[v3] malloc: Always install mtrace (bug 31892)

Message ID 87bk3xc4u0.fsf@oldenburg.str.redhat.com
State Committed
Commit 086910fc41655152812b515dc324d2ac0dc36e67
Headers
Series [v3] malloc: Always install mtrace (bug 31892) |

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Commit Message

Florian Weimer June 19, 2024, 3:47 p.m. UTC
  Generation of the Perl script does not depend on Perl, so we can
always install it even if $(PERL) is not set during the build.

Change the malloc/mtrace.pl text substition not to rely on $(PERL).
Instead use PATH at run time to find the Perl interpreter. The Perl
interpreter cannot execute directly a script that starts with
“#! /bin/sh”: it always executes it with /bin/sh.  There is no
perl command line switch to disable this behavior.  Instead, use
the Perl require function to execute the script.  The additional
shift calls remove the “.” shell arguments.  Perl interprets the
“.” as a string concatenation operator, making the expression
syntactically valid.

---
v3: Git mishap did not squash together both changes.  Restore the
    removal of the $(PERL) conditional.

 malloc/Makefile  | 4 +---
 malloc/mtrace.pl | 7 +++----
 2 files changed, 4 insertions(+), 7 deletions(-)


base-commit: 4f1cf0c0e1764bd77235b07ff63631e866939ec6
  

Comments

Carlos O'Donell June 19, 2024, 6:13 p.m. UTC | #1
On 6/19/24 11:47 AM, Florian Weimer wrote:
> Generation of the Perl script does not depend on Perl, so we can
> always install it even if $(PERL) is not set during the build.
> 
> Change the malloc/mtrace.pl text substition not to rely on $(PERL).
> Instead use PATH at run time to find the Perl interpreter. The Perl
> interpreter cannot execute directly a script that starts with
> “#! /bin/sh”: it always executes it with /bin/sh.  There is no
> perl command line switch to disable this behavior.  Instead, use
> the Perl require function to execute the script.  The additional
> shift calls remove the “.” shell arguments.  Perl interprets the
> “.” as a string concatenation operator, making the expression
> syntactically valid.

LGTM. Thanks for fixing this!

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
 
> ---
> v3: Git mishap did not squash together both changes.  Restore the
>     removal of the $(PERL) conditional.
> 
>  malloc/Makefile  | 4 +---
>  malloc/mtrace.pl | 7 +++----
>  2 files changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/malloc/Makefile b/malloc/Makefile
> index cc14cf66c9..02aff1bd1d 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -250,7 +250,6 @@ others-extras = mcheck-init.o
>  aux := set-freeres thread-freeres
>  
>  # The Perl script to analyze the output of the mtrace functions.
> -ifneq ($(PERL),no)
>  install-bin-script = mtrace
>  generated += mtrace
>  
> @@ -261,7 +260,6 @@ address-width=10
>  else
>  address-width=18
>  endif
> -endif
>  
>  # Unless we get a test for the availability of libgd which also works
>  # for cross-compiling we disable the memusagestat generation in this
> @@ -349,7 +347,7 @@ sLIBdir := $(shell echo $(slibdir) | sed 's,lib\(\|64\)$$,\\\\$$LIB,')
>  
>  $(objpfx)mtrace: mtrace.pl
>  	rm -f $@.new
> -	sed -e 's|@PERL@|$(PERL)|' -e 's|@XXX@|$(address-width)|' \
> +	sed -e 's|@XXX@|$(address-width)|' \
>  	    -e 's|@VERSION@|$(version)|' \
>  	    -e 's|@PKGVERSION@|$(PKGVERSION)|' \
>  	    -e 's|@REPORT_BUGS_TO@|$(REPORT_BUGS_TO)|' $^ > $@.new \
> diff --git a/malloc/mtrace.pl b/malloc/mtrace.pl
> index 075da0d9f1..dc6085820e 100644
> --- a/malloc/mtrace.pl
> +++ b/malloc/mtrace.pl
> @@ -1,6 +1,6 @@
> -#! @PERL@
> -eval "exec @PERL@ -S $0 $@"
> -    if 0;
> +#! /bin/sh
> +eval exec "perl -e 'shift; \$progname=shift; shift; require \$progname'" . "$0" . "$@"
> +   if 0;
>  # Copyright (C) 1997-2024 Free Software Foundation, Inc.
>  # This file is part of the GNU C Library.
>  # Based on the mtrace.awk script.
> @@ -22,7 +22,6 @@ eval "exec @PERL@ -S $0 $@"
>  $VERSION = "@VERSION@";
>  $PKGVERSION = "@PKGVERSION@";
>  $REPORT_BUGS_TO = '@REPORT_BUGS_TO@';
> -$progname = $0;
>  
>  sub usage {
>      print "Usage: mtrace [OPTION]... [Binary] MtraceData\n";
> 
> base-commit: 4f1cf0c0e1764bd77235b07ff63631e866939ec6
>
  
