mdparser/php_mdparser.h at master · iliaal/mdparser · GitHub

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/*
  +----------------------------------------------------------------------+
  | Copyright (c) 2025-2026, Ilia Alshanetsky                            |
  | Copyright (c) 2025-2026, Advanced Internet Designs Inc.              |
  +----------------------------------------------------------------------+
  | This source file is subject to the BSD 3-Clause license that is      |
  | bundled with this package in the file LICENSE.                       |
  +----------------------------------------------------------------------+
  | Author: Ilia Alshanetsky <ilia@ilia.ws>                              |
  +----------------------------------------------------------------------+
*/

#ifndef PHP_MDPARSER_H
#define PHP_MDPARSER_H

#define PHP_MDPARSER_VERSION "0.3.0"

extern zend_module_entry mdparser_module_entry;
#define phpext_mdparser_ptr &mdparser_module_entry

#ifdef PHP_WIN32
#define PHP_MDPARSER_API __declspec(dllexport)
#else
#define PHP_MDPARSER_API
#endif

#include "php.h"
#include "cmark-gfm.h"

/* PHP 8.3 compat shim for zend_register_internal_class_with_flags
 * (added in 8.4). gen_stub.php emits the 8.4+ variant when it sees
 * `final readonly class` in the stub, but we still target 8.3.
 * Providing a static inline fallback keeps the generated arginfo.h
 * unchanged and lets 8.3 builds compile and link. */
#if PHP_VERSION_ID < 80400
static inline zend_class_entry *zend_register_internal_class_with_flags(
    zend_class_entry *class_entry,
    zend_class_entry *parent_ce,
    uint32_t flags)
{
    zend_class_entry *registered = zend_register_internal_class_ex(class_entry, parent_ce);
    registered->ce_flags |= flags;
    return registered;
}
#endif

extern zend_class_entry *mdparser_parser_ce;
extern zend_class_entry *mdparser_options_ce;
extern zend_class_entry *mdparser_exception_ce;

typedef struct _mdparser_parser_obj {
    int cmark_options;
    int extension_mask;
    int postprocess_mask;
    /* Cached cmark_parser, built lazily on first render. Reused across
     * subsequent renders because cmark_parser_finish calls
     * cmark_parser_reset internally before returning, leaving the
     * parser in a clean state with the same extension list attached.
     *
     * cmark_parser_reset is static in vendor/cmark/src/blocks.c so we
     * cannot call it from outside; we rely on _finish's internal
     * reset for the happy path, and rebuild from scratch after any
     * render that did not complete cleanly (parser_dirty flag).
     *
     * Isolation invariant: after every render the parser holds no
     * state from prior input -- no link reference definitions, no
     * inline subject leftovers, no buffered partial input. Verified
     * via tests/033_parser_reuse_isolation.phpt. */
    cmark_parser *cmark_parser;
    bool parser_dirty;
    zend_object std;
} mdparser_parser_obj;

static inline mdparser_parser_obj *mdparser_parser_from_obj(zend_object *obj) {
    return (mdparser_parser_obj *)((char *)(obj) - offsetof(mdparser_parser_obj, std));
}

#define Z_MDPARSER_PARSER_P(zv) mdparser_parser_from_obj(Z_OBJ_P(zv))

/* Bits in extension_mask matching cmark-gfm core extension names. */
#define MDPARSER_EXT_TABLES        (1 << 0)
#define MDPARSER_EXT_STRIKETHROUGH (1 << 1)
#define MDPARSER_EXT_TASKLIST      (1 << 2)
#define MDPARSER_EXT_AUTOLINK      (1 << 3)
#define MDPARSER_EXT_TAGFILTER     (1 << 4)

#define MDPARSER_EXT_COUNT 5

/* Postprocess flags. These are not cmark options or extensions; they
 * select string-level transforms applied to the rendered HTML after
 * cmark is done. Currently only HTML output uses these. */
#define MDPARSER_PP_HEADING_ANCHORS (1 << 0)
#define MDPARSER_PP_NOFOLLOW_LINKS  (1 << 1)

/* Hard cap on input size. 256 MB is far above any realistic document
 * and well below cmark's internal bufsize_t (int32) overflow edge. */
#define MDPARSER_MAX_INPUT_SIZE ((size_t)(256UL * 1024UL * 1024UL))

/* Hard cap on AST walker recursion depth. cmark's own parser is
 * iterative and happily produces trees thousands of levels deep from
 * one-byte-per-level input like `>` × N. Walking such a tree with
 * a recursive PHP-array builder would smash the C stack. */
#define MDPARSER_MAX_AST_DEPTH 1000

/* Extension pointers resolved once at MINIT so per-parse attachment
 * is a bitmask loop instead of 5 registry walks with strcmp. */
typedef struct {
    int bit;
    cmark_syntax_extension *ptr;
} mdparser_cached_extension;

extern mdparser_cached_extension mdparser_cached_extensions[MDPARSER_EXT_COUNT];

/* Process-wide cmark_mem backed by Zend MM (ecalloc/erealloc/efree).
 * Passed to every cmark_*_with_mem call so cmark allocations respect
 * memory_limit and OOM goes through Zend MM bailout instead of abort. */
extern cmark_mem mdparser_zend_mem;

/* Default masks, computed once from mdparser_options_fields at MINIT. */
extern int mdparser_default_cmark_options;
extern int mdparser_default_extension_mask;
extern int mdparser_default_postprocess_mask;

/* Registration entry points (defined in the respective .c files) */
void mdparser_parser_register_class(void);
void mdparser_options_register_class(void);
void mdparser_exception_register_class(void);

/* Default-options helpers (defined in mdparser_options.c) */
void mdparser_options_init_defaults(void);
void mdparser_options_read_masks(zval *options_zv, int *cmark_options, int *extension_mask, int *postprocess_mask);

#endif /* PHP_MDPARSER_H */