# xfuncname problems with C++

7 messages from 2015-01-02 to 2015-01-02. Participants: Robert Dailey, Jonathan Nieder, Johannes Sixt.
Thread: https://gitlist.dev/t/38272

## Robert Dailey, 2015-01-02 16:49

Subject: xfuncname problems with C++
Message-ID: <CAHd499Cn8C51i_+Dm4h_U4X_Jc-nhNMjoufiZRdn5LGxFqD_HA@mail.gmail.com>
URL: https://gitlist.dev/e/CAHd499Cn8C51i_%2BDm4h_U4X_Jc-nhNMjoufiZRdn5LGxFqD_HA%40mail.gmail.com

```
I have a function like so:

void MyClass::SomeFunction(int someParameter)
{
    // Stuff changed in here
}

When I do `git diff` on the file containing this function, I get a
chunk showing some changed code in this function somewhere in the
middle of the body. However, the chunk header shows my root namespace
name in the file instead of the function header:

@@ -144,15 +149,22 @@ namespace Utils

What I expect to see:

@@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)

I've tried various regular expressions that work in regex testers I
use against this function signature, however they do not work when I
apply them to my config:

[diff "cpp"]
    xfuncname =
"^\\s*[\\w_][\\w\\d_]*\\s*.*\\s*[\\w_][\\w\\d_]*\\s*\\(.*\\)\\s*$"

File name is "foo.cpp", I even added it to my git attributes file:

*.cpp diff=cpp

Using the regex above, my chunk headers come back blank. Why is it
showing namespace? How do I make this match the nearest function
header?

```

## Robert Dailey, 2015-01-02 17:03

Subject: Re: xfuncname problems with C++
Message-ID: <CAHd499C_Z_npG3ibv_gJSU7kqrT6=DRCV8TU9_sjz9zzQ7vC-Q@mail.gmail.com>
URL: https://gitlist.dev/e/CAHd499C_Z_npG3ibv_gJSU7kqrT6%3DDRCV8TU9_sjz9zzQ7vC-Q%40mail.gmail.com
In-Reply-To: <CAHd499Cn8C51i_+Dm4h_U4X_Jc-nhNMjoufiZRdn5LGxFqD_HA@mail.gmail.com>

```
On Fri, Jan 2, 2015 at 10:49 AM, Robert Dailey <rcdailey.lists@gmail.com> wrote:
> I have a function like so:
>
> void MyClass::SomeFunction(int someParameter)
> {
>     // Stuff changed in here
> }
>
> When I do `git diff` on the file containing this function, I get a
> chunk showing some changed code in this function somewhere in the
> middle of the body. However, the chunk header shows my root namespace
> name in the file instead of the function header:
>
> @@ -144,15 +149,22 @@ namespace Utils
>
> What I expect to see:
>
> @@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)
>
> I've tried various regular expressions that work in regex testers I
> use against this function signature, however they do not work when I
> apply them to my config:
>
> [diff "cpp"]
>     xfuncname =
> "^\\s*[\\w_][\\w\\d_]*\\s*.*\\s*[\\w_][\\w\\d_]*\\s*\\(.*\\)\\s*$"
>
> File name is "foo.cpp", I even added it to my git attributes file:
>
> *.cpp diff=cpp
>
> Using the regex above, my chunk headers come back blank. Why is it
> showing namespace? How do I make this match the nearest function
> header?

Oopsie, I didn't realize the regex must be POSIX compatible. I've
updated the regex to this:
https://www.regex101.com/r/kP3dM6

The test seems to work; however git gives me an error with the regex
when I do a diff:

$ git diff Core
fatal: Invalid regexp to look for hunk header:
^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\(.*\)[[:space:]]*$

Here is how it is stored in my .gitconfig:

[diff "cpp"]
    xfuncname =
"^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\\(.*\\)[[:space:]]*$"

```

## Jonathan Nieder, 2015-01-02 20:19

Subject: Re: xfuncname problems with C++
Message-ID: <20150102201959.GG29365@google.com>
URL: https://gitlist.dev/e/20150102201959.GG29365%40google.com
In-Reply-To: <CAHd499Cn8C51i_+Dm4h_U4X_Jc-nhNMjoufiZRdn5LGxFqD_HA@mail.gmail.com>

```
Hi,

Robert Dailey wrote:

> I have a function like so:
>
> void MyClass::SomeFunction(int someParameter)
> {
>     // Stuff changed in here
> }
>
> When I do `git diff` on the file containing this function, I get a
> chunk showing some changed code in this function somewhere in the
> middle of the body. However, the chunk header shows my root namespace
> name in the file instead of the function header:
>
> @@ -144,15 +149,22 @@ namespace Utils
>
> What I expect to see:
>
> @@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)

What version of git are you using?  Could you give a full copy of the
diff so we can have more context (feeling free to mark parts of it as
CENSORED where appropriate, but keeping leading whitespace and the
first +/- column)?

Thanks,
Jonathan

