[PATCH] log -L: improve error message on malformed argument

[PATCH] log -L: improve error message on malformed argument

[Matthieu Moy]

The old message did not mention the :regex:file form.

To avoid overly long lines, split the message into two lines (in case
item->string is long, it will be the only part truncated in a narrow
terminal).

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 line-log.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/line-log.c b/line-log.c
index a490efe..e725248 100644
--- a/line-log.c
+++ b/line-log.c
@@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 
 		name_part = skip_range_arg(item->string);
 		if (!name_part || *name_part != ':' || !name_part[1])
-			die("-L argument '%s' not of the form start,end:file",
+			die("invalid -L argument '%s'.\n"
+			    "It should be of the form start,end:file or :regex:file.",
 			    item->string);
 		range_part = xstrndup(item->string, name_part - item->string);
 		name_part++;
-- 
2.4.0.rc1.42.g9642cc6

Re: [PATCH] log -L: improve error message on malformed argument

[Junio C Hamano]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> The old message did not mention the :regex:file form.
>
> To avoid overly long lines, split the message into two lines (in case
> item->string is long, it will be the only part truncated in a narrow
> terminal).
>
> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
> ---
>  line-log.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/line-log.c b/line-log.c
> index a490efe..e725248 100644
> --- a/line-log.c
> +++ b/line-log.c
> @@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
>  
>  		name_part = skip_range_arg(item->string);
>  		if (!name_part || *name_part != ':' || !name_part[1])
> -			die("-L argument '%s' not of the form start,end:file",
> +			die("invalid -L argument '%s'.\n"
> +			    "It should be of the form start,end:file or :regex:file.",
>  			    item->string);
>  		range_part = xstrndup(item->string, name_part - item->string);
>  		name_part++;

Hmm.

While I understand and even agree with the reasoning behind chomping
the line after a potentially long user-supplied argument, it
somewhat bothers me that the output of subsequent lines would begin
without the prefix.

Do we have any other multi-line die/error/warning message?

I am tempted to suggest doing something along the lines of the
attached, if we were to start using multi-line die/error/warning
like this one.  Obviously we would need something similar on the
vwritef() side as well.

 usage.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/usage.c b/usage.c
index ed14645..09710fa 100644
--- a/usage.c
+++ b/usage.c
@@ -8,9 +8,26 @@
 
 void vreportf(const char *prefix, const char *err, va_list params)
 {
-	char msg[4096];
-	vsnprintf(msg, sizeof(msg), err, params);
-	fprintf(stderr, "%s%s\n", prefix, msg);
+	char msg[4096], *bol;
+	int len;
+
+	len = vsnprintf(msg, sizeof(msg), err, params);
+	if (sizeof(msg) < len)
+		len = sizeof(msg);
+	bol = msg;
+	while (1) {
+		int linelen;
+		char *eol = memchr(bol, '\n', len);
+		if (!eol)
+			linelen = len;
+		else
+			linelen = eol - bol;
+		fprintf(stderr, "%s%.*s\n", prefix, linelen, bol);
+		if (!eol)
+			break;
+		bol = eol + 1;
+		len -= linelen + 1;
+	}
 }
 
 void vwritef(int fd, const char *prefix, const char *err, va_list params)

Re: [PATCH] log -L: improve error message on malformed argument

[Junio C Hamano]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> The old message did not mention the :regex:file form.
>
> To avoid overly long lines, split the message into two lines (in case
> item->string is long, it will be the only part truncated in a narrow
> terminal).
>
> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
> ---
>  line-log.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/line-log.c b/line-log.c
> index a490efe..e725248 100644
> --- a/line-log.c
> +++ b/line-log.c
> @@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
>  
>  		name_part = skip_range_arg(item->string);
>  		if (!name_part || *name_part != ':' || !name_part[1])
> -			die("-L argument '%s' not of the form start,end:file",
> +			die("invalid -L argument '%s'.\n"
> +			    "It should be of the form start,end:file or :regex:file.",
>  			    item->string);
>  		range_part = xstrndup(item->string, name_part - item->string);
>  		name_part++;

You forgot to update tests to match their expectations?  4211.20
wants to see 'argument.*not of the form', it seems.

