RFR: JDK-8171859: Configure check for modular boot jdk needs to be updated

[Erik Joelsson]

Here is a new patch, using --list-mods instead, seems cleaner to me.

diff -r 84c58139cbd3 common/autoconf/boot-jdk.m4
--- a/common/autoconf/boot-jdk.m4
+++ b/common/autoconf/boot-jdk.m4
@@ -305,9 +305,8 @@
    BOOT_JDK_SOURCETARGET="-source 8 -target 8"
    AC_SUBST(BOOT_JDK_SOURCETARGET)

-  ADD_JVM_ARG_IF_OK([--patch-module foo=bar], dummy, [$JAVA])
    AC_MSG_CHECKING([if Boot JDK supports modules])
-  if test "x$JVM_ARG_OK" = "xtrue"; then
+  if "$JAVA" --list-modules > /dev/null 2>&1; then
      AC_MSG_RESULT([yes])
      BOOT_JDK_MODULAR="true"
    else


/Erik


On 2016-12-22 17:48, Erik Joelsson wrote:
> Hello,
>
> Thanks for the suggestions. The way the test is currently implemented 
> is using a framework for finding valid JVM parameters. It basically runs:
>
> java $ArgToTest -version
>
> and parses the output for warnings and verifies that the version was 
> printed. After looking at this more closely, I realize the 
> --patch-module option was chosen to fit this kind of test. On the 
> other hand, we could easily change the implementation here to just run 
> "java --list-modules > /devnull" and check the return code. That's 
> probably cleaner anyway.
>
> /Erik
>
> On 2016-12-22 17:33, Mandy Chung wrote:
>> Using —-patch-module is one option.
>>
>> Alternatively, you can use other new options such as:
>>    $ java --dry-run -m jdk.compiler/com.sun.tools.javac.Main
>>
>> This stops before invoking the main method.
>>
>> or
>>    $ java —-list-modules
>>
>> This lists the observable modules in the image.
>>
>> Mandy
>>
>>> On Dec 22, 2016, at 1:39 AM, Erik Joelsson 
>>> <erik.joelsson at oracle.com> wrote:
>>>
>>> Hello,
>>>
>>> Configure has a check to see if the boot jdk is module 
>>> aware/enabled. Like many others, the build needs to adapt its 
>>> behavior when using such a boot jdk. The current check is no longer 
>>> compatible with the latest JDK 9 builds:
>>>
>>> java -version --patch-module foo=bar
>>> WARNING: Unknown module: foo specified in --patch-module
>>>
>>> I propose a simple adjustment, to instead specify java.base as the 
>>> module to patch. I also made it explicit that the directory to patch 
>>> from does not exist.
>>>
>>> I'm open to suggestions on better tests though, but would prefer if 
>>> they can be as simple as checking for a command line argument.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8171859
>>>
>>> Patch:
>>>
>>> diff -r 84c58139cbd3 common/autoconf/boot-jdk.m4
>>> --- a/common/autoconf/boot-jdk.m4
>>> +++ b/common/autoconf/boot-jdk.m4
>>> @@ -305,7 +305,9 @@
>>>    BOOT_JDK_SOURCETARGET="-source 8 -target 8"
>>>    AC_SUBST(BOOT_JDK_SOURCETARGET)
>>>
>>> -  ADD_JVM_ARG_IF_OK([--patch-module foo=bar], dummy, [$JAVA])
>>> +  # Use a non existing directory as the directory will be scanned 
>>> otherwise
>>> +  # and can potentially take a lot of time.
>>> +  ADD_JVM_ARG_IF_OK([--patch-module 
>>> java.base=SOME_DIR_THAT_DOES_NOT_EXIST], dummy, [$JAVA])
>>>    AC_MSG_CHECKING([if Boot JDK supports modules])
>>>    if test "x$JVM_ARG_OK" = "xtrue"; then
>>>      AC_MSG_RESULT([yes])
>>>
>>>
>>> /Erik
>>>
>