Re: GNU Make bug report: broken dry-run functionality with sub-make invocations
On Thu, 2022-03-17 at 18:27 +, Martin Dorey wrote: > That coped with -nj --no-print-directory on the one version of Make > that I tested it with, but I don't know how portable that would > prove. Modern versions of make guarantee a canonical format of MAKEFLAGS such that you can parse them relatively easily, and with confidence. The details are in the manual I believe but the short is: * All options that have "short" variants with no arguments (for example --dry-run -> -n) are converted to the short variants and put into the first word, with no leading "-" * All other options are added after that. * Short options have a single dash prefix and if they have an argument it's attached to the option * Long options have a double-dash prefix (obviously) and if they have an argument it's attached to the option with an "=" * Options that have both short and long forms, prefer the short form. So, for -n, you can use: $(findstring n,$(word 1,$(MAKEFLAGS))) and it will expand to "n" if dry run is enabled (regardless of which form the option was given in), or empty if not. So, the OP could use something like this: DRYRUN = $(findstring n,$(word 1,$(MAKEFLAGS))) main_target: create_logdirs $(MAKE) external_target $(if $(DRYRUN),,| tee logs/external_task.log) There are other alternatives. For example, you could add "+" as a prefix to the recipe in the create_logdirs so that the directories are created even when "-n" is given. But ultimately Martin's comment is correct: this is not a bug in make and there's no possible way that make could do anything "better" than what it does. At some level, especially if you're writing recursive makefile environments, your recipes have to be written to be resilient to the possibility that make was invoked with "-n".
Re: GNU Make bug report: broken dry-run functionality with sub-make invocations
> the statement after the pipe also gets executed
Would you have Make parse the shell command, assuming that SHELL isn't eg
/usr/bin/perl, splitting off anything after | and maybe ; and && and, why not,
||, so it only dry-runs the part of the command that invoked $(MAKE)? The
current behavior is documented,
https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html#MAKE-Variable
saying:
>> whenever a recipe line of a rule contains the variable MAKE, the flags ‘-t’,
>> ‘-n’ and ‘-q’ do not apply to that line
To put it another way: the Makefile needs to cope. Not doing the tee if the
directory doesn't exist would perhaps be most straightforward:
martind@sirius:~/tmp/ambrus-sumegi-2022-03-17$ diff -u Makefile{.orig,}
--- Makefile.orig 2022-03-17 11:13:46.000328340 -0700
+++ Makefile 2022-03-17 11:15:04.980482898 -0700
@@ -8,4 +8,4 @@
.PHONY: main_target
main_target: create_logdirs
- $(MAKE) external_target | tee logs/external_task.log
+ $(MAKE) external_target | { if test -d logs; then tee logs/external_task.log;
else cat; fi; }
martind@sirius:~/tmp/ambrus-sumegi-2022-03-17$
... though that means writing to the log with -n if the directory does exist,
which is perhaps undesirable. You could scrape the --dry-run flag out of
MAKEFLAGS, where it seems to get turned into n:
martind@sirius:~/tmp/ambrus-sumegi-2022-03-17$ diff -u Makefile{.orig,}
--- Makefile.orig 2022-03-17 11:13:46.000328340 -0700
+++ Makefile 2022-03-17 11:23:29.579910454 -0700
@@ -8,4 +8,4 @@
.PHONY: main_target
main_target: create_logdirs
- $(MAKE) external_target | tee logs/external_task.log
+ $(MAKE) external_target $(if $(findstring n,$(filter-out
--%,$(MAKEFLAGS))),,| tee logs/external_task.log)
martind@sirius:~/tmp/ambrus-sumegi-2022-03-17$
That coped with -nj --no-print-directory on the one version of Make that I
tested it with, but I don't know how portable that would prove.
Thank you for a nicely written up report with a minimal test case.
From: Bug-make on behalf of
Ambrus Sumegi
Sent: Thursday, March 17, 2022 08:59
To: bug-make@gnu.org
Subject: GNU Make bug report: broken dry-run functionality with sub-make
invocations
* EXTERNAL EMAIL *
Dear Devs,
I stumbled upon a rather rare case where Make produces a false error with the
--dry-run switch. I’ve attached a sample Makefile for reproduction.
The output of make main_target with this file is the following:
$ make main_target
mkdir logs
make external_target | tee logs/external_task.log
make[1]: Entering directory '/tmp/21176961.tmpdir/bugrepro'
This could be in a separate file somewhere
make[1]: Leaving directory '/tmp/21176961.tmpdir/bugrepro'
Nothing interesting there. But with the -n or --dry-run switch I get:
$ make main_target -n
mkdir logs
make external_target | tee logs/external_task.log
tee: logs/external_task.log: No such file or directory
make[1]: Entering directory '/tmp/21176961.tmpdir/bugrepro'
echo "This could be in a separate file somewhere"
make[1]: Leaving directory '/tmp/21176961.tmpdir/bugrepro'
make: *** [Makefile:11: main_target] Error 1
I get that the sub-make invocation gets executed with the switch passed to it
as well, and that is correct functionality. But then the statement after the
pipe also gets executed and throws an error about the missing log directory due
to the prerequisite target not having been run. This causes false failures in
release checks that use the --dry-run option of Make.
This behavior is the same in both versions of GNU make that I have access to on
the production system I’m using, 3.82 and 4.3
$ uname -r
3.10.0-693.21.1.el7.x86_64
$ make --version
GNU Make 3.82
Built for x86_64-redhat-linux-gnu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
http://gnu.org/licenses/gpl.html
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
# (…) Loading other version
$ make --version
GNU Make 4.3
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
GNU Make bug report: broken dry-run functionality with sub-make invocations
Dear Devs, I stumbled upon a rather rare case where Make produces a false error with the --dry-run switch. I've attached a sample Makefile for reproduction. The output of make main_target with this file is the following: $ make main_target mkdir logs make external_target | tee logs/external_task.log make[1]: Entering directory '/tmp/21176961.tmpdir/bugrepro' This could be in a separate file somewhere make[1]: Leaving directory '/tmp/21176961.tmpdir/bugrepro' Nothing interesting there. But with the -n or --dry-run switch I get: $ make main_target -n mkdir logs make external_target | tee logs/external_task.log tee: logs/external_task.log: No such file or directory make[1]: Entering directory '/tmp/21176961.tmpdir/bugrepro' echo "This could be in a separate file somewhere" make[1]: Leaving directory '/tmp/21176961.tmpdir/bugrepro' make: *** [Makefile:11: main_target] Error 1 I get that the sub-make invocation gets executed with the switch passed to it as well, and that is correct functionality. But then the statement after the pipe also gets executed and throws an error about the missing log directory due to the prerequisite target not having been run. This causes false failures in release checks that use the --dry-run option of Make. This behavior is the same in both versions of GNU make that I have access to on the production system I'm using, 3.82 and 4.3 $ uname -r 3.10.0-693.21.1.el7.x86_64 $ make --version GNU Make 3.82 Built for x86_64-redhat-linux-gnu Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. # (...) Loading other version $ make --version GNU Make 4.3 Built for x86_64-pc-linux-gnu Copyright (C) 1988-2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. Makefile Description: Makefile
