mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-27 04:05:34 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

[3.11] gh-92228: disable the compiler's 'small exit block inlining' optimization for blocks that have a line number (GH-94592) (GH-94643)

Browse source 
Inlining of code that corresponds to source code lines, can make it hard to distinguish later between code which is only reachable from except handlers, and that which is reachable in normal control flow. This caused problems with the debugger's jump feature.

This PR turns off the inlining optimisation for code which has line numbers. We still inline things like the implicit "return None"..
(cherry picked from commit bde06e1b83)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
This commit is contained in:
Christian Heimes 2022-07-07 12:10:32 +02:00 • committed by GitHub
parent 3517c138a8
commit 74c953d396
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
5 changed files with 34 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Python/compile.c
View file

@ -8976,6 +8976,16 @@ error:
return -1;
}
static bool
basicblock_has_lineno(const basicblock *bb) {
for (int i = 0; i < bb->b_iused; i++) {
if (bb->b_instr[i].i_lineno > 0) {
return true;
}
}
return false;
}
/* If this block ends with an unconditional jump to an exit block,
* then remove the jump and extend this block with the target.
*/
@ -8992,6 +9002,10 @@ extend_block(basicblock *bb) {
}
if (last->i_target->b_exit && last->i_target->b_iused <= MAX_COPY_SIZE) {
basicblock *to_copy = last->i_target;
if (basicblock_has_lineno(to_copy)) {
/* copy only blocks without line number (like implicit 'return None's) */
return 0;
}
last->i_opcode = NOP;
for (int i = 0; i < to_copy->b_iused; i++) {
int index = compiler_next_instr(bb);