From db991bc0f13caecbfd505e8ca155a91d0c97b1be Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Fri, 11 Oct 2024 17:50:15 +0200
Subject: [PATCH] FFI: support symbol lookup without specifying lib on Windows
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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This works similar to `dlsym(RTLD_DEFAULT, …)` with the caveat that
symbols on Windows may not be unique, and are usually qualified by the
module they are exported from.  That means that wrong symbols may be
fetched, potentially causing serious issues; therefore this usage is
not recommended for production purposes, but is a nice simplification
for quick experiments and the ext/ffi test suite.

Closes GH-16351.
---
 UPGRADING                     |  5 +++++
 ext/ffi/ffi.c                 | 34 ++++++++++++++++++++++++++++++++++
 ext/ffi/tests/100.phpt        |  7 +++----
 ext/ffi/tests/101.phpt        |  7 +++----
 ext/ffi/tests/200.phpt        |  4 ++--
 ext/ffi/tests/300-win32.h.in  |  4 ----
 ext/ffi/tests/301-win32.phpt  | 29 -----------------------------
 ext/ffi/tests/301.phpt        |  2 --
 ext/ffi/tests/bug77632b.phpt  |  6 ++----
 ext/ffi/tests/bug78714.phpt   |  3 +--
 ext/ffi/tests/bug79096.phpt   | 12 +-----------
 ext/ffi/tests/bug79177.phpt   | 12 +-----------
 ext/ffi/tests/bug79532.phpt   | 13 +------------
 ext/ffi/tests/bug80847.phpt   | 11 +----------
 ext/ffi/tests/bug_gh9090.phpt | 11 +----------
 ext/ffi/tests/gh11934b.phpt   | 12 +-----------
 ext/ffi/tests/utils.inc       | 20 +-------------------
 17 files changed, 57 insertions(+), 135 deletions(-)
 delete mode 100644 ext/ffi/tests/300-win32.h.in
 delete mode 100644 ext/ffi/tests/301-win32.phpt

diff --git a/UPGRADING b/UPGRADING
index 110080e2ee4..6a7a54f7174 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -116,6 +116,11 @@ PHP 8.5 UPGRADE NOTES
   PHP_RELEASE_VERSION are now always numbers.  Previously, they have been
   strings for buildconf builds.
 
+* FFI:
+  . It is no longer necessary to specify the library when using FFI::cdef()
+    and FFI::load(). However, this convenience feature should not be used in
+    production.
+
 ========================================
 13. Other Changes
 ========================================
diff --git a/ext/ffi/ffi.c b/ext/ffi/ffi.c
index 2648162ae9c..dc044885c02 100644
--- a/ext/ffi/ffi.c
+++ b/ext/ffi/ffi.c
@@ -2974,6 +2974,40 @@ static zend_always_inline bool zend_ffi_validate_api_restriction(zend_execute_da
 		} \
 	} while (0)
 
