[Rev 02] RFR: 8241476: Linux build warning issued on updated compilers (Ubuntu 18.04.4 / 20.04)

[Kevin Rushforth]

On Sun, 29 Mar 2020 00:38:20 GMT, Thiago Milczarek Sayao <tsayao at openjdk.org> wrote:

>> Simple fix to remove annoying warnings.
>
> Thiago Milczarek Sayao has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Sep cppFlags and cFlags

The build changes in `linux.gradle` look good. I tested it, and all warnings are gone (including those in WebKit)
except for the ones in the jfxmedia sub-project of javafx.media.

Two comments:

1. I changed the bug title in JBS to refer to gcc 9 rather than Ubuntu to reflect the actual cause of the additional
warnings. Can you update the title of this PR to match? 8241476: Linux build warnings issued on gcc 9

2. Can you add the following change to your PR as well? This will fix the remaining warnings in jfxmedia:

--- a/modules/javafx.media/src/main/native/jfxmedia/projects/linux/Makefile
+++ b/modules/javafx.media/src/main/native/jfxmedia/projects/linux/Makefile
@@ -41,7 +41,6 @@ ifdef HOST_COMPILE
                   -Wextra \
                   -Wformat-security \
                   -fstack-protector \
-                  -Werror=implicit-function-declaration \
                   -Werror=trampolines \
                  -msse2 \
                  -DGSTREAMER_LITE

-------------

PR: https://git.openjdk.java.net/jfx/pull/150