Bug #77706 [Asn->Csd]: Improve error messages in FFI for incompatible arguments

Edit report at https://bugs.php.net/bug.php?id=77706&edit=1 ID: 77706 Updated by: dmitry@php.net Reported by: ircmaxell@php.net Summary: Improve error messages in FFI for incompatible arguments -Status: Assigned +Status: Closed Type: Bug Package: Unknown/Other Function Operating System: any PHP Version: Next Minor Version Assigned To: dmitry Block user comment: N Private report: N New Comment: Automatic comment on behalf of dmitry@zend.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=a1868d22917ac189dde1f6974bc43e1c498e1c6a Log: Fixed bug #77706 (Improve error messages in FFI for incompatible arguments) Previous Comments: ------------------------------------------------------------------------ [2019-03-07 13:24:04] ircmaxell@php.net Description: ------------ When using FFI, very little useful debugging information is provided when type checking arguments for function calls/etc. In the test script, the syntax for fprintf is FILE*, const char*, ... I made a "mistake" by passing a number for the second argument. FFI gave me no indication as to which parameter was incorrect, leading to either trial-and-error debugging, or breaking out GDB to see which argument was the problem. Test script: --------------- <?php $header = ' typedef struct _IO_FILE FILE; extern FILE *stdout; extern FILE *stdin; extern FILE *stderr; int fprintf(FILE *, const char *, ...); '; $ffi = FFI::cdef($header, 'libc.so.6'); $ffi->fprintf($ffi->stdout, 123, "Hello %s\n", "World"); Expected result: ---------------- Fatal error: Uncaught FFI\Exception: Passing incompatible pointer to argument 2 of function fprintf, expecting const char*, found long long in /.../test.php:14 Stack trace: #0 /.../test.php(14): FFI->fprintf(Object(FFI\CData:<struct>*), 123, 'Hello %s\n', 'World') #1 {main} thrown in /.../test.php on line 14 Actual result: -------------- Fatal error: Uncaught FFI\Exception: Passing incompatible pointer in /.../test.php:14 Stack trace: #0 /.../test.php(14): FFI->fprintf(Object(FFI\CData:<struct>*), 123, 'Hello %s\n', 'World') #1 {main} thrown in /.../test.php on line 14 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=77706&edit=1