[8u] 8062808: Turn on the -Wreturn-type warning

[Hohensee, Paul]

Reviving this one.

Original issue: https://bugs.openjdk.java.net/browse/JDK-8062808
Original patch: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/ef7449e07592
Webrev: http://cr.openjdk.java.net/~phh/8062808/webrev.8u.00/

Applies clean except for the lack of -Wformat=2 in 8u's gcc.make, and the lack of klass_at_ignore_error in 8u's constantPool.hpp.

Thanks,
Paul

On 8/30/19, 9:31 AM, "jdk8u-dev on behalf of Liu, Xin" <jdk8u-dev-bounces at openjdk.java.net on behalf of xxinliu at amazon.com> wrote:

    Thanks, Andrew. 
    
    I saw you got review approval by Severin. How about we move forward? 
    I am good if you apply your patch for JDK-8062808. Could you also take care of 'perfData.hpp'?  we missed it. 
    
    Thanks,
    --lx
    
    
    On 8/30/19, 8:53 AM, "Andrew John Hughes" <gnu.andrew at redhat.com> wrote:
    
        
        
        On 28/08/2019 22:00, Liu, Xin wrote:
        > Hi,
        > 
        > 
        > I'd like to backport JDK-8062808.  Enabling -Wreturn-type helps us to catch undefined code.  Could you review it and update label in that issue?
        > 
        > webrev: https://cr.openjdk.java.net/~xliu/8062808/webrev/
        > 
        > 
        > It's almost a clean patch. One single difference is that original patch doesn't include perfData.hpp. It has been changed in JDK-8064811. When we backported JDK-8064811 to jdk8u, I think we drop it by mistake.
        > 
        > 
        > I have verified it using the jdk8u repo. Both fastdebug and slowdebug work as expected.
        > 
        > 
        > thanks,
        > 
        > --lx
        > 
        
        I already have a backport of this, which I intend to post once
        JDK-8141570 is in; see [0]. Doing this beforehand will break the Zero build.
        
        [0]
        https://mail.openjdk.java.net/pipermail/jdk8u-dev/2019-August/010100.html
        
        Thanks,
        -- 
        Andrew :)
        
        Senior Free Java Software Engineer
        Red Hat, Inc. (http://www.redhat.com)
        
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