+#ifdef PHP_WIN32
+# ifndef DWORD_MAX
+#  define DWORD_MAX ULONG_MAX
+# endif
+# define NUM_MODULES 1024
+/* A rough approximation of dlysm(RTLD_DEFAULT) */
+static void *dlsym_loaded(char *symbol)
+{
+	HMODULE modules_static[NUM_MODULES], *modules = modules_static;
+	DWORD num = NUM_MODULES, i;
+	void * addr;
+	if (!EnumProcessModules(GetCurrentProcess(), modules, num * sizeof(HMODULE), &num)) {
+		return NULL;
+	}
+	if (num >= NUM_MODULES && num <= DWORD_MAX / sizeof(HMODULE)) {
+		modules = emalloc(num *sizeof(HMODULE));
+		if (!EnumProcessModules(GetCurrentProcess(), modules, num * sizeof(HMODULE), &num)) {
+			efree(modules);
+			return NULL;
+		}
+	}
+	for (i = 0; i < num; i++) {
+		addr = GetProcAddress(modules[i], symbol);
+		if (addr != NULL) break;
+	}
+	if (modules != modules_static) {
+		efree(modules);
+	}
+	return addr;
+}
+# undef DL_FETCH_SYMBOL
+# define DL_FETCH_SYMBOL(h, s) (h == NULL ? dlsym_loaded(s) : GetProcAddress(h, s))
+#endif
+
 ZEND_METHOD(FFI, cdef) /* {{{ */
 {
 	zend_string *code = NULL;
diff --git a/ext/ffi/tests/100.phpt b/ext/ffi/tests/100.phpt
index 33b974a37b1..f231170315f 100644
--- a/ext/ffi/tests/100.phpt
+++ b/ext/ffi/tests/100.phpt
@@ -3,10 +3,9 @@ FFI 100: PHP symbols
 --EXTENSIONS--
 ffi
 --SKIPIF--
-<?php require_once('utils.inc'); ?>
 <?php
 try {
-    ffi_cdef("extern void *zend_printf;", ffi_get_php_dll_name());
+    FFI::cdef("extern void *zend_printf;");
 } catch (Throwable $e) {
     die('skip PHP symbols not available');
 }
@@ -17,7 +16,7 @@ ffi.enable=1
 <?php
 require_once('utils.inc');
 $fastcall = ffi_get_fastcall_specifier();
-$zend = ffi_cdef("
+$zend = FFI::cdef("
     const char *get_zend_version(void);
     //char *get_zend_version(void);
     extern size_t (*zend_printf)(const char *format, ...);
@@ -26,7 +25,7 @@ $zend = ffi_cdef("
 
     void $fastcall zend_str_tolower(char *str, size_t length);
 
-", ffi_get_php_dll_name());
+");
 var_dump(trim(explode("\n",$zend->get_zend_version())[0]));
 //var_dump(trim(FFI::string($zend->get_zend_version())));
 var_dump($zend->zend_printf);
diff --git a/ext/ffi/tests/101.phpt b/ext/ffi/tests/101.phpt
index 4730e2689e0..3362e98b9fd 100644
--- a/ext/ffi/tests/101.phpt
+++ b/ext/ffi/tests/101.phpt
@@ -3,10 +3,9 @@ FFI 101: PHP symbols (function address)
 --EXTENSIONS--
 ffi
 --SKIPIF--
-<?php require_once('utils.inc'); ?>
 <?php
 try {
-    ffi_cdef("extern void *zend_printf;", ffi_get_php_dll_name());
+    FFI::cdef("extern void *zend_printf;");
 } catch (Throwable $e) {
     die('skip PHP symbols not available');
 }
@@ -17,7 +16,7 @@ ffi.enable=1
 <?php
 require_once('utils.inc');
 $fastcall = ffi_get_fastcall_specifier();
-$zend = ffi_cdef("
+$zend = FFI::cdef("
     const char *get_zend_version(void);
     //char *get_zend_version(void);
     extern size_t (*zend_printf)(const char *format, ...);
@@ -26,7 +25,7 @@ $zend = ffi_cdef("
 
     void $fastcall zend_str_tolower(char *str, size_t length);
 
-", ffi_get_php_dll_name());
+");
 $f = $zend->get_zend_version;
 var_dump(trim(explode("\n",$f())[0]));
 //var_dump(trim(FFI::string($zend->get_zend_version())));
diff --git a/ext/ffi/tests/200.phpt b/ext/ffi/tests/200.phpt
index 92aedc5435b..aae410de7b1 100644
--- a/ext/ffi/tests/200.phpt
+++ b/ext/ffi/tests/200.phpt
@@ -6,7 +6,7 @@ ffi
 <?php require_once('utils.inc'); ?>
 <?php
 try {
-    FFI::cdef("void* zend_write;", ffi_get_php_dll_name());
+    FFI::cdef("void* zend_write;");
 } catch (Throwable $e) {
     die('skip PHP symbols not available');
 }
@@ -20,7 +20,7 @@ require_once('utils.inc');
 $zend = FFI::cdef("
     typedef size_t (*zend_write_func_t)(const char *str, size_t str_length);
     extern zend_write_func_t zend_write;
-", ffi_get_php_dll_name());
+");
 
