Fix FFI calling conventions inside nested declarators

NEWS

@@ -86,6 +86,8 @@ PHP                                                                        NEWS
 - FFI:
   . Fixed bug GH-24582 (Memory leaks in ext/ffi parser when finalize_type()
     bails out). (matyapiro31, David Carlier)
+  . Fixed calling conventions inside a nested declarator, such as
+    "void (__stdcall *f)(void)", being ignored or rejected. (Nicolas Grekas)
 
 - FPM:
   . Fixed bug GH-24229 (fcgi_close() passes shutdown() a literal 1, which is

ext/ffi/ffi.c

@@ -6497,6 +6497,22 @@ void zend_ffi_make_func_type(zend_ffi_dcl *dcl, HashTable *args, zend_ffi_dcl *n
 		}
 	}
 
+	/* The calling convention can be inside the parentheses, as in "void (__stdcall *f)(void)" */
+	if (nested_dcl->abi != ZEND_FFI_ABI_DEFAULT) {
+		if (dcl->abi != ZEND_FFI_ABI_DEFAULT) {
+			zend_ffi_cleanup_dcl(nested_dcl);
+			zend_ffi_cleanup_dcl(dcl);
+			if (args) {
+				zend_hash_destroy(args);
+				pefree(args, FFI_G(persistent));
+			}
+			zend_ffi_parser_error("Multiple calling convention specifiers at line %d", FFI_G(line));
+			return;
+		}
+		dcl->abi = nested_dcl->abi;
+		nested_dcl->abi = ZEND_FFI_ABI_DEFAULT;
+	}
+
 #ifdef HAVE_FFI_VECTORCALL_PARTIAL
 	if (dcl->abi == ZEND_FFI_ABI_VECTORCALL && args) {
 		zend_ulong i;

ext/ffi/ffi.g

@@ -798,6 +798,11 @@ nested_declarator_start:
 	|	"__attribute"
 	|	"__attribute__"
 	|	"__declspec"
+	|	"__cdecl"
+	|	"__stdcall"
+	|	"__fastcall"
+	|	"__thiscall"
+	|	"__vectorcall"
 	|	"*"
 	|	"("
 	|	"["

ext/ffi/ffi_parser.c

@@ -1807,6 +1807,21 @@ static int check_nested_declarator_start(int sym) {
 			case YY___DECLSPEC:
 				sym = get_sym();
 				break;
+			case YY___CDECL:
+				sym = get_sym();
+				break;
+			case YY___STDCALL:
+				sym = get_sym();
+				break;
+			case YY___FASTCALL:
+				sym = get_sym();
+				break;
+			case YY___THISCALL:
+				sym = get_sym();
+				break;
+			case YY___VECTORCALL:
+				sym = get_sym();
+				break;
 			case YY__STAR:
 				sym = get_sym();
 				break;

ext/ffi/tests/callconv_nested_declarator.phpt

@@ -0,0 +1,63 @@
+--TEST--
+FFI: calling convention inside a nested declarator
+--EXTENSIONS--
+ffi
+--INI--
+ffi.enable=1
+--FILE--
+<?php
+// The calling convention must apply to the function type whether it is
+// written before the parentheses, as in "void __stdcall (*f)(void)",
+// or inside them, as in "void (__stdcall *f)(void)"
+$cases = [
+    'declarator' => [
+        'typedef void %s(%s *F)(int);',
+        'F',
+        fn (FFI\CType $type) => $type->getPointerType(),
+    ],
+    'parameter declarator' => [
+        'typedef void F(void %s(%s *cb)(int));',
+        'F*',
+        fn (FFI\CType $type) => $type->getPointerType()->getFuncParameterType(0)->getPointerType(),
+    ],
+    'abstract declarator' => [
+        '',
+        'void %s(%s *)(int)',
+        fn (FFI\CType $type) => $type->getPointerType(),
+    ],
+];
+
+function func_abi(array $case, string $before, string $inside): int|string {
+    [$decl, $type, $func] = $case;
+    try {
+        $ffi = FFI::cdef(sprintf($decl, $before, $inside));
+        $type = $ffi->type(sprintf($type, $before, $inside));
+        return $func($type)->getFuncABI();
+    } catch (FFI\ParserException $e) {
+        return $e->getMessage();
+    }
+}
+
+foreach ($cases as $name => $case) {
+    echo "$name:";
+    foreach (['__cdecl', '__stdcall', '__fastcall', '__thiscall', '__vectorcall', '__attribute__((fastcall))'] as $callconv) {
+        $expected = func_abi($case, "$callconv ", '');
+        $actual = func_abi($case, '', "$callconv ");
+        if ($expected !== $actual) {
+            echo "\n  $callconv: expected ", var_export($expected, true), ", got ", var_export($actual, true);
+        }
+    }
+    echo " done\n";
+}
+
+try {
+    FFI::cdef('typedef void __cdecl (__cdecl *F)(int);');
+} catch (FFI\ParserException $e) {
+    echo $e->getMessage(), "\n";
+}
+?>
+--EXPECT--
+declarator: done
+parameter declarator: done
+abstract declarator: done
+Multiple calling convention specifiers at line 1