diff mbox series

[v5,2/7] pretty: Allow %(trailers) options with explicit value

Message ID 20190128213337.24752-3-anders@0x63.nu (mailing list archive)
State New, archived
Headers show
Series %(trailers) improvements in pretty format | expand

Commit Message

Anders Waldenborg Jan. 28, 2019, 9:33 p.m. UTC
In addition to old %(trailers:only) it is now allowed to write
%(trailers:only=yes)

By itself this only gives (the not quite so useful) possibility to have
users change their mind in the middle of a formatting
string (%(trailers:only=true,only=false)). However, it gives users the
opportunity to override defaults from future options.

Signed-off-by: Anders Waldenborg <anders@0x63.nu>
---
 Documentation/pretty-formats.txt | 14 ++++++---
 pretty.c                         | 52 +++++++++++++++++++++++++++-----
 t/t4205-log-pretty-formats.sh    | 18 +++++++++++
 3 files changed, 73 insertions(+), 11 deletions(-)

Comments

Junio C Hamano Jan. 28, 2019, 10:38 p.m. UTC | #1
Anders Waldenborg <anders@0x63.nu> writes:

> Subject: Re: [PATCH v5 2/7] pretty: Allow %(trailers) options with explicit value

Style: s/pretty: Allow/pretty: allow/ (haven't I said this often enough?)

> +** 'only[=val]': select whether non-trailer lines from the trailer
> +   block should be included. The `only` keyword may optionally be
> +   followed by an equal sign and one of `true`, `on`, `yes` to omit or
> +   `false`, `off`, `no` to show the non-trailer lines. If option is
> +   given without value it is enabled. If given multiple times the last
> +   value is used.
> +** 'unfold[=val]': make it behave as if interpret-trailer's `--unfold`
> +   option was given. In same way as to for `only` it can be followed
> +   by an equal sign and explicit value. E.g.,
> +   `%(trailers:only,unfold=true)` unfolds and shows all trailer lines.

Sounds sensible.

> diff --git a/pretty.c b/pretty.c
> index b83a3ecd23..b8d71a57c9 100644
> --- a/pretty.c
> +++ b/pretty.c
> @@ -1056,13 +1056,25 @@ static size_t parse_padding_placeholder(struct strbuf *sb,
>  	return 0;
>  }
>  
> -static int match_placeholder_arg(const char *to_parse, const char *candidate,
> -				 const char **end)
> +static int match_placeholder_arg_value(const char *to_parse, const char *candidate,
> +				       const char **end, const char **valuestart, size_t *valuelen)

An overlong line here.

> ...
> +static int match_placeholder_bool_arg(const char *to_parse, const char *candidate,
> +				      const char **end, int *val)
> +{
> +	char buf[8];
> +	const char *strval;
> +	size_t len;
> +	int v;
> +
> +	if (!match_placeholder_arg_value(to_parse, candidate, end, &strval, &len))
> +		return 0;
> +
> +	if (!strval) {
> +		*val = 1;
> +		return 1;
> +	}
> +
> +	strlcpy(buf, strval, sizeof(buf));
> +	if (len < sizeof(buf))
> +		buf[len] = 0;

Doesn't strlcpy() terminate buf[len] if len is short enough?
Even if the strval is longer than buf[], strlcpy() would truncate
and make sure buf[] is NUL terminated, no?

> +	v = git_parse_maybe_bool(buf);

Why?

This function would simply be buggy and incapable of parsing a
representation of a boolean value that is longer than 8 bytes (if
such a representation exists), so chomping an overlong string at the
end and feeding it to git_parse_maybe_bool() is a nonsense, isn't
it?

In this particular case, strlcpy() is inviting a buggy programming.
If there were a 7-letter representation of falsehood, strval may be
that 7-letter thing, in which case you would want to feed it to
git_parse_maybe_bool() to receive "false" from it, or strval may
have that 7-letter thing followed by a 'x' (so as a token, that is
not a correctly spelled falsehood), but strlcpy() would chomp and
show the same 7-letter falsehood to git_parse_maybe_bool().  That
robs you from an opportunity to diagnose such a bogus input as an
error.

