RFR: JDK-8304684: Memory leak in DirectivesParser::set_option_flag [v2]

[Dean Long]

On Tue, 21 Mar 2023 20:34:17 GMT, Justin King <jcking at openjdk.org> wrote:

>> Add missing `FREE_C_HEAP_ARRAY` call.
>
> Justin King has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update based on review
>   
>   Signed-off-by: Justin King <jcking at google.com>

Changes requested by dlong (Reviewer).

src/hotspot/share/compiler/directivesParser.cpp line 351:

> 349:         }
> 350: 
> 351:         FREE_C_HEAP_ARRAY(char, s);

This looks unsafe.  We shouldn't free the memory without clearing all references to it, otherwise there is a dangling pointer.  There is already another reference to the memory because of this call:

`(set->*test)((void *)&s);` (see the set_function_definition macro)

I think it would be better to move this copying call until after validation has been done.

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PR Review: https://git.openjdk.org/jdk/pull/13125#pullrequestreview-1351476419
PR Review Comment: https://git.openjdk.org/jdk/pull/13125#discussion_r1144052137