RFR(M) 8193373: Cleanup ElfFile and family

[Zhengyu Gu]

Hi Yumin,

Thanks for the review.

On 02/08/2018 12:51 PM, yumin qi wrote:
> Hi, Zhengyu
> 
>    Looks good to me. One minor comment:
> 
> +bool ElfFile::specifies_noexecstack(const char* filepath) {
> + // Returns true if the elf file is marked NOT to require an executable 
> stack,
> + // or if the file could not be opened.
> + // Returns false if the elf file requires an executable stack, the 
> stack flag
> + // is not set at all, or if the file can not be read.
> 
> 
>    should the comments in side the function be moved above the function?

I moved whole method as it was. I can do so if you insist.

Thanks,

-Zhengyu

> 
>     others looks OK to me.
> 
> Thanks
> Yumin
> 
> 
> 
> 
> On Mon, Feb 5, 2018 at 8:08 AM, Zhengyu Gu <zgu at redhat.com 
> <mailto:zgu at redhat.com>> wrote:
> 
>     Please review this cleanup and refactoring of elf decoder.
> 
>     * Fixed coding styles.
>        - Moved non-static members to the top of classes
>        - Fixed variable names (from Windows naming style to hotspot style)
> 
>     * Moved Linux implementation of ElfFile::specifies_noexecstack to os
>        directory
> 
>     * Refactored section cache logic into common ElfSection class.
> 
>     * Added utility classes FileReader and MarkedFileReader to cleanup
>        duplicated code.
> 
>     * Deleted section header string table once initialization is completed,
>        cause it is not used for decoding.
> 
>     * When decoder failed to cache section data, current implementation
>        tries to fallback to read data from file directly. This never
>        worked, cause it put decoder into out of memory state when it failed
>        load section data, so decoder always bailed out prematurely.
>        This patch also fixed this bug.
> 
>     Bug: https://bugs.openjdk.java.net/browse/JDK-8193373
>     <https://bugs.openjdk.java.net/browse/JDK-8193373>
>     Webrev: http://cr.openjdk.java.net/~zgu/8193373/webrev.00/
>     <http://cr.openjdk.java.net/~zgu/8193373/webrev.00/>
> 
> 
>     Test:
> 
>        hotspot_runtime on Linux 64 (fastdebug and release)
> 
>     Thanks,
> 
>     -Zhengyu
> 
>