RFR: JDK-8145115: make JAVAC_FLAGS=-g no longer works

[Magnus Ihse Bursie]

On 2015-12-10 16:02, Severin Gehwolf wrote:
> Yes, pretty please :) This is a long standing issue (not just java
> class debug info, but debug info in general). See
> JDK-8036003 with review thread:
> http://mail.openjdk.java.net/pipermail/build-dev/2015-December/016155.html
>
> Once JDK-8036003 is fixed we'd need something similar for Java classes
> and we can get rid of invoking make with build internal variables.

I agree. Yasumasa Suenaga had a pretty good implementation in 
http://cr.openjdk.java.net/~ysuenaga/JDK-8036003/webrev.04/.

I think it could form the basis of getting a proper java debug symbol 
support flag to configure. My main issue with that is that it must also 
work with the case  "--enable-debug --disable-java-debug-symbols", to 
produce a build without java debug symbols. This means that this logic 
need to interact with the logic in flags.m4:
   case $DEBUG_LEVEL in
     fastdebug | slowdebug )
       CFLAGS_JDK="$CFLAGS_JDK $CFLAGS_DEBUG_SYMBOLS $CFLAGS_DEBUG_OPTIONS"
       CXXFLAGS_JDK="$CXXFLAGS_JDK $CXXFLAGS_DEBUG_SYMBOLS 
$CXXFLAGS_DEBUG_OPTIONS"
       JAVAC_FLAGS="$JAVAC_FLAGS -g"

Without digging a bit deeper in the source, I can't say the best way to 
achieve this. Perhaps the configure flag check should set a variable 
like JAVA_DEBUG_SYMBOLS:=true/false/default that can be checked in 
flags.m4? Or we should defer the modification of JAVAC_FLAGS.

/Magnus