-2026 Rocky Bernstein <rocky@gnu.org>
 #
 #   This program is free software: you can redistribute it and/or modify
 #   it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
 #
 #   You should have received a copy of the GNU General Public License
 #   along with this program.  If not, see <http://www.gnu.org/licenses/>.
-""" Functions for working with Python frames"""
+"""Functions for working with Python frames"""
 
 import dis
 import inspect
@@ -27,9 +27,7 @@
 from reprlib import repr
 from types import CodeType, FrameType
 from typing import Optional, Tuple
-
 import xdis
-from xdis import get_opcode
 from xdis.version_info import PYTHON_IMPLEMENTATION, PYTHON_VERSION_TRIPLE
 
 from trepan.lib.bytecode import op_at_frame
@@ -48,8 +46,11 @@
 try:
     from trepan.processor.cmdfns import deparse_fn
 except ImportError:
+
     def deparse_fn(code):
         raise NotImplementedError
+
+
 try:
     from trepan.lib.deparse import deparse_offset
 
@@ -63,6 +64,8 @@ def deparse_offset(_code, _name: str, _list_i: int, _) -> tuple:
 
 _with_local_varname = re.compile(r"_\[[0-9+]]")
 
+opc = xdis.get_opcode_module(PYTHON_VERSION_TRIPLE, PYTHON_IMPLEMENTATION)
+
 
 def count_frames(frame: FrameType, count_start=0) -> int:
     """Return a count of the number of frames"""
@@ -77,6 +80,7 @@ def count_frames(frame: FrameType, count_start=0) -> int:
         return 1000
     return count
 
+
 def get_column_start_from_frame(frame: FrameType) -> int:
     """
     Given a code frame, return the start column for that
@@ -85,6 +89,7 @@ def get_column_start_from_frame(frame: FrameType) -> int:
     """
     return get_column_start_from_code(frame.f_code, frame.f_lasti)
 
+
 def get_column_start_from_code(code: CodeType, f_lasti: int) -> int:
     """
     Given a code object, return the start column for that
@@ -100,6 +105,7 @@ def get_column_start_from_code(code: CodeType, f_lasti: int) -> int:
             return position_tuple[2]
     return -1
 
+
 _re_pseudo_file = re.compile(r"^<.+>")
 
 
@@ -147,12 +153,14 @@ def deparse_source_from_code(code):
     return source_text
 
 
-def format_function_name(frame: FrameType, style: str) -> Tuple[Optional[str], Optional[str]]:
+def format_function_name(
+    frame: FrameType, style: str
+) -> Tuple[Optional[str], Optional[str]]:
     """
     Pick out the function name from ``frame`` and return both the name
     and the name styled according to ``style``
     """
-    if (exec_type := is_eval_or_exec_stmt(frame)):
+    if exec_type := is_eval_or_exec_stmt(frame):
         funcname = get_call_function_name(frame)
         if funcname is None:
             funcname = exec_type
@@ -167,7 +175,9 @@ def format_function_name(frame: FrameType, style: str) -> Tuple[Optional[str], O
     return funcname, format_token(Function, funcname, style=style)
 
 
-def format_function_and_parameters(frame: FrameType, debugger, style: str) -> Tuple[bool, str]:
+def format_function_and_parameters(
+    frame: FrameType, debugger, style: str
+) -> Tuple[bool, str]:
     """ """
 
     funcname, s = format_function_name(frame, style)
@@ -248,12 +258,12 @@ def format_return_and_location(
         elif s == "?()":
             if is_eval_or_exec_stmt(frame):
                 s = "in exec"
-                # exec_str = get_exec_string(frame.f_back)
-                # if exec_str != None:
-                #     filename = exec_str
-                #     add_quotes_around_file = False
-                #     pass
-                # pass
+                exec_str = get_exec_string(frame.f_back)
+                if exec_str is not None:
+                    filename = exec_str
+                    add_quotes_around_file = False
+                    pass
+                pass
             elif not is_pseudo_file:
                 s = "in file"
                 pass
@@ -336,6 +346,25 @@ def frame2filesize(frame):
         return None, None
 
 
+def get_exec_string(frame: FrameType) -> Optional[str]:
+    if (call_frame := frame.f_back) is not None:
+        offset = call_frame.f_lasti - 2
+        code = call_frame.f_code
+        while offset > 0:
+            inst = list(xdis.bytecode.get_logical_instruction_at_offset(
+                    code.co_code, offset, opc, constants=code.co_consts
+                ))[0]
+            if inst.opname in ("PRECALL", "CACHE"):
+                pass
+            elif inst.opname == "LOAD_CONST":
+                return inst.argval
+            else:
+                break
+            offset -= 2
+
+    return None
+
+
 def check_path_with_frame(frame, path):
     my_size = os.stat(path).st_size
     fs_size, bc_size = frame2filesize(frame)
@@ -365,9 +394,6 @@ def is_eval_or_exec_stmt(frame) -> Optional[str]:
     return None
 
