RFR 12 : 8072130 : java/lang/instrument/BootClassPath/BootClassPathTest.sh fails on Mac OSX

Brent Christian brent.christian at oracle.com
Tue Sep 18 16:42:07 UTC 2018

Any thoughts on this change?  -B

On 9/11/18 3:41 PM, Brent Christian wrote:
> Hi,
> Please review this change to how the platform encoding is determined on 
> Mac when loading agents.
> Webrev: http://cr.openjdk.java.net/~bchristi/8072130/webrev.01.cleanned/
> Additional details in the bug report:
> https://bugs.openjdk.java.net/browse/JDK-8072130
> Some background:
> Since JDK 8, if MacOS reports an encoding of US-ASCII, but no encoding 
> hints are provided in environment variables (LANG, LC_ALL, LC_CTYPE), 
> the JDK uses UTF-8 instead; see JDK-8011194[1].  (This allowed apps 
> launched via double-clicked jar to display files correctly for non-ASCII 
> languages).
> A similar encoding tweak was not made in the code path used for loading 
> agents.
> This can come into play when an agent jar includes a Boot-Class-Path 
> entry containing non-ASCII characters.  iconv() gets setup to convert 
> UTF-8 to US-ASCII[2], but will fail when encountering extended 
> characters in the entry, so the path in question is not added to the 
> bootclasspath[3].  This will likely lead to a ClassNotFoundException.
> When java/lang/instrument/BootClassPath/BootClassPathTest.sh is run on a 
>   Mac with no values for LANG/LC_ALL/LC_CTYPE, Setup.java sees a default 
>   encoding of UTF-8 (per 8011194) and creates Agent.jar with a 
> Boot-Class-Path that includes non-ASCII characters.  But the 
> Boot-Class-Path entry gets skipped when loading Agent.jar, so the 
> AgentSupport class can't be found.
> I propose this be fixed by adding the same UTF-8 encoding adjustment on 
> MacOS from 8011194 to the agent loading code path.
> An additional note:
> This bug was challenging to reproduce, in large part because the 8011194 
> code checks for an absent env var (getenv() == null), but not for env 
> vars with a blank/empty string value (getenv() == ""), so the test 
> environment had to be setup in a specific way (e.g. 'unset LANG' vs 
> 'export LANG=') to reproduce this bug.  So I'd like to update the code 
> to also check for empty string.  I also added a couple small 
> improvements to the test.
> Thanks!
> -Brent
> 1. https://bugs.openjdk.java.net/browse/JDK-8011194
> 2. 
> http://hg.openjdk.java.net/jdk/jdk/file/0517bd2a0eda/src/java.instrument/unix/native/libinstrument/EncodingSupport_md.c#l87 
> 3. 
> http://hg.openjdk.java.net/jdk/jdk/file/0517bd2a0eda/src/java.instrument/share/native/libinstrument/InvocationAdapter.c#l873 

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