[PATCH] doc: hint about GIT_DEBUGGER

[PATCH] doc: hint about GIT_DEBUGGER

[Emily Shaffer]

We check for a handy environment variable GIT_DEBUGGER when running via
bin-wrappers/, but this feature is undocumented. Add a hint to how to
use it into the CodingGuidelines (which is where other useful
environment settings like DEVELOPER are documented).

It looks like you can use GIT_DEBUGGER to pick gdb by default, or you
can hand it your own debugger if you like to use something else (or if
you want custom flags for gdb). Hopefully document that intent within
CodingGuidelines.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
Maybe this isn't the right place for this patch. But right now git grep
reveals that GIT_DEBUGGER is completely undocumented.

Alternatively, it might make sense to only add a short blurb about using
GIT_DEBUGGER flag to CodingGuidelines and then documenting how to use it
inside of wrap-for-bin.sh.

 Documentation/CodingGuidelines | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 32210a4386..e17cd75b50 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -412,6 +412,11 @@ For C programs:
    must be declared with "extern" in header files. However, function
    declarations should not use "extern", as that is already the default.
 
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+   run `GIT_DEBUGGER=debugger-binary some-args ./bin-wrappers/git foo` to
+   use your own debugger and arguments. (See `wrap-for-bin.sh`.)
+
 For Perl programs:
 
  - Most of the C guidelines above apply.
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH] doc: hint about GIT_DEBUGGER

[Elijah Newren]

Hi Emily,

On Fri, May 17, 2019 at 3:40 PM Emily Shaffer <emilyshaffer@google.com> wrote:
>
> We check for a handy environment variable GIT_DEBUGGER when running via
> bin-wrappers/, but this feature is undocumented. Add a hint to how to
> use it into the CodingGuidelines (which is where other useful
> environment settings like DEVELOPER are documented).
>
> It looks like you can use GIT_DEBUGGER to pick gdb by default, or you
> can hand it your own debugger if you like to use something else (or if
> you want custom flags for gdb). Hopefully document that intent within
> CodingGuidelines.

Thanks for working on this.

> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
> Maybe this isn't the right place for this patch. But right now git grep
> reveals that GIT_DEBUGGER is completely undocumented.

Does 'git log --grep=GIT_DEBUGGER' count?  ;-)

> Alternatively, it might make sense to only add a short blurb about using
> GIT_DEBUGGER flag to CodingGuidelines and then documenting how to use it
> inside of wrap-for-bin.sh.
>
>  Documentation/CodingGuidelines | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> index 32210a4386..e17cd75b50 100644
> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -412,6 +412,11 @@ For C programs:
>     must be declared with "extern" in header files. However, function
>     declarations should not use "extern", as that is already the default.
>
> + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> +   run `GIT_DEBUGGER=debugger-binary some-args ./bin-wrappers/git foo` to

Missing some quotes around debugger-binary and some-args:
+   run `GIT_DEBUGGER="debugger-binary some-args" ./bin-wrappers/git foo` to

Also, one thing I always wonder about with command documentation like
this is whether people will understand that "debugger-binary",
"some-args", and "foo" are just placeholders rather than literal text
-- and that everything else is literal text and not meant to be
placeholders.  Does it make since to include a couple examples, or
perhaps modify the text somehow to avoid confusion between
placeholders and literals, or maybe just tell me I overthinking this?
(I've been bit by similar problems in other contexts, so I'm just
flagging it for you to consider).

Elijah

Re: [PATCH] doc: hint about GIT_DEBUGGER

[Emily Shaffer]

[snip]

> > + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> > +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> > +   run `GIT_DEBUGGER=debugger-binary some-args ./bin-wrappers/git foo` to
> 
> Missing some quotes around debugger-binary and some-args:
> +   run `GIT_DEBUGGER="debugger-binary some-args" ./bin-wrappers/git foo` to
> 
> Also, one thing I always wonder about with command documentation like
> this is whether people will understand that "debugger-binary",
> "some-args", and "foo" are just placeholders rather than literal text
> -- and that everything else is literal text and not meant to be
> placeholders.  Does it make since to include a couple examples, or
> perhaps modify the text somehow to avoid confusion between
> placeholders and literals, or maybe just tell me I overthinking this?
> (I've been bit by similar problems in other contexts, so I'm just
> flagging it for you to consider).