 echo "Hello World!\n";
 
diff --git a/ext/ffi/tests/300-win32.h.in b/ext/ffi/tests/300-win32.h.in
deleted file mode 100644
index f8588a822db..00000000000
--- a/ext/ffi/tests/300-win32.h.in
+++ /dev/null
@@ -1,4 +0,0 @@
-#define FFI_SCOPE "TEST_300_WIN32"
-#define FFI_LIB "PHP_DLL_NAME"
-
-size_t php_printf(const char *format, ...);
diff --git a/ext/ffi/tests/301-win32.phpt b/ext/ffi/tests/301-win32.phpt
deleted file mode 100644
index 11202a43f47..00000000000
--- a/ext/ffi/tests/301-win32.phpt
+++ /dev/null
@@ -1,29 +0,0 @@
---TEST--
-FFI 301: FFI loading on Windows
---EXTENSIONS--
-ffi
---SKIPIF--
-<?php if (substr(PHP_OS, 0, 3) != 'WIN') die('skip for Windows only'); ?>
---INI--
-ffi.enable=1
---FILE--
-<?php
-require_once('utils.inc');
-$fn = __DIR__ . "/300-win32.h";
-$cont = str_replace(
-        "PHP_DLL_NAME",
-        ffi_get_php_dll_name(),
-        file_get_contents("$fn.in")
-    );
-file_put_contents($fn, $cont);
-
-$ffi = FFI::load($fn);
-$ffi->php_printf("Hello World from %s!\n", "PHP");
-?>
---CLEAN--
-<?php
-	$fn = __DIR__ . "/300-win32.h";
-	unlink($fn);
-?>
---EXPECT--
-Hello World from PHP!
diff --git a/ext/ffi/tests/301.phpt b/ext/ffi/tests/301.phpt
index 0677a2cf300..efe92633f07 100644
--- a/ext/ffi/tests/301.phpt
+++ b/ext/ffi/tests/301.phpt
@@ -2,8 +2,6 @@
 FFI 301: FFI loading
 --EXTENSIONS--
 ffi
---SKIPIF--
-<?php if (substr(PHP_OS, 0, 3) == 'WIN') die('skip not for Windows'); ?>
 --INI--
 ffi.enable=1
 --FILE--
diff --git a/ext/ffi/tests/bug77632b.phpt b/ext/ffi/tests/bug77632b.phpt
index 044c84ec097..8aedd0aa8ae 100644
--- a/ext/ffi/tests/bug77632b.phpt
+++ b/ext/ffi/tests/bug77632b.phpt
@@ -4,9 +4,8 @@ Bug #77632 (FFI function pointers with variadics)
 ffi
 --SKIPIF--
 <?php
-require_once('utils.inc');
 try {
-    FFI::cdef("extern void *zend_printf;", ffi_get_php_dll_name());
+    FFI::cdef("extern void *zend_printf;");
 } catch (Throwable $_) {
     die('skip PHP symbols not available');
 }
@@ -15,8 +14,7 @@ try {
 ffi.enable=1
 --FILE--
 <?php
-require_once('utils.inc');
-$libc = FFI::cdef("extern size_t (*zend_printf)(const char *format, ...);", ffi_get_php_dll_name());
+$libc = FFI::cdef("extern size_t (*zend_printf)(const char *format, ...);");
 $args = ["test from zend_printf\n"];
 ($libc->zend_printf)(...$args);
 $args2 = ["Hello, %s from zend_printf\n", "world"];
diff --git a/ext/ffi/tests/bug78714.phpt b/ext/ffi/tests/bug78714.phpt
index 81017b27d56..9542bdcb70c 100644
--- a/ext/ffi/tests/bug78714.phpt
+++ b/ext/ffi/tests/bug78714.phpt
@@ -6,9 +6,8 @@ ffi
 ffi.enable=1
 --FILE--
 <?php
-require_once('utils.inc');
 $def = 'char * __cdecl get_zend_version(void);';
-$ffi = ffi_cdef($def, ffi_get_php_dll_name());
+$ffi = FFI::cdef($def);
 echo substr(FFI::string($ffi->get_zend_version()), 0, 4) . "\n";
 ?>
 --EXPECT--
diff --git a/ext/ffi/tests/bug79096.phpt b/ext/ffi/tests/bug79096.phpt
index 8c7ce6cc2af..66db0a57392 100644
--- a/ext/ffi/tests/bug79096.phpt