Re: [PATCH] log -L: improve error message on malformed argument

[Eric Sunshine]

On Thu, Apr 16, 2015 at 5:45 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Matthieu Moy <Matthieu.Moy@imag.fr> writes:
>
>> The old message did not mention the :regex:file form.
>>
>> To avoid overly long lines, split the message into two lines (in case
>> item->string is long, it will be the only part truncated in a narrow
>> terminal).
>>
>> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
>> ---
>>  line-log.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/line-log.c b/line-log.c
>> index a490efe..e725248 100644
>> --- a/line-log.c
>> +++ b/line-log.c
>> @@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
>>
>>               name_part = skip_range_arg(item->string);
>>               if (!name_part || *name_part != ':' || !name_part[1])
>> -                     die("-L argument '%s' not of the form start,end:file",
>> +                     die("invalid -L argument '%s'.\n"
>> +                         "It should be of the form start,end:file or :regex:file.",
>>                           item->string);
>>               range_part = xstrndup(item->string, name_part - item->string);
>>               name_part++;
>
> You forgot to update tests to match their expectations?  4211.20
> wants to see 'argument.*not of the form', it seems.

An alternate wording might be:

    "-L argument not 'start,end:file' or ':regex:file': %s"

This can still wrap onscreen but the important information (the two
forms accepted by -L) is at the head of the error message, and the
variable (user-supplied) bit is at the end after the colon, in typical
error message form.

Re: [PATCH] log -L: improve error message on malformed argument

[Junio C Hamano]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> The old message did not mention the :regex:file form.
>
> To avoid overly long lines, split the message into two lines (in case
> item->string is long, it will be the only part truncated in a narrow
> terminal).
>
> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
> ---
>  line-log.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/line-log.c b/line-log.c
> index a490efe..e725248 100644
> --- a/line-log.c
> +++ b/line-log.c
> @@ -575,7 +575,8 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
>  
>  		name_part = skip_range_arg(item->string);
>  		if (!name_part || *name_part != ':' || !name_part[1])
> -			die("-L argument '%s' not of the form start,end:file",
> +			die("invalid -L argument '%s'.\n"
> +			    "It should be of the form start,end:file or :regex:file.",
>  			    item->string);
>  		range_part = xstrndup(item->string, name_part - item->string);
>  		name_part++;

I actually think "start,end:file" is more correct than your updated
text.

By adding :regex:file as a possibility, you are hinting that 'start'
and 'end' are *not* regular expressions but numbers, but

    $ git log -L'/^int main/,/^}/:git.c'

is a perfectly fine way to specify start (i.e. the first line that
matches '^int main') and end (i.e. the first line that matches '^}'
after that).  Perhaps rephrase it as :funcname:file to avoid giving
false impression to the other one, and use Eric's suggestion on top?

    die("-L argument not 'start,end:file' or ':funcname:file': %s",
	item->string);

With the matching update to tests, here is what I'll queue on top of
this patch for now, but please send in objections and improvements.

Thanks.

 line-log.c          | 3 +--
 t/t4211-line-log.sh | 8 ++++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/line-log.c b/line-log.c
index 5d4cb7c..51d9f7c 100644
--- a/line-log.c
+++ b/line-log.c
@@ -543,8 +543,7 @@ parse_lines(struct commit *commit, const char *prefix, struct string_list *args)
 
 		name_part = skip_range_arg(item->string);
 		if (!name_part || *name_part != ':' || !name_part[1])
-			die("invalid -L argument '%s'.\n"
-			    "It should be of the form start,end:file or :regex:file.",
+			die("-L argument not 'start,end:file' or ':funcname:file': %s",
 			    item->string);
 		range_part = xstrndup(item->string, name_part - item->string);
 		name_part++;
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 426a828..edd5ed3 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -40,14 +40,14 @@ canned_test "-L 24,+1:a.c simple" vanishes-early
 canned_test "-L '/long f/,/^}/:b.c' move-support" move-support-f
 
 test_bad_opts "-L" "switch.*requires a value"
-test_bad_opts "-L b.c" "argument.*not of the form"
-test_bad_opts "-L 1:" "argument.*not of the form"
+test_bad_opts "-L b.c" "argument not .start,end:file"
+test_bad_opts "-L 1:" "argument not .start,end:file"
 test_bad_opts "-L 1:nonexistent" "There is no path"
 test_bad_opts "-L 1:simple" "There is no path"
-test_bad_opts "-L '/foo:b.c'" "argument.*not of the form"
+test_bad_opts "-L '/foo:b.c'" "argument not .start,end:file"
 test_bad_opts "-L 1000:b.c" "has only.*lines"
 test_bad_opts "-L 1,1000:b.c" "has only.*lines"
-test_bad_opts "-L :b.c" "argument.*not of the form"
+test_bad_opts "-L :b.c" "argument not .start,end:file"
 test_bad_opts "-L :foo:b.c" "no match"
 
 test_done
-- 
2.4.0-rc2-183-g70401ab

[PATCH] Documentation: change -L:<regex> to -L:<funcname>

[Matthieu Moy]

The old wording was somehow implying that <start> and <end> were not
regular expressions. Also, the common case is to use a plain function
name here so <funcname> makes sense (the fact that it is a regular
expression is documented in line-range-format.txt).