It's a good point. I like to use placeholders that don't sound like a
real command (and failed a little here), for example,
`GIT_DEBUGGER=my-cool-debugger some-various-args`. It can be a challenge
to choose a placeholder that sounds fake but also doesn't sound too
informal (the above feels informal to me). I think the best way is to
show an example, that's a good idea. I'll come up with one and send
another round this week.

Thanks a bunch for having a look.

 - Emily

> 
> Elijah

[PATCH v2] doc: hint about GIT_DEBUGGER

[Emily Shaffer]

We check for a handy environment variable GIT_DEBUGGER when running via
bin-wrappers/, but this feature is undocumented. Add a hint to how to
use it into the CodingGuidelines (which is where other useful
environment settings like DEVELOPER are documented).

It looks like you can use GIT_DEBUGGER to pick gdb by default, or you
can hand it your own debugger if you like to use something else (or if
you want custom flags for gdb). Hopefully document that intent within
CodingGuidelines.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 Documentation/CodingGuidelines | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 32210a4386..e99af36df9 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -412,6 +412,12 @@ For C programs:
    must be declared with "extern" in header files. However, function
    declarations should not use "extern", as that is already the default.
 
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to
+   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
 For Perl programs:
 
  - Most of the C guidelines above apply.
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH v2] doc: hint about GIT_DEBUGGER

[Elijah Newren]

On Mon, May 20, 2019 at 6:01 PM Emily Shaffer <emilyshaffer@google.com> wrote:
>
> We check for a handy environment variable GIT_DEBUGGER when running via
> bin-wrappers/, but this feature is undocumented. Add a hint to how to
> use it into the CodingGuidelines (which is where other useful
> environment settings like DEVELOPER are documented).
>

Two very minor nits:

> It looks like you can use GIT_DEBUGGER to pick gdb by default, or you

I think it'd sound better without 'It looks like'; perhaps drop that part?

> can hand it your own debugger if you like to use something else (or if
> you want custom flags for gdb). Hopefully document that intent within
> CodingGuidelines.

Maybe just leave out 'Hopefully'?

>
> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
>  Documentation/CodingGuidelines | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> index 32210a4386..e99af36df9 100644
> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -412,6 +412,12 @@ For C programs:
>     must be declared with "extern" in header files. However, function
>     declarations should not use "extern", as that is already the default.
>
> + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> +   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to
> +   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
> +   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
> +

Other than the minor nits above:
Acked-by: Elijah Newren <newren@gmail.com>

Re: [PATCH v2] doc: hint about GIT_DEBUGGER

[Emily Shaffer]

On Tue, May 21, 2019 at 09:06:18AM -0700, Elijah Newren wrote:
> On Mon, May 20, 2019 at 6:01 PM Emily Shaffer <emilyshaffer@google.com> wrote:
> >
> > We check for a handy environment variable GIT_DEBUGGER when running via
> > bin-wrappers/, but this feature is undocumented. Add a hint to how to
> > use it into the CodingGuidelines (which is where other useful
> > environment settings like DEVELOPER are documented).
> >
> 
> Two very minor nits:
> 
> > It looks like you can use GIT_DEBUGGER to pick gdb by default, or you
> 
> I think it'd sound better without 'It looks like'; perhaps drop that part?
> 
> > can hand it your own debugger if you like to use something else (or if
> > you want custom flags for gdb). Hopefully document that intent within
> > CodingGuidelines.
> 
> Maybe just leave out 'Hopefully'?
> 
> >
> > Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> > ---
> >  Documentation/CodingGuidelines | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> > index 32210a4386..e99af36df9 100644
> > --- a/Documentation/CodingGuidelines
> > +++ b/Documentation/CodingGuidelines
> > @@ -412,6 +412,12 @@ For C programs:
> >     must be declared with "extern" in header files. However, function
> >     declarations should not use "extern", as that is already the default.
> >
> > + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> > +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> > +   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to
> > +   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
> > +   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
> > +
> 
> Other than the minor nits above:
> Acked-by: Elijah Newren <newren@gmail.com>

Made both the changes you recommended; I'll hang onto it locally until
this afternoon in case anybody else has something to say. Thanks for
looking, Elijah.

 - Emily

[PATCH v3] doc: hint about GIT_DEBUGGER in CodingGuidelines

[Emily Shaffer]

We check for a handy environment variable GIT_DEBUGGER when running via
bin-wrappers/, but this feature is undocumented. Add a hint to how to
use it into the CodingGuidelines (which is where other useful
environment settings like DEVELOPER are documented).

