8273072: Avoid using += in configure

[magicus]

JDK-8272700 was created to fix a bug in a variable assignment in configure. While it fixed the bug, it kept the problematic syntax that caused the bug in the first place.

We do not use the FOO+="appended" syntax for appending to variables in shell scripts, since this differs from what you'd expect (and what make produces) in that no space is added before the appended text.

Instead, we use the longer, but clearer FOO="$FOO appended".

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8273072: Avoid using += in configure

Reviewers

• David Holmes (@dholmes-ora - Reviewer) ⚠️ Review applies to 3083307
• Jie Fu (@DamonFool - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/5276/head:pull/5276
$ git checkout pull/5276

Update a local copy of the PR:
$ git checkout pull/5276
$ git pull https://git.openjdk.java.net/jdk pull/5276/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 5276

View PR using the GUI difftool:
$ git pr show -t 5276

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/5276.diff

[bridgekeeper]

👋 Welcome back ihse! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@magicus The following label will be automatically applied to this pull request:

• build

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 02: Full - Incremental (5dbc5ed1)
• 01: Full - Incremental (3083307d)
• 00: Full (a8e0c35a)

[DamonFool]

Please update the copyright year in jdk-version.m4.

Shall we also fix this one?

./devkit/createMacosxDevkit.sh:    EXCLUDE_ARGS+="--exclude=$ex "

[magicus]

Thank you for spotting this!

The exclude argument in the devkit builder looks like it has never worked. :(

[dholmes-ora]

I wouldn't have considered the m4 files as "shell scripts" and I'm surprised that the same operator in makefiles adds extra spaces - that seems unintuitive. But using the expanded format is fine.

Thanks,
David

[openjdk]

@magicus This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8273072: Avoid using += in configure

Reviewed-by: dholmes, jiefu

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 12 new commits pushed to the master branch:

• 596b075: 8258465: Headless build fails due to missing X11 headers on linux
• a49a0c5: 8273062: Generation::refs_discovery_is_xxx functions are unused
• ebd62bc: 8272846: Move some runtime/Metaspace/elastic/ tests out of tier1
• 46684a4: 8262386: resourcehogs/serviceability/sa/TestHeapDumpForLargeArray.java timed out
• c925c7f: 8273020: LibraryCallKit::sharpen_unsafe_type does not handle narrow oop array
• 76baace: 8273045: Fix misc javadoc bugs in the java.security and javax.net.ssl code
• b16a04e: 8271186: Add UL option to replace newline char
• d732c30: 8272863: Replace usages of Collections.sort with List.sort call in public java modules
• fe7d708: 8272473: Parsing epoch seconds at a DST transition with a non-UTC parser is wrong
• 845e1ce: 8272983: G1 Add marking details to eager reclaim logging
• ... and 2 more: https://git.openjdk.java.net/jdk/compare/11c9fd8298030200727a0e682fd9afb69ca8eb81...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[magicus]

@dholmes-ora The configure script is mostly shell code, with some m4 abstractions in it. (Autoconf calls this mongrel language for "m4sh". I'd rate it a 1 out of 5. Recommendation: stay away. ;-))

Makefiles, otoh, is a proper language, albeit badly designed. I'm actually a bit unsure if a construct like FOO+=BAR with no spaces would add a space (I still believe so, since make is so word-oriented), but we always use FOO += BAR. (Which is not possible in shells since that would not count as a variable assignment but a command execution...)

[magicus]

/integrate

[openjdk]

Going to push as commit a033aa5.
Since your change was applied there have been 13 commits pushed to the master branch:

• b92214a: 8272480: Remove Mutex::access rank
• 596b075: 8258465: Headless build fails due to missing X11 headers on linux
• a49a0c5: 8273062: Generation::refs_discovery_is_xxx functions are unused
• ebd62bc: 8272846: Move some runtime/Metaspace/elastic/ tests out of tier1
• 46684a4: 8262386: resourcehogs/serviceability/sa/TestHeapDumpForLargeArray.java timed out
• c925c7f: 8273020: LibraryCallKit::sharpen_unsafe_type does not handle narrow oop array
• 76baace: 8273045: Fix misc javadoc bugs in the java.security and javax.net.ssl code
• b16a04e: 8271186: Add UL option to replace newline char
• d732c30: 8272863: Replace usages of Collections.sort with List.sort call in public java modules
• fe7d708: 8272473: Parsing epoch seconds at a DST transition with a non-UTC parser is wrong
• ... and 3 more: https://git.openjdk.java.net/jdk/compare/11c9fd8298030200727a0e682fd9afb69ca8eb81...master

Your commit was automatically rebased without conflicts.

[openjdk]

@magicus Pushed as commit a033aa5.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.