---
name: "pcre2_jit_stack_assign"
section: "3"
platform: "linux"
package: "pcre2"
version: "10.49-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pcre2_jit_stack_assign"
---

# pcre2\_jit\_stack\_assign(3)

Perl-compatible regular expressions (revised API)

## NAME

PCRE2 - Perl-compatible regular expressions (revised API)

## SYNOPSIS

**#include \<pcre2.h\>**

```
void pcre2_jit_stack_assign(pcre2_match_context *mcontext,
  pcre2_jit_callback callback_function, void *callback_data);
```

## DESCRIPTION

This function provides control over the memory used by JIT as a run-time stack when **pcre2\_match()** or **pcre2\_jit\_match()** is called with a pattern that has been successfully processed by the JIT compiler. The information that determines which stack is used is put into a match context that is subsequently passed to a matching function. The arguments of this function are:

  mcontext       a pointer to a match context\
   callback       a callback function\
   callback\_data  a JIT stack or a value to be passed to the callback

If *mcontext* is NULL, the function returns immediately, without doing anything.

If *callback* is NULL and *callback\_data* is NULL, an internal 32KiB block on the machine stack is used.

If *callback* is NULL and *callback\_data* is not NULL, *callback\_data* must be a valid JIT stack, the result of calling **pcre2\_jit\_stack\_create()**.

If *callback* not NULL, it is called with *callback\_data* as an argument at the start of matching, in order to set up a JIT stack. If the result is NULL, the internal 32KiB stack is used; otherwise the return value must be a valid JIT stack, the result of calling **pcre2\_jit\_stack\_create()**.

You may safely use the same JIT stack for multiple patterns, as long as they are all matched in the same thread. In a multithread application, each thread must use its own JIT stack. For more details, see the **pcre2jit** page.

There is a complete description of the PCRE2 native API in the **pcre2api** page and a description of the POSIX API in the **pcre2posix** page.