RFR: JDK-8047177: JDK build should make use of the new -XXuserPathsFirst

[Jonathan Gibbons]

Why is sjavac ever looking at the classes in the bootclasspath of the 
boot jdk in the compilation environment?

The boot JDK should only be used to *run* sjavac. Nothing more. The 
compilation environment should only be "the new world".

-- Jon

On 10/28/2014 03:40 AM, Erik Joelsson wrote:
> Hello,
>
> Please review this small fix when using sjavac. When using a bootjdk 
> that was built at a later date than when the source tree was initially 
> cloned, there is a risk that sjavac will pick up classes from the boot 
> classpath (rt.jar of boot jdk) instead of the source files, concluding 
> that the source files won't need to be built. This is only an issue 
> when building classes that are also present in the boot classpath of 
> the bootjdk, which we normally do since we are building the jdk.
>
> The fix is to add a special option for this use case, which forces 
> sjavac to build source files if found, regardless of class file dates.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8047177
> Patch inline:
> diff -r 12d3dc35f0e8 make/common/JavaCompilation.gmk
> --- a/make/common/JavaCompilation.gmk
> +++ b/make/common/JavaCompilation.gmk
> @@ -583,8 +583,12 @@
>      $$(if $$(filter-out $$($1_SRCS), $$?), $(FIND) $$(@D) -name 
> "*.class" $(FIND_DELETE))
>      $$(call ListPathsSafely,$1_SRCS,\n, >> $$($1_BIN)/_the.$1_batch.tmp)
>      $(ECHO) Compiling $1
> +        # Run with -XXuserPathsFirst to always build source files 
> even if there happens to
> +        # be class files in the boot classpath (rt.jar of boot jdk) 
> with a newer modified
> +        # time.
>      ($$($1_JVM) $$($1_SJAVAC) \
>          $$($1_REMOTE) \
> +        -XXuserPathsFirst \
>          -j 1 \
>          --permit-unidentified-artifacts \
>          --permit-sources-without-package \
>
>
> /Erik