Instead of using "char buf[8]", just using a strbuf and avoidng
strlcpy() would make the code much better, I would think.
Anders Waldenborg Jan. 29, 2019, 6:45 a.m. UTC | #2
Junio C Hamano writes:

>> ...
>> +static int match_placeholder_bool_arg(const char *to_parse, const char *candidate,
>> +				      const char **end, int *val)
>> +{
>> +	char buf[8];
>> +	const char *strval;
>> +	size_t len;
>> +	int v;
>> +
>> +	if (!match_placeholder_arg_value(to_parse, candidate, end, &strval, &len))
>> +		return 0;
>> +
>> +	if (!strval) {
>> +		*val = 1;
>> +		return 1;
>> +	}
>> +
>> +	strlcpy(buf, strval, sizeof(buf));
>> +	if (len < sizeof(buf))
>> +		buf[len] = 0;
>
> Doesn't strlcpy() terminate buf[len] if len is short enough?
> Even if the strval is longer than buf[], strlcpy() would truncate
> and make sure buf[] is NUL terminated, no?

Yes, but no. strval is not NUL-terminated at len. E.g strval would point
to "false,something=true". `buf[len] = 0` makes sure it becomes "false".

> Instead of using "char buf[8]", just using a strbuf and avoidng
> strlcpy() would make the code much better, I would think.

Yes, taking the heap allocation hit would most likely make the intent
clearer.
Anders Waldenborg Jan. 29, 2019, 6:49 a.m. UTC | #3
In addition to old %(trailers:only) it is now allowed to write
%(trailers:only=yes)

By itself this only gives (the not quite so useful) possibility to have
users change their mind in the middle of a formatting
string (%(trailers:only=true,only=false)). However, it gives users the
opportunity to override defaults from future options.

Signed-off-by: Anders Waldenborg <anders@0x63.nu>
---
 Documentation/pretty-formats.txt | 14 ++++++---
 pretty.c                         | 52 +++++++++++++++++++++++++++-----
 t/t4205-log-pretty-formats.sh    | 18 +++++++++++
 3 files changed, 73 insertions(+), 11 deletions(-)

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 86d804fe97..d33b072eb2 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -225,10 +225,16 @@ endif::git-rev-list[]
                           linkgit:git-interpret-trailers[1]. The
                           `trailers` string may be followed by a colon
                           and zero or more comma-separated options:
-** 'only': omit non-trailer lines from the trailer block.
-** 'unfold': make it behave as if interpret-trailer's `--unfold`
-   option was given. E.g., `%(trailers:only,unfold)` unfolds and
-   shows all trailer lines.
+** 'only[=val]': select whether non-trailer lines from the trailer
+   block should be included. The `only` keyword may optionally be
+   followed by an equal sign and one of `true`, `on`, `yes` to omit or
+   `false`, `off`, `no` to show the non-trailer lines. If option is
+   given without value it is enabled. If given multiple times the last
+   value is used.
+** 'unfold[=val]': make it behave as if interpret-trailer's `--unfold`
+   option was given. In same way as to for `only` it can be followed
+   by an equal sign and explicit value. E.g.,
+   `%(trailers:only,unfold=true)` unfolds and shows all trailer lines.
 
