Customizing C Indentation

Customizing C Indentation

[rdelcueto]

Hey all,

I hope you could help me figure out how to customize Emacs to indent code in the following way.

I'm working on an EDK related project. And the EDK code standards state the following:

"Subsequent lines of multi-line function calls should line up one or two tab-
stops from the beginning of the function name."

Example:

  Status = gRT->GetVariable(
                  NORMAL_SETUP_NAME,
                  &gEfiNormalSetupGuid,
                  NULL,
                  &VarSize,
                  &SystemConfiguration
                  );

So given a function call, the arglist-intro offset, should make reference to the position of the first character of the function being called, and from there, go up an indentation level.

I've read the Emacs documentation, and I only understood how to indent in relation to the previous line's indentation level. But I haven't been able to understand how to move within the previous line's content.

-Rodrigo

Re: Customizing C Indentation

[Rodrigo González del Cueto]

On Monday, April 13, 2015 at 5:52:49 PM UTC-5, Rodrigo González del Cueto wrote:
> Hey all,
> 
> I hope you could help me figure out how to customize Emacs to indent code in the following way.
> 
> I'm working on an EDK related project. And the EDK code standards state the following:
> 
> "Subsequent lines of multi-line function calls should line up one or two tab-
> stops from the beginning of the function name."
> 
> Example:
> 
>   Status = gRT->GetVariable(
>                   NORMAL_SETUP_NAME,
>                   &gEfiNormalSetupGuid,
>                   NULL,
>                   &VarSize,
>                   &SystemConfiguration
>                   );
> 
> So given a function call, the arglist-intro offset, should make reference to the position of the first character of the function being called, and from there, go up an indentation level.
> 
> I've read the Emacs documentation, and I only understood how to indent in relation to the previous line's indentation level. But I haven't been able to understand how to move within the previous line's content.
> 
> -Rodrigo

By the way, by EDK I mean the following project: https://github.com/tianocore/edk2

Re: Customizing C Indentation

[Rodrigo González del Cueto]

On Monday, April 13, 2015 at 5:52:49 PM UTC-5, Rodrigo González del Cueto wrote:
> Hey all,
> 
> I hope you could help me figure out how to customize Emacs to indent code in the following way.
> 
> I'm working on an EDK related project. And the EDK code standards state the following:
> 
> "Subsequent lines of multi-line function calls should line up one or two tab-
> stops from the beginning of the function name."
> 
> Example:
> 
>   Status = gRT->GetVariable(
>                   NORMAL_SETUP_NAME,
>                   &gEfiNormalSetupGuid,
>                   NULL,
>                   &VarSize,
>                   &SystemConfiguration
>                   );
> 
> So given a function call, the arglist-intro offset, should make reference to the position of the first character of the function being called, and from there, go up an indentation level.
> 
> I've read the Emacs documentation, and I only understood how to indent in relation to the previous line's indentation level. But I haven't been able to understand how to move within the previous line's content.
> 
> -Rodrigo

Just realized that the code example format doesn't look the same in every computer.
I'll link to the Github source code line, for a better view.

https://github.com/tianocore/edk2/blob/5d6bf9e22973c2ad327ca7422f80144c848912dc/Vlv2TbltDevicePkg/PlatformInfoDxe/PlatformInfoDxe.c#L67

Re: Customizing C Indentation

[Rodrigo González del Cueto]

I was finally able to customize the indentation to do what I wanted. I had some trouble with nested blocks. Apparently the basic-offset (2), kept accumulating within each nested block, offsetting them by more than they should.

I guess my solution is far from elegant, but it works!

I set arglist-intro and arglist-close to use my edk-c-lineup-calls function.
Here is the code:

(defun indent-edk-func-call ()
  (save-excursion
    (progn
      (re-search-forward "[a-zA-Z][a-zA-Z0-9]+ *(" (c-point 'eol) 'move)
      (if (match-string 0)
          (progn
            ;;(message "Matched:(%s), (%s), (%s)" (match-string 0) (match-string 1) (match-string 2))
            (goto-char (match-beginning 0))
            (current-column))
        nil))))

(defun edk-c-lineup-calls (langelem)
  ;; lineup stream operators
  (save-excursion
    (let* ((relpos (cdr langelem))
           (curcol (progn (goto-char relpos)
                          (current-column)))
           (indent-size (indent-edk-func-call)))
      (progn
        ;;(message "Indentation pos:(%s),(%s)" indent-size curcol)
        (if (> indent-size 0)
            (if (> curcol 2)
                (+ indent-size 2 (- curcol))
              indent-size)
          (progn
            ;;(message "+Indentation pos:(%s),(%s)" indent-size curcol)
              '+))))))

On Monday, April 13, 2015 at 5:52:49 PM UTC-5, Rodrigo González del Cueto wrote:
> Hey all,
> 
> I hope you could help me figure out how to customize Emacs to indent code in the following way.
> 
> I'm working on an EDK related project. And the EDK code standards state the following:
> 
> "Subsequent lines of multi-line function calls should line up one or two tab-
> stops from the beginning of the function name."
> 
> Example:
> 
>   Status = gRT->GetVariable(
>                   NORMAL_SETUP_NAME,
>                   &gEfiNormalSetupGuid,
>                   NULL,
>                   &VarSize,
>                   &SystemConfiguration
>                   );
> 
> So given a function call, the arglist-intro offset, should make reference to the position of the first character of the function being called, and from there, go up an indentation level.
> 
> I've read the Emacs documentation, and I only understood how to indent in relation to the previous line's indentation level. But I haven't been able to understand how to move within the previous line's content.
> 
> -Rodrigo