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
Junio C Hamano <gitster@pobox.com> writes:

> By adding :regex:file as a possibility, you are hinting that 'start'
> and 'end' are *not* regular expressions but numbers, but
>
>     $ git log -L'/^int main/,/^}/:git.c'
>
> is a perfectly fine way to specify start (i.e. the first line that
> matches '^int main') and end (i.e. the first line that matches '^}'
> after that).

OK, but the same argument applies to the documentation (where I
cut-and-pasted from actually). So I suggest this patch in addition
(I'd apply it right before the patch on the code).

> false impression to the other one, and use Eric's suggestion on top?
>
>     die("-L argument not 'start,end:file' or ':funcname:file': %s",
> 	item->string);
>
> With the matching update to tests, here is what I'll queue on top of
> this patch for now, but please send in objections and improvements.

Very good.

Let me know if you want me to resend the 2-patch series.

 Documentation/blame-options.txt     |  2 +-
 Documentation/git-log.txt           |  2 +-
 Documentation/gitk.txt              |  4 ++--
 Documentation/line-range-format.txt | 11 ++++++-----
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt
index b299b59..a09969b 100644
--- a/Documentation/blame-options.txt
+++ b/Documentation/blame-options.txt
@@ -10,7 +10,7 @@
 	Include additional statistics at the end of blame output.
 
 -L <start>,<end>::
--L :<regex>::
+-L :<funcname>::
 	Annotate only the given line range. May be specified multiple times.
 	Overlapping ranges are allowed.
 +
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 18bc716..f0ec283 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -62,7 +62,7 @@ produced by `--stat`, etc.
 	output by allowing them to allocate space in advance.
 
 -L <start>,<end>:<file>::
--L :<regex>:<file>::
+-L :<funcname>:<file>::
 	Trace the evolution of the line range given by "<start>,<end>"
 	(or the funcname regex <regex>) within the <file>.  You may
 	not give any pathspec limiters.  This is currently limited to
diff --git a/Documentation/gitk.txt b/Documentation/gitk.txt
index 7ae50aa..d3b91ca 100644
--- a/Documentation/gitk.txt
+++ b/Documentation/gitk.txt
@@ -99,10 +99,10 @@ linkgit:git-rev-list[1] for a complete list.
 	detailed explanation.)
 
 -L<start>,<end>:<file>::
--L:<regex>:<file>::
+-L:<funcname>:<file>::
 
 	Trace the evolution of the line range given by "<start>,<end>"
-	(or the funcname regex <regex>) within the <file>.  You may
+	(or the funcname regex <funcname>) within the <file>.  You may
 	not give any pathspec limiters.  This is currently limited to
 	a walk starting from a single revision, i.e., you may only
 	give zero or one positive revision arguments.
diff --git a/Documentation/line-range-format.txt b/Documentation/line-range-format.txt
index d7f2603..829676f 100644
--- a/Documentation/line-range-format.txt
+++ b/Documentation/line-range-format.txt
@@ -22,8 +22,9 @@ This is only valid for <end> and will specify a number
 of lines before or after the line given by <start>.
 
 +
-If ``:<regex>'' is given in place of <start> and <end>, it denotes the range
-from the first funcname line that matches <regex>, up to the next
-funcname line. ``:<regex>'' searches from the end of the previous `-L` range,
-if any, otherwise from the start of file.
-``^:<regex>'' searches from the start of file.
+If ``:<funcname>'' is given in place of <start> and <end>, it is a
+regular expression that denotes the range from the first funcname line
+that matches <funcname>, up to the next funcname line. ``:<funcname>''
+searches from the end of the previous `-L` range, if any, otherwise
+from the start of file. ``^:<funcname>'' searches from the start of
+file.
-- 
2.4.0.rc1.42.g9642cc6

Re: [PATCH] Documentation: change -L:<regex> to -L:<funcname>

[Ramsay Jones]