```

## Johannes Sixt, 2015-01-02 20:25

Subject: Re: xfuncname problems with C++
Message-ID: <54A6FEB6.40305@kdbg.org>
URL: https://gitlist.dev/e/54A6FEB6.40305%40kdbg.org
In-Reply-To: <CAHd499Cn8C51i_+Dm4h_U4X_Jc-nhNMjoufiZRdn5LGxFqD_HA@mail.gmail.com>

```
Am 02.01.2015 um 17:49 schrieb Robert Dailey:
> I have a function like so:
> 
> void MyClass::SomeFunction(int someParameter)
> {
>     // Stuff changed in here
> }
> 
> When I do `git diff` on the file containing this function, I get a
> chunk showing some changed code in this function somewhere in the
> middle of the body. However, the chunk header shows my root namespace
> name in the file instead of the function header:
> 
> @@ -144,15 +149,22 @@ namespace Utils
> 
> What I expect to see:
> 
> @@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)
> 
> I've tried various regular expressions that work in regex testers I
> use against this function signature, however they do not work when I
> apply them to my config:
> 
> [diff "cpp"]
>     xfuncname =
> "^\\s*[\\w_][\\w\\d_]*\\s*.*\\s*[\\w_][\\w\\d_]*\\s*\\(.*\\)\\s*$"
> 
> File name is "foo.cpp", I even added it to my git attributes file:
> 
> *.cpp diff=cpp
> 
> Using the regex above, my chunk headers come back blank. Why is it
> showing namespace? How do I make this match the nearest function
> header?
> 

Is the line that contains 'void MyClass::...' before line 149? Does the
word 'void' begin at the left-most column?

-- Hannes

```

## Johannes Sixt, 2015-01-02 20:31

Subject: Re: xfuncname problems with C++
Message-ID: <54A7000A.3050605@kdbg.org>
URL: https://gitlist.dev/e/54A7000A.3050605%40kdbg.org
In-Reply-To: <CAHd499C_Z_npG3ibv_gJSU7kqrT6=DRCV8TU9_sjz9zzQ7vC-Q@mail.gmail.com>

```
Am 02.01.2015 um 18:03 schrieb Robert Dailey:
> On Fri, Jan 2, 2015 at 10:49 AM, Robert Dailey <rcdailey.lists@gmail.com> wrote:
>> I have a function like so:
>>
>> void MyClass::SomeFunction(int someParameter)
>> {
>>     // Stuff changed in here
>> }
>>
>> When I do `git diff` on the file containing this function, I get a
>> chunk showing some changed code in this function somewhere in the
>> middle of the body. However, the chunk header shows my root namespace
>> name in the file instead of the function header:
>>
>> @@ -144,15 +149,22 @@ namespace Utils
>>
>> What I expect to see:
>>
>> @@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)
>>
>> I've tried various regular expressions that work in regex testers I
>> use against this function signature, however they do not work when I
>> apply them to my config:
>>
>> [diff "cpp"]
>>     xfuncname =
>> "^\\s*[\\w_][\\w\\d_]*\\s*.*\\s*[\\w_][\\w\\d_]*\\s*\\(.*\\)\\s*$"
>>
>> File name is "foo.cpp", I even added it to my git attributes file:
>>
>> *.cpp diff=cpp
>>
>> Using the regex above, my chunk headers come back blank. Why is it
>> showing namespace? How do I make this match the nearest function
>> header?
> 
> Oopsie, I didn't realize the regex must be POSIX compatible. I've
> updated the regex to this:
> https://www.regex101.com/r/kP3dM6
> 
> The test seems to work; however git gives me an error with the regex
> when I do a diff:
> 
> $ git diff Core
> fatal: Invalid regexp to look for hunk header:
> ^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\(.*\)[[:space:]]*$
> 
> Here is how it is stored in my .gitconfig:
> 
> [diff "cpp"]
>     xfuncname =
> "^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\\(.*\\)[[:space:]]*$"
> 

Perhaps there is a pair of parentheses missing that capture text for the
hunk header? I you intended that to be the part inside \(...\), then
that is wrong. Use unescapted parentheses.

There are two catch-all .* in your pattern. That is very suspicious,
particularly since the first one is outside the meant-to-be capturing
parentheses.

-- Hannes

