gh-119786: remove part of devguide documentation which is duplicated …

…in InternalDocs (#1334)

internals/interpreter.rst

@@ -178,38 +178,15 @@ Then the interpreter function (``_PyEval_EvalFrameDefault()``) returns ``NULL``.
 
 However, if an exception is raised in a ``try`` block, the interpreter must jump to the corresponding ``except`` or ``finally`` block.
 In 3.10 and before, there was a separate "block stack" which was used to keep track of nesting ``try`` blocks.
-In 3.11, this mechanism has been replaced by a statically generated table, ``code->co_exceptiontable``.
-The advantage of this approach is that entering and leaving a ``try`` block normally does not execute any code, making execution faster.
-But of course, this table needs to be generated by the compiler, and decoded (by ``get_exception_handler``) when an exception happens.
-
-Exception table format
-----------------------
-
-The table is conceptually a list of records, each containing four variable-length integer fields (in a unique format, see below):
-
-- start: start of ``try`` block, in code units from the start of the bytecode
-- length: size of the ``try`` block, in code units
-- target: start of the first instruction of the ``except`` or ``finally`` block, in code units from the start of the bytecode
-- depth_and_lasti: the low bit gives the "lasti" flag, the remaining bits give the stack depth
-
-The stack depth is used to clean up evaluation stack entries above this depth.
-The "lasti" flag indicates whether, after stack cleanup, the instruction offset of the raising instruction should be pushed (as a ``PyLongObject *``).
-For more information on the design, see :cpy-file:`Objects/exception_handling_notes.txt`.
-
-Each varint is encoded as one or more bytes.
-The high bit (bit 7) is reserved for random access -- it is set for the first varint of a record.
-The second bit (bit 6) indicates whether this is the last byte or not -- it is set for all but the last bytes of a varint.
-The low 6 bits (bits 0-5) are used for the integer value, in big-endian order.
-
-To find the table entry (if any) for a given instruction offset, we can use bisection without decoding the whole table.
-We bisect the raw bytes, at each probe finding the start of the record by scanning back for a byte with the high bit set, and then decode the first varint.
-See ``get_exception_handler()`` in :cpy-file:`Python/ceval.c` for the exact code (like all bisection algorithms, the code is a bit subtle).
+In 3.11, this mechanism has been replaced by a statically generated table, ``code->co_exceptiontable``,
+which is described in detail in the `internals documentation
+<https://github.com/python/cpython/blob/main/InternalDocs/exception_handling.md>`_.
 
 The locations table
 -------------------
 
 Whenever an exception is raised, we add a traceback entry to the exception.
-The ``tb_lineno`` field of a traceback entry must be set to the line number of the instruction that raised it.
+The ``tb_lineno`` field of a traceback entry is (lazily) set to the line number of the instruction that raised it.
 This field is computed from the locations table, ``co_linetable`` (this name is an understatement), using :c:func:`PyCode_Addr2Line`.
 This table has an entry for every instruction rather than for every ``try`` block, so a compact format is very important.