[php-src] master: Prevent inlining of `zend_compile_expr_inner()` to guarantee low stack usage of compilation (#23294)

Author: Kuba Werłos (kubawerlos)
Committer: GitHub (web-flow)
Pusher: arnaud-lb
Date: 2026-08-19T11:35:00+02:00

Commit: https://github.com/php/php-src/commit/dcdc8ab02caf91a4d27c95ab3cd03a9aa00191a2
Raw diff: https://github.com/php/php-src/commit/dcdc8ab02caf91a4d27c95ab3cd03a9aa00191a2.diff

Prevent inlining of `zend_compile_expr_inner()` to guarantee low stack usage of compilation (#23294)

Changed paths:
  M  Zend/zend_compile.c


Diff:

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index f3527330a2c9..317114265c57 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -12447,7 +12447,9 @@ static void zend_compile_stmt(zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-static void zend_compile_expr_inner(znode *result, zend_ast *ast) /* {{{ */
+/* Keep this out of zend_compile_expr(): the two form a recursion cycle, so inlining merges this
+ * frame into every nesting level of an expression, tripling the stack needed to compile it. */
+static zend_never_inline void zend_compile_expr_inner(znode *result, zend_ast *ast) /* {{{ */
 {
 	/* CG(zend_lineno) = ast->lineno; */
 	CG(zend_lineno) = zend_ast_get_lineno(ast);