[PATCH] gdb/git: highlight whitespace errors source files

[PATCH] gdb/git: highlight whitespace errors source files

[Andrew Burgess]

For a long time I've had this in my ~/.gitconfig:

  [core]
          whitespace = space-before-tab,indent-with-non-tab,trailing-space

which causes git to show me if I muck up and use spaces instead of
tabs, or leave in trailing whitespace.  I find this really useful.

In this commit I'd like to propose adding something similar to our
three .gitattributes files, and enable whitespace error detection for
all .h, .c, and .cc files.

Errors are highlighted during a diff, for lines being added.
---
 gdb/.gitattributes        | 6 ++++--
 gdbserver/.gitattributes  | 6 +++++-
 gdbsupport/.gitattributes | 5 ++++-
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/gdb/.gitattributes b/gdb/.gitattributes
index 8acadb9813e..c9d3dbbc4be 100644
--- a/gdb/.gitattributes
+++ b/gdb/.gitattributes
@@ -2,6 +2,8 @@
 
 # Use cpp-style diffs for .h and .c files.  This is useful
 # if you modify classes defined in those files.
+#
+# Enable highlighting of whitespace errors in .h and .c files.
 
-*.h	diff=cpp
-*.c	diff=cpp
+*.h	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space
+*.c	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space
diff --git a/gdbserver/.gitattributes b/gdbserver/.gitattributes
index 6df25746593..5f745545212 100644
--- a/gdbserver/.gitattributes
+++ b/gdbserver/.gitattributes
@@ -2,5 +2,9 @@
 
 # Use cpp-style diffs for .h files.  This is useful
 # if you modify classes defined in a header file.
+#
+# Enable highlighting of whitespace errors in .h and .cc files.
+
+*.h	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space
+*.cc	whitespace=space-before-tab,indent-with-non-tab,trailing-space
 
-*.h	diff=cpp
diff --git a/gdbsupport/.gitattributes b/gdbsupport/.gitattributes
index 6df25746593..e9d9aee4261 100644
--- a/gdbsupport/.gitattributes
+++ b/gdbsupport/.gitattributes
@@ -2,5 +2,8 @@
 
 # Use cpp-style diffs for .h files.  This is useful
 # if you modify classes defined in a header file.
+#
+# Enable highlighting of whitespace errors in .h and .cc files.
 
-*.h	diff=cpp
+*.h	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space
+*.cc	whitespace=space-before-tab,indent-with-non-tab,trailing-space
-- 
2.25.4

Re: [PATCH] gdb/git: highlight whitespace errors source files

[Simon Marchi]

On 2022-07-18 10:43, Andrew Burgess via Gdb-patches wrote:
> For a long time I've had this in my ~/.gitconfig:
> 
>   [core]
>           whitespace = space-before-tab,indent-with-non-tab,trailing-space
> 
> which causes git to show me if I muck up and use spaces instead of
> tabs, or leave in trailing whitespace.  I find this really useful.
> 
> In this commit I'd like to propose adding something similar to our
> three .gitattributes files, and enable whitespace error detection for
> all .h, .c, and .cc files.
> 
> Errors are highlighted during a diff, for lines being added.

I think this is a good idea, it can only help.

Simon

Re: [PATCH] gdb/git: highlight whitespace errors source files

[Pedro Alves]

On 2022-07-18 4:36 p.m., Simon Marchi via Gdb-patches wrote:
> On 2022-07-18 10:43, Andrew Burgess via Gdb-patches wrote:
>> For a long time I've had this in my ~/.gitconfig:
>>
>>   [core]
>>           whitespace = space-before-tab,indent-with-non-tab,trailing-space
>>
>> which causes git to show me if I muck up and use spaces instead of
>> tabs, or leave in trailing whitespace.  I find this really useful.
>>
>> In this commit I'd like to propose adding something similar to our
>> three .gitattributes files, and enable whitespace error detection for
>> all .h, .c, and .cc files.
>>
>> Errors are highlighted during a diff, for lines being added.
> 
> I think this is a good idea, it can only help.

Agreed.

I've actually had two of these settings in my .gitconfig for a long time too,
didn't know we could set up in .gitattributes.  That's nice.

I didn't have indent-with-non-tab for some reason, which I assume it means
whoever I copied the options from didn't know about it either, and I didn't bother
to check what's available.  :-)

On 2022-07-18 3:43 p.m., Andrew Burgess via Gdb-patches wrote:
> --- a/gdb/.gitattributes
> +++ b/gdb/.gitattributes
> @@ -2,6 +2,8 @@
>  
>  # Use cpp-style diffs for .h and .c files.  This is useful
>  # if you modify classes defined in those files.
> +#
> +# Enable highlighting of whitespace errors in .h and .c files.
>  
> -*.h	diff=cpp
> -*.c	diff=cpp
> +*.h	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space
> +*.c	diff=cpp whitespace=space-before-tab,indent-with-non-tab,trailing-space

These attributes are inherited by subdirectories, right?  I'd add settings
for typical extensions used in the testsuite too, like .cc and .cpp.

But how about asking the binutils folks whether they'd be fine with
adding these in the top level .gitattributes?

GCC's top level .gitattributes also adds these settings, for example:

 https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=.gitattributes;h=e75bfc595bfb1ec14c364a650df08253f24beecc;hb=HEAD

(and from that, we see that "*.[cCh]" syntax works.)