[PATCH] perf build: Fix detection of latest openjdk

[PATCH] perf build: Fix detection of latest openjdk

[Namhyung Kim]

My fedora system fails to find openjdk even if I installed the
'java-latest-openjdk-devel' package as in the warning message.
It turns out that the directory path is different than what's in the
output of alternatives.

  Makefile.config:1122: No openjdk development package found, please install JDK package,
                        e.g. openjdk-8-jdk, java-latest-openjdk-devel

The Makefile.config has the rule like below to detect the installed
directory with a version number.

  $ alternatives --display java | tail -1 | cut -d ' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g'
  /usr/lib/jvm/java-21-openjdk

This is to find a directory where the header file (jvmti.h) is like
/usr/lib/jvm/java-21-openjdk/include/jvmti.h.  However the header file
was in a different directory.

  $ rpm -ql java-latest-openjdk-devel | grep jvmti.h
  /usr/lib/jvm/java-latest-openjdk/include/jvmti.h

It seems the directory name is fixed to provide the latest version.
Let's check the directory name before using the parsed name.  With this
change, the warning is gone on my system.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile.config | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 333ddd0e4bd814e9..e6686641761fd0bf 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -1096,8 +1096,12 @@ ifndef NO_JVMTI
   ifneq (,$(wildcard /usr/sbin/update-java-alternatives))
     JDIR=$(shell /usr/sbin/update-java-alternatives -l | head -1 | awk '{print $$3}')
   else
-    ifneq (,$(wildcard /usr/sbin/alternatives))
-      JDIR=$(shell /usr/sbin/alternatives --display java | tail -1 | cut -d' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g')
+    ifneq (,$(wildcard /usr/lib/jvm/java-latest-openjdk/include))
+      JDIR=/usr/lib/jvm/java-latest-openjdk
+    else
+      ifneq (,$(wildcard /usr/sbin/alternatives))
+        JDIR=$(shell /usr/sbin/alternatives --display java | tail -1 | cut -d' ' -f 5 | sed -e 's%/jre/bin/java.%%g' -e 's%/bin/java.%%g')
+      endif
     endif
   endif
   ifndef JDIR
-- 
2.53.0