bitbake: bitbake: event: Inject empty lines to make code match lineno in filename

So that we can get the correct error messages.

* In python 3.10.9, the error message was:
  ERROR: Unable to register event handler 'defaultbase_eventhandler':
    File "/path/to/poky/meta/classes-global/base.bbclass", line 4
      # SPDX-License-Identifier: MIT
             ^^^^^
  SyntaxError: invalid syntax

  This is hard to debug since the error line number 4 is incorrect, but nothing
  is wrong with the code in line 4.

* Now the error message and lineno is correct:
  ERROR: Unable to register event handler 'defaultbase_eventhandler':
    File "/path/to/poky/meta/classes-global/base.bbclass", line 256
      an error line
         ^^^^^
  SyntaxError: invalid syntax

And no impact on parsing time:
* Before:
$ rm -fr cache tmp; time bitbake -p
real    0m27.254s

* Now:
$ rm -fr cache tmp; time bitbake -p
real    0m27.200s

(Bitbake rev: c212933d9c786806852c87f188250a4f0a14c048)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/bitbake/lib/bb/event.py b/bitbake/lib/bb/event.py
index f8acacd80d..4761c86880 100644
--- a/bitbake/lib/bb/event.py
+++ b/bitbake/lib/bb/event.py
@@ -257,14 +257,15 @@ def register(name, handler, mask=None, filename=None, lineno=None, data=None):
         # handle string containing python code
         if isinstance(handler, str):
             tmp = "def %s(e, d):\n%s" % (name, handler)
+            # Inject empty lines to make code match lineno in filename
+            if lineno is not None:
+                tmp = "\n" * (lineno-1) + tmp
             try:
                 code = bb.methodpool.compile_cache(tmp)
                 if not code:
                     if filename is None:
                         filename = "%s(e, d)" % name
                     code = compile(tmp, filename, "exec", ast.PyCF_ONLY_AST)
-                    if lineno is not None:
-                        ast.increment_lineno(code, lineno-1)
                     code = compile(code, filename, "exec")
                     bb.methodpool.compile_cache_add(tmp, code)
             except SyntaxError: