[commit/obv] Remove trailing space in gdbarch.sh.

[commit/obv] Remove trailing space in gdbarch.sh.

[Joel Brobecker]

Hello,

I noticed this trailing space when I ran an unmodified gdbarch.sh,
and yet got a difference in gdbarch.h!  Fixed in gdbarch.sh.

gdb/ChangeLog:

        * gdbarch.sh (software_single_step): Remove trailing space in
        comment (gdbarch.h is already correct).

Checked in.

---
 gdb/ChangeLog  |    5 +++++
 gdb/gdbarch.sh |    2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7b58f00..671aa09 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2012-12-12  Joel Brobecker  <brobecker@adacore.com>
+
+	* gdbarch.sh (software_single_step): Remove trailing space in
+	comment (gdbarch.h is already correct).
+
 2012-12-11  Tom Tromey  <tromey@redhat.com>
 
 	* dwarf2read.c (dwarf2_get_dwz_file): Set 'dwz_file'.
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 81a70b0..887552e 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -586,7 +586,7 @@ m:CORE_ADDR:addr_bits_remove:CORE_ADDR addr:addr::core_addr_identity::0
 # FIXME/cagney/2001-01-18: The logic is backwards.  It should be asking if the
 # target can single step.  If not, then implement single step using breakpoints.
 #
-# A return value of 1 means that the software_single_step breakpoints 
+# A return value of 1 means that the software_single_step breakpoints
 # were inserted; 0 means they were not.
 F:int:software_single_step:struct frame_info *frame:frame
 
-- 
1.7.10.4

Re: [commit/obv] Remove trailing space in gdbarch.sh.

[Pedro Alves]

On 12/12/2012 01:56 PM, Joel Brobecker wrote:
> Hello,
> 
> I noticed this trailing space when I ran an unmodified gdbarch.sh,
> and yet got a difference in gdbarch.h!  Fixed in gdbarch.sh.

I don't see such a difference, but the patch is of course fine.

git blame on the corresponding line on gdbarch.h points at:

Author: Joel Brobecker <brobecker@gnat.com>
Date:   Wed Oct 26 21:23:54 2011 +0000

    Regenerate gdbarch.h
    
    Not sure why, but the version currently checked in as an extraneous
    trailing whitespace that showed up as a diff when I reran gdbarch.sh.
    
    gdb/ChangeLog:
    
            * gdbarch.h: Regenerate.

:-)

I'm going to guess that you've been switching between systems, and
on some of those /bin/sh is bash while on others its dash
(most likely the latter is Ubuntu).

Regenerating gdbarch.h from scratch with bash always ends up with
that whitespace stripped for me.  If I run 'dash ./gdbarch.sh'
then indeed I see the extra space ending on up gdbarch.h.

"read" trims leading and trailing whitespace by default (on bash at least).  We
can make it not do that by setting the IFS variable to empty, like in the
patch below.  This should make it so that all shells behave the same
here (tried bash and dash), which I think would be good.

WDYT?

2012-12-12  Pedro Alves  <palves@redhat.com>

	* gdbarch.sh (do_read): Set IFS to blank.
---

 gdb/gdbarch.sh |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 81a70b0..7433378 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -47,7 +47,7 @@ do_read ()
 {
     comment=""
     class=""
-    while read line
+    while IFS='' read line
     do
 	if test "${line}" = ""
 	then

Re: [commit/obv] Remove trailing space in gdbarch.sh.

[Tom Tromey]

>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:

Pedro> "read" trims leading and trailing whitespace by default (on bash
Pedro> at least).  We can make it not do that by setting the IFS
Pedro> variable to empty, like in the patch below.  This should make it
Pedro> so that all shells behave the same here (tried bash and dash),
Pedro> which I think would be good.

Pedro> WDYT?

Seems sensible.

I often wish we could replace gdbarch.sh with something nicer.

Tom

Re: [commit/obv] Remove trailing space in gdbarch.sh.

[Joel Brobecker]

> I don't see such a difference, but the patch is of course fine.
> 
> git blame on the corresponding line on gdbarch.h points at:
> 
> Author: Joel Brobecker <brobecker@gnat.com>
> Date:   Wed Oct 26 21:23:54 2011 +0000

This is my evil twin :-).

> 2012-12-12  Pedro Alves  <palves@redhat.com>
> 
> 	* gdbarch.sh (do_read): Set IFS to blank.

Looks good to me.

Good analysis, as /bin/sh is indeed a link to dash on my laptop.

Thanks,
-- 
Joel

Re: [commit/obv] Remove trailing space in gdbarch.sh.

[Pedro Alves]

On 12/13/2012 05:46 AM, Joel Brobecker wrote:

> This is my evil twin :-).

:-)

>> 2012-12-12  Pedro Alves  <palves@redhat.com>
>>
>> 	* gdbarch.sh (do_read): Set IFS to blank.
> 
> Looks good to me.
> 
> Good analysis, as /bin/sh is indeed a link to dash on my laptop.

Thanks for confirming.  I've applied it now, with an added comment.

2012-12-13  Pedro Alves  <palves@redhat.com>

	* gdbarch.sh (do_read): Set IFS to blank.

---
 gdb/gdbarch.sh |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 887552e..8a56106 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -47,7 +47,10 @@ do_read ()
 {
     comment=""
     class=""
-    while read line
+    # On some SH's, 'read' trims leading and trailing whitespace by
+    # default (e.g., bash), while on others (e.g., dash), it doesn't.
+    # Set IFS to empty to disable the trimming everywhere.
+    while IFS='' read line
     do
 	if test "${line}" = ""
 	then