RFR: 8343883: Cannot resolve user specified toolchain-path for lld after JDK-8338304

[SendaoYan]

On Tue, 12 Nov 2024 13:21:04 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

>> Hi all,
>> After [JDK-8338304](https://bugs.openjdk.org/browse/JDK-8338304), below configure command will generate failure `error: Could not find required tool for LLD`. The lld linker located in path which config with option `--with-toolchain-path`, but the check `UTIL_REQUIRE_PROGS(LLD, lld)` introduced by [JDK-8338304](https://bugs.openjdk.org/browse/JDK-8338304) was unable to find the lld. This PR add the condition to deal with user specidied `--with-toolchain-path` to find the correct lld fullpath. The change has beeen verified locally, trivial fix, the risk is low.
>> 
>> 
>> bash configure --with-jobs=128 --with-debug-level=release --enable-unlimited-crypto --with-jvm-variants=server --with-version-opt=f4008968 --with-zlib=system --with-toolchain-type=clang --with-toolchain-path=/home/yansendao/software/acc/x86_64/bin
>
> make/autoconf/flags-ldflags.m4 line 78:
> 
>> 76:       if test "x$CXX_IS_USER_SUPPLIED" = xfalse && test "x$CC_IS_USER_SUPPLIED" = xfalse; then
>> 77:         if test "x$TOOLCHAIN_PATH" != x; then
>> 78:           UTIL_REQUIRE_PROGS(LLD, lld, $TOOLCHAIN_PATH)
> 
> No, this is not correct. Did you test this patch *without* having lld in the toolchain path? Doing this will remove the normal lookup in `$PATH` and only look in `$TOOLCHAIN_PATH`.

After I remove the lld binary from `$TOOLCHAIN_PATH`, such as `mv /home/yansendao/software/acc/x86_64/bin/lld /tmp/`, the configure command generate `configure: error: Could not find required tool for LLD` as expected.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21999#discussion_r1838257682