+++ b/ext/ffi/tests/bug79096.phpt
@@ -5,7 +5,6 @@ ffi
 zend_test
 --FILE--
 <?php
-require_once('utils.inc');
 $header = <<<HEADER
 struct bug79096 {
     uint64_t a;
@@ -15,16 +14,7 @@ struct bug79096 {
 struct bug79096 bug79096(void);
 HEADER;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($header);
-} else {
-    try {
-        $ffi = FFI::cdef($header, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($header, ffi_get_php_dll_name());
-    }
-}
-
+$ffi = FFI::cdef($header);
 $struct = $ffi->bug79096();
 var_dump($struct);
 ?>
diff --git a/ext/ffi/tests/bug79177.phpt b/ext/ffi/tests/bug79177.phpt
index 2b6e449d36d..fe980f95c65 100644
--- a/ext/ffi/tests/bug79177.phpt
+++ b/ext/ffi/tests/bug79177.phpt
@@ -5,22 +5,12 @@ ffi
 zend_test
 --FILE--
 <?php
-require_once __DIR__ . '/utils.inc';
 $header = <<<HEADER
 extern int *(*bug79177_cb)(void);
 void bug79177(void);
 HEADER;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($header);
-} else {
-    try {
-        $ffi = FFI::cdef($header, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($header, ffi_get_php_dll_name());
-    }
-}
-
+$ffi = FFI::cdef($header);
 $ffi->bug79177_cb = function() {
     throw new \RuntimeException('Not allowed');
 };
diff --git a/ext/ffi/tests/bug79532.phpt b/ext/ffi/tests/bug79532.phpt
index 386c62540c1..553cfe71bef 100644
--- a/ext/ffi/tests/bug79532.phpt
+++ b/ext/ffi/tests/bug79532.phpt
@@ -5,22 +5,11 @@ ffi
 zend_test
 --FILE--
 <?php
-require_once('utils.inc');
-
 $header = <<<HEADER
 void bug79532(off_t *array, size_t elems);
 HEADER;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($header);
-} else {
-    try {
-        $ffi = FFI::cdef($header, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($header, ffi_get_php_dll_name());
-    }
-}
-
+$ffi = FFI::cdef($header);
 $array = FFI::cdef()->new("off_t[3]");
 $ffi->bug79532($array, 3);
 var_dump($array);
diff --git a/ext/ffi/tests/bug80847.phpt b/ext/ffi/tests/bug80847.phpt
index 83929de7512..da499b1586f 100644
--- a/ext/ffi/tests/bug80847.phpt
+++ b/ext/ffi/tests/bug80847.phpt
@@ -9,7 +9,6 @@ if (PHP_OS_FAMILY == 'Windows' && ((1 << 31) > 0)) die('xfail libffi doesn\'t pr
 ?>
 --FILE--
 <?php
-require_once('utils.inc');
 $header = <<<HEADER
     typedef struct bug80847_01 {
         uint64_t b;
@@ -23,15 +22,7 @@ $header = <<<HEADER
 	bug80847_02 ffi_bug80847(bug80847_02 s);
 HEADER;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($header);
-} else {
-    try {
-        $ffi = FFI::cdef($header, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($header, ffi_get_php_dll_name());
-    }
-}
+$ffi = FFI::cdef($header);
 $x = $ffi->new('bug80847_02');
 $x->a->b = 42;
 $x->a->c = 42.5;
diff --git a/ext/ffi/tests/bug_gh9090.phpt b/ext/ffi/tests/bug_gh9090.phpt
index 795e7bcaa5a..a13aaafe3aa 100644
--- a/ext/ffi/tests/bug_gh9090.phpt
+++ b/ext/ffi/tests/bug_gh9090.phpt
@@ -6,7 +6,6 @@ zend_test
 --FILE--
 <?php
 
