[8u] RFR 8036003: Add --with-native-debug-symbols=[none|internal|external|zipped]

[Severin Gehwolf]

Hi,

This work started as a patch for JDK-8207234[1], but turned out to
become a 8-backport of JDK-8036003[2] using the old build logic and
with backwards-compatibilty. We are facing an issue where
.gnu_debuglink sections get generated unconditionally on the various
JDK libs (serviceability, security, nio, awt, etc.). That's an issue,
since for our distro builds the stripping happens outside the OpenJDK
build post-factum. The result of adding debug links unconditionally is
that our binaries would have two links, one pointing to a file which
doesn't exist.

What's more, there is no real support for the kind of debug-info build
we need as downstream distribution consumers: Have all debug symbols
present, but leave them in the binary/library itself without any
stripping. That's basically what JDK 11's --with-native-debug-
symbols=internal does. This patch ports that configure flag to JDK 8u
and keeps backward-compatibility with --disable-debug-symbols and --
disable-zip-debug-info flags. More info on this in [1].

Bug(s): https://bugs.openjdk.java.net/browse/JDK-8207234
        https://bugs.openjdk.java.net/browse/JDK-8036003
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8207234/01/

Testing:

Tested all build configs that I could think of (on Linux x86_64):
 * Old config is being preserved (default build of debug symbols +
   zipped; no --disable-zip-debug-info, --disable-debug-symbols, --
   with-native-debug-symbols flags)
 * Plain external debug symbols (flag --disable-zip-debug-info)
 * No debug-symbols build (flags --disable-zip-debug-info, --disable-
   debug-symbols)
 * Only using --with-native-debug-
   symbols={none,zipped,external,internal} (no flags --disable-zip-
   debug-info, --disable-debug-symbols). Where "internal" passes tests
   in JDK-8207234

Examples:

configure output post-patch with flags --disable-zip-debug-info, --
disable-debug-symbols:

[...]
checking if we should generate debug symbols... false
checking if we should zip debug-info files... no
checking what type of native debug symbols to use (this will override previous settings)... not specified
configure: --with-native-debug-symbols not specified. Using values from --disable-debug-symbols and --disable-zip-debug-info
[...]

configure output post-patch with flags --with-native-debug-
symbols=internal:

[...]
checking if we should generate debug symbols... true
checking if we should zip debug-info files... yes
checking what type of native debug symbols to use (this will override previous settings)... internal
[...]

configure output post-patch with flags --with-native-debug-
symbols=foobar:

[...]
checking if we should generate debug symbols... true
checking if we should zip debug-info files... yes
checking what type of native debug symbols to use (this will override previous settings)... foobar
configure: error: Allowed native debug symbols are: none, internal, external, zipped
configure exiting with result code 1

Thanks,
Severin

[1] https://bugs.openjdk.java.net/browse/JDK-8207234
[2] https://bugs.openjdk.java.net/browse/JDK-8036003