In FFI, assume that identifier is a typedef if followed by '*' in parameter list #5733
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…ameter list Bug #79576 (https://bugs.php.net/bug.php?id=79576) reports that the error message shown by FFI when parsing a C function declaration which uses typedef's it doesn't know about can be confusing. For example, given this definition: int func(oid *); Since FFI has not seen a typedef for 'oid', it treats 'oid' as being the name of a parameter. But since it is followed by '*', it fails with this message: unsupported type specifier combination Interestingly, GCC is able to detect that 'oid' is a type name and reports: unknown type name 'oid' Implement a simple workaround: If the identifier in the above case is directly followed by '*', take it as being a typedef. This does not actually allow the parse to succeed, but does make it fail with a more informative message: undefined C type 'oid' Since this fix is quite simplistic, there are probably more complicated cases where it will still not display the most informative error message.
alexdowad
changed the title
cmb69
reviewed
Sep 14, 2021
| @@ -143,7 +158,7 @@ declaration_specifiers(zend_ffi_dcl *dcl): | |||
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| specifier_qualifier_list(zend_ffi_dcl *dcl): | |||
| "__extension__"? | |||
| ( ?{sym != YY_ID || zend_ffi_is_typedef_name((const char*)yy_text, yy_pos - yy_text)} | |||
| ( ?{sym != YY_ID || zend_ffi_is_typedef_name((const char*)yy_text, yy_pos - yy_text) || peek_sym() == YY__STAR} | |||
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This should probably check for YY__LBRACK as well, to cater to unknown_type[].
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The bug is fixed via #7496 |
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Bug #79576 reports that the error message shown by FFI when parsing a C function declaration which uses typedef's it doesn't know about can be confusing.
For example, given this definition:
Since FFI has not seen a typedef for 'oid', it treats 'oid' as being the name of a parameter. But since it is followed by '*', it fails with this message:
Interestingly, GCC is able to detect that 'oid' is a type name and reports:
Implement a simple workaround: If the identifier in the above case is directly followed by '*', take it as being a typedef. This does not actually allow the parse to succeed, but does make it fail with a more informative message:
Since this fix is quite simplistic, there are probably more complicated cases where it will still not display the most informative error message.
I fully expect that there may be problems with this approach, and am hoping the maintainers can point me in a better direction if necessary.