You can use GIT_DEBUGGER to pick gdb by default, or you can hand it your
own debugger if you like to use something else (or if you want custom
flags for gdb). This commit documents that intent within
CodingGuidelines.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---

Since v2, only the commit message has changed. Removed some weak
language to make the commit message read more easily.

 Documentation/CodingGuidelines | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 32210a4386..e99af36df9 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -412,6 +412,12 @@ For C programs:
    must be declared with "extern" in header files. However, function
    declarations should not use "extern", as that is already the default.
 
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to
+   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
 For Perl programs:
 
  - Most of the C guidelines above apply.
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH v3] doc: hint about GIT_DEBUGGER in CodingGuidelines

[Eric Sunshine]

On Wed, May 22, 2019 at 8:56 PM Emily Shaffer <emilyshaffer@google.com> wrote:
> We check for a handy environment variable GIT_DEBUGGER when running via
> bin-wrappers/, but this feature is undocumented. Add a hint to how to
> use it into the CodingGuidelines (which is where other useful
> environment settings like DEVELOPER are documented).
>
> You can use GIT_DEBUGGER to pick gdb by default, or you can hand it your
> own debugger if you like to use something else (or if you want custom
> flags for gdb). This commit documents that intent within
> CodingGuidelines.

This last sentence is repeating what is already stated in the first
paragraph, thus doesn't seem to add value. In fact, the remainder of
the second paragraph seems to be repeating what is in the patch
proper, thus could likely be dropped.

> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
> diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> @@ -412,6 +412,12 @@ For C programs:
> + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> +   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to

Don't you need to bind my-debugger-binary and my-args together with
shell quotes? Also, placeholders like these are often ensconced in
angle brackets, so perhaps:

    ... `GIT_DEBUGGER="<debugger> <debugger-args>" ./bin-wrappers/git ...

> +   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
> +   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)

Re: [PATCH v3] doc: hint about GIT_DEBUGGER in CodingGuidelines

[Emily Shaffer]

On Thu, May 23, 2019 at 06:09:17AM -0400, Eric Sunshine wrote:
> On Wed, May 22, 2019 at 8:56 PM Emily Shaffer <emilyshaffer@google.com> wrote:
> > We check for a handy environment variable GIT_DEBUGGER when running via
> > bin-wrappers/, but this feature is undocumented. Add a hint to how to
> > use it into the CodingGuidelines (which is where other useful
> > environment settings like DEVELOPER are documented).
> >
> > You can use GIT_DEBUGGER to pick gdb by default, or you can hand it your
> > own debugger if you like to use something else (or if you want custom
> > flags for gdb). This commit documents that intent within
> > CodingGuidelines.
> 
> This last sentence is repeating what is already stated in the first
> paragraph, thus doesn't seem to add value. In fact, the remainder of
> the second paragraph seems to be repeating what is in the patch
> proper, thus could likely be dropped.

Yes, you're right. Dropped.

> 
> > Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> > ---
> > diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
> > @@ -412,6 +412,12 @@ For C programs:
> > + - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
> > +   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
> > +   run `GIT_DEBUGGER=my-debugger-binary my-args ./bin-wrappers/git foo` to
> 
> Don't you need to bind my-debugger-binary and my-args together with
> shell quotes? Also, placeholders like these are often ensconced in
> angle brackets, so perhaps:
> 
>     ... `GIT_DEBUGGER="<debugger> <debugger-args>" ./bin-wrappers/git ...

Fixed. I did get the dq in the example but missed it with the
placeholders. :) Thanks, good catch.

> > +   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
> > +   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)

Patch update to follow. Thanks.

 - Emily

[PATCH v4] doc: hint about GIT_DEBUGGER in CodingGuidelines

[Emily Shaffer]

We check for a handy environment variable GIT_DEBUGGER when running via
bin-wrappers/, but this feature is undocumented. Add a hint to how to
use it into the CodingGuidelines (which is where other useful
environment settings like DEVELOPER are documented).

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 Documentation/CodingGuidelines | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index 32210a4386..1169ff6c8e 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -412,6 +412,12 @@ For C programs:
    must be declared with "extern" in header files. However, function
    declarations should not use "extern", as that is already the default.
 
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+   run `GIT_DEBUGGER="<debugger> <debugger-args>" ./bin-wrappers/git foo` to
+   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
 For Perl programs:
 
  - Most of the C guidelines above apply.
-- 
2.22.0.rc1.257.g3120a18244-goog