Bug #80083 [Csd]: Optimizer pass 6 removes variables used for ibm_db2 data binding

Edit report at https://bugs.php.net/bug.php?id=80083&edit=1 ID: 80083 Updated by: nikic@php.net Reported by: calvin at cmpct dot info Summary: Optimizer pass 6 removes variables used for ibm_db2 data binding Status: Closed Type: Bug Package: opcache Operating System: IBM i 7.2 PHP Version: 7.4.10 -Assigned To: +Assigned To: nikic Block user comment: N Private report: N New Comment: > I skimmed the source and I think the only symbol table mangling code is in execute called code; > though perhaps the bind code in ibm_db2 could also signal something to opcache?. I also just checked the code, and it looks like just handling db2_execute() should be sufficient. While db2_bind_param() accepts the variable name, it doesn't do anything beyond storing it. > I also didn't know opcache was willing to accept a workaround - has that happened before? Nope, but doesn't really cost us anything, as long as it's an isolated occurrence... I've committed a fix now, but haven't tested it, as I don't have the necessary environment. Previous Comments: ------------------------------------------------------------------------ [2020-09-17 08:14:53] nikic@php.net Automatic comment on behalf of nikita.ppv@gmail.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=a4f806aa79c9d0e497866e86f750e87d9bd874f1 Log: Fixed bug #80083 ------------------------------------------------------------------------ [2020-09-15 17:23:38] calvin at cmpct dot info I skimmed the source and I think the only symbol table mangling code is in execute called code; though perhaps the bind code in ibm_db2 could also signal something to opcache?. I also didn't know opcache was willing to accept a workaround - has that happened before? ------------------------------------------------------------------------ [2020-09-15 12:32:14] nikic@php.net Agree. I think it's okay for us to hardcode these functions as modifying the symtable in opcache. Do you know which functions are affected? Is it just db2_execute() that accesses local variables, or also other functions? ------------------------------------------------------------------------ [2020-09-10 16:53:55] calvin at cmpct dot info Yeah, I agree this is API is malpractice. (Looking at the db2 binding code and having it manipulate local/global scope symbol tables when no other modules did so was a bit of a head-scratcher.) Changing the db2 API would probably result in a breaking change though, and most code on ibm_db2 instead of (PDO_)ODBC is legacy; so I suspect most users running into this will either detune opcache or migrate to ODBC. (Of course, this is the IBM i perspective. I don't know what LUW people are doing here; perhaps they consider that extension more important.) ------------------------------------------------------------------------ [2020-09-10 15:39:17] nikic@php.net The db2 extension needs to change its API to not work on variable names -- it needs to accept variables by reference instead. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=80083 -- Edit this bug report at https://bugs.php.net/bug.php?id=80083&edit=1