 NOTE: Some placeholders may depend on other options given to the
 revision traversal engine. For example, the `%g*` reflog options will
diff --git a/pretty.c b/pretty.c
index b83a3ecd23..4dfbd38cf6 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1056,13 +1056,26 @@ static size_t parse_padding_placeholder(struct strbuf *sb,
 	return 0;
 }
 
-static int match_placeholder_arg(const char *to_parse, const char *candidate,
-				 const char **end)
+static int match_placeholder_arg_value(const char *to_parse, const char *candidate,
+				       const char **end, const char **valuestart,
+				       size_t *valuelen)
 {
 	const char *p;
 
 	if (!(skip_prefix(to_parse, candidate, &p)))
 		return 0;
+	if (valuestart) {
+		if (*p == '=') {
+			*valuestart = p + 1;
+			*valuelen = strcspn(*valuestart, ",)");
+			p = *valuestart + *valuelen;
+		} else {
+			if (*p != ',' && *p != ')')
+				return 0;
+			*valuestart = NULL;
+			*valuelen = 0;
+		}
+	}
 	if (*p == ',') {
 		*end = p + 1;
 		return 1;
@@ -1074,6 +1087,34 @@ static int match_placeholder_arg(const char *to_parse, const char *candidate,
 	return 0;
 }
 
+static int match_placeholder_bool_arg(const char *to_parse, const char *candidate,
+				      const char **end, int *val)
+{
+	const char *argval;
+	char *strval;
+	size_t arglen;
+	int v;
+
+	if (!match_placeholder_arg_value(to_parse, candidate, end, &argval, &arglen))
+		return 0;
+
+	if (!argval) {
+		*val = 1;
+		return 1;
+	}
+
+	strval = xstrndup(argval, arglen);
+	v = git_parse_maybe_bool(strval);
+	free(strval);
+
+	if (v == -1)
+		return 0;
+
+	*val = v;
+
+	return 1;
+}
+
 static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 				const char *placeholder,
 				void *context)
@@ -1318,11 +1359,8 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 		if (*arg == ':') {
 			arg++;
 			for (;;) {
-				if (match_placeholder_arg(arg, "only", &arg))
-					opts.only_trailers = 1;
-				else if (match_placeholder_arg(arg, "unfold", &arg))
-					opts.unfold = 1;
-				else
+				if (!match_placeholder_bool_arg(arg, "only", &arg, &opts.only_trailers) &&
+				    !match_placeholder_bool_arg(arg, "unfold", &arg, &opts.unfold))
 					break;
 			}
 		}
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 978a8a66ff..63730a4ec0 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -578,6 +578,24 @@ test_expect_success '%(trailers:only) shows only "key: value" trailers' '
 	test_cmp expect actual
 '
 
+test_expect_success '%(trailers:only=yes) shows only "key: value" trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=yes)" >actual &&
+	grep -v patch.description <trailers >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '%(trailers:only=no) shows all trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=no)" >actual &&
+	cat trailers >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '%(trailers:only=no,only=true) shows only "key: value" trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=yes)" >actual &&
+	grep -v patch.description <trailers >expect &&
+	test_cmp expect actual
+'
+
 test_expect_success '%(trailers:unfold) unfolds trailers' '
 	git log --no-walk --pretty="%(trailers:unfold)" >actual &&
 	{
Jeff King Jan. 29, 2019, 4:57 p.m. UTC | #4
On Tue, Jan 29, 2019 at 07:45:06AM +0100, Anders Waldenborg wrote:

> > Instead of using "char buf[8]", just using a strbuf and avoidng
> > strlcpy() would make the code much better, I would think.
> 
> Yes, taking the heap allocation hit would most likely make the intent
> clearer.

If you can reuse the same struct and strbuf_reset() it each time, then
that amortizes the cost of the heap (to basically once per program run,
instead of once per commit).

-Peff
diff mbox series

Patch

diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 86d804fe97..d33b072eb2 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -225,10 +225,16 @@  endif::git-rev-list[]
                           linkgit:git-interpret-trailers[1]. The
                           `trailers` string may be followed by a colon
                           and zero or more comma-separated options:
-** 'only': omit non-trailer lines from the trailer block.
-** 'unfold': make it behave as if interpret-trailer's `--unfold`
-   option was given. E.g., `%(trailers:only,unfold)` unfolds and
-   shows all trailer lines.
+** 'only[=val]': select whether non-trailer lines from the trailer
+   block should be included. The `only` keyword may optionally be
+   followed by an equal sign and one of `true`, `on`, `yes` to omit or
+   `false`, `off`, `no` to show the non-trailer lines. If option is
+   given without value it is enabled. If given multiple times the last
+   value is used.
+** 'unfold[=val]': make it behave as if interpret-trailer's `--unfold`
+   option was given. In same way as to for `only` it can be followed
+   by an equal sign and explicit value. E.g.,
+   `%(trailers:only,unfold=true)` unfolds and shows all trailer lines.
 