Andreas Schwab June 20, 2024, 8:53 a.m. UTC | #2
On Jun 19 2024, Florian Weimer wrote:

> +#! /bin/sh
> +eval exec "perl -e 'shift; \$progname=shift; shift; require \$progname'" . "$0" . "$@"

eval expands the arguments a second time, so they need to be quoted twice.
  
Florian Weimer June 20, 2024, 9:14 a.m. UTC | #3
* Andreas Schwab:

> On Jun 19 2024, Florian Weimer wrote:
>
>> +#! /bin/sh
>> +eval exec "perl -e 'shift; \$progname=shift; shift; require \$progname'" . "$0" . "$@"
>
> eval expands the arguments a second time, so they need to be quoted twice.

I acknowledge that this is a problem.  I will try to come up with a
solution.  If I can't find one, I will revert this.

Thanks,
Florian
  

Patch

diff --git a/malloc/Makefile b/malloc/Makefile
index cc14cf66c9..02aff1bd1d 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -250,7 +250,6 @@  others-extras = mcheck-init.o
 aux := set-freeres thread-freeres
 
 # The Perl script to analyze the output of the mtrace functions.
-ifneq ($(PERL),no)
 install-bin-script = mtrace
 generated += mtrace
 
@@ -261,7 +260,6 @@  address-width=10
 else
 address-width=18
 endif
-endif
 
 # Unless we get a test for the availability of libgd which also works
 # for cross-compiling we disable the memusagestat generation in this
@@ -349,7 +347,7 @@  sLIBdir := $(shell echo $(slibdir) | sed 's,lib\(\|64\)$$,\\\\$$LIB,')
 
 $(objpfx)mtrace: mtrace.pl
 	rm -f $@.new
-	sed -e 's|@PERL@|$(PERL)|' -e 's|@XXX@|$(address-width)|' \
+	sed -e 's|@XXX@|$(address-width)|' \
 	    -e 's|@VERSION@|$(version)|' \
 	    -e 's|@PKGVERSION@|$(PKGVERSION)|' \
 	    -e 's|@REPORT_BUGS_TO@|$(REPORT_BUGS_TO)|' $^ > $@.new \
diff --git a/malloc/mtrace.pl b/malloc/mtrace.pl
index 075da0d9f1..dc6085820e 100644
--- a/malloc/mtrace.pl
+++ b/malloc/mtrace.pl
@@ -1,6 +1,6 @@ 
-#! @PERL@
-eval "exec @PERL@ -S $0 $@"
-    if 0;
+#! /bin/sh
+eval exec "perl -e 'shift; \$progname=shift; shift; require \$progname'" . "$0" . "$@"
+   if 0;
 # Copyright (C) 1997-2024 Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 # Based on the mtrace.awk script.
@@ -22,7 +22,6 @@  eval "exec @PERL@ -S $0 $@"
 $VERSION = "@VERSION@";
 $PKGVERSION = "@PKGVERSION@";
 $REPORT_BUGS_TO = '@REPORT_BUGS_TO@';
-$progname = $0;
 
 sub usage {
     print "Usage: mtrace [OPTION]... [Binary] MtraceData\n";