 
-opc = get_opcode(PYTHON_VERSION_TRIPLE, PYTHON_IMPLEMENTATION)
-
-
 def get_call_function_name(frame) -> Optional[str]:
     """If f_back is looking at a call function, return
     the name for it. Otherwise, return None"""
@@ -575,6 +601,7 @@ def __init__(self):
     # print(pyc_file, getsourcefile(pyc_file))
 
     from trepan.debugger import Trepan
+
     m = MockDebugger()
 
     # For testing print_stack_entry()
@@ -597,6 +624,7 @@ def __init__(self):
         )
     )
     import sys
+
     sys.exit(0)
     # print("frame count: %d" % count_frames(frame))
     # print("frame count: %d" % count_frames(frame.f_back))
@@ -613,7 +641,11 @@ def fn(x):
         eval_str = is_eval_or_exec_stmt(frame.f_back)
         if eval_str:
             print(f"Caller is {eval_str} stmt")
-            print(format_stack_entry(dd, (frame.f_back, frame.f_back.f_code.co_firstlineno)))
+            print(
+                format_stack_entry(
+                    dd, (frame.f_back, frame.f_back.f_code.co_firstlineno)
+                )
+            )
 
         _, mess = format_function_and_parameters(frame, dd, style="tango")
         print(mess)
diff --git a/trepan/processor/print.py b/trepan/processor/print.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-#   Copyright (C) 2024-2025 Rocky Bernstein <rocky@gnu.org>
+#   Copyright (C) 2024-2026 Rocky Bernstein <rocky@gnu.org>
 #
 #   This program is free software: you can redistribute it and/or modify
 #   it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@
 import pyficache
 
 from trepan.lib.format import Filename, Hex, LineNumber, Symbol, format_token  # Opcode,
-from trepan.lib.stack import check_path_with_frame, frame2file, is_eval_or_exec_stmt
+from trepan.lib.stack import check_path_with_frame, frame2file, get_exec_string, is_eval_or_exec_stmt
 from trepan.processor import cmdfns
 from trepan.processor.cmdfns import deparse_fn
 
@@ -140,8 +140,10 @@ def prefix_for_filename(deparsed_text: str) -> str:
         lines = deparsed_text.split("\n")
         # FIXME Rather than blindly take the first line,
         # check if it is blank and if so use other lines.
-        first_text_line = lines[0]
-        return proc_obj._saferepr(first_text_line)[1:-1][:10]
+        for line in lines:
+            if line:
+                return proc_obj._saferepr(line.strip())[1:-1][:10]
+        return "..."
 
     i_stack = proc_obj.curindex
     if i_stack is None or proc_obj.stack is None:
@@ -217,8 +219,12 @@ def prefix_for_filename(deparsed_text: str) -> str:
                 # else:
                 #   print("Can't deparse", frame.f_code)
                 if source_text is None and eval_kind:
-                    source_text = f"{eval_kind}(...)"
-                    pass
+                     if (source_text := get_exec_string(frame)):
+                         filename = "string-" + prefix_for_filename(source_text) + "-"
+                     else:
+                         source_text = f"{eval_kind}(...)"
+                         pass
+                     pass
                 pass
             pass
         else:
@@ -283,7 +289,7 @@ def prefix_for_filename(deparsed_text: str) -> str:
                 # FIXME:
                 if source_text:
                     lines = source_text.split("\n")
-                    temp_name = "string-" + prefix_for_filename(source_text)
+                    temp_name = "string-" + prefix_for_filename(source_text) + "-"
                 else:
                     # try with good ol linecache and consider fixing pyficache
                     lines = linecache.getlines(filename)
@@ -298,7 +304,7 @@ def prefix_for_filename(deparsed_text: str) -> str:
                         dir=proc_obj.settings("tempdir"),
                     )
                     with fd:
-                        fd.write("".join(lines).encode("utf-8"))
+                        fd.write("\n".join(lines).encode("utf-8"))
                         remapped_file = fd.name
                         pyficache.remap_file(remapped_file, filename)
                     fd.close()
@@ -397,8 +403,15 @@ def five():
         cmdproc.event = "line"
         cmdproc.setup()
         print_location(cmdproc)
+
         cmdproc.curindex = 1
         cmdproc.curframe = cmdproc.stack[cmdproc.curindex][0]
         print_location(cmdproc)
 
+        exec("""
+cmdproc.frame = currentframe()
+cmdproc.setup()
+print_location(cmdproc)
+""")
+
     exec("five()")
