Support for FFI pointer math

Author: dstogov

ext/opcache/jit/zend_jit.c

@@ -122,6 +122,17 @@ static bool zend_jit_ffi_compatible(zend_ffi_type *dst_type, uint32_t src_info,
 	}
 	return false;
 }
+
+static bool zend_jit_ffi_compatible_addr_op(zend_ffi_type *dst_type, uint32_t src_info, zend_ffi_type *src_type, uint8_t opcode)
+{
+	if (dst_type->kind == ZEND_FFI_TYPE_POINTER
+	 && ZEND_FFI_TYPE(dst_type->pointer.type)->size != 0
+	 && src_info == MAY_BE_LONG
+	 && (opcode == ZEND_ADD || opcode == ZEND_SUB)) {
+		return true;
+	}
+	return false;
+}
 #endif
 
 #ifdef HAVE_PTHREAD_JIT_WRITE_PROTECT_NP

ext/opcache/jit/zend_jit_ir.c

@@ -14350,6 +14350,17 @@ static int zend_jit_ffi_assign_op_helper(zend_jit_ctx   *jit,
 			}
 			break;
 #endif
+		case ZEND_FFI_TYPE_POINTER:
+			ZEND_ASSERT(opcode == ZEND_ADD || opcode == ZEND_SUB);
+			ZEND_ASSERT(ZEND_FFI_TYPE(el_type->pointer.type)->size != 0);
+			type = IR_ADDR;
+			if (op2_info == MAY_BE_LONG) {
+				op2 = ir_MUL_A(jit_Z_LVAL(jit, op2_addr), ir_CONST_LONG(ZEND_FFI_TYPE(el_type->pointer.type)->size));
+			} else {
+				ZEND_UNREACHABLE();
+				return 0;
+			}
+			break;
 		default:
 			ZEND_UNREACHABLE();
 			return 0;

ext/opcache/jit/zend_jit_trace.c

@@ -4721,7 +4721,8 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 						if (op1_ffi_type
 						 && (op1_ffi_type->kind == ZEND_FFI_TYPE_ARRAY || op1_ffi_type->kind == ZEND_FFI_TYPE_POINTER)
 						 && op2_info == MAY_BE_LONG
-						 && zend_jit_ffi_compatible(op1_ffi_type->array.type, op1_data_info, op3_ffi_type)) {
+						 && (zend_jit_ffi_compatible(op1_ffi_type->array.type, op1_data_info, op3_ffi_type)
+						  || zend_jit_ffi_compatible_addr_op(op1_ffi_type->array.type, op1_data_info, op3_ffi_type, opline->extended_value))) {
 							if (!ffi_info) {
 								ffi_info = zend_arena_calloc(&CG(arena), ssa->vars_count, sizeof(zend_jit_ffi_info));
 							}
@@ -4926,7 +4927,8 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 							if (field
 							 && !field->is_const
 							 && !field->bits
-							 && zend_jit_ffi_compatible(field->type, op1_data_info, op3_ffi_type)) {
+							 && (zend_jit_ffi_compatible(field->type, op1_data_info, op3_ffi_type)
+							  || zend_jit_ffi_compatible_addr_op(field->type, op1_data_info, op3_ffi_type, opline->extended_value))) {
 								if (!ffi_info) {
 									ffi_info = zend_arena_calloc(&CG(arena), ssa->vars_count, sizeof(zend_jit_ffi_info));
 								}
@@ -4943,7 +4945,8 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 								Z_STR_P(RT_CONSTANT(opline, opline->op2)));
 							if (sym
 							 && sym->kind == ZEND_FFI_SYM_VAR
-							 && zend_jit_ffi_compatible(sym->type, op1_data_info, op3_ffi_type)) {
+							 && (zend_jit_ffi_compatible(sym->type, op1_data_info, op3_ffi_type)
+							  || zend_jit_ffi_compatible_addr_op(sym->type, op1_data_info, op3_ffi_type, opline->extended_value))) {
 								if (!ffi_info) {
 									ffi_info = zend_arena_calloc(&CG(arena), ssa->vars_count, sizeof(zend_jit_ffi_info));
 								}