Introduce ENDLIST to terminate multiline makefile lists
Hi Hacker,
Patch [1]/messages/by-id/DF6HDGB559U5.3MPRFCWPONEAE@jeltef.nl reminded me of a technique that was used long ago in my early
C/C++ projects at Lucent Technologies (for those who still remember the
company :) ). In those projects, multi-line lists in Makefiles were always
terminated with $(ENDLIST), where ENDLIST is just a global dummy variable.
The benefits are:
* It clearly marks the end of a list.
* Adding or removing items does not require worrying about a trailing “\”.
* Changes at the end of a list do not introduce extra diff noise from
adjusting backslashes.
This is not a new invention on my part. I’m simply proposing to bring this
existing technique into the PostgreSQL source tree.
In this patch, I’ve only applied $(ENDLIST) to the Makefiles touched
by [1]/messages/by-id/DF6HDGB559U5.3MPRFCWPONEAE@jeltef.nl. If this approach is acceptable, I can follow up with a patch to
apply it more broadly.
Note that since ENDLIST is defined in Makefile.global.in, this change
requires rerunning ./configure.
[1]: /messages/by-id/DF6HDGB559U5.3MPRFCWPONEAE@jeltef.nl
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
Attachments:
v1-0001-Introduce-ENDLIST-to-terminate-multiline-makefile.patchapplication/octet-stream; name=v1-0001-Introduce-ENDLIST-to-terminate-multiline-makefile.patchDownload+27-13
On Mon, Dec 29, 2025 at 09:43:30AM +0800, Chao Li wrote:
Note that since ENDLIST is defined in Makefile.global.in, this change
requires rerunning ./configure.
FWIW, I don't see an advantage in this proposal, and it has the
disadvantage of more maintenance if one needs to create a new list.
The current state of things is simpler. I do get the argument about C
enums, but there is a difference between a grammar rule trick and
something allowed in a language specification.
--
Michael
On Mon, Dec 29, 2025 at 10:08 AM Michael Paquier <michael@paquier.xyz>
wrote:
On Mon, Dec 29, 2025 at 09:43:30AM +0800, Chao Li wrote:
Note that since ENDLIST is defined in Makefile.global.in, this change
requires rerunning ./configure.FWIW, I don't see an advantage in this proposal, and it has the
disadvantage of more maintenance if one needs to create a new list.
The current state of things is simpler.
For example, a list is:
```
OBJS = \
a.o \
b.o
```
Now we need to add c.o, then:
```
OBJS = \
a.o \
b.o \ <== this line needs to add tailing \
c.o <== add this new line
```
there are two lines of changes.
With the $(ENDLIST), we just add an single line:
```
OBJS = \
a.o \
b.o \
c.o \ <== only adding this new line, a single line of diff
$(ENDLIST)
```
Could you please explain what more maintenance would be?
I do get the argument about C enums, but there is a difference between a
grammar rule trick and
something allowed in a language specification.
I didn't mention C enums. How did you get that? I think I only mentioned
C/C++ projects because they used Makefile for building.
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
Michael Paquier <michael@paquier.xyz> writes:
On Mon, Dec 29, 2025 at 09:43:30AM +0800, Chao Li wrote:
Note that since ENDLIST is defined in Makefile.global.in, this change
requires rerunning ./configure.
FWIW, I don't see an advantage in this proposal, and it has the
disadvantage of more maintenance if one needs to create a new list.
The current state of things is simpler.
Same here. This is a new bit of notation that everyone reading our
Makefiles will need to understand, and I don't think it's worth
the extra cognitive burden.
regards, tom lane