 NOTE: Some placeholders may depend on other options given to the
 revision traversal engine. For example, the `%g*` reflog options will
diff --git a/pretty.c b/pretty.c
index b83a3ecd23..b8d71a57c9 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1056,13 +1056,25 @@  static size_t parse_padding_placeholder(struct strbuf *sb,
 	return 0;
 }
 
-static int match_placeholder_arg(const char *to_parse, const char *candidate,
-				 const char **end)
+static int match_placeholder_arg_value(const char *to_parse, const char *candidate,
+				       const char **end, const char **valuestart, size_t *valuelen)
 {
 	const char *p;
 
 	if (!(skip_prefix(to_parse, candidate, &p)))
 		return 0;
+	if (valuestart) {
+		if (*p == '=') {
+			*valuestart = p + 1;
+			*valuelen = strcspn(*valuestart, ",)");
+			p = *valuestart + *valuelen;
+		} else {
+			if (*p != ',' && *p != ')')
+				return 0;
+			*valuestart = NULL;
+			*valuelen = 0;
+		}
+	}
 	if (*p == ',') {
 		*end = p + 1;
 		return 1;
@@ -1074,6 +1086,35 @@  static int match_placeholder_arg(const char *to_parse, const char *candidate,
 	return 0;
 }
 
+static int match_placeholder_bool_arg(const char *to_parse, const char *candidate,
+				      const char **end, int *val)
+{
+	char buf[8];
+	const char *strval;
+	size_t len;
+	int v;
+
+	if (!match_placeholder_arg_value(to_parse, candidate, end, &strval, &len))
+		return 0;
+
+	if (!strval) {
+		*val = 1;
+		return 1;
+	}
+
+	strlcpy(buf, strval, sizeof(buf));
+	if (len < sizeof(buf))
+		buf[len] = 0;
+
+	v = git_parse_maybe_bool(buf);
+	if (v == -1)
+		return 0;
+
+	*val = v;
+
+	return 1;
+}
+
 static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 				const char *placeholder,
 				void *context)
@@ -1318,11 +1359,8 @@  static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 		if (*arg == ':') {
 			arg++;
 			for (;;) {
-				if (match_placeholder_arg(arg, "only", &arg))
-					opts.only_trailers = 1;
-				else if (match_placeholder_arg(arg, "unfold", &arg))
-					opts.unfold = 1;
-				else
+				if (!match_placeholder_bool_arg(arg, "only", &arg, &opts.only_trailers) &&
+				    !match_placeholder_bool_arg(arg, "unfold", &arg, &opts.unfold))
 					break;
 			}
 		}
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 978a8a66ff..63730a4ec0 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -578,6 +578,24 @@  test_expect_success '%(trailers:only) shows only "key: value" trailers' '
 	test_cmp expect actual
 '
 
+test_expect_success '%(trailers:only=yes) shows only "key: value" trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=yes)" >actual &&
+	grep -v patch.description <trailers >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '%(trailers:only=no) shows all trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=no)" >actual &&
+	cat trailers >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '%(trailers:only=no,only=true) shows only "key: value" trailers' '
+	git log --no-walk --pretty=format:"%(trailers:only=yes)" >actual &&
+	grep -v patch.description <trailers >expect &&
+	test_cmp expect actual
+'
+
 test_expect_success '%(trailers:unfold) unfolds trailers' '
 	git log --no-walk --pretty="%(trailers:unfold)" >actual &&
 	{