On 19/04/15 18:29, Matthieu Moy wrote:
> The old wording was somehow implying that <start> and <end> were not
> regular expressions. Also, the common case is to use a plain function
> name here so <funcname> makes sense (the fact that it is a regular
> expression is documented in line-range-format.txt).
> 
> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
> ---
> Junio C Hamano <gitster@pobox.com> writes:
> 
>> By adding :regex:file as a possibility, you are hinting that 'start'
>> and 'end' are *not* regular expressions but numbers, but
>>
>>     $ git log -L'/^int main/,/^}/:git.c'
>>
>> is a perfectly fine way to specify start (i.e. the first line that
>> matches '^int main') and end (i.e. the first line that matches '^}'
>> after that).
> 
> OK, but the same argument applies to the documentation (where I
> cut-and-pasted from actually). So I suggest this patch in addition
> (I'd apply it right before the patch on the code).
> 
>> false impression to the other one, and use Eric's suggestion on top?
>>
>>     die("-L argument not 'start,end:file' or ':funcname:file': %s",
>> 	item->string);
>>
>> With the matching update to tests, here is what I'll queue on top of
>> this patch for now, but please send in objections and improvements.
> 
> Very good.
> 
> Let me know if you want me to resend the 2-patch series.
> 
>  Documentation/blame-options.txt     |  2 +-
>  Documentation/git-log.txt           |  2 +-
>  Documentation/gitk.txt              |  4 ++--
>  Documentation/line-range-format.txt | 11 ++++++-----
>  4 files changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt
> index b299b59..a09969b 100644
> --- a/Documentation/blame-options.txt
> +++ b/Documentation/blame-options.txt
> @@ -10,7 +10,7 @@
>  	Include additional statistics at the end of blame output.
>  
>  -L <start>,<end>::
> --L :<regex>::
> +-L :<funcname>::
>  	Annotate only the given line range. May be specified multiple times.
>  	Overlapping ranges are allowed.
>  +
> diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
> index 18bc716..f0ec283 100644
> --- a/Documentation/git-log.txt
> +++ b/Documentation/git-log.txt
> @@ -62,7 +62,7 @@ produced by `--stat`, etc.
>  	output by allowing them to allocate space in advance.
>  
>  -L <start>,<end>:<file>::
> --L :<regex>:<file>::
> +-L :<funcname>:<file>::
>  	Trace the evolution of the line range given by "<start>,<end>"
>  	(or the funcname regex <regex>) within the <file>.  You may

perhaps this should read the same as the hunk below, namely:
        (or the funcname regex <funcname>) ...

[I haven't actually given it any thought, I just noticed the difference ...]

Thanks!

ATB,
Ramsay Jones

>  	not give any pathspec limiters.  This is currently limited to
> diff --git a/Documentation/gitk.txt b/Documentation/gitk.txt
> index 7ae50aa..d3b91ca 100644
> --- a/Documentation/gitk.txt
> +++ b/Documentation/gitk.txt
> @@ -99,10 +99,10 @@ linkgit:git-rev-list[1] for a complete list.
>  	detailed explanation.)
>  
>  -L<start>,<end>:<file>::
> --L:<regex>:<file>::
> +-L:<funcname>:<file>::
>  
>  	Trace the evolution of the line range given by "<start>,<end>"
> -	(or the funcname regex <regex>) within the <file>.  You may
> +	(or the funcname regex <funcname>) within the <file>.  You may
>  	not give any pathspec limiters.  This is currently limited to
>  	a walk starting from a single revision, i.e., you may only
>  	give zero or one positive revision arguments.
> diff --git a/Documentation/line-range-format.txt b/Documentation/line-range-format.txt
> index d7f2603..829676f 100644
> --- a/Documentation/line-range-format.txt
> +++ b/Documentation/line-range-format.txt
> @@ -22,8 +22,9 @@ This is only valid for <end> and will specify a number
>  of lines before or after the line given by <start>.
>  
>  +
> -If ``:<regex>'' is given in place of <start> and <end>, it denotes the range
> -from the first funcname line that matches <regex>, up to the next
> -funcname line. ``:<regex>'' searches from the end of the previous `-L` range,
> -if any, otherwise from the start of file.
> -``^:<regex>'' searches from the start of file.
> +If ``:<funcname>'' is given in place of <start> and <end>, it is a
> +regular expression that denotes the range from the first funcname line
> +that matches <funcname>, up to the next funcname line. ``:<funcname>''
> +searches from the end of the previous `-L` range, if any, otherwise
> +from the start of file. ``^:<funcname>'' searches from the start of
> +file.
>