```

## Robert Dailey, 2015-01-02 21:27

Subject: Re: xfuncname problems with C++
Message-ID: <CAHd499DpyO6Csji8gp1E6HsrvtBa7QMKBah2xOewrWAfNgQUHg@mail.gmail.com>
URL: https://gitlist.dev/e/CAHd499DpyO6Csji8gp1E6HsrvtBa7QMKBah2xOewrWAfNgQUHg%40mail.gmail.com
In-Reply-To: <54A7000A.3050605@kdbg.org>

```
On Fri, Jan 2, 2015 at 2:31 PM, Johannes Sixt <j6t@kdbg.org> wrote:
> Am 02.01.2015 um 18:03 schrieb Robert Dailey:
>> On Fri, Jan 2, 2015 at 10:49 AM, Robert Dailey <rcdailey.lists@gmail.com> wrote:
>>> I have a function like so:
>>>
>>> void MyClass::SomeFunction(int someParameter)
>>> {
>>>     // Stuff changed in here
>>> }
>>>
>>> When I do `git diff` on the file containing this function, I get a
>>> chunk showing some changed code in this function somewhere in the
>>> middle of the body. However, the chunk header shows my root namespace
>>> name in the file instead of the function header:
>>>
>>> @@ -144,15 +149,22 @@ namespace Utils
>>>
>>> What I expect to see:
>>>
>>> @@ -144,15 +149,22 @@ void MyClass::SomeFunction(int someParameter)
>>>
>>> I've tried various regular expressions that work in regex testers I
>>> use against this function signature, however they do not work when I
>>> apply them to my config:
>>>
>>> [diff "cpp"]
>>>     xfuncname =
>>> "^\\s*[\\w_][\\w\\d_]*\\s*.*\\s*[\\w_][\\w\\d_]*\\s*\\(.*\\)\\s*$"
>>>
>>> File name is "foo.cpp", I even added it to my git attributes file:
>>>
>>> *.cpp diff=cpp
>>>
>>> Using the regex above, my chunk headers come back blank. Why is it
>>> showing namespace? How do I make this match the nearest function
>>> header?
>>
>> Oopsie, I didn't realize the regex must be POSIX compatible. I've
>> updated the regex to this:
>> https://www.regex101.com/r/kP3dM6
>>
>> The test seems to work; however git gives me an error with the regex
>> when I do a diff:
>>
>> $ git diff Core
>> fatal: Invalid regexp to look for hunk header:
>> ^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\(.*\)[[:space:]]*$
>>
>> Here is how it is stored in my .gitconfig:
>>
>> [diff "cpp"]
>>     xfuncname =
>> "^[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*.*[[:space:]]*[[:word:]_][[:word:][:digit:]_]*[[:space:]]*\\(.*\\)[[:space:]]*$"
>>
>
> Perhaps there is a pair of parentheses missing that capture text for the
> hunk header? I you intended that to be the part inside \(...\), then
> that is wrong. Use unescapted parentheses.
>
> There are two catch-all .* in your pattern. That is very suspicious,
> particularly since the first one is outside the meant-to-be capturing
> parentheses.

My regex actually is intended to not have any capture groups. Is that
required? The documentation I read didn't mention any requirements, so
I am not sure.

The 'void' does not start on the leftmost column, due to tabbing there
can be any number of whitespace (the regex should account for this).

```

## Jonathan Nieder, 2015-01-02 22:05

Subject: Re: xfuncname problems with C++
Message-ID: <20150102220556.GH29365@google.com>
URL: https://gitlist.dev/e/20150102220556.GH29365%40google.com
In-Reply-To: <CAHd499DpyO6Csji8gp1E6HsrvtBa7QMKBah2xOewrWAfNgQUHg@mail.gmail.com>

```
Robert Dailey wrote:

> The 'void' does not start on the leftmost column, due to tabbing there
> can be any number of whitespace (the regex should account for this).

Ah, that explains it.  The default C++ pattern assumes the 'void'
starts at the leftmost column, so that the funcname header represents
whatever top-level construct forms the context (e.g., "class foo {").

(Jump targets or access declarations)
!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])

(functions/methods, variables, and compounds at top level)
^((::[[:space:]]*)?[A-Za-z_].*)$

Thanks,
Jonathan

```