-require_once 'utils.inc';
 $h = <<<'EOD'
 void (*bug_gh9090_void_none_ptr)();
 void (*bug_gh9090_void_int_char_ptr)(int, char *);
@@ -19,15 +18,7 @@ void bug_gh9090_void_int_char(int i, char *s);
 void bug_gh9090_void_int_char_var(int i, char *fmt, ...);
 EOD;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($h);
-} else {
-    try {
-        $ffi = FFI::cdef($h, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($h, ffi_get_php_dll_name());
-    }
-}
+$ffi = FFI::cdef($h);
 
 $func_ptrs = [
     'bug_gh9090_void_none_ptr',
diff --git a/ext/ffi/tests/gh11934b.phpt b/ext/ffi/tests/gh11934b.phpt
index 707c27c889c..61af90faa4f 100644
--- a/ext/ffi/tests/gh11934b.phpt
+++ b/ext/ffi/tests/gh11934b.phpt
@@ -5,21 +5,11 @@ ffi
 zend_test
 --FILE--
 <?php
-require_once __DIR__ . '/utils.inc';
 $header = <<<HEADER
 extern int gh11934b_ffi_var_test_cdata;
 HEADER;
 
-if (PHP_OS_FAMILY !== 'Windows') {
-    $ffi = FFI::cdef($header);
-} else {
-    try {
-        $ffi = FFI::cdef($header, 'php_zend_test.dll');
-    } catch (FFI\Exception $ex) {
-        $ffi = FFI::cdef($header, ffi_get_php_dll_name());
-    }
-}
-
+$ffi = FFI::cdef($header);
 $ffi->gh11934b_ffi_var_test_cdata->cdata = 2;
 var_dump($ffi->gh11934b_ffi_var_test_cdata);
 $source = $ffi->new('int');
diff --git a/ext/ffi/tests/utils.inc b/ext/ffi/tests/utils.inc
index 63c020fb539..d5a9fc31e6e 100644
--- a/ext/ffi/tests/utils.inc
+++ b/ext/ffi/tests/utils.inc
@@ -1,28 +1,10 @@
 <?php
 
-function ffi_cdef($code, $lib)
-{
-    if (isset($lib)) {
-        return FFI::cdef($code, $lib);
-    } else {
-        return FFI::cdef($code);
-    }
-}
-
-function ffi_get_php_dll_name()
-{
-    if (PHP_OS_FAMILY === 'Windows') {
-        return "php" . PHP_MAJOR_VERSION . (PHP_ZTS ? "ts" : "") . (PHP_DEBUG ? "_debug" : "") . ".dll";
-    } else {
-        return null;
-    }
-}
-
 function ffi_get_fastcall_specifier()
 {
     foreach (['__attribute__((fastcall))', '__fastcall', '__vectorcall'] as $spec) {
         try {
-            ffi_cdef("extern size_t $spec zend_list_insert(void *ptr, int type);", ffi_get_php_dll_name());
+            FFI::cdef("extern size_t $spec zend_list_insert(void *ptr, int type);");
             return "$spec ";
         } catch (Throwable $e) {}
     }