On 19. 5. 26 00:53, Johan Corveleyn wrote:
On Mon, May 4, 2026 at 4:19 AM<[email protected]> wrote:
Author: brane
Date: Mon May 4 02:19:20 2026
New Revision: 1933796
Log:
Silence JavaHL compiler warnings about missing bootstrap classpath.
Use the --release option instead of -source and -target if the Java
compiler supports it.
* build/ac-macros/java.m4
(SVN_FIND_JDK): Check the javac version and adjust flags accordingly.
If debugging is enabled, silence warnings about the target JVM version
8 (1.8) being deprecated.
Modified:
subversion/trunk/build/ac-macros/java.m4
Modified: subversion/trunk/build/ac-macros/java.m4
==============================================================================
--- subversion/trunk/build/ac-macros/java.m4 Mon May 4 00:35:48 2026
(r1933795)
+++ subversion/trunk/build/ac-macros/java.m4 Mon May 4 02:19:20 2026
(r1933796)
@@ -166,12 +166,27 @@ AC_DEFUN(SVN_FIND_JDK,
# The release for "-source" could actually be greater than that
# of "-target", if we want to cross-compile for lesser JVMs.
if test -z "$JAVAC_FLAGS"; then
- JAVAC_FLAGS="-target $JAVA_OLDEST_WORKING_VER -source 1.8"
+ java_version=[`"$JDK/bin/javac" -version 2>&1 | $SED -e 's/^[^0-9]*//'
-e 's/\.[^.]*$//'`]
+ java_major=[`echo $java_version | $SED -e 's/\.[^.]*$//'`]
+ java_minor=[`echo $java_version | $SED -e 's/^[^.]*\.//'`]
+ if test "$java_major" -eq 1 && test "$java_minor" -lt 9; then
+ JAVAC_FLAGS="-target $JAVA_OLDEST_WORKING_VER -source 1.8"
+ else
+ java_release=[`echo $JAVA_OLDEST_WORKING_VER | $SED -e 's/^[^.]*\.//'`]
+ JAVAC_FLAGS="--release $java_release"
The sed pattern looks a bit tricky to me, it will only work as long as
$JAVA_OLDEST_WORKING_VER is of the form 1.x, or if there would be no
'.' at all.
Yes. This is how Java version numbers are reported by the JVM. It was
1.X.y up to 1.10.y, then 11.x.y, 12.x.y etc. from then on. [1] The value
of this variable is completely under our control.
I see this value is only set in configure.ac:
[[[
# The minimum version for the JVM runtime for our Java bytecode.
JAVA_OLDEST_WORKING_VER='1.8'
# SVN_CHECK_JDK sets $JAVA_CLASSPATH
SVN_CHECK_JDK($JAVA_OLDEST_WORKING_VER)
]]]
I suppose whoever updates this someday will put '11' or '21' in there,
and not '11.0' or somesuch, but who knows.
We know, it's our variable and the build will fail if it's not properly
formatted. I assume that whoever changes this value — it has never
changed since it was introduced – will have the presence of mind to test
if the new value works.
Maybe (only converting 1.x to x):
java_release=[`echo $JAVA_OLDEST_WORKING_VER | $SED -e 's/^1\.//'`]
?
That's inconsistent with how the JRE reports its version number, see above.
+ fi
+
if test "$enable_debugging" = "yes"; then
JAVAC_FLAGS="-g -Xlint -Xlint:unchecked -Xlint:serial -Xlint:path
$JAVAC_FLAGS"
if test -z "$JAVAC_COMPAT_FLAGS"; then
JAVAC_COMPAT_FLAGS="$JAVAC_FLAGS -Xlint:-unchecked -Xlint:-deprecation
-Xlint:-dep-ann -Xlint:-rawtypes"
fi
+ else
+ dnl Ignore warnings about deprecated version 8 (from --release 8)
+ JAVAC_FLAGS="-Xlint:options"
+ if test -z "$JAVAC_COMPAT_FLAGS"; then
+ JAVAC_COMPAT_FLAGS="$JAVAC_FLAGS"
+ fi
I'm a bit confused. In the commit message you said: "If debugging is
enabled, silence warnings about the target JVM version 8 (1.8) being
deprecated.". But the change above is in the else branch of checking
for $enable_debugging. Did you mean to say "If debugging is *not*
enabled" in your commit message?
It's a psychic comment ... and a bug in the code. The current state of
that conditional block, also proposed for backport, is:
if test "$enable_debugging" = "yes"; then
JAVAC_FLAGS="-g -Xlint -Xlint:unchecked -Xlint:serial -Xlint:path
$JAVAC_FLAGS"
else
dnl Ignore warnings about deprecated version 8 (from --release 8)
JAVAC_FLAGS="-Xlint:-options $JAVAC_FLAGS"
fi
if test -z "$JAVAC_COMPAT_FLAGS"; then
JAVAC_COMPAT_FLAGS="$JAVAC_FLAGS -Xlint:-unchecked -Xlint:-deprecation
-Xlint:-dep-ann -Xlint:-rawtypes"
fi
The main purpose was to start using the --release 8 instead of -source
1.8 -target 1.8 flags from JDK 9 onwards. That removed the bootclasspath
warnings, but added warnings about release 8 being deprecated when
compiled with a newer JDK. I accidentally reversed the meaning of the
-Xlint:options flag in this commit but fixed it later.
Or ... IIUC -Xlint:options does warn about problems with command line
options. From "javac --help-lint" (with openjdk 21):
options Warn about issues relating to use of command
line options.
So perhaps here you intentionally enable warnings for "options" when
debugging is not enabled (and leave it to the recommended lint options
+ (unchecked, serial, path) if debugging is enabled)?
Options warnings are enabled by default, so they're on when configured
with --enable-debug or in maintainer mode.
-- Brane
[1] https://en.wikipedia.org/wiki/Java_version_history
